Connection module for an inverter control unit of an electric machine and connection system for an inverter control unit

Abstract

The invention relates to a connection module (20) for an inverter control unit (8) of an inverter (4) of an electric machine (2), comprising an input terminal (26) and an output terminal (28) of a DC voltage, the input terminal (26) being connectable to an external power source (12) and the output terminal (28) being connectable to a voltage supply terminal of the inverter control unit; a converter circuit arrangement (22) having a buck converter (30) and arranged to convert an input voltage provided at the input connection (26) into a lower output voltage to be provided at the output connection (28), the converter circuit arrangement (22) having an overvoltage protection circuit (40), the overvoltage protection circuit is configured to limit an input voltage to a preset maximum input level.

Description

Technical Field

[0001] The invention relates to a connection module for an inverter control unit of an electric machine, a connection system for the inverter control unit and a device having an electric machine and a connection system. Background Art

[0002] In (motor) vehicles, such as cars or trucks, electric machines can be used to drive the motor vehicle or, in the case of hybrid vehicles, partially and / or temporarily. The electric machine can be operated both as an electric motor (e.g. during acceleration processes of the motor vehicle) and as a generator (e.g. during braking processes of the motor vehicle or for generating electricity). The voltage is applied to the windings of the electric machine using a so-called "inverter" (converter circuit), which is controlled by an inverter control unit. The inverter control unit receives the desired indicators (e.g. target speed or target torque) from a higher-level control unit of the motor vehicle, such as a machine control unit or a vehicle control unit (VCU, vehicle control unit), for example, and controls the electric machine accordingly. Electromagnetic interference in the power supply of the inverter control unit can lead to erroneous control of the inverter and of the electric machine.

[0003] Therefore, it is best to ensure error-free power supply of the inverter control unit. Summary of the invention

[0004] Against this background, the invention proposes a connection module for an inverter control unit of an electric machine, a connection system for an inverter control unit, and an arrangement with an electric machine and a connection system having the features of the independent claims. Advantageous developments are the subject matter of the dependent claims and of the following description.

[0005] One aspect of the present invention relates to a connection module of an inverter control unit for an inverter of an electric machine. The connection module has an input terminal and an output terminal of a DC voltage, wherein the input terminal can be connected to an external power supply, and the output terminal can be connected to a voltage supply terminal of the inverter control unit. The connection module also has a converter circuit device, the converter circuit device has a buck converter, and the converter circuit device is configured to convert an input voltage provided at the input terminal into a lower output voltage to be provided at the output terminal, wherein the converter circuit device has an overvoltage protection circuit, and the overvoltage protection circuit is configured to limit the input voltage to a preset maximum input level. The connection module also has a first communication terminal, a second communication terminal and a communication line, wherein the first communication terminal and the second communication terminal are connected through the communication line, so that data communication signals can be forwarded through the connection module. The connection module also has a housing, wherein the converter circuit device is arranged on a circuit board, the circuit board is encapsulated in the housing, wherein the input terminal and the output terminal are arranged in the wall of the housing, wherein the communication line extends in the housing, and wherein the first communication terminal and the second communication terminal are arranged in the wall of the housing.

[0006] By means of such a connection module, the inverter control unit can be supplied with power at a suitable voltage level corresponding to the output voltage, thereby protecting the inverter control unit by limiting the input voltage if necessary and at the same time from electrical or electromagnetic interference.

[0007] Unless otherwise stated, the terms "connected", "connectable" or similar terms are to be understood in the sense of an electrically conductive connection.

[0008] According to at least one embodiment, the first and second communication terminals and the communication line are suitable for a CAN bus (Controller Area Network). The CAN bus is usually implemented in vehicles, so that the connection module can advantageously use existing systems.

[0009] According to at least one embodiment, the connection module further comprises a safety circuit device, which is connected between the converter circuit device and the output terminal and is configured to limit the output voltage to a preset maximum output level, thereby protecting the inverter control unit.

[0010] According to at least one embodiment, the safety circuit arrangement has a semiconductor switch and a switch controller which is configured to switch the semiconductor switch to a non-conducting state when a maximum output voltage is exceeded. The inverter control unit can thereby be protected.

[0011] According to at least one embodiment, the safety circuit arrangement is designed to implement short-circuit protection, thereby making it possible to protect the inverter control unit.

[0012] According to at least one embodiment, the converter circuit arrangement and the safety circuit arrangement are arranged on a printed circuit board, thereby reducing the size accordingly.

[0013] According to at least one embodiment, the overvoltage protection circuit has at least one suppressor diode in order to limit the input voltage, thereby protecting the overvoltage protection circuit.

[0014] According to at least one embodiment, the converter circuit arrangement comprises a filter circuit for suppressing electromagnetic interference, wherein the filter circuit is connected between the input terminal and the buck converter. As a result, the inverter control unit is protected.

[0015] According to at least one embodiment, the filter circuit has inductors and capacitors of particularly suitable dimensions in order to meet the requirements of electromagnetic compatibility (Electromagnetische The inverter control unit is thus protected.

[0016] According to at least one embodiment, the converter circuit arrangement is configured to receive an input voltage in the range of 10 V to 32 V, in particular approximately 24 V, and / or to provide an output voltage in the range of 6 V to 16 V, in particular approximately 12 V. This means that an inverter control unit designed for a passenger car with a conventional 12 V electrical system can also be used for a commercial vehicle with a higher vehicle supply voltage, for example 24 V.

[0017] According to at least one embodiment, the maximum input level is in the range of 50 V to 70 V, in particular about 60 V, and / or the maximum output level is in the range of 12 V to 20 V, in particular about 16 V. This means that an inverter control unit designed for a passenger car with a conventional 12 V electrical system can also be used for a commercial vehicle with a higher vehicle supply voltage (e.g. 48 V to 60 V).

[0018] According to at least one embodiment, the connection module further comprises a fastening device, which is designed to fixedly mount the connection module on the inverter control unit or the motor, wherein the fastening device is arranged on the housing of the connection module. This means that the connection module can be fastened to the inverter control unit without being lost.

[0019] Another aspect of the present invention relates to a connection system for an inverter control unit of an inverter for an electric machine, the connection system comprising a connection module. The connection module has an input terminal and an output terminal of a DC voltage, wherein the input terminal can be connected to an external power supply, and the output terminal can be connected to a voltage supply terminal of the inverter control unit. The connection module also has a converter circuit device, the converter circuit device has a buck converter, and the converter circuit device is configured to convert an input voltage provided at the input terminal into a lower output voltage to be provided at the output terminal, wherein the converter circuit device has an overvoltage protection circuit, and the overvoltage protection circuit is configured to limit the input voltage to a preset maximum input level. The connection module also has a housing, wherein the converter circuit is arranged on a circuit board, the circuit board is encapsulated in the housing, wherein the input terminal and the output terminal are arranged in the wall of the housing. The output terminal of the connection module can be connected to the voltage supply terminal of the inverter control unit. The connection system also includes a power supply line, which is connected to the input terminal of the connection module and can be connected to a power supply.

[0020] According to at least one embodiment, the connection system has a connection module according to the invention. This means that the explained advantages can be achieved in a simple manner.

[0021] Another aspect of the invention relates to an apparatus comprising an electric machine supplied with an AC voltage via an inverter, an inverter control unit for controlling the inverter, a power supply, a machine control unit and a connection system according to the invention, wherein the output terminal of the connection module is connected to a voltage supply terminal of the inverter control unit, wherein the second communication terminal of the connection module is connected to a data communication terminal of the inverter control unit, wherein the power supply line is connected to the power supply, and wherein the control line is connected to the machine control unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Further advantages and improvements of the invention are apparent from the description and the accompanying drawings.

[0023] The invention is schematically illustrated by way of example in the drawings and will be described below with reference to the drawings.

[0024] Figure 1 The structure of an electric drive system including a connection module according to one embodiment is exemplarily shown.

[0025] Figure 2 The structure of a connection module according to an exemplary embodiment is shown.

[0026] Figure 3 A circuit diagram of an exemplary buck converter is shown. DETAILED DESCRIPTION

[0027] exist Figure 1 In the drawing, the structure of an electric drive system including a connection module according to an embodiment of the present invention is shown in a highly simplified manner.

[0028] The electric drive system has a motor 2 (e.g. a synchronous motor), the windings of which are loaded with an AC voltage via an inverter 4. For example, the inverter 4 is connected to a battery, called a drive battery 6 (or an electric vehicle battery), which provides a DC voltage in a low voltage range (e.g. 12 / 24 / 48V) or a high voltage range (e.g., in the range of several hundred to 1 to 2 kV), from which an AC voltage is generated by appropriate control of the switching elements of the inverter 4. Alternatively or additionally, the inverter can also be connected to an electrical device via, for example, an electrical system. In generator operation, the drive battery and / or the load use the generated electricity. The switching element is typically a semiconductor switching element, for example, a FET, a MOSFET or an IGBT in a half-bridge arrangement.

[0029] An inverter control unit 8 is provided, which generates a control signal or a control voltage at the control input (gate) of the semiconductor switching element of the inverter 4. The inverter control unit 8 has, for example, a computing unit (e.g., a microcontroller, an integrated circuit, an ASIC, etc.), which is configured or programmed to implement a control or regulation method for the inverter. For example, the control signal for the semiconductor switching element is determined by the inverter control unit 8 so that the motor achieves or maintains an indicator (e.g., a target speed or a target torque). The indicator can be transmitted to the inverter control unit 8 by a superior machine control unit 10 of a device or machine (e.g., a vehicle) in which the electric drive system is used via a communication connection, for example, via a field bus, in particular a CAN bus (controller area network, CAN), for example, by connecting to a data communication terminal of the inverter control unit 8 via a control line 11.

[0030] The inverter control unit 8 is supplied with electrical energy via a supply line 13 from a battery 12 (current source or voltage source) independent of the drive battery 6 , such as a so-called starter battery, so that the inverter control unit 8 is supplied with electrical energy, in particular independently of the charge state of the drive battery 6 .

[0031] The battery 12 may have a preset voltage level, for example approximately 24 V in more modern applications or commercial vehicle applications, which is not suitable for the inverter control unit 8 which, in particular, requires a conventional vehicle supply voltage of approximately 12 V for controlling the semiconductor switching elements.

[0032] In environments where electric drive systems are used, such as motor vehicles or in particular trucks, electrical or electromagnetic interference may also occur, which results in, for example, voltage spikes. Such electromagnetic interference can impair the functionality of the inverter control unit and, in extreme cases, can lead to damage to the inverter, for example if the semiconductor switching elements are not activated at the correct time.

[0033] In order to solve these problems, a connection module 20 is provided, which, on the one hand, provides the inverter control unit 8 with an appropriate voltage level based on the voltage of the battery 12 and, on the other hand, suppresses voltage spikes. In particular, the use of the connection module makes it possible to integrate the electric drive as an additional drive into an already existing drive system, such as a drive system of a motor vehicle, in particular a truck, in which there is a battery with a voltage that is not suitable for the inverter control unit and no or few measures are taken to avoid electromagnetic interference.

[0034] Furthermore, it is more preferred that the control line 11 is routed together with the power supply line 13 in a common cable harness to the connection module 20. Thereby, the inverter control unit can be connected to the machine control unit 10 and the battery 20 in a simple manner via the connection module 20, wherein little installation space is required and the need for separate cabling is eliminated.

[0035] Figure 2 The basic structure of a connection module 20 according to an exemplary embodiment is shown (highly simplified). The connection module 20 comprises a converter circuit arrangement 22 and optionally a safety circuit arrangement 24. The connection module 20 also has an input terminal 26 and an output terminal 28. Obviously, the converter circuit arrangement 22 and the safety circuit arrangement 24 or, for example, the components constituting them can be positioned differently on a circuit board than shown, which serves in particular to illustrate the various functions. In addition to the shown components of the converter circuit arrangement 22 and the necessary safety circuit arrangement 24, further electronic components, in particular passive components (resistors, capacitors, inductors) are generally provided, which are not shown. Figure 2 The simplified diagram is shown and can be configured by a technician as needed.

[0036] The converter circuit arrangement 22 has a step-down converter 30 (English: step-down converter or buck converter), for example Figure 3. The block 32 has active elements (especially switches) and possible control circuits for controlling the active elements, and can be designed as a chip as a whole. The buck converter 30 is configured to convert the input voltage provided at the input terminal 26 into a lower output voltage to be provided at the output terminal 28. The converter circuit device 22 or its buck converter 30 is particularly configured so that it is suitable for an input voltage that is or should be in the range of 10V to 32V, for example, about 24V. The converter circuit device 22 or its buck converter 30 is particularly configured so that it generates an output voltage so that the output voltage is or should be in the range of 6V to 16V, for example, about 12V. The expression "should be" here means that, for example, in the case of interference, it may be impossible to maintain the corresponding voltage range for at least a short time.

[0037] On the input side, an overvoltage protection circuit 40 is provided, which is designed to limit the input voltage below a preset maximum input level. The overvoltage protection circuit 40 can be regarded as part of the converter circuit arrangement 22. The overvoltage protection circuit 40 is specifically connected between the input terminal 26 and the buck converter 30, so that the voltage occurring on the input side of the buck converter 30 is limited to a maximum input level. With reference to the above-mentioned input voltage range, the maximum input level can be, for example, in the range of 50V to 70V, in particular about 60V. In particular, the overvoltage protection circuit 40 can include at least one capacitor and / or at least one suppression diode 42 (two of which are shown respectively by way of example) to realize the overvoltage protection function.

[0038] In addition, the converter circuit 22 can include a filter circuit 50, for example, connected between the overvoltage protection circuit 40 and the buck converter 30. The filter circuit 50 is designed to suppress electromagnetic interference or interference. On the one hand, this relates to electromagnetic interference that acts on the converter circuit device 22 or the connection module 20 from the outside, and / or on the other hand, it relates to electromagnetic interference that comes from the converter circuit device 22 or the connection module 20 and may affect other devices. For example, the filter circuit 50 has an inductor and a capacitor (capacitance) of suitable size.

[0039] The safety circuit device 24 (if any) is connected downstream of the converter circuit device 22, i.e., between the converter circuit device 22 and the output terminal 28. The safety circuit device 24 is designed to limit the output voltage to a preset maximum output level. With reference to the above-mentioned range of output voltages, the maximum output level can be, for example, in the range of 12 V to 20 V, in particular about 16 V. The safety circuit device 24 can be implemented by a semiconductor switching element, in particular by a MOSFET 62 (metal-oxide-semiconductor field-effect transistor), which is controlled by a switch controller 64 so that the semiconductor switching element 62 switches to a non-conducting state when the maximum output level is reached or exceeded (e.g., the converter circuit device 22 is connected to the output terminal 28 via the drain-source path of the MOSFET 62, and the gate terminal of the MOSFET is correspondingly controlled by the switch controller 64).

[0040] The connection module 20, in particular the converter circuit device 22, is preferably configured to comply with the requirements of the corresponding ISO 16750-2 (2012) standard. The connection module 20, in particular the converter circuit device 24, is preferably configured to comply with the requirements of the corresponding ASIL B (ASIL: Automotive Safety Integration Level) or ISO 126262 (2018) standard.

[0041] The input terminal 26 can be connected to a battery, in particular the battery 12. The output terminal 28 can be connected to a voltage supply terminal of the inverter control unit. For example, the connection can be realized by a plug connection, that is, each is provided with a plug or a corresponding socket, which has contacts, pins, or the like for conductive connection. The input terminal 26 and the output terminal 28 (here shown in simplified form) have at least two conductive contacts, pins, or the like (corresponding to the two potentials provided by the power supply voltage), one of which is used for the supply voltage and the other is used for grounding. In Figure 1 In the figure, only the electrical circuits of the supply voltage are shown in a simplified form. Of course, a grounding circuit (not shown) is also provided, which is connected to the corresponding circuit elements (represented by the grounding symbol in the figure) and passes through the connection module (so as to connect the grounding contacts of the input terminals and the output terminals).

[0042] In addition, the connection module can have a first communication terminal 16, a second communication terminal 18 and a communication line 17. The communication line 17 connects the first communication terminal 16 and the second communication terminal 18 to each other, so that data or data signals can be transmitted or transferred from the first communication terminal to the second communication terminal (i.e., forming a loop) through the connection module. The second communication terminal 18 can be connected to the data communication terminal of the inverter. In particular, the above-mentioned embodiments can be realized, that is, the control line 11 should be guided to the connection module 20 together with the power supply line 13 in the common cable harness. In particular, the first communication terminal and the second communication terminal and the communication line are suitable for the CAN bus. According to the bus or system for data communication, the control line 11 and the communication line 17 (here simplified as a single line) have one or more signal lines or one or more wires; for example, in the case of the CAN bus, there are usually two (CAN_high, CAN_low). Therefore, the first communication terminal and the second communication terminal 16, 18 have one or more conductive contacts, terminal pins, or similar things, which are connected to the wire through the corresponding terminals. The power supply line 13 has two (or more) leads, one for the supply voltage and one for the ground voltage (these leads are connected to corresponding contacts, pins, or the like corresponding to those of the input terminal 26).

[0043] In particular, the converter circuit arrangement 22 and the safety circuit arrangement 24 or the components forming them can be arranged on a single circuit board. The circuit board can be enclosed in a housing 70, wherein the conductive connections for the input terminals 26 and the output terminals 28 are arranged in the wall of the housing or lead to the outside; for example, in the form of plug connections.

[0044] Likewise, if desired, the first communication terminal 16 and the second communication terminal 18 are arranged in the wall of the housing 70 or are guided through the wall. Optionally, the communication line 17 extends within the housing 70, and the communication line can be arranged on a circuit board or wired separately from the circuit board. Preferably, the first communication terminal 16 and the input terminal 26 are arranged together on the first side surface of the housing 70. In particular, the first communication terminal 16 and the input terminal 26 are arranged to be close to or adjacent to each other in space, so that they are integrated in a single connecting element (on the first side surface), such as a single plug connection. Therefore, the power supply line 13 and the control line 11 can be wired in a single cable harness, which can be connected to the connecting element on the first side surface via corresponding connecting elements.

[0045] The second communication terminal 18 and the output terminal 28 may also be arranged together on a second side surface (particularly different from the first side surface). The connection module 20 or its housing may also have a fastening device or a fastening element, and the converter circuit device 22 and the safety circuit device 24 or the elements constituting them are encapsulated in the housing (for example, arranged on a circuit board as described above), for example, the connection module may be fastened or mounted on the inverter by screw connection.

[0046] Figure 3 A circuit diagram of an exemplary buck converter 30 is shown. Buck converters (as shown) and their functions are known to the skilled person.

[0047] The input voltage 72 is converted by the buck converter 30 to a lower output voltage 74. The input voltage and the output voltage exist between the line at the top of the diagram and the line at the bottom of the diagram. For example, the line shown at the bottom corresponds to the ground line.

[0048] The buck converter 30 has a switch 76 (e.g., a semiconductor switch element or a transistor), an inductor 78 (coil), a capacitor 80 (capacitor) and a diode 82, wherein the output voltage 74 is the voltage of the capacitor 80. The switch 76 is alternately closed and opened (e.g., at a frequency in the range of 10kHz to 10MHz). When the switch 76 is closed, the current flowing through the inductor 78 (the electrical device connected to the output side) increases, so that the inductor 78 generates a voltage opposite to the original input voltage, which causes the output voltage to be less than the input voltage, or a buck conversion occurs. When the switch 76 is closed, the inductor 78 releases the stored energy, wherein the current flows through the load and the diode 82. Alternatively, a corresponding controlled semiconductor switch element can be used instead of the diode 82. The output voltage 74 is smoothed by the capacitor 80.

Claims

1. A connection module (20) for an inverter control unit (8) of an inverter (4) of an electric machine (2), comprising - an input terminal (26) and an output terminal (28) for a direct voltage, wherein the input terminal can be connected to an external power source (12) and the output terminal can be connected to a voltage supply terminal of the inverter control unit; a converter circuit arrangement (22) having a buck converter (30) and being arranged to convert an input voltage provided at the input terminal (26) to a lower output voltage to be provided at the output terminal (28), wherein the converter circuit arrangement (22) has an overvoltage protection circuit (40) arranged to limit the input voltage to a preset maximum input level; - a first communication terminal (16), a second communication terminal (18) and a communication line (17), wherein the first communication terminal and the second communication terminal are connected via the communication line so that data communication signals can be forwarded via the connection module; and - a housing (70), wherein the converter circuit arrangement (22) is arranged on a circuit board encapsulated in the housing, wherein the input terminal (26) and the output terminal (28) are arranged in a wall of the housing, wherein the communication line (17) extends within the housing, and wherein the first communication terminal and the second communication terminal are arranged in the wall of the housing.

2. The connection module (20) according to claim 1, wherein: The first communication terminal, the second communication terminal and the communication line are suitable for a CAN bus.

3. The connection module (20) according to claim 1 further comprises a safety circuit device (24), which is connected between the converter circuit device (22) and the output terminal (28) and is configured to limit the output voltage to a preset maximum output level.

4. The connection module (20) according to claim 3, wherein: The safety circuit arrangement (24) has a semiconductor switch (62) and a switch controller (64) which is configured to switch the semiconductor switch (62) into a non-conducting state when a maximum output voltage is exceeded.

5. The connection module (20) according to claim 3, wherein: The safety circuit arrangement (24) is provided for short-circuit protection.

6. The connection module (20) according to claim 3, wherein: The converter circuit arrangement (22) and the safety circuit arrangement (24) are arranged on the printed circuit board.

7. The connection module (20) according to claim 1, wherein: The overvoltage protection circuit (40) has at least one suppression diode (42) to limit the input voltage.

8. The connection module (20) according to claim 1, wherein: The converter circuit arrangement (22) comprises a filter circuit (50) for suppressing electromagnetic interference, the filter circuit being connected between the input terminal (26) and the buck converter (30).

9. The connection module (20) according to claim 8, wherein: The filter circuit (50) has inductors and capacitors of suitable sizes to meet the EMC requirements.

10. The connection module (20) according to claim 1, wherein: The converter circuit arrangement (22) is configured to receive an input voltage in the range of 10V to 32V, in particular approximately 24V, and / or to provide an output voltage in the range of 6V to 16V, in particular approximately 12V.

11. The connection module (20) according to claim 1, wherein: The maximum input level is in the range of 50V to 70V, in particular approximately 60V, and / or the maximum output level is in the range of 12V to 20V, in particular approximately 16V.

12. The connection module (20) according to claim 1 further comprises a fastening device, which is designed to fixedly mount the connection module (20) on the inverter control unit (8) or the motor (2); wherein the fastening device is arranged on the housing (70) of the connection module.

13. A connection system for an inverter control unit (8) of an inverter (4) of an electric machine (2), the connection system comprising a connection module (20), The connection module (20) has - an input terminal (26) and an output terminal (28) for a direct voltage, wherein the input terminal can be connected to an external power source (12) and the output terminal can be connected to a voltage supply terminal of the inverter control unit; a converter circuit arrangement (22) having a buck converter (30) and being arranged to convert an input voltage provided at the input terminal (26) to a lower output voltage to be provided at the output terminal (28), wherein the converter circuit arrangement (22) has an overvoltage protection circuit (40) arranged to limit the input voltage to a preset maximum input level; as well as a housing (70), wherein the converter circuit (22) is arranged on a circuit board, the circuit board being enclosed in the housing, wherein the input terminal (26) and the output terminal (28) are arranged in a wall of the housing; in, The output terminal (28) of the connection module (20) can be connected to the voltage supply terminal of the inverter control unit (8); as well as The connection system further comprises a power supply line (13) which is connected to an input terminal (26) of the connection module and can be connected to a power source (12).

14. The connection system according to claim 13, The connection module has a first communication terminal (16), a second communication terminal (18) and a communication line (17), wherein the first communication terminal and the second communication terminal are connected via the communication line, so that a data communication signal can be forwarded via the connection module; in, The second communication terminal (18) of the connection module (20) is connectable to a data communication terminal of the inverter control unit (8); the connection module further comprises a control line (11) connected to the first communication terminal (16) and connectable to a machine control unit (10), wherein the power supply line (13) and the control line (11) are at least partially wired in a common cable harness.

15. An arrangement comprising an electric machine (2) supplied with an alternating voltage via an inverter (4), an inverter control unit (8) for controlling the inverter, a power supply (12), a machine control unit (10) and a connection system according to claim 14, in, The output terminal (28) of the connection module (20) is connected to the voltage supply terminal of the inverter control unit, The second communication terminal (18) of the connection module (20) is connected to the data communication terminal of the inverter control unit. wherein the power supply line (13) is connected to the power source (12), and Wherein, the control circuit (11) is connected to the machine control unit (10).

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