Compensation device for leakage current

Abstract

A compensation device (20) for compensating a leakage current comprises a compensation current generating device (28), a potential generating device (150), an active conductor terminal (61, 62, 63, 64) and a protective conductor terminal (65), the active conductor terminal (61, 62, 63, 64) having a first active conductor terminal (61) and a second active conductor terminal (62; 64), the potential generating device (150) being connected to the first active conductor terminal (61) and having a potential generating device terminal (155), the potential generating device (150) being configured to provide a potential at the potential generating device terminal (155) which is at least temporarily different from the potential at the first active conductor terminal (61), and the compensation current generating device (28) being configured to cause a compensation current (I_COMP) between the potential generating device terminal (155) and the protective conductor terminal (65).

Description

Technical Field

[0001] The invention relates to a compensation device for compensating leakage current, and the compensation device is particularly used in a charging device of a vehicle. Background Art

[0002] Leakage current is the current which flows under normal operating conditions in an undesired current path, for example from the outer conductors (L1 to L3) to the protective conductor (PE). In practice, such leakage currents are generated, for example, by the filter capacitors of the power supply filter, which are connected on one side to the AC voltage path and on the other side to the protective conductor (PE).

[0003] DE 195 25 417 C2 discloses an arrangement for ground fault current compensation of a power supply network having a passive impedance element.

[0004] DE 10 2010 013 642 A1 discloses a method for compensating leakage currents.

[0005] EP 2 724 443 B1 shows a compensation system for leakage currents. Summary of the invention

[0006] The object of the present invention is to provide a novel compensation device for compensating leakage current and a vehicle having such a compensation device.

[0007] This object is achieved by the compensation device of the present invention described below.

[0008] A compensation device for compensating a leakage current comprises a compensation current generating device, a potential generating device, an active conductor terminal and a protective conductor terminal, the active conductor terminal comprising a first active conductor terminal and a second active conductor terminal, the potential generating device being connected to the first active conductor terminal and comprising a potential generating device terminal, the potential generating device being configured to provide a potential at the potential generating device terminal, the potential being at least temporarily different from the potential at the first active conductor terminal, and the compensation current generating device being configured to cause a compensation current between the potential generating device terminal and the protective conductor terminal. By providing the potential generating device, the realization of a compensation current by the compensation current generating device is simplified.

[0009] According to a preferred embodiment, the potential generating device is connected to the second active conductor terminal and is configured to provide a potential at the potential generating device terminal that is at least temporarily different from the potential at the second active conductor terminal. By connecting the potential generating device to a plurality of active conductor terminals, the potential at the potential generating device terminal can be advantageously influenced.

[0010] According to a preferred embodiment, the potential generating device has a first capacitor component, and the potential generating device terminal is connected to the first active conductor terminal via the first capacitor component. Providing a capacitor component can achieve a positive influence on the compensation current.

[0011] According to a preferred embodiment, the potential generating device has a second capacitor component, and the potential generating device terminal is connected to the second active conductor terminal via the second capacitor component. As a result, the two capacitor components can cooperate.

[0012] According to a preferred embodiment, the compensation device has a power grid filter, which has an X capacitor component for suppressing differential mode interference and a Y capacitor component for suppressing common mode interference, the X capacitor component includes a first X capacitor component between the first active conductor terminal and the second active conductor terminal, and the first capacitor component and the second capacitor component together form the first X capacitor component.

[0013] According to a preferred embodiment, the X-capacitor assembly comprises a second X-capacitor assembly between the first active conductor terminal and a further active conductor terminal, the further active conductor terminal being not the second active conductor terminal, the first X-capacitor assembly having a first capacitance, the second X-capacitor assembly having a second capacitance, and the second capacitance being in the range between 70% and 130% of the first capacitance. This results in a substantially symmetrical X-capacitor assembly design.

[0014] According to a preferred embodiment, the Y capacitor assembly has a first Y capacitor assembly and a second Y capacitor assembly, the first Y capacitor assembly is connected between the first active conductor terminal and the protective conductor terminal, and the Y capacitor assembly is connected between the second active conductor terminal and the protective conductor terminal. Providing the Y capacitor assembly improves the grid filter.

[0015] According to a preferred embodiment, the active conductor terminals have a third active conductor terminal, the potential generating device has a third capacitor component, and the potential generating device terminal is connected to the third active conductor terminal via the third capacitor component. This can make it possible to form a virtual neutral conductor or to use the capacitor components together for larger currents.

[0016] According to a preferred embodiment, the potential generating device has a fourth capacitor component, which is connected between the compensation current generating device and the potential generating device terminal. By providing the fourth capacitor component, the total capacitance of the potential generating device can be influenced without influencing the capacitance between the first active conductor terminal and the second active conductor terminal.

[0017] According to a preferred embodiment, the compensation device has a DC intermediate circuit, Y capacitors are arranged at the DC intermediate circuit, the Y capacitors have a first total capacitance, and in the compensation device the potential generating device has a second total capacitance, wherein the second total capacitance is in the range between 60% and 140% of the first total capacitance. As a result, the compensation device behaves like a Y capacitor and a connection can be achieved, by which leakage currents are passively reduced when connecting a power supply network with phases in opposite phases.

[0018] This object is also achieved by the compensation device of the invention described below.

[0019] A compensation device for compensating leakage current has a compensation current generating device, an active conductor terminal, a protective conductor terminal, a power supply, and a control device, the active conductor terminal having a first active conductor terminal and a second active conductor terminal, the compensation current generating devices including a first compensation current generating device and a second compensation current generating device, the first compensation current generating device being connected between the first active conductor terminal and the protective conductor terminal, the second compensation current generating device being connected between the second active conductor terminal and the protective conductor terminal, the compensation current generating devices respectively having a compensation current regulating component, and the control device being formed to control the compensation current regulating component by means of the power supply so as to generate a compensation current. By providing a plurality of compensation current generating devices, phases of opposite phases can be utilized, and the power supply can control the compensation current regulating component even when the phases have a low voltage.

[0020] According to a preferred embodiment, the compensation current generating devices each have a voltage reducer, which is arranged between the compensation current regulating component and the associated active conductor terminal and is formed to reduce the voltage at the associated compensation current regulating component relative to the voltage at the associated active conductor terminal. By reducing the voltage, the compensation current regulating component can be formed for lower voltages, which reduces costs and technical expenditure.

[0021] According to a preferred embodiment, the voltage reducers each have a resistor or a voltage limiter. Both solutions work well for the compensation current generating device.

[0022] According to a preferred embodiment, the compensation current generating devices each have a current measuring member in order to measure the compensation current passing through the compensation current generating device. By measuring directly in the compensation current generating device, it is possible to better and more quickly check whether the compensation current is suitable for compensation.

[0023] According to a preferred embodiment, the compensating current adjustment components are respectively formed to realize compensating current in two directions. Through this bidirectionality, current can be realized in the positive half-wave and the negative half-wave of the phases by turning on the compensating current adjustment components.

[0024] According to a preferred embodiment, a vehicle has a charging device for a traction battery, the charging device having a rectifier and a traction battery connected directly or indirectly to the rectifier, wherein the traction battery is galvanically coupled to the active conductor terminals, and wherein the charging device has a compensation device. Compensation is particularly important in such charging devices, and the use of a compensation device is very advantageous. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Further details and advantageous developments of the invention are obtained from the exemplary embodiments described below and shown in the drawings, which are not to be understood as limiting the invention in any way, and from preferred embodiments. In the drawings:

[0026] Figure 1 An embodiment of a compensation device is shown,

[0027] Figure 2 Another embodiment of the compensation device is shown,

[0028] Figure 3 Show Figure 1 A detailed embodiment of a part of the compensation device,

[0029] Figure 4 Another embodiment of the compensation device is shown,

[0030] Figure 5 Show Figure 4 Schematic diagram of the role of the capacitor,

[0031] Figure 6 Another embodiment of the compensation device is shown,

[0032] Figure 7 Another embodiment of the compensation device is shown, and

[0033] Figure 8 A vehicle is shown with a charging device and a compensating device.

[0034] In the following, identical or identically acting components are provided with the same reference numerals and are generally described only once. The description is organized across the figures to avoid unnecessary repetitions. DETAILED DESCRIPTION

[0035] Figure 1An embodiment of a compensation device 20 is shown. Four active conductor terminals 61, 62, 63, 64 with four conductors 51, 52, 53, 54 and a protective conductor terminal 65 with conductor 55 are provided. In the case of a three-phase current network, the active conductor terminals 61 to 63 can be connected, for example, to the outer conductors (phases) L1, L2 and L3, the active conductor terminal 64 can be connected to the neutral conductor N, and the protective conductor terminal 65 can be connected to the protective conductor PE.

[0036] The differential current measuring device 22 measures the differential current of the conductors 51 to 54. The differential current measuring device 22 can be formed, for example, as a current transformer in the form of a winding around the conductors 51 to 54. When no fault current or leakage current occurs, the sum of the currents through the conductors 51 to 54 and thus also the current through the winding is zero. In contrast, when, for example, a leakage current flows from the phase L1 via the Y capacitor of the power filter via the rectifier to the protective conductor PE, the differential current measuring device 22 obtains the resulting differential current. It is also possible, for example, to measure separately the sum currents through the conductors 51 to 53 (on the one hand) and through the conductor 54 (on the other hand), and then calculate the sum or difference between the two values ​​depending on the respective winding direction.

[0037] The signal I_DIFF is supplied to a signal processing device 24 via a conductor 23. In the signal processing device 24, for example, an A / D conversion is performed, and the resulting digital signal is referred to as I_DIFF_D. The signal processing device 24 transmits the signal I_DIFF_D to a control device 26 via a conductor 25. The control device 26 (for example, designed as a microcontroller or a computing unit) calculates a suitable compensation current value or a compensation current preset signal I_COMP_S based on the measured differential current signal I_DIFF_D. This signal I_COMP_S is supplied to a compensation current generating device 28 via a conductor 27, which is formed as an amplifier, for example.

[0038] The compensation current generating device 28 generates a corresponding compensation current I_COMP depending on the compensation current preset signal I_COMP_S. To this end, the compensation current generating device 28 is connected to the protection conductor 99 so as to enable current to flow out of or to the protection conductor 99.

[0039] The compensation current generating device 28 may be designed as a differential amplifier having an operational amplifier, for example, or alternatively, may be a digital-to-analog converter or a class-D amplifier, for example.

[0040] The compensation current generating device 28 is connected to the compensation current selecting device 36 via a conductor 32 and supplies the signal I_COMP to the compensation current selecting device.

[0041] Control device 26 can control compensation current selection device 36 with signal V_SEL via line 37. Compensation current selection device 36 can supply compensation current via line 38 to first feed device 39, via line 40 to second feed device 41 and / or via line 138 to potential generating device terminal 155 of potential generating device 150.

[0042] A power supply network identification device 42 is provided to identify the power supply network connected to the conductors 51 to 55. To this end, the power supply network identification device 42 measures the voltage at the terminals 61 to 65, for example, by means of a voltage measuring device and supplies the corresponding signal V_GRID to the control device 26 via the conductor 43. This can be done directly in the power supply network identification device 42, or it can also be done in the control device 26. In the three-phase power grid in Central Europe, the conductors 51 to 55 are connected to the terminals L1, L2, L3, N and PE shown on the left. In the split-phase power grid in the United States, preferably the terminal HOT1 is connected to the conductor 51, the terminal HOT2 with a phase shift of 180° is connected to the conductor 54, and the protective conductor PE is connected to the conductor 55. In the single-phase power grid in Central Europe, since there is not a clear assignment relationship between the plug and the socket in all countries, either the conductor 51 is connected to L1 and the conductor 54 is connected to N, or the conductor 51 is connected to N and the conductor 54 is connected to L1. Therefore, the assignment relationship is not necessarily unique.

[0043] The feeding devices 39 and 41 may perform feeding by capacitive coupling or inductive coupling, for example.

[0044] In a supply network with a neutral conductor N, feeding in this neutral conductor is preferred, since the voltage at the neutral conductor N is usually lower and the supply voltage used for feeding can therefore be lower compared to the voltage on the phases.

[0045] The calculation of the signal I_COMP_S for generating the compensation current I_COMP is performed, for example, by obtaining the spectrum of the differential current or signal I_DIFF, wherein a frequency range of 20 Hz to 300 kHz, for example, may be sufficient. The spectrum contains corresponding amplitudes, and the signal I_COMP_S is generated with a phase shift of 180° (in antiphase) to facilitate corresponding compensation. Other calculation methods for calculating the integral are also possible.

[0046] The potential generating device 150 is connected to the conductor 51 or the terminal 61 via the feeding device 141 and to the conductor 54 or the terminal 64 via the feeding device 144. The feeding devices 141 and 144 can be formed as direct connection devices to the corresponding conductor 51 or 54, respectively. The potential generating device 150 is formed to provide a potential at the potential generating device terminal 155, which potential is at least temporarily different from the potential at the active conductor terminal 61 and the active conductor terminal 64. Because the potential at the active conductor terminal is sinusoidal or at least periodic, this can conveniently cause the potential at the active conductor terminal 61 or 64 to coincide with the potential at the potential generating device terminal 155.

[0047] The potential generating device 150 has a first capacitor component 151 and a second capacitor component 152 , and the potential generating device terminal 155 is connected to the first active conductor terminal 61 via the first capacitor component 151 and to the second active conductor terminal 64 via the second capacitor component 152 .

[0048] When a power supply network 10 of the US split-phase type is connected with the phase HOT1 at the active conductor terminal 61 and the phase HOT2 at the active conductor terminal 64, in the case where the amplitudes of the phases HOT1 and HOT2 are symmetrical and the capacitors of the capacitor assemblies 151, 152 are identical, the anti-phase phases HOT1 and HOT2 result in a voltage of 0 V at the potential generating device terminal 155, and the compensation current I_COMP can therefore be well fed into the potential generating device terminal 155. In the case where the amplitudes of the phases HOT1 and HOT2 are not identical or the capacitances of the capacitor assemblies 151, 152 are not identical, the voltage at the potential generating device terminal 155 is not always 0 V, but it is less than the amplitudes of the phases HOT1 and HOT2.

[0049] Figure 2Another embodiment of the compensation device 20 is shown. The potential generating device 150 has a potential generating device terminal 155, which is connected to a capacitor assembly 151, a capacitor assembly 152 and a capacitor assembly 153. The capacitor assembly 151 is connected to the conductor 51 via the feed device 141, the capacitor assembly 152 is connected to the conductor 52 via the feed device 142, and the capacitor assembly 153 is connected to the conductor 53 via the feed device 143. When a three-phase power supply network with phases L1, L2 and L3 is connected to the active conductor terminals 61, 62, 63, a virtual neutral conductor is formed at the potential generating device terminal 155 by the capacitor assemblies 151, 152, 153, which neutral conductor has a voltage of 0 V when the amplitudes of the phases L1, L2, L3 are the same and the capacitances of the capacitor assemblies 151, 152, 153 are the same, and has a voltage of at least one lower than the amplitude of these phases under imperfect conditions. It is also possible to connect to a US split-phase type power supply network 10. In this case, for example, the phase HOT1 can be supplied at the terminal 61 and the phase HOT2 can be supplied at the terminal 63 .

[0050] In other respects, the compensating device 20 may correspond, for example, to Figure 1 Compensation device 20.

[0051] Figure 3 Show Figure 1 Detail of an embodiment with a power supply network 10 and conductors 51, 52, 53, 54, 55. In the input region, a mains filter 160 is provided by way of example. The mains filter 160 has X-capacitor components 150, 252, 253, 254, 255, 256 for suppressing differential-mode interference and Y-capacitor components 261, 262, 263, 264 for suppressing common-mode interference.

[0052] The X capacitor assemblies 150 , 252 , 253 , 254 , 255 , 256 are respectively arranged between two of the active conductors 51 , 52 , 53 , 54 , and the Y capacitor assemblies 261 , 262 , 263 , 264 are respectively arranged between one of the active conductors 51 , 52 , 53 , 54 and the guard conductor 55 .

[0053] The mains filter 160 may additionally have an inductance, and the mains filter may also be formed in multiple stages.

[0054] The X-capacitor assembly 150 is divided into two capacitors connected in series, wherein the midpoint is connected to the potential generating device terminal 155. The X-capacitor assembly 150 preferably has a capacitance that is within the capacitance range of at least one of the other X-capacitor assemblies. Preferably, the capacitance of the at least one other X-capacitor assembly 252, 253, 254, 255, 256 is in the range between 70% and 130% of the X-capacitor assembly 150. This results in a symmetrical grid filter 160.

[0055] Figure 4 1 shows another embodiment of the compensation device 20. The potential generating device 150 has a capacitor assembly 151 between the potential generating device terminal 155 and the feeding device 141. No other feeding device is arranged between the potential generating device terminal 155 and the conductors 51 to 54. In other respects, the structure of the compensation device 20 can be the same as Figure 1 The structure corresponds to .

[0056] On the right side, a DC intermediate circuit is provided with a terminal 301 (e.g., a high-voltage positive terminal) and a terminal 302 (e.g., a high-voltage negative terminal). Terminal 301 is connected to a midpoint 304 via an intermediate circuit capacitor 303, and midpoint 304 is connected to terminal 302 via an intermediate circuit capacitor 305. Midpoint 304 is connected to conductor 54. Terminal 301 is connected to protective conductor 55 (protective conductor symbol 99) via a Y capacitor 307, and terminal 302 is connected to protective conductor 55 via a Y capacitor 308.

[0057] For example, a battery 306 is connected to the terminals 301 , 302 as a power consumer.

[0058] The power electronic device 300 is electrically connected to the conductor 51 and to the terminals 301 , 302 .

[0059] During operation, when connected to a US split-phase type power supply network, the power electronic device 300 can be operated with the phases HOT1, HOT2 at the active conductor terminals 61, 64 and the protective conductor PE at the terminal 65, and the power electronic device acts as a rectifier to rectify the phases HOT1, HOT2 and supply energy to the terminals 301, 302.

[0060] Figure 5 The capacitances acting between phase HOT1 and PE or HOT2 and PE are schematically shown. A first path leads from the protective conductor PE via the Y capacitors 307, 308 and via the intermediate circuit capacitors 303, 305 to the phase HOT2 or the neutral conductor N. A second path leads from the protective conductor PE via the circuits 28, 36 (see Figure 4 ) and capacitor 151 to phase HOT1.

[0061] The leakage current from phase HOT2 to the protective conductor PE is mainly determined by the Y-capacitors 307, 308, and the intermediate circuit capacitors 303, 305 can be largely ignored. When the capacitance of capacitor 151 is selected to be in the order of magnitude of the capacitance of the parallel circuit of Y-capacitors 307, 308 and the potential generating device terminal 155 is connected to the protective conductor PE (protective conductor symbol 99) via the compensation current generating device 28, the leakage currents flowing between phase HOT1 and PE and between phase HOT2 and PE have similar magnitudes, but opposite signs, since phases HOT1 and HOT2 are in anti-phase. The sum of the leakage currents is therefore zero or at least relatively small. In other words, the impedance between phase HOT1 or HOT2 and the protective conductor PE is similar at low frequencies, for example 50 Hz or 60 Hz, and this produces a passive compensation of the leakage current.

[0062] If leakage currents still occur in actual operation due to asymmetries, a compensation current can be actively introduced via the compensation current generating device 28. The compensation current generating device 28 can be designed as a voltage source or a current source in order to generate the required compensation current.

[0063] In the experiment, the Y capacitors 307, 308 each had a capacitance of 680 nF, and the capacitance of the capacitor 151 was selected to be 1.29 μF, i.e., this corresponds approximately to the capacitance of the parallel circuit of the Y capacitors 307, 308. The passive compensation by the capacitor 151 makes the leakage current to be actively compensated significantly smaller and thus relieves the load on the compensation current generating device 28.

[0064] Figure 6 FIG. 2 shows another embodiment of the compensation device 20. The potential generating device 150 has a Figure 2 In the embodiment of the present invention, three capacitor assemblies 151, 152, 153 are connected between the potential generating device terminal 155 and the feeding device 141, 142 or 143 respectively. In the case of a three-phase power supply network 10, the capacitor assemblies 151, 152, 153 form a virtual neutral conductor at the potential generating device terminal 155. When the phase HOT1 or L1 is connected (not shown) to all three terminals 61, 62, 63 (see Figure 3 ), the capacitors 151, 152, 153 act as a parallel circuit. In addition, a capacitor 170 is connected between the potential generating device terminal 155 and the compensation current generating device 28. By means of the capacitors 151, 152, 153, the capacitance of the X capacitors resulting from the respective series circuits can be matched to the capacitance of the remaining X capacitors. Furthermore, by means of the additional capacitor 170, the total capacitance of the potential generating device 150 can be matched to the total capacitance of the remaining Y capacitors, so as to at least partially facilitate passive compensation.

[0065] Figure 7 Another embodiment of the compensation device 20 is shown. The compensation device 20 has a first compensation current generating device 28A and a second compensation current generating device 28B.

[0066] The compensation current generating device 28A, 28B is connected between the conductor 51 or 52 and the protective conductor 55 .

[0067] The compensation current generating device 28A has a voltage reducer 401, a compensation current adjusting member 403 and preferably a current measuring member 405. The conductor 51 is connected to the guard conductor 55 via the voltage reducer 401, the wire 402, the compensation current adjusting member 403, the wire 404 and the current measuring member 405.

[0068] The compensation current generating device 28B has a voltage reducer 411, a compensation current adjusting member 413 and preferably a current measuring member 415. The conductor 52 is connected to the guard conductor 55 via the voltage reducer 411, the wire 412, the compensation current adjusting member 413, the wire 414 and the current measuring member 415.

[0069] The control device 26 is connected to the compensation current adjustment component 403 via a line 421 and to the compensation current adjustment component 413 via a line 431 .

[0070] The current measuring member 405 is connected to the control device 26 via a wire 422 , and the current measuring member 415 is connected to the control device 26 via a wire 432 .

[0071] Preferably, a power supply 450 is provided, which is connected to the conductor 51 via a line 451, to the conductor 52 via a line 452, and to the protective conductor 55 via a line 455, in order to supply a positive voltage on a line 461, a negative voltage on a line 462, and a zero voltage on a line 465 to the control device 26. The power supply 450 is provided so that the power supply can be buffered.

[0072] The voltage reducers 401 and 411 are formed to reduce the voltage at the associated compensating current regulating member 403 or 413 relative to the voltage on the associated conductor 51 or 52. In a simple embodiment, the voltage reducers 401, 411 can be formed as resistors. The voltage reducers 401, 411 can also be formed as voltage limiters that limit the voltage on the conductor 402 or 412. For example, when an amplitude of 120V appears on the conductor 51, an 80V voltage can be reduced at the voltage reducer 401 and a 40V voltage can be reduced at the compensating current regulating member 403.

[0073] The current measuring means 405 , 415 are formed for measuring the current between the conductor 51 or 52 and the wire 55 , for example by means of a voltage dropped across a measuring resistor or by means of a voltage induced in a coil by the current.

[0074] The compensation current adjustment component 403 or 413 is preferably formed as a linear amplifier, for example, as a FET circuit or a circuit with bipolar transistors. A desired compensation current can be set by the compensation current adjustment component 403 or 413.

[0075] Providing power supply 450 has the advantage that a control voltage is provided regardless of the actual voltage at conductors 51, 52 in order to control compensating current regulating component 403 or 413. Thus, compensating current regulating component 403 or 413 can be controlled even when phase HOT1 or HOT2 has a zero crossing.

[0076] The compensating device 20 is also intrinsically safe and it is not possible to generate erroneous currents by the compensating current generating devices 28A, 28B when no phase HOT1 or HOT2 is applied at the conductors 51 or 52. The compensating current generating devices 28A, 28B are preferably operated in a bipolar manner so that a suitable current can be added in each phase. In other words, in each compensating current generating device 28A, 28B, depending on the phase, the compensating current can flow in both directions.

[0077] Figure 8 An exemplary embodiment is shown for use of conductors 51 to 55 with a schematically illustrated compensation device 20 in a vehicle 10, in particular in an electric vehicle or hybrid vehicle. Conductors 51 to 53 (phase conductors or outer conductors), 54 (neutral conductor) and conductor 55 (protective conductor) are connected to a rectifier (AC / DC converter) 300, and conductors 301 (+) and 302 (-) are provided at the output of the rectifier 300, at which a DC voltage is present. The assembly can thus be used as a charging device 12. Conductor 301 is connected to protective conductor 99 via capacitor 307, and conductor 302 is connected to protective conductor 99 via capacitor 308. Conductors 301, 302 are connected directly or indirectly (for example via an additional DC / DC converter) to an electrical consumer 306 (for example a traction battery).

[0078] The compensation device 20 can compensate for the leakage current to such an extent that the fuses of the power supply network are not triggered during normal operation due to exceeding the limit value of the leakage current.

[0079] This is particularly advantageous in charging devices 12 for electric vehicles or hybrid vehicles, which have a galvanic coupling between the DC intermediate circuit 301, 302 and the conductors 51 to 54 or between the load and the conductors 51 to 54. Unlike in vehicles with galvanic isolation (which may be the case, for example, in vehicles with a transformer in the rectifier 300 or the DC / DC converter), leakage currents accumulate in the case of galvanic coupling and are visible in the supply network. Therefore, the use of the compensation device 20 in vehicles with galvanic coupling is particularly advantageous.

[0080] Naturally, numerous variations and modifications are possible within the scope of the invention.

[0081] In these embodiments, the capacitor components 151 , 152 , 153 , 154 are each implemented as one capacitor, but they can also be implemented by a plurality of capacitors connected in parallel and / or in series.

Claims

1. A compensation device (20) for compensating a leakage current, the compensation device (20) comprising a compensation current generating device (28), a potential generating device (150), an active conductor terminal and a protective conductor terminal (65), The active conductor terminal has a first active conductor terminal and a second active conductor terminal, The potential generating device (150) is connected to the first active conductor terminal and has a potential generating device terminal (155), the potential generating device (150) being configured to provide a potential at the potential generating device terminal (155) which is at least temporarily different from the potential at the first active conductor terminal, and the compensating current generating device (28) is configured to cause a compensating current I_COMP between the potential generating device terminal (155) and the protective conductor terminal (65), wherein the potential generating device (150) has a first capacitor component, and wherein the potential generating device terminal (155) is connected to the first active conductor terminal via the first capacitor component, wherein the potential generating device (150) has a second capacitor component (152), and wherein the potential generating device terminal (155) is connected to the second active conductor terminal via the second capacitor component (152), in, The compensation device (20) has a DC intermediate circuit (303, 305), on which Y capacitors (307, 308) are arranged, which have a first total capacitance, and in the compensation device (20) the potential generating device (150) has a second total capacitance, wherein the second total capacitance is in the range between 60% and 140% of the first total capacitance.

2. The compensation device (20) according to claim 1, wherein the potential generating device (150) is connected to the second active conductor terminal, and wherein the potential generating device (150) is configured to provide a potential at the potential generating device terminal (155) which is at least temporarily different from the potential at the second active conductor terminal.

3. The compensation device (20) according to claim 1, comprising a power grid filter (160), the power grid filter comprising an X capacitor component for suppressing differential mode interference and a Y capacitor component for suppressing common mode interference, the X capacitor component comprising a first X capacitor component between the first active conductor terminal and the second active conductor terminal, and the first capacitor component and the second capacitor component (152) together form the first X capacitor component.

4. The compensation device (20) of claim 3, wherein the X-capacitor assembly comprises a second X-capacitor assembly between the first active conductor terminal and a further active conductor terminal, the further active conductor terminal being not the second active conductor terminal, wherein the first X-capacitor assembly has a first capacitance, wherein the second X-capacitor assembly has a second capacitance, and wherein the second capacitance is in the range between 70% and 130% of the first capacitance.

5. The compensation device (20) according to claim 3 or 4, wherein the Y capacitor assembly has a first Y capacitor assembly and a second Y capacitor assembly, the first Y capacitor assembly being connected between the first active conductor terminal and the protective conductor terminal (65), and wherein the Y capacitor assembly is connected between the second active conductor terminal and the protective conductor terminal (65).

6. Compensation device (20) according to one of claims 1 to 4, wherein the active conductor terminals have a third active conductor terminal, wherein the potential generating device (150) has a third capacitor component (153), and wherein the potential generating device terminal (155) is connected to the third active conductor terminal via the third capacitor component (153).

7. The compensation device (20) according to claim 1, wherein the potential generating device (150) has a fourth capacitor component (170) which is connected between the compensation current generating device (28) and the potential generating device terminal (155).

8. A compensation device (20) for compensating a leakage current, the compensation device (20) comprising a compensation current generating device, an active conductor terminal, a protective conductor terminal (65), a power supply (450) and a control device (26), The active conductor terminal has a first active conductor terminal and a second active conductor terminal, the compensating current generating devices include a first compensating current generating device and a second compensating current generating device, the first compensating current generating device is connected between the first active conductor terminal and the protective conductor terminal (65), the second compensating current generating device is connected between the second active conductor terminal and the protective conductor terminal (65), the compensating current generating devices respectively have a compensating current regulating component (403, 413), and the control device (26) is formed to control the compensating current regulating component (403, 413) by means of the power supply so as to generate a compensating current.

9. The compensation device (20) according to claim 8, wherein the compensation current generating devices each have a voltage dropper (401, 411), which is arranged between the compensation current adjustment component (403, 413) and the associated active conductor terminal and is formed to reduce the voltage at the associated compensation current adjustment component (403, 413) relative to the voltage at the associated active conductor terminal.

10. The compensation device (20) according to claim 9, wherein the voltage reducers (401, 411) each have a resistor or a voltage limiter. 11 . The compensation device ( 20 ) according to claim 8 , wherein the compensation current generating devices each have a current measuring component ( 405 , 415 ) in order to measure a compensation current passing through the compensation current generating device.

12. The compensating device (20) according to one of claims 8 to 10, wherein the compensating current adjustment components (403, 413) are each designed to realize a compensating current in two directions.

13. A vehicle (10) having a charging device (12) for a traction battery (306), the charging device (12) having a rectifier (300) and a traction battery (306) directly or indirectly connected to the rectifier (300), wherein the traction battery (306) is galvanically coupled to the active conductor terminals, and wherein the charging device (12) has a compensation device (20) according to one of the preceding claims 1 to 12.

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