Electrical switching device for providing a test voltage during a dielectric strength test of a battery system for a vehicle, and method for providing a test voltage

Abstract

Electrical switching device (1) for providing a test voltage during a dielectric strength test of a vehicle battery system. The electrical switching device (1) includes a test unit (2) configured to provide a positive voltage component (100) and a negative voltage component (101) for the test voltage. Furthermore, the electrical switching device (1) includes a first disconnect switching unit (3) configured to selectively connect or disconnect the positive voltage component (100) to a positive output (102) of the electrical switching device (1). Additionally, the electrical switching device (1) includes a second disconnect switching unit (4) configured to selectively connect or disconnect the negative voltage component (101) to a negative output (103) of the electrical switching device (1).Furthermore, the electrical switching device (1) comprises a switching unit (5) configured to selectively connect either the positive voltage component (100) or the negative voltage component (101) to a neutral output (104), or to disconnect both the positive voltage component (100) and the negative voltage component (101) from the neutral output (104). Finally, the electrical switching device (1) comprises a control circuit (6) configured to control the first isolating switching unit (3), the second isolating switching unit (4), and the switching unit (5).

Description

[0001] The invention relates to an electrical switching device for providing a test voltage during a dielectric strength test of a battery system for a vehicle according to claim 1. Furthermore, the invention relates to a method for providing a test voltage during a dielectric strength test of a battery system for a vehicle, comprising the electrical switching device.

[0002] During the manufacture of electrical products, a dielectric strength test can be performed to ensure that no insulation distances have been reduced and that the product is in good working order. A high test voltage can be applied to the insulation distance being tested. When testing IT (Insulated Ground) networks, it is important to ensure that both potentials relative to ground are tested with a sufficient test voltage. Particularly in high-voltage battery systems, which have high system voltages, the series connection of the battery cells can result in one system potential being tested without a sufficient test voltage, requiring a separate test for this potential. Special attention must be paid to the direction of the applied test voltage during the dielectric strength test.

[0003] From US 7 026 822 B1, a high-voltage switching matrix for selectively connecting a multitude of different voltage / current sources or inputs to a multitude of different outputs is known, which includes a common or shared relay for each of the voltage / current source inputs.

[0004] Furthermore, electrical switching devices capable of providing test voltages are already known in the prior art. The number of automotive battery systems requiring testing with such an electrical switching device is relatively small.

[0005] The object of the present invention is to provide a test voltage flexibly and safely at various outputs during a dielectric strength test of a battery system.

[0006] This problem is solved by the electrical switching device and by the method according to the independent claims. Advantageous embodiments are specified in the dependent claims.

[0007] One aspect of the invention relates to an electrical switching device for providing a test voltage during a dielectric strength test of a vehicle battery system. The electrical switching device includes a test circuit configured to provide a positive and a negative voltage component for the test voltage. The electrical switching device has a first isolating switching unit configured to selectively connect or disconnect the positive voltage component of the test circuit to a positive output of the electrical switching device. The electrical switching device has a second isolating switching unit configured to selectively connect or disconnect the negative voltage component of the test circuit to a negative output of the electrical switching device.The electrical switching device includes a switching unit configured to selectively connect either the positive voltage component of the test device or the negative voltage component of the test device to a neutral output of the electrical switching device, or to disconnect both the positive and negative voltage components from the neutral output. The electrical switching device includes a control circuit configured to control the first disconnecting switching unit, the second disconnecting switching unit, and the switching unit.

[0008] In other words, the control circuit can control the first isolating switching unit, the second isolating switching unit, and the switching unit in such a way that the positive and negative voltage components of the test device are available at different outputs of the electrical switching device. For example, the positive voltage component of the test device can be disconnected from the neutral output via the switching unit, and the negative voltage component of the test device can be disconnected from the neutral output independently via the switching unit.

[0009] A battery system can, for example, include a series arrangement of several battery cells. Such a battery system is characterized, for example, by a positive battery terminal, a negative battery terminal, and a neutral battery terminal, typically configured as a ground terminal.

[0010] The aforementioned elements of the electrical switching device can be implemented in a housing, so that the device can be provided as a module or unit.

[0011] One advantage of the electrical switching device according to the invention is the flexible switching of the test voltage to the battery system under test. Different voltage potentials can be provided at the positive, negative, and neutral outputs of the electrical switching device. Firstly, this accelerates the test sequence, as the connection between the electrical switching device and the battery system under test does not need to be manually or externally disconnected, but can be controlled by the control circuit. Secondly, the number of required test devices can be reduced to a minimum, for example, to a single test device, without omitting any necessary steps in the test sequence.

[0012] According to an advantageous embodiment, the electrical switching device is configured to test a dielectric strength in accordance with ISO 6469 for a high-voltage component, HV component, designed for a high-voltage electrical system.

[0013] The term high voltage (HV) refers here and in the following to a voltage range greater than 60 VDC. HV components in a vehicle must, through system design, have a voltage withstand rating in accordance with ISO 6469. In particular, the system voltage for an HV battery system under test can also be higher, for example, 400 VDC or 800 VDC.

[0014] One advantage of this embodiment is that an HV battery system can be tested flexibly and comprehensively. It may be possible to avoid manually or otherwise disconnecting the electrical switching device from the HV battery system during the test procedure. This can accelerate the test procedure for the HV battery system. According to an advantageous embodiment, the switching unit is mechanically designed in the form of a first switching unit.

[0015] In other words, the first switching unit can selectively connect either the positive or the negative voltage component to the neutral output of the electrical switching device, and the first switching unit may, in particular, include a center position. In the center position, the neutral output can, for example, be connected neither to the positive nor to the negative voltage component. The center position can also be referred to as the OFF position.

[0016] One advantage of this embodiment is that the first switching unit offers increased protection against an unwanted internal short circuit, since the positive voltage component cannot be connected to the negative voltage component.

[0017] According to an advantageous embodiment, the first disconnecting unit, the second disconnecting unit and the switching unit are mechanically designed in the form of a three-pole changeover switch.

[0018] In other words, in the first operating mode of the three-pole changeover switch, the positive voltage component of the test device can be connected to the positive output of the electrical switching device, and the negative voltage component of the test device can be connected to the neutral output of the electrical switching device, while the connection to the negative output of the electrical switching device may be open. In the second operating mode of the three-pole changeover switch, the negative voltage component of the test device can be connected to the negative output of the electrical switching device, and the positive voltage component of the test device can be connected to the neutral output of the electrical switching device, while the connection to the positive output of the electrical switching device may be open.

[0019] One advantage of this embodiment is that the electrical switching device is designed with a reduced number of components. In particular, this embodiment saves installation space and, for example, reduces assembly costs.

[0020] According to an advantageous embodiment, the electrical switching device has a third isolating switching unit which is configured to selectively connect or disconnect the positive voltage component of the test device with the negative output of the electrical switching device, wherein the control circuit is configured to control the third isolating switching unit.

[0021] In other words, the test voltage can be supplied to the battery system under test with reversed polarity; in particular, the negative output of the electrical switching device can supply the positive voltage component to the test equipment.

[0022] In particular, the second disconnecting unit and the third disconnecting unit can be mechanically designed in the form of a second switching unit, wherein the second switching unit can, for example, include a middle position.

[0023] One advantage of this embodiment is that the number of tests within the test sequence can be increased without, for example, having to manually or otherwise disconnect the electrical switching device from the battery system during the test sequence.

[0024] According to an advantageous embodiment, the electrical switching device has a fourth isolating switching unit which is configured to selectively connect or disconnect the negative voltage component of the test device with the positive output of the electrical switching device, wherein the control circuit is configured to control the fourth isolating switching unit.

[0025] In other words, the test voltage can be supplied to the battery system under test with reversed polarity; in particular, the positive output of the electrical switching device can supply the negative voltage component to the test equipment.

[0026] In particular, the first disconnecting unit and the fourth disconnecting unit can be mechanically designed in the form of a third switching unit, wherein the third switching unit can, for example, include a middle position.

[0027] One advantage of this embodiment is that the number of tests within the test sequence can be increased without, for example, having to manually or otherwise disconnect the electrical switching device from the battery system during the test sequence.

[0028] According to an advantageous embodiment, in a first switching state the control circuit controls all disconnecting switching units and the switching unit in such a way that the corresponding connections are disconnected.

[0029] One advantage of this design is that safe operation is ensured in the first switching state.

[0030] According to an advantageous embodiment, in a second switching state, the control circuit controls the first isolating switching unit in such a way that the positive voltage component of the test device is connected to the positive output of the electrical switching device, and the second isolating switching unit in such a way that the negative voltage component of the test device is disconnected from the negative output of the electrical switching device, and the switching unit in such a way that the negative voltage component of the test device is connected to the neutral output of the electrical switching device.

[0031] One advantage of this embodiment is that safe operation is ensured in the second switching state.

[0032] According to an advantageous embodiment, in a third switching state, the control circuit controls the first isolating switching unit in such a way that the positive voltage component of the test device is disconnected from the positive output of the electrical switching device, and the second isolating switching unit in such a way that the negative voltage component of the test device is connected to the negative output of the electrical switching device, and the switching unit in such a way that the positive voltage component of the test device is connected to the neutral output of the electrical switching device.

[0033] One advantage of this embodiment is that safe operation is ensured in the third switching state.

[0034] According to an advantageous embodiment, in a fourth switching state, the control circuit controls the first isolating switching unit such that the positive voltage component of the test device is connected to the positive output of the electrical switching device, and the second isolating switching unit such that the negative voltage component of the test device is connected to the negative output of the electrical switching device, and the switching unit such that both the positive voltage component of the test device and the negative voltage component of the test device are disconnected from the neutral output.

[0035] One advantage of this embodiment is that safe operation is ensured in the fourth switching state.

[0036] According to an advantageous embodiment, in a fifth switching state, the control circuit controls the first isolating switching unit in such a way that the positive voltage component of the test device is disconnected from the positive output of the electrical switching device, and the second isolating switching unit in such a way that the negative voltage component of the test device is disconnected from the negative output of the electrical switching device, and the switching unit in such a way that the negative voltage component of the test device is connected to the neutral output of the electrical switching device, and the third isolating switching unit in such a way that the positive voltage component of the test device is connected to the negative output of the electrical switching device.

[0037] One advantage of this embodiment is that safe operation is ensured in the fifth switching state.

[0038] According to an advantageous embodiment, in a sixth switching state, the control circuit controls the first isolating switching unit in such a way that the positive voltage component of the test device is disconnected from the positive output of the electrical switching device, and the second isolating switching unit in such a way that the negative voltage component of the test device is disconnected from the negative output of the electrical switching device, and the switching unit in such a way that the positive voltage component of the test device is connected to the neutral output of the electrical switching device, and the fourth isolating switching unit in such a way that the negative voltage component of the test device is connected to the positive output of the electrical switching device.

[0039] One advantage of this design is that safe operation is ensured in the sixth switching state.

[0040] According to a further aspect of the invention, a method for providing a test voltage during a dielectric strength test of a test object, in particular a battery system for a vehicle, is presented, wherein the following test sequence is carried out. First, the test object is connected to the positive output, the negative output, and the neutral output of the electrical switching device. Then, the first switching state is set. Next, to perform a test, the second, third, fourth, fifth, or sixth switching state is set. Thereupon, the first switching state is set. Finally, the battery system is disconnected from the positive output, the negative output, and the neutral output of the electrical switching device.

[0041] One advantage of this design is that it ensures safe operation. After the test has been carried out, the connection between the positive and negative voltage components of the battery system under test can be interrupted. This, in particular, ensures the prerequisite for an immediately subsequent test with a different switching state.

[0042] Further advantages, features, and details of the invention will become apparent from the following description of a preferred embodiment and from the drawings. The features and combinations of features mentioned above in the description, as well as those mentioned below in the figure description and / or shown in the figures alone, can be used not only in the combinations specified, but also in other combinations or individually, without departing from the scope of the invention.

[0043] This shows: Fig. 1 a schematic block diagram of an exemplary embodiment of an electronic switching device for providing a test voltage according to the invention; Fig. 2 a further schematic block diagram of an exemplary embodiment of an electronic switching device according to the invention; Fig. 3 a further schematic block diagram of an exemplary embodiment of an electronic switching device according to the invention; Fig. 4 a further schematic block diagram of an exemplary embodiment of an electronic switching device according to the invention.

[0044] In the figures, identical or functionally equivalent elements are provided with the same reference symbols.

[0045] Fig. Figure 1 shows a schematic block diagram of an exemplary embodiment of an electrical switching device 1 for providing a test voltage during a dielectric strength test of a battery system for a vehicle. The electrical switching device 1 comprises, in the following exemplary embodiment, a test device 2, a first disconnect switching unit 3, a second disconnect switching unit 4, a switching unit 5, and a control circuit 6.

[0046] The test device 2 is configured to provide a positive voltage component at node 100 and a negative voltage component at node 101. The first isolating switching unit 3 is configured to selectively connect or disconnect the positive voltage component at node 100 with a positive output at node 102 (hereinafter referred to as "positive output 102") of the electrical switching device 1. The second isolating switching unit 4 is configured to selectively connect or disconnect the negative voltage component at node 101 with a negative output at node 103 (hereinafter referred to as "negative output 103") of the electrical switching device 1.

[0047] The switching unit 5 is configured to selectively connect either the positive voltage component at node 100 (hereinafter referred to as: positive voltage component 100) or the negative voltage component at node 101 (hereinafter referred to as: negative voltage component 101) to a neutral output at node 104 (hereinafter referred to as: neutral output 104) of the electrical switching device 1, or to disconnect both the positive voltage component 100 and the negative voltage component 101 from the neutral output 104. Fig. Figure 1 shows in particular that the switching unit 5, in a special embodiment, contains two independently switchable disconnect switches 5.1 and 5.2 to achieve the described switching effect. The first disconnect switch 5.1 can disconnect the positive voltage component 100 from the neutral output 104, and the second disconnect switch 5.2 can disconnect the negative voltage component 101 from the neutral output 104.

[0048] The control circuit 6 is designed to control the first isolating switching unit 3, the second isolating switching unit 4, the switching unit 5 and in particular the first isolating switch 5.1 and the second isolating switch 5.2 separately via control lines marked with dashed lines.

[0049] Fig. Figure 2 shows another schematic block diagram of an electrical switching device 1. In the present embodiment, it is shown in particular that the switching unit 5 can be mechanically designed in the form of a first switching unit. The remaining elements of the switching device correspond to those of Fig. 1.

[0050] The first switching unit is in Fig. 2 is designed, in particular, with a center position. In the center position, neither the positive voltage component 100 nor the negative voltage component 101 is connected to the neutral output 104. The first switching unit can also be controlled by the control circuit 6. In the illustrated embodiment, a single control line may suffice for this purpose.

[0051] The in Fig. The embodiment shown in section 2 can – unless otherwise stated – have all the same features analogously as shown in section 2. Fig. 1.

[0052] Fig. Figure 3 shows another schematic block diagram of an electrical switching device 1. In this embodiment, a third isolating switching unit 7 can be used to selectively connect or disconnect the positive voltage component 100 with the negative output 103.

[0053] Furthermore, a fourth isolating switching unit 8 can optionally connect or disconnect the negative voltage component 101 with the positive output 102.

[0054] The in Fig. The embodiment shown in section 3 can be adapted analogously to all features from Fig. 1 or Fig. 2. In particular, the switching unit 5 can also include two individual disconnect switches (5.1 and 5.2).

[0055] Fig. Figure 4 shows another schematic block diagram of an electrical switching device 1. In the present embodiment, it is shown in particular that the first isolating switching unit 3, the second isolating switching unit 4, and the switching unit 5 are mechanically designed in the form of a three-pole changeover switch 9. In a first operating state, the three-pole changeover switch 9 can connect the positive voltage component 100 to the positive output 102 and the negative voltage component 101 to the neutral output 104. In a second operating state, the three-pole changeover switch 9 can connect the positive voltage component 100 to the neutral output 104 and the negative voltage component 101 to the negative output 103.

[0056] It may then be provided that the three-pole changeover switch 9 is designed, for example, with a center position. In the center position, which can be considered the third operating state, all connections may, for example, be disconnected from each other.

[0057] In this embodiment, the control circuit 6 can control the three-pole changeover switch 9, for example as shown in Fig. Figure 3 shows a single control line that can jointly control three individual switches of the three-pole changeover switch. Independent control lines for the individual switches of the three-pole changeover switch are also conceivable.

[0058] To implement the dielectric strength test in IT networks with high system voltages, the system can, for example, be tested in at least one switching state. Starting from a first switching state in which all switches can be open, the positive voltage component 100 is connected to the positive output 102 via the first disconnect switch 3 to realize a second switching state. The ground of the device under test at the neutral output 104 is connected to the negative voltage component 101, for example, by means of the second disconnect switch 5.2. All other switches must remain open during this process.

[0059] Before a third switching state is established, all switches are first opened. This corresponds to the first switching state. In the second switching state for testing the battery system, the negative voltage component 101 is connected to the negative output 103 via the second disconnect switch 4, and the ground of the device under test is connected to the positive voltage component 100 via the first disconnect switch 5.1 at the neutral output 104.

[0060] In addition to the described switching states, a fourth switching state allows the potential between the positive output 102 and the negative output 103 to be measured by only switching the first isolating switching unit 3 and the second isolating switching unit 4 to conduct, while all other switches remain open.

[0061] It is also conceivable to increase the test voltage at the opposite end of the battery system by using a third isolating switching unit 7 and a fourth isolating switching unit 8, reversing the first and second switching states. The third isolating switching unit 7 creates a fifth switching state in which the positive voltage component 100 is connected to the negative output 103 and the negative voltage component 101 is connected to the neutral output 104. Furthermore, the fourth isolating switching unit 8 creates a sixth switching state in which the negative voltage component 101 is connected to the positive output 102 and the positive voltage component 100 is connected to the neutral output 104.

Claims

[1] Electrical switching device (1) for providing a test voltage during a dielectric strength test of a battery system for a vehicle, comprising: - a test device (2) which is configured to provide a positive voltage component (100) and a negative voltage component (101) for the test voltage and - a first disconnecting switching unit (3) which is configured to selectively connect or disconnect the positive voltage component (100) of the test device (2) with a positive output (102) of the electrical switching device (1) and - a second isolating switching unit (4) which is configured to selectively connect or disconnect the negative voltage component (101) of the test device (2) with a negative output (103) of the electrical switching device (1) and - a switching unit (5) configured to selectively connect either the positive voltage component (100) of the test device (2) or the negative voltage component (101) of the test device (2) to a neutral output (104) of the electrical switching device (1) or to disconnect both the positive voltage component (100) and the negative voltage component (101) from the neutral output (104) and - a control circuit (6) configured to control the first isolating switching unit (3), the second isolating switching unit (4) and the switching unit (5) and - the first disconnecting unit (3), the second disconnecting unit (4) and the switching unit (5) are mechanically designed in the form of a three-pole changeover switch (9). [2] Electrical switching device (1) according to claim 1, wherein the electrical switching device (1) is configured to test a voltage withstand capability in accordance with ISO 6469 for a high-voltage component, HV component, designed for a high-voltage vehicle electrical system. [3] Electrical switching device (1) according to one of the preceding claims, comprising: - a third isolating switching unit (7) which is configured to selectively connect or disconnect the positive voltage component (100) of the test device (2) with the negative output (103) of the electrical switching device (1), wherein - the control circuit (6) is configured to control the third isolating switching unit (7). [4] Electrical switching device (1) according to one of the preceding claims, comprising: - a fourth isolating switching unit (8) which is configured to selectively connect or disconnect the negative voltage component (101) of the test device (2) with the positive output (102) of the electrical switching device (1), wherein - the control circuit (6) is configured to control the fourth disconnecting unit (8). [5] Electrical switching device (1) according to one of the preceding claims, wherein in a first switching state the control circuit (6) controls all disconnect switching units (3, 4, 7, 8) and the switching unit (5) such that the corresponding connections are disconnected. [6] Electrical switching device (1) according to one of the preceding claims, wherein in a second switching state the control circuit (6) - controls the first disconnecting switching unit (3) such that the positive voltage component (100) of the test device (2) is connected to the positive output (102) of the electrical switching device (1) and - controls the second disconnecting switching unit (4) in such a way that the negative voltage component (101) of the test device (2) is disconnected from the negative output (103) of the electrical switching device (1) and - controls the switching unit (5) such that the negative voltage component (101) of the test device (2) is connected to the neutral output (104) of the electrical switching device (1). [7] Electrical switching device (1) according to one of the preceding claims, wherein in a third switching state the control circuit (6) - controls the first disconnecting switching unit (3) in such a way that the positive voltage component (100) of the test device (2) is disconnected from the positive output (102) of the electrical switching device (1) and - controls the second disconnecting unit (4) such that the negative voltage component (101) of the test device (2) is connected to the negative output (103) of the electrical switching device (1) and - controls the switching unit (5) such that the positive voltage component (100) of the test device (2) is connected to the neutral output (104) of the electrical switching device (1). [8] Method for providing a test voltage during a dielectric strength test of a battery system for a vehicle, comprising the electrical switching device (1) according to any one of claims 1 to 7, wherein the following test sequence is carried out: - the battery system is connected to the positive output (102), the negative output (103) and the neutral output (104) of the electrical switching device (1), - the first switching state according to claim 5 is set, - to carry out a test, the second switching state according to claim 6 or the third switching state according to claim 7 is set, - the first switching state according to claim 5 is set and - the battery system is disconnected from the positive output (102), the negative output (103) and the neutral output (104) of the electrical switching device (1).

Images