Title of Invention

AN IMPROVED POWER CAPACITOR ADAPTABLE FOR APPLICATION IN CAPACITOR BATTERIES

Abstract

The invention relates to an improved power capacitor adaptable for application in capacitor batteries, in which a low-inductive circuiting takes place with the help of flat strip lines, comprising a housing (1) and at least one pluggable functional element (5) arranged against the capacitor housing (1). The circuiting between capacitor and a flat line (2) taken place with the help of said at least one pluggable functional element (5).

Full Text

Power Capacitior The invention pertains to a power capacitor which is foreseen for application in capacitor batteries, in which a low-inductive circuiting takes place with the help of flat strip lines. Such a capacitor is known from the document EP 0 450 122 B1. The development of power electronics capacitors strongly orients itself to the systems development of inverters and the semi conductor valves available to them. Meanwhile, IGBT (Insulated Gate Bipoler Transistor)-semiconductors are used not only in the 100 KW-range, but there are concepts for presenting high-power inverter for traction and industry in the range upto 6 MW. The development thereby concentrates on modularity and standardization of the assembly groups. From this strategy emerges also the demand for corresponding optimized components. The available intermediate circle capacitors have indeed achieved significant success due to reduction in structural size and sinking of the dispersion inductivity, however the present market demands can be only suboptimally fulfilled at the moment. It is the task of this invention to present a power capacitor of the already mentioned type with optimum properties adapted to the application in IGBT-inverters with simultaneous cost reduction. This task is fulfilled as per the invention, in that the circuiting between capacitor and strip line is done with the help of plug elements. The invention is described in details on the basis of the following design examples. accompanying The following are shown in the drawing: Fig. 1 A capacitor housing with pluggable functional element; Fig. 2 A top view of the housing with pluggable strip lines; Figs.3 and 4 Sectional images according to the section lines given in fig. 2; and Fig. 5 An enlarged depiction of the pluggable functional element shown in fig. 1. In fig. 1 a housing 1 is shown, into which the capacitor is built-in. On the housing, pluggable functional elements 5 are arranged, which are described in more details in fig. 5. The housing 1 is later mounted on a IGBT-inverter module which is not shown in the figure. In fig. 2, the top view on a strip line 2 is shown, which lies above the capacitor housing 1 drawn in the figure with dashed-dots. As one can see from figures 3 or 4, the strip line 2 is designed pluggable, for which the metal material of the strip line 2 is suitably punched out and bent (knife-contact). This bending sequence can be done cost-effectively while manufacturing the strip line 2, whereby an additional component is not required. The contact is established through the bent metal strip 6 or an additionally mounted metal angle, in conjunction with the counterpiece 7 of the pluggable functional unit 5 which is shown in fig. 5. The counterpiece is produced from several resilient contact elements in order to minimize the transition resistance. The capacitor housing 3 can additionally be equipped with one or several design elements with catch- or snap function 9, 10, and can be mounted vibration-free on to the strip line 2 with the help of an auxiliary fixture. From fig. 5 it is further clear that the pluggable functional element 5 can be designed with a number of resilient contact points 8. Contrary to the design example shown in the figures, the plug elements can also be designed in such a way that the counterpiece. 7 is functionally comparably mounted on the strip line 2 with the resilient contact elements 8 as shown in fig. 5, and the metal strip (knife contact 6) is arranged in a suitable manner against the capacitor housing 1. With the help of the design as per the invention with plug elements, one can fulfil the requirements of an IGBT-intermediate circle- or decoupling capacitor, in which comparatively high currents (10 - 500 A), low parasite inductivities LoKond (in the range Due to the circuiting of several capacitors with the help of the strip lines 2, the demand for a circular inductivity Lkreis = 100 nh is possible-through short cable lengths, whereby simultaneously the number of parallely connected capacitors nkOnd can be optimized in order to exploit the effect Lkries~ (l/nkond A further advantage in the circuiting as per the invention with the help of plug elements lies in the fact that no noteworthy assembly costs are incurred, so that on considering the assembly costs the number of used components can be adapted to the demands for low circular inductivity LKries without any problem, and one can do away with the frequently used decoupling capacitors with complicated circuitry. The number of plug elements is laid down according to the criterion of current carrying capacity (operating current e.g. 200 Aeff/capacitor) and the permissible parasite inductivity Lakond, whereby the number should not be below two. Preferably, four to six pluggable functional elements 5 are arranged against the capacitor housing 1. WE CLAIM: 1. An improved power capacitor adaptable for application in capacitor batteries, in which a low-inductive circuiting takes place with the help of a flat strip lines, comprising a housing (1) and at least one pluggable functional element (5) arranged against the capacitor housing (1), characterized in that the circuiting between capacitor and a flat line (2) takes place with the help of said at least one pluggable functional element (5). 2. The power capacitor as claimed in claim 1, wherein the number of pluggable functional elements (5) per capacitor is = 2. 3. The power capacitor as claimed in claim 2, wherein the number of pluggable functional elements (5) per capacitor is 4 to 6. 4. The power capacitor as claimed in one of the claims 1 to 3, wherein the pluggable functional elements (5) are configured as knife contact. 5. The power capacitor as claimed in claim 4, wherein the knife contact comprises a metal strip (6) bent from the strip line (2), which grips into a pluggable functional element (5) disposed against the capacitor housing (1). 6. The power capacitor as claimed in claim 5, wherein the pluggable functional element (5) comprises a plurality of resilient contact elements (7,8). 7. The power capacitor as claimed in one of the claims 4 to 6, wherein the metal strip (6) and the pluggable functional elements (5) are joined to one another by means of one of a catch function The invention relates to an improved power capacitor adaptable for application in capacitor batteries, in which a low- inductive circuiting takes place with the help of a flat strip lines, comprising a housing (1) and at least one pluggable functional element (5) arranged agaisnt the capacitor housing (1).The circuiting between capacitor and a flat line (2) takes place with the help of said at least one pluggable functional element (5).

Documents:

00309-cal-1999 correspondence.pdf

00309-cal-1999-abstract.pdf

00309-cal-1999-claims.pdf

00309-cal-1999-correspondence.pdf

00309-cal-1999-description (complete).pdf

00309-cal-1999-drawings.pdf

00309-cal-1999-form 1.pdf

00309-cal-1999-form 2.pdf

00309-cal-1999-form 3.pdf

00309-cal-1999-form 5.pdf

00309-cal-1999-letter patent.pdf

00309-cal-1999-pa.pdf

00309-cal-1999-priority document others.pdf