阅读说明：本技术 用于车辆高压电池的至少一个开关装置的综合测试的测试设备和方法 (Test device and method for the integrated testing of at least one switching device of a high-voltage battery of a vehicle ) 是由 S·哈达巴斯克 W·瓦格 F·普里舍尔 A·里贝罗 于 2019-03-27 设计创作，主要内容包括：本发明涉及一种用于测试用于车辆高压电池(1)的至少一个开关装置(3)的测试设备(10),包括用于在所述至少一个开关装置(3)的正高压路径(HV+)和负高压路径(HV-)之间产生测试电压(U)的电压源(19),所述测试设备(10)具有第一连接装置(14)和用于将第一测试电流(I<Sub>1</Sub>)馈入正高压路径(HV+)的第一电流源(13),在测试所述至少一个开关装置(3)时,第一连接装置(14)、第一电流源(13)和正高压路径(HV+)一起形成第一电路(15),并且测试设备(10)具有第二连接装置(17)和用于将第二测试电流(I<Sub>2</Sub>)馈入负高压路径(HV-)的第二电流源(16),在测试所述至少一个开关装置(3)时,第二连接装置(17)、第二电流源(16)和负高压路径(HV-)一起形成第二电路(18)。(The invention relates to a test device (10) for testing at least one switching device (3) for a high-voltage battery (1) of a vehicle, comprising a voltage source (19) for generating a test voltage (U) between a positive high-voltage path (HV +) and a negative high-voltage path (HV-) of the at least one switching device (3), the test device (10) having a first connecting device (14) and a second connecting device (I) for supplying a first test current (I) 1 ) A first current source (13) fed into the positive high voltage path (HV +), the first connection means (14), the first current source (13) and the positive high voltage path (HV +) forming together a first circuit (15) when testing the at least one switching device (3), and the test apparatus (10) having a second connection meansIs arranged (17) and is used for applying a second test current (I) 2 ) A second current source (16) feeding into the negative high voltage path (HV-), the second connection means (17), the second current source (16) and the negative high voltage path (HV-) together forming a second circuit (18) when testing the at least one switching device (3).)

1. Test apparatus (10) for testing at least one switching device (3) for a high-voltage battery (1) of a vehicle, comprising a voltage source (19) for generating a test voltage (U) between a positive high-voltage path (HV +) and a negative high-voltage path (HV-) of the at least one switching device (3), characterized in that the test apparatus (10) has a first connecting device (14) and a second connecting device (I) for applying a first test current (I)₁) A first current source (13) fed into the positive high voltage path (HV +), the first connection means (14), the first current source (13) and the positive high voltage path (HV +) forming together a first circuit (15) when testing the at least one switching device (3), and the test apparatus (10) having second connection means (17) and means for applying a second test current (I) to the test apparatus₂) A second current source (16) feeding into the negative high voltage path (HV-), the second connection means (17), the second current source (16) and the negative high voltage path (HV-) together forming a second circuit (18) when testing the at least one switching device (3).

2. A test device (10) according to claim 1, characterized in that the test device (10) has third connecting means (20), the voltage source (19), the third connecting means (20) and the insulating means (7) of the switching means (3) forming a third circuit (20) between the positive high voltage path (HV +) and the negative high voltage path (HV-).

3. Test device (10) according to claim 1 or 2, characterized in that the test device (10) has at least one isolation means for galvanically isolating the voltage source (19), the first current source (13) and/or the second current source (16) from the power supply network.

4. The test device (10) according to any one of the preceding claims, characterized in that the test device (10) has a control device (22) for independently controlling the voltage source (19), the first current source (13) and/or the second current source (16).

5. Test device (10) according to one of the preceding claims, characterized in that the test voltage (U) generated by the voltage source (19) is greater than 100 volts, in particular greater than 250 volts, and the test current (I) provided by the first current source (13) and/or the second current source (16) is₁、I₂) Is greater than 100 amperes, in particular greater than 200 amperes.

6. Test device (10) according to any one of the preceding claims, characterized in that the first circuit (15) and/or the second circuit (18) have at least two branches (23, 24) for respective inputs (4a, 4b) and/or outputs (5a, 5a ', 5b') of the switching means (3).

7. A test apparatus (10) according to any of the preceding claims, characterized in that, when testing at least two serially electrically connected switching devices (3), the respective positive high voltage path (HV +) is part of a first circuit (15) and the respective negative high voltage path (HV-) is part of a second circuit (18).

8. The testing device (10) according to any one of the preceding claims, characterized in that the voltage source (19), the first current source (13) and/or the second current source (16) are arranged in one common housing.

9. The testing device (10) according to any one of claims 1 to 7, characterized in that the voltage source (19), the first current source (13) and/or the second current source (16) are each arranged in a separate housing.

10. System (9) comprising a test device (10) according to any one of the preceding claims and comprising at least one switching device (3).

11. Method for testing at least one switching device (3) for a high-voltage battery (1) of a vehicle, in which method a test voltage (U) is generated between a positive high-voltage path (HV +) and a negative high-voltage path (HV-) of the at least one switching device (3) by means of a voltage source (19), characterized in that a first test current (I) is supplied by means of a first current source (13)₁) A positive high-voltage path (HV +), wherein, during the testing of the at least one switching device (3), the first connecting device (14), the first current source (13) and the positive high-voltage path (HV +) form a first circuit (15) and a second test current (I) is supplied by means of a second current source (16)₂) A negative high-voltage path (HV-), wherein the second connection device (17), the second current source (16) and the negative high-voltage path (HV-) together form a second circuit (18) when testing the at least one switching device (3).

Technical Field

The invention relates to a test device for testing at least one switching device for a high-voltage battery of a vehicle, comprising a voltage source for generating a test voltage between a positive high-voltage path and a negative high-voltage path of the at least one switching device. The invention further relates to a system having such a test device and at least one switching device. Finally, the invention relates to a method for testing at least one switching device for a high-voltage battery of a vehicle.

Background

High voltage batteries, such as those used in electric vehicles, typically include electrical and/or electromechanical components that carry high currents. These components are used, for example, for current measurement, voltage measurement and/or for switching off high-voltage batteries. A high voltage is applied across these components and the components conduct a high current. These components can be arranged in a common housing or distributed in the high-voltage battery. But these components may also be located outside the high voltage battery.

Such a component is a so-called switchgear. The switching device may also be referred to as a switch Box, a contactor Box (schultz-Box), a battery disconnection unit or a battery management unit. The switching device comprises a positive high voltage path and a negative high voltage path through which the operating current of the switching device flows when a switching element in the switching device, which is normally present in the switching device, is closed. Common switching elements are electromechanical relays, safety devices, pyrotechnic disconnectors or the like. When the switching element is closed, the high-voltage path itself is in each case designed to be low-resistive, so that less heat is generated during operation. The positive and negative high-voltage paths are isolated from each other in the switchgear with high resistance by means of an insulation resistance.

Furthermore, DE102014215260a1 describes a method for testing the function of a switching device, in particular of a battery system. The switching device is operated by applying a voltage or a current. Stipulating: the switching device is excited to oscillate by a voltage or current signal and the voltage or current profile of the switching device is subsequently monitored. However, a response signal generated by the actuated switching device can be detected, from which the function of the switching device is deduced.

If the switching device is tested separately, but at a full test voltage and at a full test current, the battery cell replacing the high voltage battery typically uses a voltage source that can generate a high test current and a high test voltage simultaneously. The voltage source is required to be designed for high powers, since it must provide both a high test voltage and a high test current. The voltage source is very expensive and bulky. In addition, for testing switchgear, electronic loads are usually used as loads, which also absorb correspondingly high electrical power. In a typical configuration for testing a switchgear, the components must be able to provide or be designed for high power. However, this electrical power is not dissipated in the test object or the switching device itself, but rather is merely moved between the voltage source and the load, as is the case in actual high-voltage batteries.

Disclosure of Invention

The object of the present invention is to provide a solution which enables a switching device of the type mentioned at the outset to be tested more efficiently and at lower cost.

According to the invention, this object is achieved by a test device, a system and a method having the features according to the independent claims. Advantageous embodiments of the invention are specified in the dependent claims.

The test apparatus according to the invention is used for testing at least one switching device for a high-voltage battery of a vehicle. The test apparatus comprises a voltage source for generating a test voltage between a positive high voltage path and a negative high voltage path of the at least one switching device. Furthermore, the test apparatus has a first connection device and a first current source for feeding a first test current into the positive high-voltage path, the first connection device, the first current source and the positive high-voltage path together forming a first circuit when testing the at least one switching device. Furthermore, the test device has a second connection means and a second current source for feeding a second test current into the negative high-voltage path, the second connection means, the second current source and the negative high-voltage path together forming a second circuit when testing the at least one switching means.

The switching device can be tested or tested by means of a test device. In particular, the test equipment is used for high current and high voltage testing of the switching device. Switching devices are commonly used as components of high voltage batteries for vehicles, in particular electric vehicles. The switching device has a positive high voltage path and a negative high voltage path. The positive and negative high voltage paths may have an input and an output, respectively. If the switching device is used in a high-voltage battery, the input can be connected to electrically interconnected battery cells and the output can be connected to a load or consumer. In the positive high-voltage path and/or the negative high-voltage path, respective switching elements for galvanically isolating the respective high-voltage path may be provided. Such a switching element may be a switch, a contactor, a relay, a transistor, a pyrotechnic isolation device or the like. Additionally, fuses may be provided in the positive high voltage path and/or the negative high voltage path. An insulating means for electrically insulating the positive high voltage path from the negative high voltage path may be provided between the positive high voltage path and the negative high voltage path. Furthermore, a measuring resistor can be arranged between the positive high-voltage path and the negative high-voltage path, at which measuring resistor a voltage can be measured. The insulation means and the possible measuring resistor form a high-resistance insulation resistor. Before the switchgear is installed in the high voltage battery, the function of the switchgear must be tested. Test equipment is used for this purpose.

The test device comprises a voltage source, by means of which a test voltage can be applied between the positive and negative high-voltage paths or across the insulating device in order to test the switching device. The test voltage may in particular be a high voltage of a few hundred volts. According to an important aspect of the invention, it is provided that the test device also has a first current source. A first test current can be fed into the positive high-voltage path by means of a first current source. The test apparatus further comprises first connection means for electrically connecting a first current source with the positive high voltage path. In the simplest case, the first connection means may be provided by respective electrical connection wires or cables. The first connection means may for example provide a plug connection between the first current source and the positive high voltage path. It is provided that, during the testing of the at least one switching device, the first connecting device, the first current source and the positive high-voltage path together form a first circuit. In particular, it is provided that a closed first circuit is provided by the first connection device, the first current source and the positive high-voltage path when the switching element in the first high-voltage path is closed. The first current source is provided separately from the voltage source. In addition, the second current source is provided separately from the voltage source and the first current source. The second current source is for feeding a second test current into the negative high voltage path. Furthermore, the test device comprises second connection means which, together with the second current source and the negative high voltage path, form a second circuit. The second connecting device can also be constructed similarly to the first connecting device. The second circuit is in particular also designed as a closed circuit when the switching element in the negative high-voltage path is closed. The first current source and the second current source can each preferably provide a so-called high current, in particular a current with a current intensity of several hundred amperes.

The test device according to the invention thus enables high current and high voltage testing of the switching device without a high power source and a corresponding high power load. The first current source, the second current source and the voltage source are isolated from one another, so that only low power needs to be implemented in each case. As already explained, in the simplest case the test device can have a voltage source and a first and a second current source. The first and second current sources generate a high test current but only provide a low voltage, since they only need to operate the low resistance of the (benzodienen) positive and negative high voltage paths, respectively. A high test voltage can be provided by the voltage source, but only a low current can be generated, which only flows through the high insulation resistance. Thus, the voltage or current source does not need to have high electrical power, as no one power source has to generate high voltage and high current simultaneously. The at least one switching device can thus be tested more efficiently and at a lower cost.

Preferably, the test device has a third connection means, the voltage source, the third connection means and the insulation means of the switching means forming a third circuit between the positive high voltage path and the negative high voltage path. The third circuit is in particular a closed circuit when a test device for testing the switching device is connected to the switching device. The third circuit may be constructed separately from the first circuit and/or the second circuit. The first, second and third circuits may also be partially connected to each other. These circuits can be connected to each other with high resistance by insulating means. The insulation device can optionally have an insulation resistance together with the measuring resistance. The insulation resistance may typically range between a few mega-ohms to a few giga-ohms. The voltage source may provide a test voltage of several hundred volts. Therefore, the switching device can be subjected to high voltage testing by means of the voltage source.

Furthermore, it is advantageous if the test device has at least one isolation device for galvanically isolating the voltage source, the first current source and/or the second current source from the supply network. The voltage source, the first current source and the second current source may be supplied with electrical energy by a power supply network. The power supply is galvanically isolated from the supply network. This can be achieved by means of the at least one isolation device, which comprises at least one isolation transformer. The isolation device may be installed in the respective power supply itself. Alternatively or additionally, the voltage source, the first current source and/or the second current source may each be connected to the power supply network via a separate isolation transformer. So that the first current source can be brought to the potential of the positive high voltage path and the second current source to the potential of the negative high voltage path.

In a further embodiment, the test device has a control device for independently controlling the voltage source, the first current source and/or the second current source. For the control, a corresponding control signal can be transmitted to the first current source, the second current source and/or the voltage source by means of the control device. The test voltage supplied by the voltage source can be adjusted or varied by controlling the voltage source with the control device. The current intensity of the first test current can be determined or adjusted by controlling the first current source with the control device. Furthermore, the current intensity of the second test current can be determined or adjusted by controlling the second current source with the control device. Thus, for example, a time profile of the test voltage, the first test current and/or the second test current can be predefined for testing the switching device. The test device can also have a corresponding memory, on which the curves of the test voltage, the first test current and/or the second test current are stored. The voltage source, the first current source and the second current source can then be controlled according to these curves or according to a characteristic curve. Different tests or detection methods can therefore be carried out in a simple manner. Furthermore, the characteristics of the actual load or the actual consumer can be simulated by adjusting the test voltage, the first test current and the second test current.

In a further embodiment, the test voltage generated by the voltage source is greater than 100 volts, in particular greater than 250 volts, and the current intensity of the test current provided by the first current source and/or the second current source is greater than 100 amperes, in particular greater than 200 amperes. As already explained, a high voltage or high voltage is provided as the test voltage by the voltage source. The test voltage preferably exceeds 250 volts. For example the test voltage may be 500 volts. In particular, a dc voltage is provided as the test voltage. Furthermore, a high current, in particular a current of more than 200 amperes, is provided by the first current source and the second current source, respectively. For example, the first test current and/or the second test current may each be 400 amps. The first test current and the second test current are each provided in particular as direct currents. The current intensity provided by the voltage source may be relatively low and may be, for example, a few microamperes to milliamperes. The voltage provided by the respective current source may be a few millivolts to a few volts. Therefore, the respective power sources provide low electric power. Thereby providing a more space-saving and lower cost power supply.

Furthermore, it is advantageous if the first circuit and/or the second circuit has at least two branches for respective inputs and/or outputs of the switching device. It may be the case that the switching device to be tested may have a plurality of inputs or outputs. For this purpose, the first circuit and/or the second circuit may each have at least two branches. Each branch can be assigned a resistor or a resistive element. Thus creating a parallel connection circuit of the resistances of the branches. The respective branch can then be connected to the corresponding input or output. Thus, a switching device having a plurality of inputs and/or outputs can also be tested by means of the test apparatus. In general, other energy-conducting components, such as power distributors, can also be tested according to this principle. For a power distributor, it may be necessary to implement a plurality of current sources in order to be able to regulate the current individually on each output.

In a further embodiment, when testing at least two switching devices electrically connected in series, the respective positive high voltage path is part of a first circuit and the respective negative high voltage path is part of a second circuit. In many tests, it is necessary to test a plurality of identical switching devices simultaneously, for example in order to determine the scatter of the test results. In this case, a plurality of switching devices may be connected in series. Thus, for example, protective measures according to the LV124 standard can be implemented, in which a greater number of test subjects are required. Six switching devices can be electrically connected in series. All positive high voltage paths are supplied by a first current source and all negative high voltage paths are supplied by a second current source. Furthermore, a test voltage supplied by a voltage source is applied to each insulation resistor.

According to another embodiment, the voltage source, the first current source and/or the second current source are arranged in a common housing. Provision may also be made for the control device to be arranged in the housing. Furthermore, the at least one isolation device or isolation transformer may be disposed within the housing. A compact structure can be achieved. Alternatively, the voltage source, the first current source and/or the second current source may each be provided within a separate housing. This allows for flexible positioning of the individual power sources.

The system according to the invention comprises a test device according to the invention and at least one switching device. The system may also include a plurality of switching devices electrically connected in series.

The method according to the invention is used for testing at least one switching device for a high-voltage battery of a vehicle. In this case, a test voltage is generated between the positive high-voltage path and the negative high-voltage path of the at least one switching device by means of a voltage source. Furthermore, a first electrical test current is fed into the positive high-voltage path by means of a first current source, wherein the first connection device, the first current source and the positive high-voltage path together form a first circuit when testing the at least one switching device, and a second test current is fed into the negative high-voltage path by means of a second current source, wherein the second connection device, the second current source and the negative high-voltage path together form a second circuit when testing the at least one switching device.

The preferred embodiments and advantages thereof given in connection with the test device according to the invention apply correspondingly to the system according to the invention and to the method according to the invention.

Drawings

Further features of the invention emerge from the claims, the figures and the description of the figures. The features and feature combinations mentioned above in the description and the features and feature combinations mentioned below in the description of the figures and/or shown in the figures individually can be used not only in the combinations indicated, but also in other combinations or alone.

The invention will now be explained in detail by means of preferred embodiments and with reference to the accompanying drawings. The attached drawings are as follows:

fig. 1 shows a schematic diagram for a high-voltage battery for a vehicle, which includes a switching device.

Fig. 2 shows a system with a switching device and a test apparatus for testing the switching device according to the prior art;

FIG. 3 shows a system with a test device according to a first embodiment;

FIG. 4 shows a system with test equipment according to another embodiment, wherein the switching device has a plurality of outputs; and

FIG. 5 illustrates a system in which switching devices are electrically connected in series according to another embodiment.

Detailed Description

In the figures, identical or functionally identical elements are provided with the same reference symbols.

Fig. 1 shows a high-voltage battery 1 for a vehicle in a schematic representation. The high-voltage battery 1 can be used in particular as a traction battery and supplies the drive motor of the vehicle with electrical energy. The high voltage battery 1 includes a plurality of battery cells 2 electrically connected in series. Furthermore, the high-voltage battery 1 comprises a switching device 3, which is electrically connected to the battery unit 2. The switching means 3 has a positive high voltage path HV +, which connects the first input 4a and the first output 5 a. The switching device 3 also has a negative high voltage path HV-which connects the second input terminal 4b and the second output terminal 5 b. The respective high-voltage paths HV + and HV "each have a switching element 6, which can be designed as a relay, a switch, a pyrotechnic disconnector, or the like. Further, a fuse S is provided in the positive high-voltage path HV +. The high-voltage paths HV + and HV "are both designed to have a low resistance (when the switching element 6 is closed). For example, the respective high voltage paths HV + and HV-may have a resistance between 0.5 and 10 milliohms, respectively. The high-voltage paths HV + and HV-are isolated in the switching device 3 with high resistance by the insulating device 7. The insulation means 7 has an insulation resistance which can typically be several mega-ohms to several giga-ohms. A very high measuring resistor for measuring the voltage can also be connected in parallel with the insulation resistor. The first output 5a of the switching device 3 is connected to a positive terminal 8a of the high-voltage battery 1 and the second output 5b is connected to a negative terminal 8b of the high-voltage battery 1.

Fig. 2 shows a system 9 with a switching device 3 and a test apparatus 10 according to the prior art, wherein the test apparatus 10 is used for testing the switching device 3. If the switching device 3 is tested separately, but at full voltage and with full current, a high power supply 11 is used instead of the battery unit 2, which can generate a high current I and a high test voltage U at the same time. The high-power supply 11 is connected to the input terminals 4a, 4b of the switching device 3. An electronic load 12 or a high-power load, which can also absorb high electrical power, is connected to the outputs 5a, 5 b. In such a structure or system 9 according to the prior art, the high power supply 11 and the load 12 are designed for high electric power. This results in the disadvantage of high costs.

Fig. 3 shows a system 9 with a switching device 3 and a test apparatus 10 according to a first embodiment. High current and high voltage tests can also be carried out on the switching device 3 with the aid of this test apparatus 10, without the need for a high-power supply 11 and a load 12. The test device 10 comprises a first current source 13 by means of whichA current source for supplying a first test current I₁Fed into the positive high voltage path HV + of the switching device 3. Furthermore, the test device 9 comprises first connecting means 14, by means of which the first current source 13 and the positive high-voltage path HV + can be electrically connected to each other. The first current source 13, the first connection means 14 and the positive high voltage path HV + form a first circuit 15 when testing the switching device 3 or when connecting the test apparatus 10 to the switching device 3 as specified. The test device 9 furthermore comprises a second current source 16, by means of which a second test current I can be supplied₂Is fed into the negative high voltage path HV-of the switching device 3. The test equipment 9 further comprises second connection means 17 for electrically connecting the second current source 16 with the negative high voltage path HV-. The second current source 16, the second connecting means 17 and the negative high voltage path HV-together form a second circuit 18. Furthermore, the test device 9 comprises a voltage source 19 which is connected to the positive high-voltage path HV + and the negative high-voltage path HV-via third connection means 20. The test voltage U can be applied to the insulation means 7 or between the positive high-voltage path HV + and the negative high-voltage path HV-by means of the voltage source 19. The voltage source 19, the third connecting means 20 and the insulating means 7 form a third electric circuit 21. The respective connection means 14, 17 and 20 may be provided, for example, by respective connecting wires, cables and/or plug connectors.

In the present embodiment, the current sources 13, 16 and the voltage source 19 are isolated from each other, and thus only a small electric power needs to be realized. The three separate circuits mentioned above, namely the first circuit 15, the second circuit 18 and the third circuit 21, are produced here. Generating a high test current I by means of a first current source 13 and a second current source 16₁And I₂But only low voltages are generated, respectively, since they only have to operate the small resistances of the positive and negative high voltage paths HV + and HV-, respectively. The voltage source 19 supplies a high test voltage U, but only a very small current, which flows through the high insulation resistance of the insulation means 7. The current sources 13, 16 or the voltage source 19 do not have to have a high power, because neither of these power sources 13, 16, 19 has to generate a high voltage and a high current at the same time.

Furthermore, the test device 9 comprises a control device 22, which is connected to the first current source 13, the second current source 16 and the voltage source 19. By means of the control device 22, for example, a transmission to the power supplies 13, 16 and 19 is possibleA control signal. The control device 22 can control the power supplies 13, 16, 19 by transmitting control signals in such a way that the test voltage U of the voltage source 19 and the test current I of the current sources 13, 16 can be set₁And I₂The corresponding current strength of. In this way, the behavior of the actual load, i.e. the test current I, can be simulated₁、I₂The relation with the test voltage U corresponds to reality. Furthermore, it is provided that the test device 9 has at least one isolating device, not shown here, for galvanically isolating the power supplies 13, 16, 19 from the supply network. Such isolation means may be installed in the respective power supply 13, 16, 19 or provided by means of an isolation transformer.

The costs are considerably reduced by the test device 9, since the respective power supply 13, 16, 19 does not have to provide high electrical power. However, a nearly actual operation of the switching device 3 can be simulated by the power supplies 13, 16, 19 when the switching element 6 is closed. This is particularly useful for long duration service life tests. If, for example, the system is tested with a 500 volt test voltage and a 400 amp test current, the electrical power in the structure or system 9 according to the prior art is 200 kw at 500 volts x400 amps. In the proposed test structure, assuming that the resistances of the positive and negative high voltage paths HV + and HV-, respectively, are 2 milliohms and the insulation resistance of the insulation arrangement 7 is 1 megaohm, the power of the three power supplies 13, 16, 19 amounts to: 2x 400 amps x 2 milli-ohms +500 volts x 500 volts/1 megaohms 0.64025 kilowatts. The power required is therefore more than 300 times less than with the structure according to the prior art.

Fig. 4 shows a system 9 according to another embodiment. The switching device 3 has two first outputs 5a and 5 a'. The switching device 3 furthermore has two second outputs 5b and 5 b'. In the first circuit 15, respective branches 23 and 24 are assigned to the respective outputs 5a and 5 a'. A first resistor R1 is provided in the first branch 23 assigned to the output 5 a. A second resistor R2 is provided in the second circuit 24 assigned to the second output 5 a'. In the second circuit 18, two branches 23, 24 are likewise provided for the respective outputs 5b and 5 b'. In this case, too, a first resistor R1 is provided in the first branch 23 connected to the output 5b and a second resistor R1 is provided in the second branch 24 connected to the output 5bAnd R2. The corresponding test current I can be adjusted through the resistors R1 and R2₁、I₂To the respective output 5a, 5a ', 5 b'. If the switching device 3 has a plurality of inputs, a corresponding branch can be provided for this purpose.

In many tests a plurality of switching devices 3 need to be tested. A plurality of switching devices 3 may be electrically connected in series for this purpose. This is exemplarily illustrated in fig. 5, which shows a system 9 in which two switching devices 3 are electrically connected in series. The respective positive high voltage path HV + of the respective switching device 3 is assigned to the first circuit. Furthermore, the corresponding negative high-voltage path HV "of the switching device 3 is assigned to the second circuit 18. The test voltage U supplied by the voltage source 19 is applied to the respective insulation means 7 or insulation resistor.

List of reference numerals

1 high-voltage battery

2 Battery cell

3 switching device

4a input terminal

4b input terminal

5a output terminal

5a' output terminal

5b output terminal

5b' output terminal

6 switching element

7 insulating device

8a terminal

8b terminal

9 System

10 test device

11 high power supply

12 load

13 first current source

14 first connecting device

15 first circuit

16 second current source

17 second connecting device

18 second circuit

19 Voltage Source

20 third connecting device

21 third circuit

22 control device

23 route

24 route

HV + positive high voltage path

HV-positive and negative road roller

I current

I₁A first test current

I₂Second test current

R1 resistor

R2 resistor

S fuse

U test voltage