Title of Invention

DEVICE FOR THE FEEDING OF AUXILIARY OPERATING FACILITIES FOR A FUEL-ELECTRICALLY DRIVEN VEHICLE

Abstract A device for the feeding of auxiliary operating facilities for a fuel-electrically driven vehicle with a combustion engine (1) is stated, which device comprises a generator (2) driven by the combustion engine (1) and a rectifier (3) connected with a generator (2) on the AC voltage side, wherein the rectifier (3) on the DC voltage side is connected with a first and a second connection (5, 6) of a DC voltage circuit (4). Alternatively, first and second rectifiers (3a, 3b) connected with the generator (2) on the AC voltage side are provided, wherein the first rectifier (3a) is connected on the DC voltage side with a first and a second connection (5a, 6a) of a first DC voltage circuit (4a) and the second rectifier (3b) on the DC voltage side with a first and a second connection (5b, 6b) of a second DC voltage circuit (4b). Saving of space required and increased robustness and resistance to faults are achieved in that a first and a second step-down converter (7, 8) each is connected with the first and second connection (5, 6) of the DC voltage circuit (4), and that the first step-down converter (7) is connected with a first DC voltage rail system (9a) for the feeding of first auxiliary operating facilities (10a) and that the second step-down converter (8) is connected with a second DC voltage rail system (9b) for the feeding of second auxiliary operating facilities (10b). As an alternative to the second step-down converter (8) a further rectifier (22) connected with the generator (2) on the AC voltage side can also be provided, wherein then the first step-down converter (7) is still connected with the first DC voltage rail system (9a) for the feeding of first auxiliary operating facilities (10a) and the further rectifier (22) is connected with the second DC voltage rail system (9b) for the feeding of second auxiliary operating facilities (10b).
Full Text

Device for the feeding of auxiliary operating facilities for a fuel-electrically driven vehicle
DESCRIPTION
Technical area
The invention relates to the area of auxiliary operating facilities for fuel-electrically driven vehicles. It is based on a device for the feeding of auxiliary operating facilities for a fuel-electrically driven vehicle according to the preamble of the independent claims.
Prior art
Today, auxiliary operating facilities for fuel-electrically driven vehicles are mainly employed in diesel-electric locomotives or large diesel-electric mine vehicles, where the auxiliary operating facilities are constructed as fans, air-conditioning systems, actuators, on-board network converters etc. Such auxiliary operating facilities are popularly fed by means of a suitable device. Such a device for the feeding of auxiliary operating facilities for a fuel-electrically driven vehicle is for example mentioned in the US 6,087,791 and in the DE 200 01 113 U1. In it the device has a combustion engine, a generator driven by the combustion engine and a rectifier connected with the generator on the AC voltage side. On the DC voltage side the rectifier is

connected with a first and a second connection of a DC voltage circuit. In addition, with the device according to DE 200 01 113 U1, a multiplicity of inverters is connected to the first and second connection of the DC voltage circuit, which inverters each supply the relevant auxiliary operating facility such as for example fan, air-conditioning system, actuator, on-board network converter etc. with electric energy. According to the US 6,087,791 and the DE 200 01 113 U1 a drive inverter is also connected to the first and second connection of the DC voltage circuit, which drive inverter on the AC voltage side feeds one or several drive motors of the vehicle.
Obviously it is also conceivable that a second rectifier connected with a generator is provided. The second rectifier is then connected on the DC voltage side with a first and a second connection of a second DC voltage circuit, while a second drive inverter is connected to the first and second connection of the second DC voltage circuit, which second drive inverter on the AC voltage side feeds one or several drive motors of the vehicle.
Since the power requirement of such drive motors is very high, a DC voltage of several kilo-volts is typically present between the first and the second connection of the DC voltage circuit in order to be able to provide the appropriate power. Problematic in this context with the device for the feeding of auxiliary operating facilities for a fuel-electrically driven vehicle of the US 6,087,791 and the DE 200 01 113 U1 is that the inverters connected to the first and second connection of the DC voltage circuit have to be designed to the high DC voltage mentioned above, i.e. the power semiconductor switches of the respective inverters have to have a high blocking capability and suitable protective facilities and operating methods specifically adapted to these. The construction of the inverters is thus highly complicated, susceptible to faults and accordingly requires a lot of space. In addition, insulation distances of the supply lines and rails to the inverters and between the inverters themselves have to be maintained, which requires additional space. This complicated and space-intensive construction of the inverters and the device for the feeding of auxiliary operating facilities consequently causes major expenditure in terms of installation and maintenance. Especially a simple, compact and robust construction of the device for the feeding of auxiliary operating facilities however is extremely desirable with a fuel-electrically driven vehicle.

In the DE 94 13 638 U1 a device for the feeding of auxiliary operating facilities for a fuel-electrically driven vehicle is also disclosed, which device has a first combustion engine and a first generator driven by the first combustion engine. On the AC voltage side with the first generator, a first rectifier assigned to the first generator is connected, wherein a first step-down converter is connected downstream of the first rectifier. An assigned first DC voltage circuit is connected downstream of the first step-down converter with which first DC voltage circuit a first inverter for the feeding of auxiliary operating facilities is connected. In addition to this, the device of the DE 94 13 638 U1 has a second combustion engine and a second generator driven by the second combustion engine. On the AC voltage side a second rectifier assigned to the second generator is connected to the second generator while a second step-down converter is connected downstream of the second rectifier. An assigned second DC voltage circuit is connected downstream of the second step-down converter with which second DC voltage circuit a second inverter for the feeding of auxiliary operating facilities is connected.
Presentation of the invention
The object of the invention therefore is to state a device for the feeding of auxiliary operating facilities for a fuel-electrically driven vehicle which has low space requirements and is additionally sturdy and not susceptible to faults. This object is solved through the characteristics of claim 1, claim 2 and claim 16 respectively. In the dependent claims advantageous developments of the invention are stated.
The device for the feeding of auxiliary operating facilities for a fuel-electrically driven vehicle according to the invention comprises a combustion engine, a generator driven by the combustion engine, and a rectifier connected with the generator on the AC voltage side and assigned to the generator, wherein the rectifier on the DC voltage side is connected to a first and a second connection of a DC voltage circuit assigned to the rectifier and connected downstream of the rectifier. According to the invention, a first and a second step-down converter is provided, wherein the first and second step-down converter each is connected to the first and second connection of the DC voltage circuit and the first step-down converter is further connected to a first DC voltage rail system for the feeding of first auxiliary operating fa-

cilities assigned to a first step-down converter connected downstream of the first step-down converter and the second step-down converter is connected with a second DC voltage rail system for the feeding of second auxiliary operating facilities assigned to the second step-down converter and connected downstream of the second step-down converter. Inverters of the respective auxiliary operating facilities and/or DC voltage converters of the auxiliary operating facilities are connected to the first and second DC voltage rail system for their feeding.
Through the two step-down converters the voltage on the respective DC voltage rail system can be set with advantage. This setting is performed such that the voltage on the DC voltage rail system is lower than the voltage between the first and second connection of the DC voltage circuit. By means of the voltage of the DC voltage rail system which is lower compared with the DC voltage circuit the insulation distance of the DC voltage rail system, i.e. of the rail system legs of the DC voltage rail system, can be reduced so that space can be saved with advantage and the installation and maintenance expenditure kept low in addition. Furthermore feeding of the DC voltage rail system not affected by the fault or failure is still possible by means of the respective step-down converters in the event of a fault or a failure of a step-down converter, so that the auxiliary operating facilities can continue to be fed via their inverters and/or DC voltage converters. As a result, the device according to the invention is highly robust, not susceptible to faults and characterized by high availability.
By means of the voltage of the DC voltage rail system which is lower in comparison with the DC voltage circuit the inverters and/or DC voltage converters of the auxiliary operating facilities, i.e. the power semiconductor switches of the inverters and/or DC voltage converters with corresponding protective facilities and operating methods for example need not be designed to the high voltage of the DC voltage circuit as is known from the prior art, but merely to the lower voltage of the DC voltage rail system. Advantageously the construction of the inverters and/or DC voltage converters is simplified as a result, the inverters and/or DC voltage converters are less susceptible to faults and require correspondingly less space. In addition, the simple and space-saving construction of the inverters and/or DC voltage converters causes less installation and maintenance expenditure.
As an alternative to the second step-down converter a further rectifier connected with the generator on the AC voltage side and assigned to the generator is provided wherein the first

step-down converter is still connected with the first DC voltage rail system for the feeding of first auxiliary operating facilities assigned to the first step-down converter and connected downstream of the first step-down converter and the further rectifier is connected with the second DC voltage rail system for the feeding of the auxiliary operating facilities assigned to the further rectifier and connected downstream of the further rectifier.
Through the first step-down converter and the further rectifier the voltage on the DC voltage rail system can likewise be set with advantage as has already been explained with the solution with two step-down converters. By means of the voltage of the DC voltage rail system achieved which is lower in comparison with the DC voltage circuit, the insulation distance of the DC voltage rail system, i.e. the rail system legs of the DC voltage rail system can be reduced so that with advantage space can be saved and the installation and maintenance expenditure kept low in addition. Furthermore feeding of the second DC voltage rail system not affected by the fault or failure is still possible by means of the further rectifier in the event of a fault or a failure of the first step-down converter, so that the second auxiliary operating facilities can continue to be fed via their inverters and/or DC voltage converters. As a result, the device according to the invention is highly robust not susceptible to faults and characterized by high availability.
With the alternative solution with the first step-down converter and the further rectifier, too, the inverters and/or DC voltage converters of the auxiliary operating facilities for instance need not be designed for the high voltage of the DC voltage circuit as is known from the prior art because of the voltage of the DC voltage rail system, which is lower in comparison with the DC voltage circuit, but merely for the lower voltage of the DC voltage rail system. Advantageously, the construction of the inverters and/or DC voltage converters is simplified as a result, the inverters and/or DC voltage converters are less susceptible to faults and require correspondingly less space. In addition, the simple and space-saving construction of the inverters and/or DC voltage converters causes less installation and maintenance expenditure.
As a further alternative the device for the feeding of auxiliary operating facilities for a fuel-electrically driven vehicle according to the invention comprises a combustion engine, a generator driven by the combustion engine and first and second rectifiers connected with the generator on the AC voltage side and assigned to the generator, wherein the first rectifier is

connected on the DC voltage side with a first and a second connection of a first DC voltage circuit assigned to the first rectifier and connected downstream of the first rectifier and the second rectifier on the DC voltage side with a first and a second connection of a second DC voltage circuit assigned to the second rectifier and connected downstream of the second rectifier. According to the invention a first and a second step-down converter is then provided wherein the first step-down converter is connected with the first and second connection of the first DC voltage circuit and the second step-down converter with the first and second connection of the second DC voltage circuit and the first step-down converter is further connected with a second DC voltage rail system for the feeding of the auxiliary operating facilities assigned to the second step-down converter and connected downstream of the second step-down converter. Inverters of the auxiliary operating facilities and/or DC voltage converters of the auxiliary operating facilities are then also connected to the first and second DC voltage rail system for their feeding. The advantages mentioned above also apply to this alternative solution.
These and further objects, advantages and characteristics of the present invention become obvious from the following detailed description of preferred embodiments of the invention in connection with the drawing.
Brief description of the drawings
It shows:
Fig. 1 a first embodiment of a device for the feeding of auxiliary operating facilities
for a fuel-electrically driven vehicle according to the invention,
Fig. 2 a second embodiment of the device according to the invention,
Fig. 3 a third embodiment of the device according to the invention,
Fig. 4 a fourth embodiment of the device according to the invention,

Fig. 5 a fifth embodiment of the device according to the invention,
Fig. 6 a sixth embodiment of the device according to the invention,
Fig. 7 a seventh embodiment of the device according to the invention,
Fig. 8 an eighth embodiment of the device according to the invention,
Fig. 9 a ninth embodiment of the device according to the invention and
Fig. 10 a tenth embodiment of the device according to the invention.
The reference numbers used in the drawing and their meaning are listed in summary in the list of reference numbers. As a matter of principle, identical parts are provided with identical reference numbers in the Figures. The described embodiments stand as examples for the subject matter of the invention and have no restrictive effect.
Ways of carrying out the invention
In Fig. 1, a first embodiment of the device for the feeding of auxiliary operating facility for a fuel-electrically driven vehicle according to the invention is shown. The device according to Fig. 1 according to the invention comprises a combustion engine 1, a generator 2 driven by the combustion engine 1 and a rectifier 3 connected on the AC voltage side with the generator 2 and assigned to the generator 2, wherein the rectifier 3 on the DC voltage side is connected with a first and second connection 5, 6 of a DC voltage circuit 4 assigned to the rectifier 3 and connected downstream of the rectifier 3. According to the invention, a first and a second step-down converter 7, 8 is provided, wherein each the first and the second step-down converter 7, 8 is connected with the first and second connection 5, 6 of the DC voltage circuit 4. According to Fig. 1more preferably the first and the second step-down converter is connected downstream of the DC voltage circuit 4. In addition, the first step-down converter 7 is connected with a first DC voltage rail system 9a for the feeding of first auxiliary operating

facilities 10a assigned to the first step-down converter 7 and connected downstream of the first step-down converter 7 and the second step-down converter 8 is connected with a first DC voltage rail system 9b for the feeding of first auxiliary operating facilities 10b assigned to the second step-down converter 8 and connected downstream of the second step-down converter 8. According to Fig.1, each DC voltage rail system 9a, 9b has two rail system legs. According to Fig. 1, inverters of the first auxiliary operating facilities 10a and/or DC voltage converters of the first auxiliary operating facilities 10a are connected to the first DC voltage rail system 9a and inverters of the second auxiliary operating facilities 10b and/or DC voltage converters of the second auxiliary operating facilities 10b are connected to the second DC voltage rail system 9b for their feeding.
Through the two step-down converters 7, 8 the voltage can be set on each respective DC voltage rail system 9a, 9b with advantage. This setting is carried out such that the voltage on the DC voltage rail system 9a, 9b is lower than the voltage between the first and second connection 5, 6 of the DC voltage circuit 4. Through the voltage of the DC voltage rail system 9a, 9b which is lower in comparison with the DC voltage circuit 4 the insulation distance of the rail system legs of the respective DC voltage rail system 9a, 9b can be reduced so that advantageously space can be saved and additionally the installation and maintenance expenditure kept low or minimised. Furthermore, further feeding of the second DC voltage rail system 9b not affected by the fault or the failure for example of the first step-down converter 7 is possible through the respective second step-down converter 8 so that the second auxiliary operating facilities 10b can continue to be fed by way of their inverters and/or DC voltage converters. The device according to the invention is thus highly robust, not susceptible to faults and characterized by high availability.
According to Fig. 1 the respective step-down converter 7, 8 is formed through a series circuit of a controllable power semiconductor switch 11 with a diode 12 and through a capacity 13 connected in parallel with the series circuit of the controllable power semiconductor switch 11 with the diode 12. According to Fig. 1 the controllable power semiconductor switch 11 is designed as bipolar transistor with gate electrode arranged in an insulated manner (IGBT). However it is also conceivable that the controllable power semiconductor switch is designed as power MOSFET, as turn-off thyristor (GTO - Gate Turn-Off Thyristor) or as integrated thy-ristor with commutated gate electrode (IGCT - Integrated Gate Commutated Thyristor). Ac-

cording to Fig. 1, the controllable power semiconductor switch 11 with the respective step-down converter 7, 8 is additionally connected with the first connection 5 of the DC voltage circuit 4 and the diode 12 with the second connection 6 of the DC voltage circuit 4. In addition, with the respective step-down converter 7, 8, the diode 12 is connected through a first connection 14 and the connection point of the diode 12 with the controllable power semiconductor switch 11 through a second connection 15 with the respective DC voltage rail system 9a, 9b, i.e. with the first step-down converter 7 the diode 12 is connected through the first connection 14 and the connecting point of the diode 12 with the controllable power semiconductor switch 11 is connected with the second DC voltage rail system 9b through the second connection 15. The respective step-down converter 7, 8 consequently manages with a minimum number of components and can thus be realised very easily and space-savingly. Through the low number of components the first and second step-down converter 7, 8 is particularly robust and not susceptible to faults and therefore has a high availability.
According to Fig. 1 with the respective step-down converter 7, 8, i.e. with the first step-down converter 7 and with the second step-down converter 8 a filter circuit 16 is additionally connected between the first connection 14 and the respective DC voltage rail system 9a, 9b and to the second connection 15. The filter circuit 16 advantageously results in that undesirable voltage fluctuations and current fluctuations created through switching actions of the respective step-down converter 7, 8 are filtered out so that the voltage of the first and second DC voltage rail system 9a, 9b, i.e. the voltage present between the respective rail system legs, is nearly a DC voltage.
In contrast with the first embodiment according to Fig. 1, a current direction limitation element 17 each is connected with the respective step-down converter 7, 8 in the first connection 14 and in the second connection 15 in a second embodiment of the device according to the invention according to Fig. 2. The respective current direction limitation element 17 serves to ensure that only a current in defined current direction flows from the respective step-down converter 7, 8 to the respective DC voltage rail system 9a, 9b and, in a defined manner, back again. As a result, it is advantageously avoided that a fault current, for example caused through faults of the respective DC voltage rail system 9a, 9b and/or a fault in one or in several auxiliary operating facilities 10a, 10b can flow back to the respective step-down converter 7, 8 and damage or even destroy the respective step-down converter 7, 8. The respec-

tive current direction limitation element 17 according to Fig. 2 is preferably designed as a diode and can thus be advantageously realised very easily and space-savingly.
In contrast with the first and second embodiment of the device according to Fig. 1 and Fig. 2 the respective step-down converter 7, 8 in a third embodiment of the device according to the invention, according to Fig. 3, is formed through a first and a second series circuit 7a, 7b, 8a, 8b each of a controllable power semiconductor switch 11a, 11b with a diode 12a, 12b and through a capacity 13 each connected in parallel with each series circuit, wherein, with the respective step-down converter 7,8 the diode 12a of the first series circuit 7a, 8a is connected with the diode 12b of the second series circuit 7b, 8b. According to Fig. 3 the controllable power semiconductor switch 11a, 11 b is designed as a bipolar transistor with gate electrode designed in an insulated manner (IGBT). However it is also conceivable that the controllable power semiconductor switch is designed as power MOSFET, as turn-off thyristor (GTO - Gate Turn-Off Thyristor) or as integrated thyristor with commutated gate electrode (IGCT - Integrated Gate Commutated Thyristor). According to Fig. 3 with the respective step-down converter 7, 8, the controllable power semiconductor switch 11a of the first series circuit 7a, 8a is connected with the first connection 5 of the DC voltage circuit 4 and the controllable power semiconductor switch 11 b of the second series circuit 7b, 8b with the second connection 6 of the DC voltage circuit 4. In addition, with the respective step-down converter 7, 8, the connecting point of the diode 12a of the first series circuit 7a, 8a with the controllable power semiconductor switch 11 a of the first series circuit 7a, 8a is connected with the respective DC voltage rail system 9a, 9b through a first connection 14, i.e. with the first step-down converter 7 the connecting point of the diode 12a of the first series circuit 7a with the controllable power semiconductor switch 11a is connected with the first DC voltage rail system 9a through the first connection 14 and with the second step-down converter 8 the connecting point of the diode 12a of the first series circuit 8a with the controllable power semiconductor switch 11a of the first series circuit 8a is connected with the second DC voltage rail system 9b through the first connection 14. In addition, with the respective step-down converter 7, 8, the connecting point of the diode 12b of the second series circuit 7b, 8b with the controllable power semiconductor switch 11b of the second series circuit 7b, 8b is connected with the respective DC voltage rail system 9a, 9b through a second connection 15, i.e. with the first step-down converter 7 the connecting point of the diode 12b of the second series circuit 7b with the controllable power semiconductor switch 11b is connected with the first DC

voltage rail system 9a through a second connection 15 and with the second step-down converter 8 the connecting point of the diode 12b of the second series circuit 8b with the controllable power semiconductor switch 11 b of the second series circuit 8b is connected with the second DC voltage rail system 9b through a second connection 15. Through the embodiment of the first and second step-down converter 7, 8 described above a voltage of the DC voltage circuit 4 which is higher compared with the embodiment of the first and second step-down converter 7, 8 according to Fig. 1 and Fig. 2 can be connected since this voltage is split over the two capacities 13 of the respective step-down converter 7, 8. If however a comparable voltage of the DC voltage 4 as with the embodiment of the first and second step-down converter 7, 8 according to Fig. 1 and Fig. 2 is selected, more economical low-voltage semiconductors can be used for the relevant controllable power semiconductor switches 11a, 11b and diodes 12a, 12b because of the splitting of this voltage over the two capacities 13, which can be operated with a high switching frequency. Step-down converters 7, 8 designed in this way advantageously generate less undesirable voltage fluctuations and current fluctuations and consequently cause less EMC problems. In addition, step-down converters 7, 8 designed in this way only have minimum conductance and switching losses so that the step-down converter 7, 8 can be operated particularly efficiently. The respective step-down converter 7, 8 according to Fig. 3 additionally manages to get by with a minimum quantity of components and can therefore be realised very easily and space-savingly. Through the low quantity of components the first and second step-down converters 7, 8 are particularly robust and not susceptible to faults and therefore have a high availability.
According to Fig. 3 with the respective step-down converter 7, 8 a filter circuit 16 is connected between the first connection 14 and the respective DC voltage rail system 9a, 9b and between the second connection 15 and the respective DC voltage rail system 9a, 9b. The filter circuit 16 advantageously results in that undesirable voltage fluctuations and current fluctuations created through switching actions of the respective step-down converter 7, 8 are filtered out so that the voltage of the first and second DC voltage rail system 9a, 9b, i.e. the voltage present between the rail system legs of the first and second DC voltage rail system 9a, 9b, is nearly a DC voltage.
In a fourth embodiment of the device according to the invention according to Fig. 4, in contrast with the third embodiment according to Fig. 3, a current direction limitation element 17

I.
each is connected with the respective step-down converter 7, 8 in the first connection 14 and in the second connection 15. The respective current direction limitation element 17 serves to ensure that only a current in defined current direction flows from the respective step-down converter 7, 8 to the respective DC voltage rail system 9a, 9b and, in a defined manner, back again. As a result it is advantageously avoided that a fault current, for instance caused through a fault of the respective DC voltage rail system 9a, 9b and/or a fault in one or in several auxiliary operating facilities 10a, 10b, can flow back to the respective step-down converter 7, 8 and damage or even destroy the respective step-down converter 7, 8. The respective current direction limitation element 17 according to Fig. 4 is preferably designed as a diode and therefore advantageously realised very easily and space-savingly.
In a fifth and sixth embodiment of the device according to the invention according to Fig. 5 and Fig. 6 a further rectifier 22 connected with the generator 2 and assigned to the generator 2 on the AC voltage side is provided alternatively to the first, second, third and fourth embodiment according to Fig. 1, Fig. 2, Fig. 3 and Fig. 4 instead of the step-down converter 8, wherein the first step-down converter 7 is connected with the first DC voltage rail system 9a for the feeding of first auxiliary operating facilities 10a assigned to the first step-down converter 7 and connected downstream of the first step-down converter 7 and the further rectifier 22 is connected with the second DC voltage rail system 9b for the feeding of second auxiliary operating facilities 10b assigned to the further rectifier 22 and connected downstream of the further rectifier 22. According to Fig. 5 and Fig. 6 the first step-down converter 7 is connected downstream more preferably of the DC voltage circuit 4. According to Fig. 5 and Fig. 6 the further rectifier 22 is connected with the second DC voltage rail system 9a through a first connection 14 and through a second connection 15. In addition, the first step-down converter 7 according to Fig. 5 is embodied and connected or switched according to the first step-down converter according to Fig. 1 and Fig. 2 and has the already mentioned advantages. Moreover the first step-down converter 7 according to Fig. 6 is designed and connected or switched according to the first step-down converter according to Fig. 3 and Fig. 4 and also has the already mentioned advantages.
Through the first step-down converter 7 and the further rectifier 22 the voltage on the respective DC voltage rail system 9a, 9b can be set with advantage. This setting is performed such that the voltage on the DC voltage rail system 9a, 9b is lower than the voltage between the

first and second connection 5, 6 of the DC voltage circuit 4. Through the voltage of the DC voltage rail system 9a, 9b which is lower in comparison with the DC voltage circuit 4 the insulation distance of the rail system legs of the DC voltage rail system 9a, 9b can be reduced so that advantageously space can be saved and additionally the installation and maintenance expenditure can be kept low or minimised. Furthermore, further feeding of the second DC voltage rail system 9b not affected by the fault or the failure for example of the first step-down converter 7 is possible through the further rectifier 22 so that the second auxiliary operating facilities 10b can continue to be fed by way of their inverters and/or DC voltage converters. The device according to the invention is thus highly robust, not susceptible to faults and characterized by high availability.
According to Fig. 5 and Fig. 6 a current direction limitation element 17 each is connected to the first connection 14 and to the second connection 15 with the further rectifier 22 as well as with the first step-down converter 7. The respective current direction limitation element 17 serves to ensure that only a current flows in defined current direction from the respective step-down converter 7, 8 to the respective DC voltage rail system 9a, 9b and, in a defined manner, back again. As a result, it is advantageously avoided that a fault current, for example caused through a fault of the respective DC voltage rail system 9a, 9b and/or a fault in one or in several auxiliary operating facilities 10a, 10b, is able to flow back to the first step-down converter 7 or the further rectifier 22 and damage or even destroy the first step-down converter 7 or the further rectifier 22. The respective current direction limitation element 17 according to Fig. 5 and Fig. 6 is preferably designed as a diode and can therefore be advantageously realised highly simply and space-savingly.
According to Fig.5 and Fig. 6, to isolate the faulty or failed first step-down converter 7 or the further rectifier 22 as mentioned above, an isolating element 21 is connected into the first and second connection 14, 15 both with the further rectifier 22 and the first step-down converter 7. As a result, it is advantageously ensured that the faulty or failed first step-down converter 7 or further rectifier 22 does not for example short-circuit the corresponding first and second connection 14, 15. The isolating element 21 is preferably embodied as low-inductive switch, for example as a mechanical or controllable power semiconductor switch, or as a fuse.

With all embodiments of the device according to the invention according to Fig. 1 to Fig. 6 the first and the second DC voltage rail system 9a, 9b each has an overvoltage limitation network 18. The overvoltage limitation network 18 is formed through a resistor and a controllable switch, preferably a controllable power semiconductor switch, wherein the overvoltage limitation network 18 is actuated by closing the switch when an overvoltage of the voltage of the respective DC voltage rail system 9a, 9b occurs. Advantageously, when the switch is actuated, energy of the DC voltage rail system 9a, 9b is converted into heat in the resistor and consequently the voltage of the DC voltage rail system 9a, 9b reduced easily, quickly and effectively. The actuation of the overvoltage limitation network 18 preferably takes place for a specified period of time. This period of time is preferably specified as a function of the thermal capacity of the resistor. Actuation takes place according to criteria known to the expert which will not be discussed in more detail at this point.
In addition to this, with all embodiments of the device according to the invention according to Fig. 1 to Fig 6, a connecting element 20 is connected between the first connection 14 relative to the first DC voltage rail system 9a and the first connection 14 relative to the second DC voltage rail system 9b and between the second connection 15 relative to the first DC voltage rail system 9a and the second connection 15 relative to the second DC voltage rail system 9b. In normal operation of the device according to the invention the connecting element 20 is open, i.e. the first connection 14 relative to the first DC voltage rail system 9a and the first connection 14 relative to the second DC voltage rail system 9b are not connected with each other and the second connection 15 relative to the first DC voltage rail system 9a and the second Connection 15 relative to the second DC voltage rail system 9b are not connected with each other either. In the event of a fault or a failure for example of the first step-down converter 7 the connecting element 20 is closed, i.e. the first connection 14 relative to the first DC voltage rail system 9a and the first connection 14 relative to the second DC voltage rail system 9b are then connected with each other and the second connection 15 relative to the first DC voltage rail system 9a and the second connection 15 relative to the second DC voltage rail system 9b are then also connected. Feeding of the first DC voltage rail system 9a Is thus advantageously effected by way of the second step-down converter 8 and the further rectifier 22 respectively so that the first auxiliary operating facilities 10 can continue to be fed via their inverters and/or DC voltage converters. Such a possible redundant feed of the re-

spective DC voltage rail system 9a, 9b brings about further improvement of the robustness and the non-susceptibility to faults, while the availability can be further increased at the same time The connecting element is 20 is preferably embodies as a low-inductive switch, for example as mechanical or as controllable power semiconductor switch. To isolate a faulty or failed step-down converter 7, 8 as mentioned above, an isolating element 20 is connected into the first and second connection 14, 15 with the respective step-down converter 7, 8 with the embodiments of the device according to the invention according to Fig. 1 to Fig. 4. As a result, it is advantageously ensured that the faulty or failed step-down converter 7, 8 does not for example short-circuit the corresponding first and second connection 14,15. The isolating element 20 is preferably embodied as a low-inductive switch, for example as a mechanical or controllable power semiconductor switch or as a fuse.
In a seventh, eighth, ninth and tenth embodiment of the device according to the invention according to Fig. 7, Fig. 8, Fig. 9 and Fig. 10, alternatively to the first, second, third, fourth, fifth and sixth embodiment according to Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5 and Fig. 6 instead of a single rectifier 3 connected on the AC voltage side with the generator 2, first and second rectifiers 3a, 3b assigned to the generator 2 are now connected with the generator 2 on the AC voltage side, wherein the first rectifier 3a on the DC voltage side is connected with a first and a second connection 5a, 6a of a first DC voltage circuit 4a assigned to the first rectifier 3a and connected downstream of the first rectifier 3a and the second rectifier 3b on the DC voltage side with a first and a second connection 5b, 6b of a second DC voltage circuit 4b assigned to the second rectifier 3b and connected downstream of the second rectifier 3b. According to the invention, a first and a second step-down converter 7, 8 is then provided, wherein the first step-down converter 7 is connected with the first and second connection 5a( 6a of the first DC voltage circuit 4a and the second step-down converter 8 with the first and second connection 5b, 6b of the second DC voltage circuit 4b. In addition, the first step-down converters 7 is connected with a first DC voltage rail system 9a for the feeding of the auxiliary operating facilities 10a assigned to the first step-down converter 7 and connected downstream of the first step-down converter 7 and the second step-down converters 8 is connected with a second DC voltage rail system 9b for the feeding of the auxiliary operating facilities 10b assigned to the second step-down converter 8 and connected downstream of the second step-down converter 8. According to Fig. 7 to Fig. 10 the first step-down converter 7 is more preferably connected downstream of the first DC voltage circuit 4a and the second

step-down converter 8 more preferably connected downstream of the second DC voltage circuit 4b.
According to Fig. 7, Fig. 8, Fig. 9 and Fig. 10 each DC voltage rail system 9a, 9b has two rail system legs. According to Fig. 7, Fig. 8, Fig. 9 and Fig. 10 inverters of the first auxiliary operating facilities 10a and/or DC voltage converters of the first auxiliary operating facilities 10a are connected to the first DC voltage rail system 9a and according to Fig. 7, Fig. 8, Fig. 9 and Fig. 10 inverters of the second auxiliary operating facilities 10b and/or DC voltage converters of the second auxiliary operating facilities 10b are connected to the second DC voltage rail system 9b for their feeding.
Through the two step-down converters 7, 8 according to Fig. 7, Fig. 8, Fig. 9 and Fig. 10 the voltage on the respective DC voltage rail system 9a, 9b can be set with advantage. This setting is performed such that the voltage on the DC voltage rail system 9a, 9b is lower than the voltage between the first and second connection 5a, 5b, 6a, 6b of the respective DC voltage circuit 4a, 4b. Through the voltage of the DC voltage rail system 9a, 9b which is lower in comparison with the respective DC voltage circuit 4a, 4b the insulation distance of the rail system legs of the DC voltage rail system 9a, 9b can be reduced so that advantageously space can be saved and the installation and maintenance expenditure additionally kept low or minimised. Furthermore, further feeding of the second DC voltage rail system 9b not affected by the fault or the failure for example of the first step-down converter 7 is possible through the respective second step-down converter 8 so that the second auxiliary operating facilities 10b can continue to be fed by way of their inverters and/or DC voltage converters. The device according to the invention is thus highly robust, not susceptible to faults and characterized by high availability.
According to Fig. 7, Fig. 8, Fig. 9 and Fig. 10 the respective step-down converter 7, 8 is formed through a series circuit of a controllable power semiconductor switch 11 with a diode 12 and through a capacity 13 connected parallel to the series circuit of the controllable power semiconductor switch 11 with the diode 12. According to Fig. 7, Fig. 8, Fig. 9 and Fig. 10 the controllable power semiconductor switch 11 is designed as a bipolar transistor with gate electrode arranged in an insulated manner (IGBT). However, it is also conceivable that the controllable power semiconductor switch is designed as power MOSFET, as turn-off thyristor (GTO - Gate Turn-Off Thyristor) or as integrated thyristor with commutated gate electrode

(IGCT - Integrated Gate Commutated Thyristor). According to Fig. 7, Fig. 8, Fig. 9 and Fig.
10 with the respective step-down converter 7, 8 the controllable power semiconductor switch
11 is additionally connected with the first connection 5a, 5b of the respective DC voltage cir
cuit 4a, 4b and the diode 12 with the second connection 6a, 6b of the respective DC voltage
circuit 4a, 4b. In addition, with the respective step-down converter 7, 8, the diode 12 is con
nected through a first connection 14 and the connection point of the diode 12 with the con
trollable power semiconductor switch 11 through a second connection 15 with the respective
DC voltage rail system 9a, 9b, i.e. with the first step-down converter 7 the diode 12 is con
nected through the first connection 14 and the connecting point of the diode 12 with the con
trollable power semiconductor switch 11 is connected with the second DC voltage rail system
9b through the second connection 15. The respective step-down converter 7, 8 consequently
manages with a minimum number of components and can thus be realised very easily and
space-savingly. Through the low number of components the first and second step-down con
verter 7, 8 is particularly robust and not susceptible to faults and therefore has a high avail
ability..
According to Fig. 7, Fig. 8, Fig. 9 and Fig. 10 with the respective step-down converter 7, 8, i.e. with the first step-down converter 7 and with the second step-down converter 8 a filter circuit 16 is additionally connected between the first connection 14 and the respective DC voltage rail system 9a, 9b and to the second connection 15. The filter circuit 16 advantageously results in that undesirable voltage fluctuations and current fluctuations created through switching actions of the respective step-down converter 7, 8 are filtered out so that the voltage of the first and second DC voltage rail system 9a, 9b, i.e. the voltage present between the rail system legs, is nearly a DC voltage.
In the eighth embodiment of the device according to the invention according to Fig. 8, in contrast with the seventh embodiment according to Fig. 7, with the respective step-down converter 7,8, a current direction limitation element 17 each is connected to the first connection 14 and to the second connection 15. The respective current direction limitation element 17 serves to ensure that only a current in defined current direction flows from the respective step-down converter 7, 8 to the respective DC voltage rail system 9a, 9b and, in a defined manner, back again. As a result, it is advantageously avoided that a fault current, for example caused through faults of the respective DC voltage rail system 9a, 9b and/or a fault in

one or in several auxiliary operating facilities 10a, 10b, can flow back to the respective step-down converter 7, 8 and damage or even destroy the respective step-down converter 7,8. The respective current direction limitation element 17 according to Fig. 8 is preferably designed as a diode and consequently can be realised very easily and space-savingly.
In a ninth embodiment of the device according to the invention according to Fig. 9 in contrast with the seventh and eighth embodiment according to Fig. 7 and Fig.8 the respective step-down converter 7, 8 is formed through a first and a second series circuit 7a, 7b, 8a, 8b each of a controllable power semiconductor switch 11a, 11b with a diode 12a, 12b and through a capacity 13 each connected in parallel with each series circuit, wherein with the respective step-down converter 7,8 the diode 12a of the first series circuit 7a, 8a is connected with a diode 12b of the second series circuit 7b, 8b. According to Fig. 9 the controllable power semiconductor switch 11a, 11b is designed as a bipolar transistor with gate electrode arranged in an insulated manner (IGBT). However it is also conceivable that the controllable power semiconductor switch is designed as power MOSFET, as turn-off thyristor (GTO - Gate Turn-Off Thyristor) or as integrated thyristor with commutated gate electrode (IGCT - Integrated Gate Commutated Thyristor). According to Fig. 9 with the respective step-down converter 7, 8, the controllable power semi-conductor switch 11a of the first series circuit 7a, 8a is connected with the first connection 5a, 5b of the corresponding DC voltage circuit 4a, 4b and the controllable power semiconductor switch 11b of the second series circuit 7b, 8b with the second connection 6a, 6b of the respective DC voltage circuit 4a, 4b. Furthermore, with the respective step-down converter 7, 8, the connecting point of the diode 12a of the first series circuit 7a, 8b with the controllable power semiconductor switch 11 a of the first series circuit 7a, 8a is connected with the respective DC voltage rail system 9a, 9b through a first connection 14, i.e. with the first step-down converter 7 the connecting point of the diode 12a of the first series circuit 7a with the controllable power semiconductor switch 11a of the first series circuit 7a is connected with the first DC voltage rail system 9a through the first connection 14 and with the second step-down converter 8 the connecting point of the diode 12a of the first series circuit 8a with the controllable power semiconductor switch 11a of the first series circuit is connected with the second DC voltage rail system 9b through the first connection 14. In addition, with the respective step-down converter 7, 8 the connecting point of the diode 12b of the second series circuit 7b, 8b with the controllable power semiconductor switch 11 b of the second series circuit 7b, 8b is connected with the respective DC voltage rail system 9a,

9b through a second connection 15, i.e. with the first step-down converter 7 the connecting point of the diode 12b of the second series circuit 7b with the controllable semiconductor switch 11b of the second series circuit 7b is connected with the first DC voltage rail system 9a through a second connection 15 and with the second step-down converter 8 the connecting point of the diode 12 b of the second series circuit 8b with the controllable power semiconductor switch 11 b of the second series circuit 8b is connected with the second DC voltage rail system 9b through a second connection 15. Through the embodiment of the first and second step-down converter 7, 8 described above a higher voltage of the respective DC voltage 4a, 4b in comparison with the embodiment of the first and second step-down converter 7, 8 according to Fig. 7 and Fig. 8 can be connected since this voltage is split over the two capacities 13 of the respective step-down converters 7, 8. If however a comparable voltage of the respective DC voltage circuit 4a, 4b as with the embodiment of the first and second step-down converter 7, 8 according to Fig. 7 and Fig. 8 is selected, because of the splitting of this voltage over the two capacities 13 of the respective step-down converter 7, 8, economical low voltage semiconductors can be used for the corresponding controllable semiconductor switches 11a, 11b and diodes 12a, 12b, which can be operated with a high switching frequency. Step-down converters 7, 8 designed such advantageously generate less undesirable voltage fluctuations and current fluctuations and consequently cause less EMC problems. In addition, step-down converters 7, 8 designed thus only have minimum conductance and switching losses so that the step-down converters 7, 8 can be operated particularly efficiently. The respective step-down converter 7, 8 according to Fig. 9 additionally manages with a minimum quantity of components and can consequently be realised very easily and space-savingly. Through the low quantity of components the first and second step-down converter 7, 8 is particularly robust and not susceptible to faults and thus has a high availability.
According to Fig. 9 with the respective step-down converter 7, 8, i.e. with the first step-down converter 7 and with the second step-down converter 8 a filter circuit 16 is additionally connected between the first connection 14 and the respective DC voltage rail system 9a, 9b and to the second connection 15. The filter circuit 16 advantageously results in that undesirable voltage fluctuations and current fluctuations created through switching actions of the respective step-down converter 7, 8 are filtered out so that the voltage of the first and second DC voltage rail system 9a, 9b, i.e. the voltage present between the respective rail system legs, is nearly a DC voltage.

In a tenth embodiment of the device according to the invention according to Fig. 10, in contrast with the ninth embodiment according to Fig. 9, with the respective step-down converter 7, 8, a current direction limitation element 17 each is connected to the first connection 14 and to the second connection 15. The respective current direction limitation element 17 serves to ensure that only a current in defined current direction flows from the respective step-down converter 7, 8 to the respective DC voltage rail system 9a, 9b and, in a defined manner, back again. As a result it is advantageously avoided that a fault current for example caused through a fault of the respective DC voltage rail system 9a, 9b and/or a fault in one or in several auxiliary operating facilities 10a, 10b can flow back to the respective step-down converter 7, 8 and damage or even destroy the respective step-down converter 7, 8. The respective current direction limitation element 17 according to Fig. 10 is preferably designed as a diode and can thus be realised advantageously very easily and space-savingly.
With all embodiments of the device according to the invention according to Fig. 7, Fig. 8, Fig. 9 and Fig. 10 the first and the second DC voltage rail system 9a, 9b each has an overvoltage limitation network 18. The overvoltage limitation network 18 is formed through a resistor and a controllable switch, preferably a controllable power semiconductor switch, wherein the overvoltage limitation network 18 is actuated through closing of the switch in the event that an overvoltage of the voltage of the DC voltage rail system 9a, 9b should occur. Advantageously energy of the DC voltage rail system a, 9b is converted into heat in the resistor when the switch is actuated and the voltage of the DC voltage rail system 9a, 9b consequently reduced easily, quickly and effectively. The actuation of the overvoltage limitation network 18 is preferably carried out for a specified period of time. This period of time is preferably specified as a function of the thermal capacity of the resistor. Actuation is performed according to criteria known to the expert which will not be discussed in more detail at this point.
In addition to this, with all embodiments of the device according to the invention according to Fig. 7, Fig 8, Fig. 9 and Fig 10, a connecting element 20 is connected between the first connection 14 relative to the first DC voltage rail system 9a and the first connection 14 relative to the second DC voltage rail system 9b and between the second connection 15 relative to the first DC voltage rail system 9a and the second connection 15 relative to the second DC voltage rail system 9b. In normal operation of the device according to the invention the connect-

ing element 20 is open, i.e. the first connection 14 relative to the first DC voltage rail system 9a and the first connection 14 relative to the second DC voltage rail system 9b are not connected with each other and the second connection 15 relative to the first DC voltage rail system 9a and the second Connection 15 relative to the second DC voltage rail system 9b are not connected with each other either. In the event of a fault or a failure for example of the first step-down converter 7 the connecting element 20 is closed, i.e. the first connection 14 relative to the first DC voltage rail system 9a and the first connection 14 relative to the second DC voltage rail system 9b are then connected with each other and the second connection 15 relative to the first DC voltage rail system 9a and the second connection 15 relative to the second DC voltage rail system 9b are then also connected. Feeding of the first DC voltage rail system 9a is thus advantageously effected by way of the second step-down converter 8 so that the first auxiliary operating facilities 10 can continue to be fed via their inverters and/or DC voltage converters. Such a possible redundant feed of the respective DC voltage rail system 9a, 9b brings about further improvement of the robustness and the non-susceptibility to faults, while the availability can be further increased at the same time The connecting element is 20 is preferably embodies as a low-inductive switch, for example as mechanical or as controllable power semiconductor switch.
To isolate a faulty or failed step-down converter 7, 8 as mentioned above an isolating element 20 is connected to the first and second connection 14,15 with the respective step-down converter 7, 8 in all embodiments of the device according to the invention according to Fig. 7, Fig. 8, Fig. 9 and Fig. 10. As a result, it is advantageously ensured that the faulty or failed step-down converter 7, 8 does not for example short-circuit the corresponding first and second connection 14, 15. The isolating element 20 is preferably embodied as low-inductive switch, for example as a mechanical or as controllable power semiconductor switch, or as a fuse.

List of reference numbers
1 Combustion engine
2 Generator
3 Rectifier
3a First rectifier
3b Second rectifier
4 DC voltage circuit
4a First DC voltage circuit
4b Second DC voltage circuit
5 First connection of the DC voltage circuit
5a First connection of the first DC voltage circuit
5b First connection of the second DC voltage circuit
6 Second connection of the DC voltage circuit
6a Second connection of the first DC voltage circuit
6b Second connection of the second DC voltage circuit
7 First step-down converter
7a First series circuit of the first step-down converter
7b Second series circuit of the first step-down converter
8 Second step-down converter
8a First series circuit of the second step-down converter
8b Second series circuit of the second step-down converter
9a First DC voltage rail system
9b Second DC voltage rail system
10 Auxiliary operating facilities
11 Controllable power semiconductor switch
11a Controllable power semiconductor switch of the first series circuit of the first
and second step-down converter
11b Controllable power semiconductor switch of the second series circuit of the
first and second step-down converter
12 Diode

12a Diode of the first series circuit of the first and second step-down converter
12b Diode of the second series circuit of the first and second step-down converter
13 Capacity
14 First connection
15 Second connection
16 Filter circuit
17 Current direction limitation element
18 Overvoltage limitation network
19 Capacity of the first voltage increase limitation network
20 Connecting element
21 Isolating element
22 Further rectifier







PATENT CLAIMS
1. A device for the feeding of auxiliary operating facilities for a fuel-electrically driven vehi
cle with a combustion engine (1), with a generator (2) driven by the combustion engine
(1), with a rectifier (3) connected with the generator (2) on the AC voltage side and as
signed to the generator (2), wherein the rectifier (3) on the DC voltage side is connected
with a first and a second connection (5, 6) of a DC voltage circuit (4) assigned to the rec
tifier (3) and connected downstream of the rectifier (3), characterized in that,
a first and a second step-down converter (7, 8) each is connected with the first and second connection (5, 6) of the DC voltage circuit (4) and that the first step-down converter (7) is connected to a first DC voltage rail system (9a) for the feeding of the auxiliary operating facilities (10a) assigned to the first step-down converter (7) and connected downstream of the first step-down converter (7) and the second step-down converter (8) is connected to a second DC voltage rail system (9b) for the feeding of the auxiliary operating facilities (10b) assigned to the second step-down converter (8) and connected downstream of the second step-down converter (8).
2. A device for the feeding of auxiliary operating facilities for a fuel-electrically driven vehi
cle with a combustion engine (1), with a generator (2) driven by the combustion engine
(1), with a rectifier (3) connected with the generator (2) on the AC voltage side and as
signed to the generator (2), wherein the rectifier (3) on the DC voltage side is connected
with a first and a second connection (5, 6) of a DC voltage circuit (4) assigned to the rec
tifier (3) and connected downstream of the rectifier (3), characterized in that
a first step-down converter (7) is connected with the first and second connection (5, 6) of the DC voltage circuit (4) and that
the first step-down converter (7) is connected to a first DC voltage rail system (9a) for the feeding of the auxiliary operating facilities (10a) assigned to the first step-down converter (7) and connected downstream of the first step-down converter (7) and a further rectifier (22) is connected with the generator (2) on the AC voltage side and assigned to the generator (2) is connected with a DC voltage rail system (9b) for the feeding of auxiliary operating facilities (10b) assigned to the further rectifier (22) and connected downstream of the further rectifier (22).

3. The device according to claim 2, characterized in that the further rectifier (22) is con
nected with the second DC voltage rail system (9b) through a first connection (14) and
through a second connection (15).
4. The device according to any one of the claims 1 to 3, characterized in that the respective
step-down converter (7, 8) is formed through a series circuit of a controllable power semi
conductor switch (11) with a diode (12) and through a capacity (13) connected parallel to
the series circuit of the controllable power semiconductor switch (11) with the diode (12).
5. The device according to claim 4, characterized in that with the respective step-down con
verter (7, 8) the controllable power semiconductor switch (11) is connected with the first
connection (5) of the DC voltage circuit (4) and the diode (12) with the second connec
tion (6) of the DC voltage circuit (4) and
that with the respective step-down converter (7, 8) the diode (12) is connected with the respective DC voltage rail system (9a, 9b) through a first connection (14) and the connecting point of the diode (12) with the controllable power semiconductor switch (11) through a second connection (15).
6. The device according to claim 5, characterized in that with the respective step-down con
verter (7, 8) a filter circuit (16) is connected between the first connection (14) and the re
spective DC voltage rail system (9a, 9b) and to the second connection (15).
7. The device according to any one of the claims 1 to 3, characterized in that the
respective step-down converter (7, 8) is formed through a first and a second series circuit
(7a, 7b, 8a, 8b) each of a controllable power semiconductor switch (11a, 11b) with a di
ode (12a, 12b) and through a capacity (13) each connected parallel to each series circuit,
wherein the diode (12a) of the first series circuit (7a, 8a) is connected with the diode
(12b) of the second series circuit (7b, 8b).
8. The device according to claim 7, characterized in that with the respective step-down
converter (7, 8) the controllable power semiconductor switch (11 a) of the first series cir
cuit (7a, 8a) is connected with the first connection (5) of the DC voltage circuit (4) and the

controllable power semiconductor switch (11b) of the second series circuit (7b, 8b) with the second connection (6) of the DC voltage circuit (4), that with the respective step-down converter (7, 8) the connecting point of the diode (12a) of the first series circuit (7a, 8a) with the controllable power semiconductor switch (11a) of the first series circuit (7a, 8a) is connected with the respective DC voltage rail system (9aT 9b) through a first connection (14), and that with the respective step-down converter (7, 8) the connecting point of the diode (12b) of the second series circuit (7b, 8b) with the controllable power semiconductor switch (11b) of the second series circuit (7b, 8b) is connected with the respective DC voltage rail system (9a, 9b) through a second connection (15).
9. The device according claim 8, characterized in that with the respective step-down con
verter (7, 8) a filter circuit (16) is connected between the first connection (14) and the re
spective DC voltage rail system (9a, 9b) and between the second connection (15) and
the respective DC voltage rail system (9a, 9b).
10. The device according to any one of the claims 5, 6, 8 or 9, characterized in that with the
respective step-down converter (7, 8) a current direction limitation element (17) each is
connected to the first connection (14) and into the second connection (15).
11. The device according to any one of the claims 5, 6, 8, 9 or 10, characterized in that with
a connecting element (20) is connected between the first connection (14) relative to the
first DC voltage rail system (9a) and the first connection (14) relative to the second DC
voltage rail system (9b) and between the second connection (15) relative to the first DC
voltage rail system (9a) and the second connection (15) relative to the second DC volt
age rail system (9b).
12. The device according to claim 11, characterized in that with the respective step-down
converter (7, 8) an isolating element (21) is connected to the first connection (14) and to
the second connection (15).
13. The device according to claims 3, characterized in that with the further rectifier (22) a
current direction limitation element (17) each is connected to the first connection (14)
and the second connection (15).

14. The device according to claim 3 or 13, characterized in that with the further rectifier (22)
an isolating element (21) is connected to the first and second connection (14, 15).
15. The device according to any one of the preceding claims, characterized in that the first
and second DC voltage rail system (9a, 9b) each has an overvoltage limitation network
(18)
16. The device for the feeding of auxiliary operating facilities for a fuel-electrically driven ve
hicle with a combustion engine (1), with a generator (2) driven by the combustion engine
(1), with first and second rectifiers (3a, 3b) connected with the generator (2) on the AC
voltage side and assigned to the generator (2), wherein the first rectifier (3a) on the DC
voltage side is connected with a first and a second connection (5a, 6a) of a first DC volt
age circuit (4) assigned to the first rectifier (3a) and connected downstream of the first
rectifier (3a) and the second rectifier (3b) on the DC voltage side with a first and a sec
ond connection (5b, 6b) of a second DC voltage circuit (4b) assigned to the second recti
fier (3b) and connected downstream of the second rectifier (3b), characterized in that,
a first step-down converter (7) is connected with the first and second connection (5a, 6a) of the first DC voltage circuit (4a) and a second step-down converter (8) with the first and second connection (5b, 6b) of the second DC voltage circuit (4b), and that the first step-down converter (7) is connected with a first DC voltage rail system (9a) for the feeding of the auxiliary operating facilities (10a) assigned to the first step-down converter (7) and connected downstream of the first step-down converter (7) and that the second step-down converter (8) is connected with a second DC voltage rail system (9b) for the feeding of the auxiliary operating facilities (10b) assigned to the second step-down converter (8) and connected downstream of the first step-down converter (8).
17. The device according to claim 16, characterized in that the respective step-down con
verter (7, 8) is formed through a series circuit of a controllable power semiconductor
switch (11) with a diode (12) and through a capacity (13) switched parallel with the series
circuit of the controllable power semiconductor switch (11) with the diode (12).

18. The device according to claim 17, characterized in that with the respective step-down
converter (7, 8) the controllable power semiconductor switch (11) is connected with the
first connection (5a, 5b) of the respective DC voltage circuit (4a, 4b) and the diode (12)
with the second connection (6a, 6b) of the corresponding DC voltage circuit (4a, 4b), and
that
with the respective step-down converter (7, 8) the diode (12) is connected with the respective DC voltage rail system (9a, 9b) through a first connection (14) and the connecting point of the diode (12) with the controllable power semiconductor switch (11) through a second connection (15).
19. The device according to claim 18, characterized in that with the respective step-down
converter (7, 8) a filter circuit (16) is connected between the first connection (14) and the
respective DC voltage rail system (9a, 9b) and to the second connection (15).
20. The device according to claim 16, characterized in that the respective step-down con
verter (7, 8) is formed through a first and a second series circuit (7a, 7b, 8a, 8b) each of
a controllable power semiconductor switch (11a, 11b) with a diode (12a, 12b) and
through a capacity (13) each connected in parallel with each series circuit, wherein the
diode (12a) of the first series circuit (7a, 8a) is connected with the diode (12b) of the sec
ond series circuit (7b, 8b).
21. The device according to claim 20, characterized in that with the respective step-down
converter (7, 8) the controllable power semiconductor switch (11a) of the first series cir
cuit (7a, 8a) is connected with the first connection (5a, 5b) of the respective DC voltage
circuit (4a, 4b) and the controllable power semiconductor switch (11 b) of the second se
ries circuit (7b, 8b) with the second connection (6a, 6b) of the respective DC voltage cir
cuit (4a, 4b) that, with the respective step-down converter (7, 8) the connecting point of
the diode (12a) of the first series circuit (7a, 8a) with the controllable power semiconduc
tor switch (11a) of the first series circuit (7a, 8a) is connected with the respective DC
voltage rail system (9a, 9b) through a first connection (14), and
that with the respective step-down converter (7, 8) the connecting point of the diode (12b) of the second series circuit (7b, 8b) with the controllable power semiconductor

switch (11 b) of the second series circuit (7b, 8b) is connected with the respective DC voltage rail system (9a, 9b) through a second connection (15).
22. The device according to claim 21, characterized in that with the respective step-down
converter (7, 8) a filter circuit (16) is connected between the first connection (14) and the
respective DC voltage rail system (9a, 9b) and between the second connection (15) and
the respective DC voltage rail system (9a, 9b).
23. The device according to any one of the claims 18, 19, 21 or 22, characterized in that with
the respective step-down converter (7, 8) a current direction limitation element (17) each
is connected to the first connection (14) and to the second connection (15).
24. The device according to any one of the claims 18, 19, 21, 22 or 23, characterized in that
with a connecting element (20) is connected between the first connection (14) relative to
the first DC voltage rail system (9a) and the first connection (14) relative to the second
DC voltage rail system (9b) and between the second connection (15) relative to the first
DC voltage rail system (9a) and the second connection (15) relative to the second DC
voltage rail system (9b).
25. The device according to claim 24, characterized in that with the respective step-down
converter (7, 8) an isolating element (21) is connected to the first and second connection
(14, 15).
26. The device according to any one of the claims 16 to 25, characterized in that the first and
second DC voltage rail system (9a, 9b) each has an overvoltage limitation network (18).
Dated this 23 day of February 2007


Documents:

793-CHENP-2007 AMENDED CLAIMS 08-12-2011.pdf

793-CHENP-2007 POWER OF ATTORNEY 08-12-2011.pdf

793-CHENP-2007 EXAMINATION REPORT REPLY RECEIVED 08-12-2011.pdf

793-CHENP-2007 CORRESPONDENCE OTHERS 29-04-2011.pdf

793-chenp-2007 correspondence others.pdf

793-chenp-2007 form-3.pdf

793-chenp-2007-abstract.pdf

793-chenp-2007-claims.pdf

793-chenp-2007-correspondnece-others.pdf

793-chenp-2007-description(complete).pdf

793-chenp-2007-drawings.pdf

793-chenp-2007-form 1.pdf

793-chenp-2007-form 3.pdf

793-chenp-2007-form 5.pdf

793-chenp-2007-pct.pdf


Patent Number 250536
Indian Patent Application Number 793/CHENP/2007
PG Journal Number 02/2012
Publication Date 13-Jan-2012
Grant Date 09-Jan-2012
Date of Filing 23-Feb-2007
Name of Patentee ABB Schweiz AG
Applicant Address BROWN BOVERI STRASSE 6, CH-5400 BADEN, SWITZERLAND
Inventors:
# Inventor's Name Inventor's Address
1 GUGGISBERG, BEAT DORFSTRASSE 46E, CH-5417 UNTERSIGGENTHAL, SWITZERLAND
2 BISEN, VISHAL BLUMENWEG 1, CH-5300 TURGI, SWITZERLAND
PCT International Classification Number H02M 3/158
PCT International Application Number PCT/CH05/00486
PCT International Filing date 2005-08-19
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 04405532.5 2004-08-26 EUROPEAN UNION