MXPA96006301A - Improved topology of emi filter for ener inversers - Google Patents

Abstract

The present invention relates to an EMI filter for an electric vehicle propulsion system, which comprises first (62) and second (72) capacitive elements electrically connected in parallel with first (130) and second (132) power conductors , an inductive element (106) electrically connected in series with the first power conductor (130), and separating the first (62) and second (72) capacitive elements, and first (134) and second (136) junctions that electrically connect the second capacitive element (72) with an electronic switch (68), where the sum of the internal inductances (135, 137) of the first (134) and second (136) joints is less than the internal inductance (75) ) of the second capacitive element (7)

Description

IMPROVED TOPOLOGY OF EMI FILTER FOR ENERGY INVESTORS RELATED REQUESTS The following documents are recognized as the state of the art: UK Patent GB-A-2-242 580 entitled "Inverter Unit with Improved busplate configuration" • EPE'91 vol. 2, 1991 Florence entitled "Design Aspects of High Power PWM Inverters with IGBT. "The following patent applications of the United States of America were filed on the same date as the present application and are referred to herein as the state of the art. Patent of the United States of America entitled "Fiat Topping Concept" bearing the case number 58.95, and which was filed on the same date herewith; United States Patent Application North American titled "Electric Induction Motor And Related Method Of Cooling" that takes the number of case No. 58,332, and that was presented in the same date with the present one; The patent application of the United States of North America entitled "Automotive 12 Volt System For Electric Vehicles "bearing the case number 58,333, and which was filed on the same date with the present; United States Patent Application North America titled "Direct Cooled Switching Module For Electric Vehicle Propulsion System "bearing the case number 58,334, and which was filed on the same date herewith: The United States of America Patent Application entitled" Electric Vehicle Propulsion System "bearing the case number 58,335, and that it was filed on the same date with the present; The United States patent application of North America titled "Speed Control and Bootstrap Technique For High Voltage Motor Control "bearing the case number 58,336, and that it was filed on the same date with this, - The United States patent application of North America titled "Vector Control Board For An Electric Vehicle Propulsion System Motor Controller "bearing the case number 58,337, and which was filed on the same date with the present; United States Patent Application North America titled "Digital Pulse Width Modulator Wit Integrated Test And Control "which carries the case number 58,338, and that it was filed on the same date with the present; The United States of America Patent Application entitled "Control Mechanism For Electric Vehicle" bearing case number 58,339, and which was filed on the same date herewith; The United States patent application of North American entitled "Fault Detection Circuit For Sensing Lea age Currents Between Power Source And Chassis" which bears the case number 58,341, and which was filed on the same date with the present; The United States patent application of North America entitled "Electric Vehicle Relay Assembly" bearing the case number 58,342, and which was filed on the same date herewith; The patent application of the United States of North America entitled "Three Phase Power Bridge Assembly" bearing the case number 58,343, and which was filed on the same date herewith; The United States patent application of North America entitled "Electric Vehicle Propulsion System Power Bridge With Built-In Test" that bears the case number 58,344, and which was filed on the same date with the present; The United States patent application of North American entitled "Method For Testing A Power Bridge For An Electric Vehicle Propulsion System" bearing the case number 58,345, and which was filed on the same date with this; The United States of America Patent Application entitled "Electric Vehicle Power Distribution Module" bearing the number of case 58,346, and which was filed on the same date herewith; The patent application of the United States of North America entitled "Electric Vehicle C assis Controller" bearing the case number 58,347, and which was filed on the same date herewith; The patent application of the United States of North America entitled "Electric Vehicle System Control Unit Housing" bearing the case number 58,348, and which was filed on the same date herewith; The United States patent application of North American entitled "Low Cost Fluid Cooled Housing for Electric Vehicle System Control Unit" bearing the case number 58,349, and which was filed on the same date with this; The United States patent application of North America entitled "Electric Vehicle Coolant Pump Assembly" bearing the case number 58,350, and which was filed on the same date herewith; The United States of America Patent Application entitled "Heat Dissipating Transformer Coil" bearing case number 58,351, and which was filed on the same date herewith; The patent application of the United States of North America entitled "Electric Vehicle Battery Charger" bearing the case number 58,352, and which was filed on the same date herewith.

BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to electromagnetic interference (EMI) filters. More particularly, the present invention relates to electromagnetic interference filter for use in a propulsion system of an electric vehicle. Although the invention is subject to a wide range of applications, it is especially convenient for use in electric vehicles that use batteries or a combination of batteries and other sources, for example, a heat engine coupled to an alternator, as a source of energy, and will be particularly described in connection with this.

Description of the Related Art For an electric vehicle to be commercially viable, its cost and performance must be competitive with that of its counterparts energized with gasoline. Typically, the vehicle propulsion system and the battery are the main factors that contribute to the competitiveness in cost and performance of the vehicle. Generally, to achieve commercial acceptance, a propulsion system for electric vehicles must provide the following characteristics: (1) vehicle performance equivalent to typical propulsion systems energized with gasoline; (2) even control of the propulsion of the vehicle; (3) regenerative braking; (4) high efficiency, - (5) low cost, - (6) self-cooling; (7) confinement of electromagnetic interference (EMI); (8) fault detection and self-protection; (9) self-test and diagnostic capability, - (10) control and status interfaces with external systems; (11) safe operation and maintenance; (12) flexible ability to charge the battery; and (13) 12 volt auxiliary power from the main battery. However, in previous practice the design of electric vehicle propulsion systems consisted largely of matching an engine and a controller with a set of vehicle performance goals, so that performance was often sacrificed to allow a design practical motor and controller. In addition, little attention was paid to the above characteristics that increase commercial acceptance. For example, a conventional typical electric vehicle propulsion system comprises, among other things, an energy bridge that includes high-energy switching transistors to supply current to the windings of a motor. In operation, the energy bridge rapidly changes high currents from the power source creating substantial electromagnetic interference, such as voltage peaks, harmonic currents, and parasitic oscillations. This conductive electromagnetic interference will cause the power conductors that interconnect the power bridges and other components to act as radiators, emitting radiant electromagnetic interference that can interfere with internal electronic equipment such as computers and radio receivers. Likewise, in a high-voltage system such as an electric propulsion system for an electric vehicle, conductive electromagnetic interference may also interrupt system operations and may damage or degrade the components of the system. Even more, conventional electronic filter elements, such as an active protection capacitor assembly, generally include resistance elements to compensate for the scattered inductance in the filter circuit. These resistance elements denigrate the efficiency of the system and generate additional heat energy. Thus, in an electric vehicle propulsion system where high efficiency and self-cooling are highly desirable, these resistance elements are disadvantageous.

COMPENDIUM OF THE INVENTION In accordance with the foregoing, the present invention is directed to an electromagnetic interference filter for use in an electric vehicle propulsion system that substantially obviates one or more of the problems due to the limitations and disadvantages of the technique related The features and advantages of the invention will be presented in the description that follows, and in part will be apparent from the description or can be learned by the practice of the invention. The objects and other advantages of the invention will be realized and attained by means of the apparatus particularly indicated in the written description and in the claims thereof as well as the attached drawings. In order to achieve these and other advantages according to the purpose of the invention, as it is widely incorporated and described, the invention provides an electromagnetic interference filter for an electric vehicle propulsion system, comprising a first capacitor element electrically connected in parallel with the first and second power conductors, and a second capacitor element having first and second terminals and an internal inductive component. The first and second terminals of the second capacitor element are electrically connected to the first and second power conductors. The electromagnetic interference system filter further includes an inductive element electrically connected in series with the first power conductor so that the first inductor element separates the first and second capacitor elements. The electromagnetic interference filter also includes first and second junctions electrically connecting the first and second terminals of the second capacitor element to the first and second terminals of an electronic switch. The first and the second junctions having first and second internal inductive components, the sum of the inductances of the first and second internal inductive components of the first and second junctions is smaller than the inductance of the internal inductive component of the second capacitor element. It will be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide additional explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are included to provide a better understanding of the invention and are incorporated and constitute a part of this specification, illustrate a currently preferred embodiment of the invention and, together with the description, serve to explain the principles of the invention. In the drawings: Figure 1 is a block diagram of an electric vehicle propulsion system; Figure 2 is a schematic diagram of the motor of the electric vehicle propulsion system of Figure 1; Figure 3 is a functional diagram of the motor controller of the electric vehicle propulsion system of Figure 1, - Figure 4 is a schematic diagram of a first power bridge assembly for an electric vehicle propulsion system; Figure 5 is a schematic diagram of a second power bridge assembly for an electric vehicle propulsion system; Figure 6 is a schematic diagram of the input filter and the relay control unit of the motor controller of Figure 3. Figure 7 is a schematic diagram of the electromagnetic interference filter of the input filter and the relay control unit of Figure 6 according to the preferred embodiment of the present invention; and Figure 8 is an exploded view of a portion of the dual energy bridge assembly for an electric vehicle propulsion system.

DESCRIPTION OF THE PREFERRED MODALITY Reference will now be made in detail to a currently preferred embodiment of the invention, an example of which is illustrated in the accompanying drawings. The present invention, which relates to an electric vehicle assembly, will be described with respect to an electric vehicle propulsion system 10, as shown in Figure 1. The electric vehicle propulsion system 10 comprises a system control unit 12, an engine assembly 24, a cooling system 32, a battery 40, and a DC / DC converter 38. The system control unit 12 includes a cold plate 14, a battery charger 16, a motor controller 18, a power distribution module 20, and a chassis controller 22. The motor assembly 24 includes a spacer 26, a motor 28, and a filter 30. The cooling system 32 includes an oil pump unit 34 and a radiator / fan 36. The battery 40 serves as the primary source of energy for the electric propulsion system 10. "The battery 40 comprises, for example, a sealed lead acid battery, a monopolar lithium-sulfide metal battery, a bipolar battery r of lithium-sulfide metal, or the like, to provide an output of 320 volts. Preferably, the electric propulsion system 10 operates over a wide voltage range, for example 120 volts to 400 volts, to accommodate changes in battery output voltage 40 due to the discharge load or depth. However, the electric vehicle propulsion system 10 is preferably optimized for nominal battery voltages of approximately 320 volts. As shown in Figure 2, the motor 28 is a 3-phase AC induction motor having two identical windings, electrically insulated, per phase (windings Al and A2 are for phase "A", windings Bl and B2 are for phase "B", and windings Cl and C2 are for phase "C") to produce high torque at zero speed to provide performance comparable to internal combustion engines. Preferably, the two windings in each phase of the motor 28 are substantially aligned on top of one another and are electrically in phase so that each winding provides about half of the total energy of the phase. As shown in Figure 3, the input filter and relay control unit DC 44, which includes some components of the electromagnetic interference filter of the present invention, is included in the motor controller 18. The motor controller 18 also includes a low voltage power supply 42, a vector control board 46, and a first and a second power bridge and gate actuator 48 and 50, respectively.

The low voltage power supply 42 converts the 12 volt output of the DC / DC converter 38 to provide outputs of + 15V, +/- 15V, and + 20V to the input filter and relay control unit DC 44, the board vector control 46, the first energy bridge 48, and the second energy bridge 50. The low voltage power supply 42 may comprise a commercially available power supply as is known in the art. The vector control board 46 comprises a digital and analog electronic system based on a microprocessor. As its primary function, the vector control board 46 receives acceleration initiated by the driver and braking requests from the chassis controller 22. The vector control board 46 then acquires measurements of the rotor position from separator 26 and current measurements from the first and second power bridges 48 and 50, respectively, and use these measurements to generate pulse width modulated voltage (PWM) waveforms to drive the first and second power bridges 48 and 50, respectively, to produce the desired acceleration or braking effects in the motor 28. Modulated pulse width voltage waveforms are generated in accordance with a control program that is designed to result in the production of the requested torque. As described above, the vector control board 46 also has the function of controlling the input filter and relay control unit DC 44, the oil pump unit 34, the radiator / fan 36, the battery charger 16, the input filter and DC 44 relay control unit, integrated test circuits, vehicle communication, and fault detection. In Figure 4 a schematic diagram of a first energy bridge 48 is shown, and in Figure 5 a schematic diagram of a second energy bridge 50 is shown. The first and second energy bridges 48 and 50 convert direct current Input in alternating current of three output phases. The first energy bridge 48 receives a high-voltage input current from the battery 40, preferably 340 volts, and outputs an alternating current at the terminals Al, Bl, and Cl. The second energy bridge 50 also receives a high voltage current from the battery 40, preferably 340 volts, and outputs an alternating current at the terminals A2, B2 and C2. The first energy bridge 48 includes three isolated gate bipolar transistor circuits (IGBT) 52a, 52b and 52c, while the second energy bridge 50 includes three identical bipolar transistor circuits 54a, 54b and 54c. Preferably, the three insulated gate bipolar transistor circuits 52a, 52b and 52c and the three bipolar transistor circuits 54a, 54b and 54c produce a three phase alternating current in six outputs. In each insulated gate bipolar transistor circuit 52a-54c, two insulated gate bipolar transistors 68 are connected together in series. A diode 70 is connected through the current path of each bipolar insulated gate transistor 68, and a second capacitor element 72 is connected through the combined current paths of the insulated gate bipolar transistors 68. Referring specifically to the insulated gate bipolar transistor circuit 52a as an example, a collector 69a of the insulated gate bipolar transistor 68a is electrically connected to the positive side of the battery 40, an emitter 71a of the insulated double-pole gate transistor 68b is electrically connected to the collector 69b of the insulated gate bipolar transistor 68b, and an emitter 71b of the insulated gate bipolar transistor 68b is electrically connected to the negative side of the battery 40. The output terminal Al is electrically connected to the emitter 71a of the bipolar insulated gate transistor 68a and the collector 69b of the insulated gate bipolar transistor 68b. The diodes 70 are connected through the current paths of the insulated gate bipolar transistors 68a and 68b. The doors 73 of the insulated gate bipolar transistors 68 in the first energy bridge 48 are connected to the gate drive circuits 56a, 56b, and 56c, while the doors 73 of the bipolar gate transistors isolated in the second bridge 50 are connected to the gate drive circuits 58a, 58b, and 58c. The gate drive circuits 56a, 56b, 56c, 58a, 58b, and 58c produce pulses that are supplied to the gates 73 of the insulated gate bipolar transistors 68 to selectively change the insulated gate bipolar transistors 68. In this way, the drive circuits 56a, 56b and 56c control the synchronization of the switching in the first energy bridge 48, while the drive circuits 58a, 58b and 58c control the switching synchronization in the second energy bridge 50. The filter input and relay control unit DC 44, which includes components of the electromagnetic interference filter of the present invention, comprises electrical connections for coupling a 320 volt output of the power distribution module 20 to the first and second power bridges 48 and 50, respectively. AND? input filter and relay control unit DC 44 further includes a relay circuit to disconnect the coupling of the 320 volt output of the energy distribution module 20 to the first and second energy bridges 48 and 50, respectively, and several Integrated test circuits that include voltage sensing circuits and a chassis ground loss circuit. Preferably, the input filter and DC relay control unit 44 receives control signals from and sends status signals, e.g., integrated test signals, to the vector control board 46. 5 Figure 6 is an electrical diagram of the circuit comprising an input filter and a DC relay control unit 44. As described above, the circuit couples the 320 volt output of the distribution module 20 to the first and second energy bridges 48 and 50. The The input and relay control unit 44 includes a fault detection circuit 152, first and second voltage detectors 154 and 156, a main relay circuit 158, and a precharge / discharge relay circuit 60. The circuit of fault detection 152 detects spillage of current to the vehicle chassis and receives control signals from and sends status signals to vector control board 46. The first voltage detector 154 detects the input voltage in the input filter and relay control unit DC 44 and sends signals of state to the vector control board 46. The 0 second voltage detector 156 detects the voltage to be supplied from the main relay circuit 158 and the precharge / discharge relay circuit 60 to the first capacitor element 62. The second detector of voltage 156 also sends state signals to vector control board 46. In response 5 to the control signals of vector control board 46, main relay circuit 158 selectively connects and disconnects the 320 volt output of the energy distribution module 20 to the first and second energy bridges 48 and 50, respectively. The input filter and relay control unit 44 further includes components of the electromagnetic interference filter of the present invention which includes an inductive element 106, a first capacitor element 62, and a common mode choke 142. FIG. 7 is a diagram schematic of one embodiment of the electromagnetic interference filter of the present invention, including connections to the insulated gate bipolar transistors 68 connected in series with the first and second power bridges 48 and 50, respectively. The electromagnetic interference filter of the present invention comprises a first capacitor element 62 electrically connected in parallel with the first and second power conductors 130 and 132, respectively. Preferably, the first capacitor element 62 is a polarized capacitor such as an electrolytic capacitor having a capacitance of about 3500 microfarads. The first and second power conductors 130 and 132, respectively, provide electrical connections to the power distribution module 20 for electrical connection to the battery 40 of the electric vehicle propulsion system 10. The first and second power conductors 130 and preferably we comprise a combination of insulated power cables, laminated bus sections, and input terminals (described below). The electromagnetic interference filter of the present invention further comprises six second capacitor elements 72. A second capacitor element 72 is associated with each of the insulated gate bipolar transistor circuits 52a, 52b, 52c, 54a, 54b and 54c. Each second capacitor element 72 includes first and second terminals 74a and 74b, respectively. Each second capacitor element 72 is preferably composed of a plurality of film capacitors such as polypropylene film capacitors. Each second capacitor element 72 includes an internal inducing component 75. The internal inducing component 75 of the second capacitor element 72 is the dispersed or intrinsic inductance of the component. The film capacitors of the second capacitor element 72 are electrically interconnected and physically accommodated in a manner that reduces the inductance of the internal inductive component 75 of the second capacitive element 72. Preferably, the inductance of the internal inductive component 75 of each second capacitor element 72 it is less than 10 nanohenries and the capacitance of the second capacitor element 72 is approximately 45 microfarads. The model component no. MP9-11049K from Electronic Concepts, Inc. of Eatontown, New Jersey is convenient for use as the second capacitor element 72. The first and second terminals 74a and 74b of each second capacitor element 72 are electrically connected to the insulated gate bipolar transistors. 68 associating the first and second junctions 134 and 136, respectively. Each of the first and second junctions 134 and 136 have first and second internal inductive components 135 and 137, respectively. The first and second internal inductive components 135 and 137 of the first and second junctions 134 and 136, respectively, are the intrinsic dispersion or inductance of those components. The first and second junctions 134 and 136, respectively, are configured to reduce their associated internal inductive components. Preferably, the sum of the inductances of the first and second internal inductive components 135 and 137 of each pair of first and second junctions 134 and 136, respectively, are less than the inductance of the internal inductive component 75 of each second associated capacitive element. 72. For example, the sum of the inductances of the first and second internal inductive components 135 and 137 of each pair of the first and second junctions 134 and 136, respectively, is less than about 10 nanohenries. To reduce the inductance of the first and second internal inductive components 135 and 137 of each pair of first and second junctions 134 and 136, respectively, the second capacitive elements 72 associated with each pair of first and second junctions 134 and 136, respectively, are preferably connects to its isolated gate bipolar transistors connected in series as shown in Figure 8. Figure 8 shows an exploded view of the dual energy bridge 48 with one of the six insulated gate bipolar transistor circuits 52 shown. A description of this assembly including the capacitors 72 is presented below and is also presented in the United States of America patent application entitled "Three Phase Power Bridge Assembly" bearing the case number 58,343, and which was filed in the same date with the present. A dual energy bridge 48 is assembled in a laminated bus bar 82. An upper plate 84 of the bus bar 82 electrically connects to the power distribution module 20 through the input terminal 90, and a lower plate 86 of the bus The collector also electrically connects the energy distribution module 20 through the input terminal 92, whereby the upper plate 84 and the terminal 90 form a part of the second power conductor 132 and the lower plate 86 and the input terminal 90 form a part of the first energy conductor 130. An insulating layer 88 is placed in the middle of the upper and lower plates. Electrical switches and capacitors wall laminated bus bar 82. With this structure, two fasteners, one for positive voltage and one for negative voltage can connect bus 82, capacitors, and switches both electrically and mechanically. As shown in Figure 8, the busbar 82 is sandwiched between a second capacitor element 72 and a packet of insulated gate bipolar transistors 96 containing the insulated gate bipolar transistors 68 and the diodes 70. Two insulated gate bipolar transistors 68 and the associated diodes 70 are enclosed in the insulating electrically insulating composite, such as a plastic, to form the insulated gate bipolar transistor package 96. FIG. 8 shows a U-shaped bus bar 82 which is preferably used in the dual energy bridge mode. Each side of the busbar will connect three packets of insulated gate bipolar transistors 96 with their associated second capacitor elements 72. In an alternative single energy bridge mode, a straight line bus is preferably used to connect three packets of insulated door bipolar transistors 96 with their second capacitor elements 72. In the dual energy bridge mode, an insulated gate bipolar transistor package manufactured by Toshiba Part No. MG300J2YS45 can be used, and in the single energy bridge mode an insulated gate bipolar transistor package manufactured by Powerex, Part No. CM400DY-12H can be used. A conductive base plate 118 is attached to a side of the insulated gate bipolar transistor package 96, and electrical terminals 122, 124, and 126 are attached to the opposite side of the insulated gate bipolar transistor package 96. An electrically and thermally conductive gasket 131 is inserted between the insulated gate bipolar transistor package 96 and a chiller plate ( not shown). Using the insulated gate bipolar transistor circuit 52a of FIG. 4 as an example, the electrical terminal 122 is connected to the emitter of the insulated gate bipolar transistor 68b, the electrical terminal 124 is connected to the collector of the insulated gate bipolar transistor 68a, and the electrical terminal 126 is connected to the emitter of the insulated gate bipolar transistor 68a and to the collector of the insulated gate bipolar transistor 68b. The holes 114 and 116 are formed in the electrical terminals 122 and 124 respectively. The holes 114 and 116 can be formed, for example, by drilling or molding. The gate driver circuit (Figure 4) 56a connects terminals 128 and 129. The second capacitor element 72 includes holes 110 and 112 which are exposed to the first and second terminals 74a and 74b (Figure 7), respectively, of the second. capacitor element 72. The second capacitor element 72, the busbar 82, and the insulated gate bipolar transistor package 96 are connected together with the electrically conductive connectors 98 and 100 (Figure 8). The connector 98 is fitted through the hole 110, the hole in the lower plate 107, and the hole 116. The connector 100 is fitted through the hole 112, the hole in the upper plate 108, and the hole 114. Use connectors such as rods, clips, bolts, rims, or screws, although screws are preferred. If screws are used as shown in Figure 8, holes 114 and 116 have rope. In this manner, the first and second junctions 134 and 136 are accommodated so that bipolar isolated-gate transistor packets protrude to their second capacitor element 72. This minimizes the length of the radiant cycle, reducing radiant electromagnetic interference. The electromagnetic interference filter of the present invention further comprises an inductor element 106 in parallel with the first energy conductor 130. The inductor element 106 comprises a coil inductor with a ferrite core as is known in the art. The inductance of the inductor element 106 is preferably about 10 microhenries. The inductor element 106 separates the first capacitor element 62 from the second capacitor element 72. Inductively isolating the first capacitor element 62 from the second capacitor elements 72, the first and the second energy bridges 48 and 50, respectively, after switching, extract the most current of the associated second capacitor elements 72, ensuring that the majority of current is drawn from a small radiant cycle with relatively smaller dietary inductance, thus reducing both electromagnetic radiating interference and conductive electromagnetic interference caused by, for example, parasitic oscillations . The electromagnetic interference filter a common mode choke 142 (Figure 7) and first and second power capacitors 138 and 140, repectively. The common mode choke 142 is electrically connected in parallel with the first and second power conductors 130 and 132, respectively, and has an inductance of about 10 microhenries. The common mode choke 142, formed by passing the first and second power conductors 130 and 132 through toroidal cores of ferrite material, is used to filter common mode noise from the first and second power conductors. The first and second feeder capacitors 138 and 140 are electrically connected between the first and second power conductors 130 and 132, respectively, and a common circuit connection 141. The film capacitors each have a capacitance of approximately 0.4 microfarads and act to filter high frequency noise from the first and second power conductors 130 and 132. Preferably, the first and second power capacitors 138 and 140, respectively, are located near a limit of a ground cover of the motor controller (not shown) to avoid high frequency noise from being radiated to other parts of the first and the second. second energy conductors 130 and 132, respectively. It should be apparent to those skilled in the art that various modifications and variations may be made without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided that anexae and its equivalents are within the scope of the claim.

Claims (25)

1. An electromagnetic interference filter for an electric vehicle propulsion system that includes a power source, an electronic switch having first and second terminals, and first and second power conductors that electrically connect the first and second terminals, respectively, with the power source, comprising - a first capacitive element (62) electrically connected in parallel with the first (130) and the second (132) power conductors, - a second capacitive element (72) having a first (74a) ) and a second (74b) terminate and an internal inductive component (75), the first (74a) and second (74b) terminals being electrically connected to the first (130) and the second (132) power conductors, respectively, - an inductive element (106) electrically connected in the field with the first power conductor (130), the first inductive element (106) that pertains to the first (62) and second (72) capacitive element; and the first (134) and the second (136) junctions electrically connect the first (74a) and the second (74b) terminals of the second capacitive element (72) with the first and second terminals of the electronic switch (68), respectively, having the first and second connections first (135) and second (137) internal inductive components, respectively, - where a sum of inductances of the first (135) and the second (136) junctions is smaller than an inductance of the internal inductive component of the second capacitor element (75). The electromagnetic interference filter of claim 1, wherein the inductance of the internal inductive component (75) of the second capacitive element (72) is less than 10 nanohenries. 3. The electromagnetic interference filter of claim 1, wherein the second capacitive element (72) is embedded in the electronic switch (61). 4. The electromagnetic interference filter of claim 2, wherein the first capacitive element (62) comprises an electrolytic capacitor. 5. The electromagnetic interference filter wherein the second capacitive element (72) comprises a film capacitor. The electromagnetic interference filter of claim 5 wherein the second capacitive element (72) comprises a polypropylene film capacitor. The electromagnetic interference filter of claim 4, wherein the second capacitive element (72) comprises a plurality of film capacitors. The electromagnetic interference filter of claim 5, wherein: the first capacitive element (62) has a capacitance of about 3500 microfarads, - the second capacitive element (72) has a capacitance of about 45 microfarads, - and the element inductive (106) has an inductance of about 10 microhenries. The electromagnetic interference filter of claim 2 further comprising: a first feeder capacitor (138) electrically connected between the first power conductor (130) and a common circuit connection (141); a second feeder capacitor (140) electrically connected between the second power conductor (132) and the common circuit connection (141); and a common mode choke (142) connected in series with the first (130) and the second (132) power conductors. The electromagnetic interference filter of claim 8 further comprises a first feeder capacitor (138) electrically connected between the first power conductor (130) and a common circuit connection (141); a second feeder capacitor (140) electrically connected between the second power conductor (132) and the common circuit connection (141); and a common mode choke (142) connected in series with the first and second power conductors. 11. The electromagnetic interference filter of claim 10, wherein: the first feeder capacitor (138) comprises a film capacitor having a capacitance of about 0.4 microfarad: the second feeder capacitor (140) comprises a film capacitor having a capacitance of about 0.4 microfarad: and the capacitor Common mode (142) has an inductance of approximately 10 microhenries. 1

2. An electromagnetic interference filter for a seventh electric vehicle propulsion including a power source, an electronic commutator having first and second terminals, and first and second power conductors electrically connecting the first and second terminals, respectively , to the power source, comprising: a first capacitive element (62) electrically connected in parallel with the first (130) and second (132) power conductors, the first capacitive element (62) comprising an electrolytic capacitor having a capacitance of about 3500 microfarads: a second capacitive element (72) comprising a plurality of film capacitors, first (74a) and second (74b) terminals, an internal inductive component (75), and an internal capacitance component, being the first (74a) and second (74b) terminals electrically connected to the first (130) and second (132) conductors in ergía, respectively; an inductive element (106) electrically connected in series with the first power conductor (130), the first inductive element (106) separating the first (62) and second (72) capacitive elements and having an inductance of about 10 microhenries : and first (134) and second (136) junctions that electrically connect the first (74a) and the second (74b) terminals of the second capacitive element (72) with the first and second ends of the electronic switch (68), respectively, having the first (134) and the second (136) first (135) and second (137) internal inductive components, respectively: where a sum of inductances of the first (135) and second (137) internal inductive components of the first (134) and second (136) junctions is less than 10 nanohenries, an inductance of the internal inductive component (75) of the second capacitive element is less than 10 nanohenries, and a capacitance of the internal capacitance component ( 72) is approximately 45 microfarads. The electromagnetic interference filter of claim 12 wherein the second capacitive element (72) is embedded in the electronic switch (68). The electromagnetic interference filter of claim 13 further comprising: a first feeder capacitor (138) electrically connected between the first power conductor (130) and a common circuit connection (141); a second feeder capacitor (140) electrically connected between the second power conductor (130) and a common circuit connection (141); and a common mode choke (142) connected in series with the first (130) and the second (132) power conductors: wherein the first feeder capacitor (138) comprises a film capacitor having a capacitance of approximately 0.4 microfarads : the second feeder capacitor (140) comprises a film capacitor having a capacitance of about 0.4 microfarads: and the common mode choke (142) has an inductance of about 10 microhenries. 15. An electromagnetic interference filter for an electric vehicle propulsion system including a power source, a plurality of electronic switches having first and second terminals, and first and second power conductors electrically connecting the first and second terminals of the plurality of electronic switches, respectively, to the power source, comprising: a first capacitive element (62) electrically connected in parallel with the first (130) and second (132) power conductors: a second capacitive element (72) ) associated with each of the plurality of electronic switches, each of the second capacitive elements (72) having first (74a) and second (74b) terminals and an internal inductive component (75), the first (74a) and the second (74b) terminals of each of the second capacitive elements (72) electrically connected to the first (130) and the second (1) 32) energy conductors, respectively: a first inductive element (106) electrically connected in series with the first energy conductor (130), separating the first inductive element (106) from the first capacitive element (62) and the plurality from second ( 72) capacitive elements; and a first (134) and second (136) joint associated with each of the second capacitive elements (72), connecting each of the first (134) and second (136) junctions to the first (74a) and the second (74b) terminals of the second capacitive elements (72) with the first and second terminals of the electronic switches asociated (68), respectively, each having the plurality of first (134) and second (136) unionee first (135) and second (137) internal inductive components; where a sum of inductances of the first (135) and second (137) internal inductive components associated with each of the first (134) and second (136) junctions is less than an inductance of the internal inductive component (75) of the second associated capacitive element (72). 16. The electromagnetic interference filter of claim 1 wherein the inductance of the internal inductive component (75) of each of the second capacitive elements (72) is less than 10 nanohenriee. The electromagnetic interference filter of claim 1 wherein each electronic switch (68) is embedding each second associated capacitive element (72). 18. The electromagnetic interference filter of claim 16 wherein the first capacitive element (62) comprises an electrolytic capacitor. 19. The electromagnetic interference filter of claim 17 wherein each second capacitive element (72) comprises a film capacitor. The electromagnetic interference filter of claim 17 wherein each second capacitive element (72) comprises a polypropylene film capacitor. The electromagnetic interference filter of claim 17 wherein each second capacitive element (72) comprises a plurality of film capacitors. 22. The electromagnetic interference filter of claim 17 wherein: the first capacitive element (62) has a capacitance of about 3500 microfarads, - each second capacitive element (72) has a capacitance of about 45 microfarad, - and the inductor ( 106) has an inductance of approximately 10 microhenrie. 2

3. The electromagnetic interference filter of claim 15 further comprising: a first feeder capacitor (138) electrically connected between the first power conductor (130) and a common circuit connection (141); a second feeder capacitor (140) electrically connected between the second power conductor (132) and the common circuit connection (141), - and a common mode choke (142) connected in series with the first (130) and the second (132) power conductors. The electromagnetic interference filter of claim 22 further comprising: a first feeder capacitor (138) electrically connected between the first power conductor (130) and a common circuit connection (141); a second feeder capacitor (140) electrically connected between the second power conductor (132) and the common circuit connection (141); and a common mode choke (142) connected in series with the first (130) and the second (132) power conductors. The electromagnetic interference filter of claim 24, wherein: the first feeder capacitor comprises a film capacitor (138), the first feeder capacitor (138) has a capacitance of approximately 0.4 microfarad .- the second feeder capacitor comprises a capacitor capacitor (140), the second conductor (132) through the capacitor having a capacitance of approximately 0.4 microfarads; and the common mode choke (142) has an inductance of about 10 microhenries.