Title of Invention | A.C. MOTOR (OTHER THAN AN INDUCTION MOTOR) RECEVING A FLUCTUATING INPUT SUPPLY VOLTAGE, YET PROVIDING SUBSTANTIALLY THE SAME RATED POWER OUTPUT |
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Abstract | An a.c. motor (other than an induction motor), receiving a fluctuation input supply voltage, yet providing substantially the same rated power output, comprising a stator coil winding of N strands per phase; sensing means for sensing the input supply voltage; switching means which, whenever activated by the sensing means on sensing on input supply voltage fluctuation from the rated value to a falling one of N bands, connects the said strands together predetermined relationship, to present a predetermined number of turns of the said winding to the input supply voltage, thus providing substantially the same rated power output. |
Full Text | This invention relates to an a.c. motor (other than an induction motor) receiving a fluctuating input supply voltage, yet providing substantially the same rated power output. Substantially the same rated power output becomes possible since the equation power is proportional to V.I (P VI) has two compensating variables V and I. This invention is applicable to single phase as well as to multi-phase a.c. motors (other than induction motors) A normal a.c. motor (other than an induction motor) is designed for a specific supply voltage, also called the rated supply voltage. The motor can satisfactorily operate within a variation (fluctuation) margin e.g. plus or minus 5% of the rated input voltage without noticeably affecting the power output- When the input voltage falls below, or rises above, the rated voltage, beyond the margin, the current increases drastically; and the power output, as well as the efficiency, drops considerably. This invention, accordingly, proposes an a.c. motor (other than an induction motor) which, although, receiving a fluctuating input supply voltage, yet provides substantially the same rated power output. Some of the advantages of this invention are: * Coil burnouts due to voltage fluctuations can be minimised * The motor is optimally loaded * Reduced heating of the stator * Higher efficiency and power factor under varying voltage conditions * Easier starting under low voltage conditions. Various other advantages of this invention will be apparent from the following further description thereof. According to this invention, the a.c. motor (other than an induction motor) although receiving a fluctuating input supply voltage, yet providing substantially the same rated power output. comprises a stator coil winding of N strands per phase; sensing means for sensing the input supply voltage; switching means which, whenever activated by the sensing means on sensing an input supply voltage fluctuation from the rated value to a value falling in one of N bands, connects the said strands together in predetermined relationship, to present a predetermined number of turns of the said winding to the input supply voltage, thus providing substantially the same rated power output. If the cross-sectional area of the winding conductor of the standard a.c. motor In the drawings Fig. 1 illustrates the phase winding of a normal a.c. motor Fig. 2 illustrates the phase winding of the a.c. motor (other than an induction motor) proposed herein Fig. 3 illustrates four input supply voltage values Va Vb Vc Vd; corresponding current density curves la lb Ic and Id and Fig. 4 illustrates the layout diagram of one of possible embodiments of the the a-c. motor proposed herein including the sensing and switching means. As stated earlier, the motor can comfortably operate at a supply voltage band width of around 5% plus or minus of the rated input supply voltage. Fig. 1 illustrates the winding of a single phase in a standard a.c. mootor In the proposed a.c. motor (other than an induction motor) the winding (Fig.2) of a single phase consists of 4 strands S corresponding to the 4 bands of a fluctuating input supply voltage values. Sensing means are provided for sensing the input supply voltage, such as, an electrical sensor e.g. a voltmeter system, an electronic sensor system or a microprocessor system A connected to the input lines of the motor M for sensing the input supply voltage. Switching means (such as an electrical contactor system, a multipole-multiposition switch or an electronic switching system B) are provided for being activated by the sensing means, whenever the input supply voltage fluctuates from the rated value and falls in one of the four bands. On activation, the said switching means connect the said 4 strands together in predetermined relationship, to present a predetermined number of turns of the said winding to the input supply voltage. This predetermined number of turns is the number required for producing substantially the same rated power output. Thus, if the voltage fluctuation is of a value falling between Va and Vb, the microprocessor A senses the value and activates the switching means B. Once activated, the switching means B connects the strands S of the winding to obtain a predetermined number of turns required to furnish substantially the same rated power output. The above operation can also be carried out manually. Thus, if the voltage fluctuation is of a value falling between Va and Vb, a voltmeter (used as sensing means) senses the value. The Operator viewing a prepared chart manually activates the multipole-multiposition switch B The predetermined relationship of the said strands comprises connection thereof in series, parallel, series-parallel relationship. The terms and expressions in this specification are of description and not of limitation, there being no intention to exclude any equivalents of the features thereof, but it is understood that various other embodiments of the a.c. motor (other than an induction motor) proposed herein are possible without departing from the scope and ambit of this invention. I Claim: 1. An s.c. motor (other than an induction motor), receiving a fluctuating input supply voltage, yet providing substantially the same rated power output, comprising a stator coil winding of N strands per phase; sensing means for sensing the input supply voltage; switching means which, whenever activated by the sensing means on sensing an input supply voltage fluctuation from the rated value to a value falling in one of N bands, connects the said strands together in predetermined relationship, to present a predetermined number of turns of the said winding to the input supply voltage, thus providing substantially the same rated power output. 2. An a.c. motor (other than an induction motor) as claimed in Claim 1 wherein the cross-sectional area of each of the N strands is a fraction of the cross- sectional area of the conductor of the winding of the corresponding known standard a.c. motor (other than an induction motor) so that the sum total of the cross- sectional areas of the N strands substantially equals the cross-sectional area of the said conductor. 3. An a.c. motor (other than an induction motor) as claimed in any one of the preceding Claims wherein the sensing means comprise an electronic sensor system for sensing the input supply voltage. 4. An a.c. motor (other than an induction motor) as claimed in any one of the preceding Claims 1 and 2 wherein the sensing means comprise an electrical sensor system for sensing the input supply voltage. 5. An a.c. motor (other than an induction motor) as claimed in any one of the preceding Claims 1 and 2 wherein the sensing means comprise a microprocessor for sensing the input supply voltage. b. An a.c. motor (other than an induction motor) as claimed in anyone of the preceding Claims wherein the switching means comprise an electrical switching system. 7. An a.c. motor (other than an induction motor) as claimed in any one of the preceding Claims 1 to 5 wherein the switching means comprise an electronic switching system. 8. An a.c. motor (other than an induction motor) as claimed in any one of the preceding Claims 1 to 5 wherein the switching means comprise a manual switching system. 9. An a.c. motor (other than an induction motor) as claimed in any one of the preceding Claims wherein the predetermined relationship of the said strands comprises connection thereof in series, parallel, series-parallel relationship. 10. An a.c. motor (other than an induction motor) as claimed in any one of the preceding Claims provided with a single phase winding. 11. An a.c. motor (other than an induction motor) as claimed in any one of the preceding Claims 1 to 9 provided with a multi-phase winding. 12. An a.c. motor (other than an induction motor) receiving a fluctuating input supply voltage, yet providing substantially the same rated power output, substantially as herein described with reference to, and as illustrated in, the accompanying drawings. |
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335-mas-2002 abstract duplicate.pdf
335-mas-2002 claims duplicate.pdf
335-mas-2002 correspondence others.pdf
335-mas-2002 correspondence po.pdf
335-mas-2002 description (complete) duplicate.pdf
335-mas-2002 description (complete).pdf
335-mas-2002 drawing duplicate.pdf
Patent Number | 201629 | ||||||||
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Indian Patent Application Number | 335/MAS/2002 | ||||||||
PG Journal Number | 08/2007 | ||||||||
Publication Date | 23-Feb-2007 | ||||||||
Grant Date | 04-Aug-2006 | ||||||||
Date of Filing | 01-May-2002 | ||||||||
Name of Patentee | MS. DAMAYANTI RAMACHANDRAN | ||||||||
Applicant Address | 20 A.T.D STREET, RACE COURSE, COIMBATORE 641 018 | ||||||||
Inventors:
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PCT International Classification Number | H02P 9/00 | ||||||||
PCT International Application Number | N/A | ||||||||
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