Drive circuit for an electric vehicle

Abstract

A drive circuit (100) for an electric vehicle, comprising a frequency converter (10) with a direct current side for connecting a battery (2) of the electric vehicle and an alternating current side for connecting an electric motor (3) of the electric vehicle, and a blocking circuit (60) connected to the frequency converter (10) on the direct current side, which blocking circuit has an inductive path with a primary inductance (61) and a capacitive path parallel to the inductive path with a capacitance (63), which blocking circuit has a capacitor with the capacitance (63) and a parasitic inductance (62), wherein the primary inductance (61) of the inductive path and the parasitic inductance (62) of the capacitor form a total inductance (61, 62) of the blocking circuit (60), and the total inductance (61, 62) and the capacitance (63) define a blocking frequency of the blocking circuit (60), and wherein the primary inductance (61) and the parasitic inductance (62) are chosen such thatthat a suction frequency of the capacitive path is different from each harmonic of a clock frequency of the frequency converter (10) and the blocking frequency is equal to a harmonic of the clock frequency of the frequency converter (10).,

Description

[0001] The invention relates to a drive circuit for an electric vehicle, which comprises a frequency converter with a direct current side for connecting a battery of the electric vehicle and an alternating current side for connecting an electric motor of the electric vehicle. Furthermore, the invention relates to a drive circuit and an electric vehicle.

[0002] Electric vehicles, such as EVs (Electric Vehicles) or PHEVs (Plug-In Hybrid Electric Vehicles), collectively referred to as electric vehicles, comprise an electric motor and a battery that supplies electrical energy to the electric motor. The battery is designed as a high-voltage battery, or HV battery for short, and provides a high direct voltage (e.g., 800 V or higher) and, accordingly, a direct current. The electric motor is typically designed as a three-phase motor, which is supplied with an alternating voltage and usually has three terminals for three different three-phase current phases: U, V, and W.

[0003] To convert the direct current supplied by the battery into the three-phase alternating current required by the electric motor, electric motor-powered vehicles also include a frequency converter, which has a direct current side and an alternating current side and is connected to the battery on the direct current side and to the electric motor on the alternating current side. The frequency converter is also referred to as an inverter.

[0004] The battery, the electric motor, and all electrical and / or electronic components connected between the battery and the electric motor, and connecting the electric motor to the battery, form a drive circuit of the electric vehicle. The drive circuit is part of a so-called high-voltage electrical system of the electric vehicle. These electrical and / or electronic components accordingly form a drive circuit of the electric vehicle.

[0005] The frequency converter typically comprises a semiconductor module and a so-called intermediate circuit. The semiconductor module comprises a plurality of switchable power semiconductors, which can be arranged, for example, in a B6 bridge circuit. Therefore, the frequency converter is also commonly referred to as power electronics.

[0006] In its simplest form, the intermediate circuit comprises a single capacitor connected to the two DC-side terminals of the frequency converter. The intermediate circuit smooths the DC voltage in the high-voltage electrical system, i.e., it reduces the AC voltage superimposed on the DC voltage, also known as ripple voltage.

[0007] During normal operation of the electric vehicle, the direct current supplied by the battery is converted into three-phase alternating current by the frequency converter, and the electric motor is fed with the converted alternating current to generate torque that drives the electric vehicle. For this purpose, the power semiconductors of the semiconductor module are switched by a clock generator at a specific clock frequency (e.g., 10 kHz) and in a specific sequence.

[0008] However, if the electric vehicle is powered by another means, for example, while being towed by another vehicle, the electric motor acts like a dynamo, generating a three-phase alternating voltage at the three terminals, which is converted into direct voltage by the frequency converter. The converted direct voltage increases with increasing towing speed.

[0009] However, other components connected to the high-voltage electrical system, such as a DC-DC converter intended to supply a low-voltage electrical system of the electric vehicle, can be damaged by an overvoltage resulting from towing at high speed.

[0010] To prevent such damage, DE 10 2011 009 706 A1 discloses a frequency converter with a semiconductor module and a DC link capacitor. The frequency converter can be connected to a high-voltage electrical system on the DC side and to an electric motor of an electric vehicle on the AC side. The frequency converter has an internal voltage limiting device that ensures that the DC voltage generated by the frequency converter during towing of the electric vehicle does not exceed a predetermined maximum value, even at high speeds of the towed electric vehicle.

[0011] Thanks to the voltage limiting device, the DC-DC converter connected to the frequency converter on the DC side is reliably protected against overvoltage. This eliminates the need for costly safety design of the DC-DC converter and / or the installation of a costly coupling to mechanically decouple the electric motor from the driven wheels during towing.

[0012] Another problem of a drive circuit of an electric vehicle is that switching operations of the semiconductor module of the frequency converter on the DC side cause high-frequency alternating currents in the form of ripple currents, which can cause electromagnetic interference in the environment of the electric vehicle.

[0013] Accordingly, drive circuits of electric vehicles must be electromagnetically compatible, i.e., they must comply with a predetermined electromagnetic compatibility (EMC) standard. In many cases, this can be achieved using a special filter circuit.

[0014] For example, DE 10 2008 062 133 A1 discloses an EMC module for an electric vehicle, which can be connected to a frequency converter of the electric vehicle and a battery of the electric vehicle. The EMC module comprises a secondary circuit arrangement. The secondary circuit arrangement comprises a resonant circuit with a first inductance, a second inductance, and a capacitor, and is connected to ground via an ohmic resistor. The first inductance of the secondary circuit arrangement is arranged on a toroidal core together with three inductances of the EMC module, each assigned to an AC phase. With a suitable design, the secondary circuit arrangement can positively influence a filter characteristic of the EMC module.

[0015] Furthermore, the expensive and sensitive battery of an electric vehicle can gradually suffer damage due to ripple voltages in the high-voltage electrical system, resulting in a reduced service life. Therefore, efforts are being made to counteract harmful ripple voltages at the battery output.

[0016] DE 10 2016 203 044 A1 discloses a drive circuit for an electric vehicle that can reduce the amplitude of a ripple voltage. The drive circuit comprises a battery, an intermediate circuit, a clock generator, two semiconductor modules controlled by the clock generator at a clock frequency, and two electric motors, each connected to a semiconductor module on the AC side. Furthermore, the drive circuit comprises a measuring device for detecting a ripple voltage on the DC side of the semiconductor modules and a clock generator coupled to the measuring device, which adjusts a relative phase of the semiconductor modules depending on the measured ripple voltage in order to minimize it.

[0017] The reduction in the amplitude of the ripple voltage at the battery output is achieved here by negative interference, i.e., partial mutual cancellation, of two ripple voltages. Accordingly, this method requires at least two electric motors and is not applicable to electric vehicles with a single electric motor.

[0018] Further circuits which can be used to dampen ripple voltages are disclosed in GB 1 411 440 A, DE 10 2016 224 472 A1 and US 2011 / 0 095 846 A1.

[0019] The invention is therefore based on the object of providing an improved drive circuit for an electric vehicle that avoids the described disadvantages and extends the battery life. Furthermore, the object of the invention is to propose a drive circuit for an electric vehicle and an electric vehicle.

[0020] One subject of the present invention is a drive circuit for an electric vehicle, comprising a frequency converter with a DC side for connecting a battery of the electric vehicle and an AC side for connecting an electric motor of the electric vehicle. The frequency converter has two terminals on the DC side and three terminals on the AC side for the three-phase phases U, V, and W. The frequency converter can comprise a semiconductor module with a plurality of switched power semiconductors and an intermediate circuit.

[0021] In the simplest case, the intermediate circuit comprises a single capacitor on the DC side of the frequency converter, such that the capacitor is connected to each DC-side terminal of the frequency converter. However, it is also possible for the intermediate circuit to comprise a plurality of capacitors with different capacitances and / or a plurality of different inductances, which are connected in series or parallel in a complex circuit. The drive circuit as a whole is designed for operation in a high-voltage electrical system of the electric vehicle, i.e., it can be connected to a high-voltage battery (approx. 800 V or higher).

[0022] During operation of the semiconductor module, the switching processes of the power semiconductors on the DC side of the semiconductor module generate alternating currents whose amplitudes each exhibit a local maximum at the harmonics of the clock frequency. Within the context of the present invention, a harmonic is understood to be the clock frequency of the semiconductor module itself (e.g., 10 kHz) or an integer multiple of the clock frequency (e.g., 20 kHz, 30 kHz, 40 kHz, 50 kHz, etc.) of the semiconductor module. The amplitudes of the generated alternating currents are usually globally maximum at the second harmonic, i.e., maximum among the many harmonic maxima of the amplitude spectrum.

[0023] The drive circuit according to the invention comprises a blocking circuit connected to the frequency converter on the DC side. The blocking circuit is provided on the DC side of the frequency converter, between the frequency converter and the battery, and is designed to prevent a ripple current emanating from the frequency converter at a specific frequency from passing through to a battery connected to the drive circuit. In this way, the blocking circuit prevents a ripple voltage at the specific frequency at the battery output, which is associated with an extended battery life.

[0024] In a preferred embodiment, the drive circuit comprises an EMC module connected to the frequency converter on the DC side. The EMC module serves to suppress high-frequency alternating currents on the DC side and can be designed as a filter circuit with a plurality of capacitors, each connected individually or in series and each connected to a DC-side terminal of the frequency converter. In addition to a nominal capacitance, the capacitors also have a parasitic inductance and a parasitic ohmic resistance.The shape, size and / or arrangement of the supply lines and / or the capacitor surfaces, which determine the respective capacitances of the capacitors and the respective parasitic inductances and ohmic resistances, can be selected and designed such that the capacitances and parasitic inductances together form a suction circuit with a desired suction frequency, which frequency-selectively short-circuits alternating currents causing electromagnetic interference.

[0025] In one variant, the blocking circuit is connected to the frequency converter, and the EMC module is connected to the blocking circuit. In other words, the EMC module is separated from the frequency converter by the blocking circuit. Accordingly, an alternating current with a frequency blocked by the blocking circuit cannot reach the EMC module.

[0026] In this variant, the frequency converter can include an intermediate circuit on the DC side, and the blocking circuit can be located directly adjacent to the intermediate circuit. This allows for a particularly compact joint arrangement of the intermediate circuit and the blocking circuit.

[0027] In an alternative variant, the EMC module is connected to the frequency converter, and the blocking circuit is connected to the EMC module. In other words, a battery connected to the drive circuit is separated from the EMC module by the blocking circuit. This connection of the blocking circuit also reliably protects the connected battery from harmful ripple voltages.

[0028] In embodiments according to the invention, the blocking circuit has an inductive path with a primary inductance and a capacitive path with a capacitance parallel to the inductive path. In other words, the primary inductance and the capacitance form a parallel resonant circuit with a frequency-dependent alternating current resistance, which is commonly referred to as impedance Z. Due to the frequency dependence of the impedance, in particular the impedance magnitude |Z|, the parallel resonant circuit can pass or suppress alternating currents depending on its respective frequency.

[0029] In these embodiments, the capacitive path may comprise a capacitor with the capacitance, a parasitic inductance, and a parasitic ohmic resistance, wherein the primary inductance of the inductive path and the parasitic inductance of the capacitor form a total inductance of the trap circuit, and the total inductance and the capacitance define a trap frequency of the trap circuit. The frequency in Hz (s -1 ) measured blocking frequency f0 of the blocking circuit can be calculated using the formula f0=12πLC where L is the total inductance measured in H (henries) and C is the capacitance of the trap circuit measured in F (farads).

[0030] According to the invention, the primary inductance and the parasitic inductance are further selected such that a suction frequency of the capacitive path is different from each harmonic of a clock frequency of the frequency converter and / or the blocking frequency is equal to a harmonic of the clock frequency of the frequency converter.

[0031] The parasitic inductance of the capacitor and the capacitance of the capacitor form a series resonant circuit with a frequency-dependent impedance. Due to the frequency dependence of the impedance, especially the magnitude of the impedance, the series resonant circuit can pass or suppress alternating currents depending on their respective frequencies.

[0032] The capacitive path of the trap circuit acts like a trap circuit, i.e., in itself, opposite to the effect of the trap circuit. The parasitic inductance and the capacitance of the capacitor define a trap frequency. The trap frequency f0 can also be calculated using the above formula. The capacitive path essentially represents a short circuit for an alternating current with the trap frequency, allowing it to pass, while suppressing an alternating current with a frequency different from the trap frequency.

[0033] To prevent unwanted passage of alternating current, the trap frequency of the capacitive path should ideally not be equal to a harmonic of the frequency converter's clock frequency. However, for effective blocking, the trap frequency of the trap circuit should ideally be equal to a harmonic, preferably the second harmonic, of the frequency converter's clock frequency. These two conditions determine the appropriate distribution of the total inductance between the primary inductance of the inductive path and the parasitic inductance of the capacitive path.

[0034] Another criterion for selecting the inductances and capacitance of the trap circuit is the respective quality requirements of the trap circuit or the absorption circuit. The quality determines how narrow the frequency range with the blocking effect or the absorption effect is. The quality factor Q of a trap circuit can be calculated using the formula Q=R⋅CL On the other hand, the quality factor Q of a suction circuit can be calculated using the formula Q=1R⋅LC where L and C are defined as above and R is the respective parasitic ohmic resistance measured in Ω (Ohm).

[0035] The invention also relates to a drive circuit for an electric vehicle comprising a drive circuit according to the invention, a battery connected to the drive circuit on the DC side, and an electric motor connected to the drive circuit on the AC side. In the drive circuit, the battery is protected from harmful ripple voltage, thereby extending its service life.

[0036] Another subject of the invention is an electric vehicle with a drive circuit according to the invention. Due to the extended battery life, the electric vehicle also has a longer service life, thereby improving the cost-effectiveness of the electric vehicle and thus customer satisfaction with the electric vehicle.

[0037] A key advantage of the drive circuit according to the invention is that harmful ripple voltage at the outputs of the battery and other components of the high-voltage electrical system is reduced or eliminated. Furthermore, electromagnetic compatibility is further improved thanks to the effect of the blocking circuit.

[0038] Furthermore, the blocking circuit can simplify the EMC module. Likewise, with the blocking circuit, capacitors with lower capacitances can be selected for the intermediate circuit than without it. Since the ripple voltage has a relatively low amplitude, a capacitor with a low dielectric strength can also be selected for the blocking circuit.

[0039] A further advantage is therefore that the drive circuit according to the invention can be manufactured more cost-effectively and in a more space-saving manner, since capacitors with lower capacitance and lower dielectric strength are more cost-effective and space-saving than capacitors with higher capacitance or higher dielectric strength.

[0040] The invention is schematically illustrated in the drawings using an embodiment and will be further described with reference to the drawings. It shows: Fig. 1 shows a circuit diagram of an embodiment of a drive circuit for an electric vehicle according to the prior art with an intermediate circuit; Fig. 2 in a circuit diagram an enlarged detailed representation of the Fig. 1 shown intermediate circuit; Fig. 3 in a double logarithmic function graph a characteristic curve of an impedance value of the Fig. 1 shown intermediate circuit; Fig. 4 in a function graph a frequency spectrum of an amplitude of an alternating current in the intermediate circuit of the Fig. 1 shown drive circuit; Fig. 5 shows a circuit diagram of an embodiment of a drive circuit according to the invention for an electric vehicle.

[0041] Fig. Figure 1 shows a circuit diagram of an embodiment of a drive circuit 1 for an electrically powered vehicle, in particular an electric vehicle, according to the prior art. The drive circuit 1 comprises a battery 2 designed as a high-voltage battery and an electric motor 3 designed as a three-phase motor, which is only symbolically indicated here by three inputs for three-phase phases U, V, and W. Furthermore, the drive circuit 1 comprises a frequency converter 10 forming a drive circuit with an intermediate circuit 20 and a semiconductor module 30.

[0042] The semiconductor module 30 comprises six power semiconductors S1, S2, S3, S4, S5, and S6, which are arranged and interconnected in a B6 bridge circuit. The battery 2 is connected to the frequency converter 10 on the DC side, and the electric motor 3 is connected to the frequency converter 10 on the AC side. The intermediate circuit 20 is connected to two DC-side outputs of the semiconductor module 30 and two terminals of the battery 2.

[0043] Fig. 2 shows a circuit diagram showing a detailed representation of the Fig. 1. The intermediate circuit 20 comprises a single capacitor having a nominal capacitance 21 (C), a parasitic ohmic resistance 22 (R), and a parasitic inductance 23 (ESL). The parasitic ohmic resistance 22 (ESR) and the parasitic inductance 23 (ESL) are determined by the shape, size, and / or arrangement of the leads and / or the capacitor surfaces. The nominal capacitance 21 (C), the parasitic ohmic resistance 22 (ESR), and the parasitic inductance 23 (ESL) are connected in series and form a series resonant circuit. The series resonant circuit acts as a resonant circuit with a blocking frequency that is uniquely determined by the nominal capacitance 21 (C) and the parasitic inductance 23 (ESL).

[0044] Fig. 3 shows in a double logarithmic function graph 40 a characteristic curve 43 of an impedance value |Z| of the Fig. 1. A clock frequency of the semiconductor module 30 is plotted logarithmically in Hz along the abscissa 41 of the function graph 40. An impedance value |Z| of the intermediate circuit 20 is plotted logarithmically in ohms along the ordinate 42. The characteristic curve 43 shows that the impedance value |Z|, i.e., the effective AC resistance, of the intermediate circuit 20 has a minimum at approximately 50 kHz, i.e., the absorption frequency of the intermediate circuit 20 is approximately 50 kHz. For comparison, the characteristic curve 44 shows the constant parasitic ohmic resistance (ESR) of the intermediate circuit 20, which, unlike the impedance Z, is not frequency-dependent.The effective total resistance of the intermediate circuit 20 is therefore minimal for an alternating current with the suction frequency and equal to the parasitic ohmic resistance (ESR), while an alternating current with a frequency deviating from the suction frequency is suppressed to the greater extent the greater the difference between the frequency and the suction frequency.

[0045] During operation of the drive circuit 1, the semiconductors S1, S2, S3, S4, S5, S6 of the semiconductor module 30 are switched by a clock generator (not shown) with a clock frequency of, for example, 10 kHz. The switching operations of the semiconductor module 30 generate a DC voltage superimposed on an AC voltage (ripple voltage) on the DC side, which correspondingly produces an AC current superimposed on an AC current (ripple current) on the DC side of the semiconductor module 30. The DC voltage and the AC voltage are applied to the intermediate circuit 20, whereby the DC current does not pass through the intermediate circuit 20 due to the galvanic isolation by the capacitance 21 (C) of the intermediate circuit 20, while the AC current passes through the intermediate circuit 20 with a current intensity determined by the impedance |Z|.

[0046] Fig. 4 shows in a function graph 50 a frequency spectrum 53 of an amplitude of an alternating current in the intermediate circuit 20 of the Fig. 1. The abscissa 51 represents the frequency of the semiconductor module 30 in kHz. The ordinate 52 represents the current I of the alternating current flowing in the intermediate circuit in A (amperes). The frequency spectrum 53 shows that the amplitude of the DC-side alternating current has a local maximum at each harmonic of the clock frequency, i.e., at 10 kHz, 20 kHz, 30 kHz, 40 kHz, 50 kHz, etc., with the global maximum of the amplitude being at the second harmonic.

[0047] For example, if the intermediate circuit 20 comprises several capacitors of different capacitance connected in parallel such that the absorption frequencies each correspond to a different local maximum of the amplitude of the DC-side alternating current, all corresponding alternating currents can be short-circuited, whereby alternating currents within a wider frequency range do not reach the outputs of the battery 2.

[0048] Fig. Figure 5 shows a circuit diagram of an embodiment of a drive circuit 100 according to the invention for an electric vehicle. The drive circuit 100 comprises a frequency converter 10 with a direct current side for connecting a battery 2 of the electric vehicle and an alternating current side for connecting an electric motor of the electric vehicle. A battery 2 is connected to the drive circuit 100 on the direct current side, forming a drive circuit, and an electric motor (not shown) is connected to the alternating current side. Furthermore, all parasitic inductances and parasitic ohmic resistances relevant to the design of the drive circuit 100 are shown in the circuit diagram.

[0049] The frequency converter 10 comprises a semiconductor module 30, symbolized here merely as a power source, and an intermediate circuit 20 on its DC side. The intermediate circuit 20 is formed, for example, by a single capacitor, but can also comprise a plurality of capacitors with different nominal capacitances and / or different inductances, which are connected in parallel and / or in series.

[0050] Furthermore, the drive circuit 100 comprises a blocking circuit 60 connected to the frequency converter 10 on the DC side. The blocking circuit 60 is arranged directly adjacent to the intermediate circuit 20 and has an inductive path with a primary inductance 61 and a capacitive path with a capacitance 63 parallel to the inductive path.

[0051] The capacitive path comprises a capacitor with the nominal capacitance 63 and a parasitic inductance 62, wherein the primary inductance 61 of the inductive path and the parasitic inductance 62 of the capacitor form a total inductance 61, 62 of the blocking circuit 60 and the total inductance 61, 62 and the capacitance 63 define a blocking frequency of the blocking circuit 60.

[0052] During operation of the drive circuit 100, the semiconductor module 30 is switched by a clock generator with a clock frequency of, for example, 10 kHz. The switching operations of the semiconductor module 30 generate a DC voltage superimposed on an AC voltage (ripple voltage) on the DC side, which correspondingly generates an AC current superimposed on an AC current (ripple current) on the DC side of the semiconductor module 30.

[0053] The primary inductance 61 and the parasitic inductance 62 are selected such that a trap frequency of the capacitive path is different from each harmonic of the clock frequency of the frequency converter 10 and / or the trap frequency is equal to a harmonic of the clock frequency of the frequency converter 10, preferably equal to the second harmonic of the clock frequency of the frequency converter 10 (see Fig. 4). With this selection, it is achieved that an alternating current with a preferential second harmonic of the clock frequency is suppressed by the blocking circuit 60, but no alternating current with any harmonic of the clock frequency passes through the blocking circuit 60 through the capacitive path of the blocking circuit 60 and reaches the battery 2.

[0054] Furthermore, the drive circuit 100 comprises an EMC module 70 for filtering high-frequency AC components on the DC side, thereby improving the electromagnetic compatibility (EMC) of the drive circuit 100. The circuit diagram of the EMC module 70 shown is merely exemplary and can vary as required without deviating from the essence of the invention. The EMC module 70 is connected to the DC side of the frequency converter 10. The blocking circuit 60 is connected to the frequency converter 10, and the EMC module 70 is connected to the blocking circuit 60, i.e., the EMC module 70 is separated from the frequency converter 10 by the blocking circuit 60.

[0055] Alternatively, the EMC module 70 can be connected to the frequency converter 10 and the blocking circuit 60 to the EMC module 70, ie the battery 2 is separated from the EMC module 70 by the blocking circuit 60. LIST OF REFERENCE SYMBOLS: 1 drive circuit according to the state of the art 2 batteries 3 electric motor 10 frequency converters 20 intermediate circuit 21 capacity 22 parasitic ohmic resistance 23 parasitic inductance 30 semiconductor modules 40 Function graph 41 Abscissa 42 ordinates 43 Impedance value 44 parasitic ohmic resistance 50 Function graph 51 Abscissa 52 ordinates 53 amperage 60 blocking circuit 61 primary inductance 62 capacity 63 parasitic inductance 70 EMC module 100 drive circuit

Claims

[1] Drive circuit (100) for an electric vehicle, which comprises a frequency converter (10) with a direct current side for connecting a battery (2) of the electric vehicle and an alternating current side for connecting an electric motor (3) of the electric vehicle and a blocking circuit (60) connected to the frequency converter (10) on the direct current side, which blocking circuit has an inductive path with a primary inductance (61) and a capacitive path parallel to the inductive path with a capacitance (63), which has a capacitor with the capacitance (63) and a parasitic inductance (62), wherein the primary inductance (61) of the inductive path and the parasitic inductance (62) of the capacitor form a total inductance (61, 62) of the blocking circuit (60) and the total inductance (61,62) and the capacitance (63) define a blocking frequency of the blocking circuit (60), and wherein the primary inductance (61) and the parasitic inductance (62) are selected such that a blocking frequency of the capacitive path is different from each harmonic of a clock frequency of the frequency converter (10) and the blocking frequency is equal to a harmonic of the clock frequency of the frequency converter (10). [2] Drive circuit according to claim 1, comprising an EMC module (70) which is connected to the frequency converter (10) on the DC side. [3] Drive circuit according to claim 2, wherein the blocking circuit (60) is connected to the frequency converter (10) and the EMC module (70) is connected to the blocking circuit (60). [4] Drive circuit according to claim 3, wherein the frequency converter (10) comprises an intermediate circuit (20) on the DC side and the blocking circuit (60) is arranged immediately adjacent to the intermediate circuit (20). [5] Drive circuit according to claim 2, wherein the EMC module (70) is connected to the frequency converter (10) and the blocking circuit (60) is connected to the EMC module (70). [6] Drive circuit for an electric vehicle with a drive circuit (100) according to one of claims 1 to 5, a battery (2) connected to the drive circuit (100) on the direct current side and an electric motor (3) connected to the drive circuit (100) on the alternating current side. [7] Electric vehicle with a drive circuit according to claim 6.

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