High-voltage device for motor vehicle

Abstract

The invention relates to a high-voltage system (2) for a motor vehicle (1), comprising an electrical energy source (3) and an operating part (5) which can be coupled to a drive part (4) by means of a switching device (6), and comprising an insulation monitoring device (8) which is designed to detect an insulation state of the high-voltage system (2), the switching device (6) being switchable depending on a fault state of the high-voltage system (2) detected by means of the insulation monitoring device (8), in particular, the Cy capacitance is reduced.

Description

Technical Field

[0001] The invention relates to a high-voltage device for a motor vehicle, comprising an electrical energy source and a working part that can be coupled to a drive part by means of a switching device, and also comprises an insulation monitoring device configured to detect the insulation state of the high-voltage device. Background Art

[0002] The prior art generally discloses high-voltage systems for motor vehicles, which include an electrical energy source for supplying electrical energy to a drive part and a working part. The drive part may, for example, include an electric motor, which is configured as a drive device for driving the motor vehicle. The working part may be configured to perform a work task. To this end, the working part may include a working device. For example, the working part may include a lifting device, a stirring device, a pump device, an extruder, a temperature control device, or any other working device configured to perform a specific work task.

[0003] To ensure safe operation of high-voltage equipment, in particular to ensure that there are no defects in the insulation of electrical conductors, the high-voltage equipment includes an insulation monitoring device. This insulation monitoring device is designed to determine the insulation state of the high-voltage equipment. This insulation state may indicate, for example, that there are no defects in the insulation or that the electrical conductor is at least partially exposed, thereby enabling a corresponding report to be issued.

[0004] It is also known that in the event of a fault in the high-voltage system, such as a defect in the insulation of an electrical conductor, the electrical energy stored in the system of the high-voltage system is crucial for protecting people. As is known from the prior art, this can be essentially divided into Cx capacitance and Cy capacitance, with the Cy capacitance ultimately relating to the electrical energy stored between the vehicle chassis and the high-voltage system, for example in the form of energy stored in so-called interference suppression capacitors. In addition to insulation faults in the high-voltage conductors, insulation faults can also occur in any high-voltage component of the system (e.g., inverters, motors, DC / DC converters, etc.).

[0005] Typically, when a so-called "first fault" in the insulation occurs, such as a defect in the insulation of a single conductor, a fault report is issued, but no further action is taken. If a so-called second fault occurs, such as a defect in the insulation of both the "+" and "-" lines, further action is taken. As the performance and design of high-voltage equipment continue to improve, the amount of electrical energy stored in the system is also increasing, especially for Cy capacitors, leading to increasing safety requirements. Summary of the Invention

[0006] The object of the present invention is to provide a high-voltage device for a motor vehicle which is improved compared to the above.

[0007] This object is achieved by a high-voltage device for a motor vehicle having the features of claim 1. Advantageous embodiments are the subject matter of the dependent claims.

[0008] As described, the present invention relates to a high-voltage device for a motor vehicle, which has an electrical energy source, a drive part and a working part. The working part is coupled to the drive part or can be coupled to the drive part via a switching device. In other words, the coupling between the working part and the drive part can be established or cut off by the state of the switching device, such as the open state (i.e., the cut-off state) or the closed state (i.e., the connected state). The electrical energy source is arranged on the drive part side (seitens), that is, connected to the drive part. The electrical energy source can be cut off from the drive part or connected to it, for example, in the form of battery protection. Therefore, in order to supply electrical energy to the working part, the switching device must be closed and the working part must be connected to the drive part. In other words, the working part is connected to the electrical energy source via the drive part.

[0009] The present invention is based on the recognition that a switching device can be disconnected based on a fault state of the high-voltage equipment detected by means of an insulation monitoring device, in particular in order to reduce the Cy capacitance. As described, the insulation state of the high-voltage equipment can be detected by means of an insulation monitoring device. If the insulation state indicates a fault state, for example due to a defect in the insulation of a conductor of the high-voltage equipment, the working part can be disconnected from the drive part by correspondingly operating the switching device. In other words, the insulation monitoring device monitors the insulation state of the high-voltage equipment, wherein the switching device is disconnected, i.e., opened, when a fault state occurs. This disconnects the working part from the drive part. This can be used in particular to reduce the Cy capacitance of the entire system (i.e., the entire high-voltage equipment including the working part and the drive part) because the Cy capacitance of the working part is excluded from the total capacitance due to the disconnection of the switching device. Therefore, the energy stored in the sub-capacitors can be distributed according to the amount of energy required by the subsystem and / or in accordance with the standard.

[0010] This demonstrates that taking measures already at the time of a so-called first fault, specifically reducing the Cy capacitance, is advantageous for maintaining safety in all operating states. This further improves personal safety in the area of ​​the high-voltage equipment, for example, in terms of contact protection. It is well known that high-voltage equipment differs from conventional systems in motor vehicles in its operating voltage. The high-voltage equipment described in this application has significantly higher voltages than other equipment in motor vehicles that operate at 12, 24, or 48 V, for example, voltages in the range of >100 V, particularly voltages of several hundred volts, such as 400 V or 800 V.

[0011] Therefore, the high-voltage device proposed in the present application realizes that the working part is disconnected from the drive part in the so-called first fault condition, and thus reduces the Cy capacitance. This will especially reduce the electrical energy or capacitance between the high-voltage system of the high-voltage device and the chassis of the vehicle, which is related to the faulty subsystem. By dividing the entire system into its components, namely the drive part and the working part, when someone touches the subsystem with a defect that causes the fault state, since the switching device is cut off, only the already reduced capacitance of the subsystem is relevant. In other words, the capacitance related to the contact protection is limited to the faulty subsystem. When the switching device is disconnected, only the sub-capacitance is relevant, not the entire capacitance (as is the case in the connected state of the switching device). This reduces the amount of related energy and thereby improves the protection of personnel.

[0012] According to another embodiment of the high-voltage installation, the diagnostic device of the high-voltage installation can be configured to attribute a detected fault state to the drive part or the working part by disconnecting the switching device. As described, the fault state or insulation state of the high-voltage installation is detected by the insulation monitoring device. Based on the fault state detected by the insulation monitoring device, the switching device is disconnected, i.e., disconnected.

[0013] The diagnostic device can then determine whether the fault state detected by the insulation monitoring device is present in the drive section or the working section. This can be achieved, in particular, based on changes in the fault state detected before and after the switching device's closed state changes. In principle, the diagnostic device thus allows determination of which subsystem of the high-voltage equipment is faulty, i.e., in which part of the high-voltage equipment the fault state has occurred. This allows narrowing down the high-voltage equipment component responsible for the fault state, allowing appropriate measures to be taken. In particular, it can be determined in which device the fault state should be eliminated, particularly in the workroom responsible for the drive section or the workroom responsible for the working section.

[0014] In particular, the diagnostic device of the high-voltage equipment can be constructed to attribute the fault state to the working part when the fault state disappears after the switching device is switched off, and / or to attribute the fault state to the drive part when the fault state still exists after the switching device is switched off. As described, the insulation monitoring device can be used to detect the fault state. The insulation monitoring device can also be called an "Iso-Guard". Depending on whether the insulation monitoring device is arranged in the working part or in the drive part, it is possible to attribute the fault state to the faulty subsystem of the high-voltage equipment based on different states of the switching device with the help of the diagnostic device. It is generally assumed that the insulation monitoring device is arranged on the drive part side. If the insulation monitoring device detects the fault state, the switching device is switched off as described. If the fault state still exists thereafter, that is, if the insulation monitoring device still detects the fault state when the switching device is switched off, the fault state exists in the drive part because the working part has been separated and is therefore no longer monitored by the insulation monitoring device.

[0015] If the fault state disappears when the switching device is switched off, i.e., if the insulation monitoring device can no longer detect the previously detected fault state when the switching device is switched off, the fault state is attributed to the working part because the switching device has been switched off and the insulation monitoring device is therefore no longer able to detect the fault state in the working part. If the insulation monitoring device is not located in the drive part but in the working part or is assigned to the working part, the previously described diagnosis can be performed in the opposite manner and the fault state can be attributed in the opposite manner.

[0016] In one refinement of the high-voltage system, the control device can be configured to, in particular, continue operating the drive unit in a safe state or shut down the high-voltage system, based on an attribution made by the diagnostic device. As described, the diagnostic device can detect, based on the transition of the switching device from the connected state to the disconnected state, whether the fault condition primarily occurs in the drive unit or in the working unit. If the fault condition occurs on the working unit side, the drive unit can continue to operate as desired with the switching device disconnected, since the drive unit is unaffected by the fault condition. In this case, for example, a notification can be issued to a user of the vehicle or the high-voltage system informing them that the working unit has a fault and requires inspection. In this case, for example, the working unit can be shut down while the drive unit continues to be used.

[0017] The attribution performed with the help of the diagnostic device can also indicate that the fault state exists in the drive part. In this case, the working part can also remain disconnected because the working part can be connected to the drive part via the switching device. By separating the working part from the drive part, the Cy capacitance will be reduced in any case, thereby improving the protection of personnel. In this case, the control device can be used to decide whether the drive part can continue to operate in a safe state, for example, in order to find the nearest workshop. If the fault state is more serious, the control device can also stop the high-voltage equipment. Accordingly, the control device can determine whether it is necessary to continue to operate the drive part, operate in a safe state, for example, operate with a reduced functional range or emergency program, or stop the drive part completely based on the fault state. A motor vehicle with high-voltage equipment can, for example, use another drive device, such as another motor, another drive part or an internal combustion engine to move.

[0018] There are many options for controlling high-voltage equipment, especially for operating the switching device. For example, a control device on the drive part side or a central control device can be configured to disconnect the switching device based on a fault state. The high-voltage equipment can, for example, have a control device for the drive part and a control device for the working part. Similarly, the high-voltage equipment can also have a central control device in addition to or as an alternative to the control device on the drive part side. Since the insulation monitoring device is usually arranged on this side of the drive part, the insulation monitoring device can communicate with the control device on the drive part side or the central control device, so that, for example, the insulation monitoring device feeds back the fault state to the central control device, and the control device then disconnects the switching device.

[0019] It can also be proposed for the high-voltage equipment that the control device on the working part side is constructed to disconnect the switching device based on the fault state, or that the control device on the working part side is constructed to transmit the fault state to the drive part side or the central control device, wherein the drive part side or the central control device is constructed to disconnect the switching device based on the fault state. Therefore, in principle, a control device can also be provided in the working part, one of the purposes of which is to control the working part, for example, when performing a work task. The control device on the working part side can be constructed to disconnect the switching device based on a fault state that is fed back to the control device on the working part side or obtained by it. It can also be proposed that the control device on the working part side transmits the fault state to the central control device or the control device on the drive part side, so that the control device is constructed to subsequently disconnect the switching device.

[0020] The high-voltage installation can be further improved so that the high-voltage installation includes a second insulation monitoring device assigned to the working part, wherein the control device of the working part is configured to disconnect the switching device based on a fault state detected by the second insulation monitoring device. According to this embodiment, the working part can be assigned its own insulation monitoring device, which can monitor the insulation of the conductors in the working part for defects. If the second insulation monitoring device detects a fault state, the control device of the working part can disconnect the switching device again. This has the advantage that the working part is self-contained and can detect fault states using its own insulation monitoring device.

[0021] In addition to high-voltage equipment, the present invention also relates to a motor vehicle, in particular a commercial vehicle, comprising a high-voltage equipment as described above. The present invention further relates to a method for operating a high-voltage equipment, in particular a high-voltage equipment as described above, comprising an electrical energy source and a working part that can be coupled to a drive part by means of a switching device, and an insulation monitoring device configured to detect the insulation state of the high-voltage equipment. The switching device is disconnected based on a fault state of the high-voltage equipment detected by the insulation monitoring device, in particular to reduce the Cy capacitance. The term "disconnection" particularly means establishing necessary distances, in particular distances necessary for the electrical safety of the conductors, in particular air distances and creepage distances.

[0022] All advantages, details and features described with regard to the high-voltage device are fully applicable to the motor vehicle and the method. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present invention will be explained below by way of example with reference to the accompanying drawings. These drawings are schematic and illustrate:

[0024] Figure 1 A portion of a motor vehicle having a high voltage device is shown; and

[0025] Figure 2 A flow chart of a method for operating a high-voltage system is shown. DETAILED DESCRIPTION

[0026] Figure 1 A schematic diagram shows a portion of a motor vehicle 1 having a high-voltage device 2. The high-voltage device 2 includes an electrical energy source 3, such as an electrical energy storage device. The electrical energy source 3 is connected to a drive unit 4 of the high-voltage device 2. The drive unit 4 may include various components for driving the motor vehicle 1, such as at least one electric motor, an inverter for operating the electric motor, and the like. The electrical energy storage device of the electrical energy source 3 may also be integrated into the drive unit.

[0027] In addition to the drive section 4, the high-voltage device 2 also has a working section 5. The working section 5 can also include various components, such as an inverter, a motor, and the like. The components of the working section 5 can be understood, for example, as working devices configured to perform specific working tasks. Depending on the use of the motor vehicle 1, which can be understood as a commercial vehicle, different working sections 5 can be provided to perform different working tasks. For example, the working section 5 can include a lifting device, a stirring device, a pump device, an extruder, a temperature control device, and the like.

[0028] A switching device 6 is provided between the drive section 4 and the working section 5. This switching device can be switched between a closed state and an open state, that is, between a connected state and a disconnected state. If the switching device 6 is closed, the working section 5 is coupled to the drive section 4, meaning that the working section 5 can be supplied with electrical energy via the energy source 3. When the switching device 6 is closed, that is, when the switching device 6 is connected, the total Cy capacitance "Cy" is composed of the individual Cy capacitances of the drive section 4, labeled "Cy1," and the individual Cy capacitances of the working section 5, labeled "Cy2." The Cy capacitance refers to the amount of electrical energy stored between the system of the high-voltage device 2 and the vehicle chassis 7, such as the electrical energy stored in interference suppression capacitors (not shown).

[0029] In addition, the high-voltage device 2 also has an insulation monitoring device 8, which is assigned to the drive part 4 in the present embodiment. The insulation monitoring device 8 can monitor defects on the insulation of the electrical conductor of the high-voltage device 2. If the insulation monitoring device 8 detects a so-called "first fault", for example, the switching device 6 can be changed from a closed state, i.e., a connected state, to a disconnected state using the control device 9. The control device 9 can schematically represent a central control device, a control device of the drive part 4, or a control device of the working part 5. The control device 9 can, for example, directly disconnect the switching device 6 as the control device 9 of the drive part 5 or send such a request to the central control device. Similarly, the control device 9 can directly disconnect the switching device 6 as the central control device or as the control device 9 of the drive part 4 or send a corresponding request signal to another control device 9.

[0030] When the insulation monitoring device 8, also known as the "Insulation Guard," detects a fault condition, it disconnects the working part 5, reducing the Cy capacitance from the previously described total capacitance "Cy" to the individual Cy capacitances "Cy1" and "Cy2." In other words, only the amount of energy stored in the subsystem where the fault condition occurs is relevant. For example, if a fault condition occurs in the working part 5, it is not the total capacitance Cy that is relevant, but only the Cy capacitance Cy2 of the working part 5. Similarly, if a fault condition occurs in the drive part 4, only the Cy capacitance Cy1 of the drive part 4 is relevant. This significantly reduces the Cy capacitance during a fault condition, thereby improving personnel protection.

[0031] Figure 2 A method for controlling a high voltage device 2, in particular Figure 1 Schematic flow chart of a method for operating a high-voltage device 2. Figure 1 All advantages, details and features described for the high-voltage device 2 are fully applicable to the method and vice versa. Figure 1 The method is performed on the high-voltage device 2 in FIG. The method begins at block 10, where the insulation state of the high-voltage device 2 is monitored using the insulation monitoring device 8. This monitoring can be performed continuously or at set time intervals. If a fault state is detected, the switching device 6 is disconnected in block 11, thereby disconnecting the working part 5 from the drive part 4.

[0032] Subsequently or simultaneously, a diagnosis can be performed in block 12, in particular with the aid of a diagnostic device. In particular, it can be analyzed whether a fault state detected before the switching device 6 is switched off can also be subsequently detected in block 11 after the switching device 6 is switched off. If so, the fault state can be attributed to the drive section 4, since the working section 5 is decoupled from the insulation monitoring device 8. If the previously detected fault state disappears after the switching device 6 is switched off, the fault state can be attributed to the working section 5. Alternatively, a separate insulation monitoring device 8 can be assigned to the working section 5, so that in block 12 it can be determined in which subsystem of the high-voltage system 2 the fault state subsequently occurred, i.e., the drive section 4 or the working section 5.

[0033] Based on the results of the diagnosis in block 12, appropriate measures can be taken in block 13. If a fault condition occurs in the operating part 5, for example, the switching device 6 can be maintained in the off state, and the operating part 5 can be shut down. Since the drive part 4 has not experienced a fault condition, it can continue to operate as desired. For example, a report can be issued indicating that the operating part 5 has stopped operating due to a fault.

[0034] If a fault condition occurs in the drive unit 4, it can continue to operate in a safe state, for example, using emergency procedures or a reduced operating scale, or, depending on the type of fault condition, can be completely shut down. Based on the diagnosis in block 12, appropriate measures can also be initiated to eliminate the fault condition, in particular to narrow down the cause of the fault at an early stage. This allows, for example, targeted fault handling, particularly by the manufacturer of the drive unit 4 or the working part 5, since the subsystem that is faulty can already be diagnosed in block 12.

[0035] In any case, by switching off the switching device 6 , the total capacitance Cy is reduced to the sub-capacitances Cy1 , Cy2 , so that even when measures are taken to eliminate the fault state, better personal protection is achieved.

[0036] List of reference numerals:

[0037] 1 Motor Vehicle

[0038] 2 High-voltage equipment

[0039] 3 Energy

[0040] 4. Drive part

[0041] 5 Working part

[0042] 6 Switching device

[0043] 7 Vehicle chassis

[0044] 8 Insulation monitoring device

[0045] 9 Control device

[0046] Boxes 10-13.

Claims

1. A high-voltage device (2) for a motor vehicle (1), comprising an electrical energy source (3) and a working part (5) that can be coupled to a drive part (4) by means of a switching device (6), and further comprising an insulation monitoring device (8), the insulation monitoring device being configured to detect the insulation state of the high-voltage device (2), characterized in that: The switching device (6) can be switched off in response to a fault state of the high-voltage device (2) detected by means of the insulation monitoring device (8), in particular in order to reduce the Cy capacitance.

2. The high-voltage device (2) according to claim 1, characterized in that The diagnostic device of the high-voltage device (2) is configured to attribute the detected fault state to the drive part (4) or the working part (5) by switching off the switching device (6).

3. The high-voltage device (2) according to claim 2, characterized in that The diagnostic device is configured to attribute the fault state to the working part (5) when the fault state disappears after the switching device (6) is turned off, and / or to attribute the fault state to the driving part (4) when the fault state still exists after the switching device (6) is turned off.

4. The high-voltage device (2) according to claim 2 or 3, characterized in that The control device (9) is designed to continue operating the drive part (4) in a safe state or to shut down the high-voltage device (2), in particular depending on the attribution made by means of the diagnostic device.

5. High-voltage device (2) according to any one of the preceding claims, characterized in that A drive-side or central control device (9) is designed to switch off the switching device (6) based on the fault state.

6. High-voltage device (2) according to any one of the preceding claims, characterized in that The control device (9) on the working part side is configured to disconnect the switching device (6) based on the fault state, or the control device (9) on the working part side is configured to transmit the fault state to the control device (9) on the drive part side or the central control device (9), wherein the control device (9) on the drive part side or the central control device (9) is configured to disconnect the switching device (6) based on the fault state.

7. High-voltage device (2) according to any one of the preceding claims, characterized in that The high-voltage device (2) has a second insulation monitoring device (8) assigned to the working part (5), wherein a control device (9) of the working part (5) is designed to disconnect the switching device (6) as a function of a fault state detected by means of the second insulation monitoring device (8).

8. Motor vehicle (1), in particular a commercial vehicle, comprising a high-voltage device (2) according to any one of the preceding claims.

9. Method for operating a high-voltage device (2), in particular according to any one of claims 1 to 7, comprising an electrical energy source (3) and a working part (5) that can be coupled to a drive part (4) by means of a switching device (6), and also comprising an insulation monitoring device (8), which is designed to detect the insulation state of the high-voltage device (2), characterized in that The switching device (6) is disconnected according to the fault state of the high-voltage device (2) detected by means of the insulation monitoring device (8), in particular to reduce the Cy capacitance.

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