Power supply system for a power electronic circuit

Abstract

Energy supply system for a power electronic circuit of an at least partially electrically powered motor vehicle, comprising an accumulator and an electric motor (EM) with at least one phase (U, V, W), wherein - a driver board with components arranged on it, which are configured to control the power electronic circuit, wherein predetermined components of the driver board are supplied with a supply voltage, and wherein furthermore - at least one monitoring device (10) is provided which is designed to monitor the supply voltage, and - a circuit arrangement with a switching element (5) which is arranged between at least one phase (U, V, W) of the electric motor (EM) and the driver board such that it can provide a power supply from the electric motor (EM) for one or more components of the driver board, wherein, in the event that the monitoring device (10) detects a failure or reduction of the supply voltage of one or more components of the driver board, the switching element (5) is switched by the monitoring device (10) from an open state, in which it does not provide a power supply from the electric motor (EM) for one or more components of the driver board, to a closed state, in which it provides a power supply from the electric motor (EM) for one or more components of the driver board where the supply voltage has failed or dropped.

Description

[0001] The present invention relates to the field of electromobility, in particular to power electronics modules for an electric drive.

[0002] The use of electronic modules, such as power electronics modules, in motor vehicles has increased significantly in recent decades. This is due, on the one hand, to the need to improve fuel economy and vehicle performance, and, on the other hand, to advances in semiconductor technology. Semiconductor chips are used in power electronics. These are connected in parallel to form a topological switch if the current carrying capacity needs to be increased. Semiconductor chips that are connected in parallel and are usually made of silicon or silicon carbide can be installed in individual, pre-packaged components, so-called discrete components, or together in a circuit carrier, the so-called power electronics module or power module. A high packing density must be ensured in power modules in order to avoid unwanted effects such as oscillations or overvoltages.This allows even large potential differences to be located very close to one another, which offers advantages in terms of electrical behavior. In addition, the parallelized chips are packaged locally close to one another to reduce, for example, differences in dynamic current distribution.

[0003] In the event of a component malfunction, failure, or drop in supply voltage, the entire power electronic circuit may fail.

[0004] US 2023 / 0 029 680 A1 describes a device for emergency power supply of a control unit for an inverter by a high-voltage direct current source.

[0005] Therefore, the object of the invention is to provide a power supply in the event of a failure or a drop in the supply voltage at one of the components of the driver board of the power electronic circuit.

[0006] This problem is solved by the features of the independent claims. Advantageous embodiments are the subject of the dependent claims.

[0007] A power supply system for a power electronic circuit of an at least partially electrically driven motor vehicle is proposed, comprising a rechargeable battery and an electric motor with at least one phase, wherein a driver board is provided with components arranged thereon which are designed to control the power electronic circuit, wherein predetermined components of the driver board are supplied with a supply voltage, and wherein at least one monitoring device is provided which is designed to monitor the supply voltage, and a circuit arrangement with a switching element which is arranged between at least one phase of the electric motor and the driver board in such a way that it supplies power from the electric motor for a or several components of the driver board, wherein in the event that the monitoring device detects a failure or a reduction in the supply voltage of one or more components of the driver board, the switching element is switched by the monitoring device from an open state in which it provides no power supply from the electric motor for one or more components of the driver board, to a closed state in which it provides power supply from the electric motor for one or more components of the driver board for which the supply voltage has failed or dropped.

[0008] According to an alternative not according to the invention, the energy supply can also be provided via an accumulator of the motor vehicle instead of via the electric motor.

[0009] In one embodiment, it is provided that the monitoring device, in the event that it detects a failure or a reduction in the supply voltage, outputs an emergency signal to the switching element, which is designed to then change its state.

[0010] In one embodiment, the power electronic circuit comprises a topological switch with at least two power semiconductors connected in parallel to one another, as well as at least one driver supplied with a supply voltage, which is configured to control the power semiconductors.

[0011] In one embodiment, a voltage divider and at least one diode as well as the switching element are arranged between the electric motor and the driver.

[0012] In one embodiment, the energy supply system is part of an electronic module of the motor vehicle. Furthermore, a motor vehicle is provided, comprising the energy supply system.

[0013] Furthermore, a method is provided for providing an energy supply for a power electronic circuit of an at least partially electrically driven motor vehicle, comprising an accumulator and an electric motor with at least one phase, wherein a driver board is provided with components arranged thereon which are designed to control the power electronic circuit, wherein predetermined components of the driver board are supplied with a supply voltage, wherein in the event that a failure or a reduction in the supply voltage of one or more components of the driver board is detected, an energy supply is provided by the electric motor for the one or more components of the driver board for which the supply voltage has failed or dropped.

[0014] Further features and advantages of the invention will become apparent from the following description of exemplary embodiments of the invention, with reference to the figures of the drawing, which illustrate details of the invention, and from the claims. The individual features can be implemented individually or in combination in a variant of the invention.

[0015] Preferred embodiments of the invention are explained in more detail below with reference to the accompanying drawings. Fig. 1 shows a basic structure of a power electronic circuit with a defective power semiconductor according to the state of the art. Fig. 2 shows a basic structure of a power supply system for a power electronic circuit according to an embodiment of the present invention.

[0016] In the following descriptions of the figures, the same elements or functions are provided with the same reference symbols.

[0017] The present invention relates to a power supply system for a power electronic circuit such as an inverter for use in the automotive sector, in particular for applications in at least partially electrically powered vehicles.

[0018] According to the following explanations, a vehicle's accumulator or the energy source of the electric motor EM (also referred to as an electric motor) is connected to the driver supply as a backup, i.e., used to replace a failed or dropped supply voltage for components of the driver board that require a supply voltage. This creates a redundant power supply (current and / or voltage). Only the embodiment variant in which the electric motor serves as an emergency power supply is in accordance with the invention.

[0019] In all embodiments, the power electronic circuit comprises at least one topological switch 100 formed from at least two power semiconductors 1, 2 connected in parallel. These are advantageously formed as a MOS-FET (as shown in the figures) or an IGBT, although other transistors suitable for the intended application may also be used. Furthermore, the power electronic circuit comprises a driver board with various components such as a driver 3 configured to control the power semiconductors 1, 2, as well as an associated gate resistor R_gate connected in series, as shown in Fig. 1. A load 4 is also shown to supply current to the power semiconductors 1, 2. The HV voltage U1 is also shown. This setup is a standard setup according to the state of the art and in Fig. 1. The components of the driver board can be passive or require a supply voltage (HV or LV), such as driver 3.

[0020] For example, in the event of a defective power semiconductor 2 in the power electronic circuit, the power supply of driver 3 may collapse (fail) or its power source (provision of the supply voltage) may no longer be sufficient (drop) to establish the safe state, i.e., to switch all power semiconductors 1, 2 of a topological switch on. The invention serves to avoid such a situation as far as possible by providing a redundant power source to continue supplying power to components of the power electronic circuit even in the event of a fault (failure / drop in the supply voltage).

[0021] The prerequisite for this is that it is detected that the supply voltage of one of the components of the driver board of the power electronic circuit has failed or dropped. For this purpose, a voltage monitor in the form of a monitoring device 10 is provided, which also serves to issue an emergency signal EC if a failure or drop in the supply voltage is detected. In response to this emergency signal EC, the electric motor EM or the accumulator is then used as a backup energy source.

[0022] Voltage monitoring can be implemented using a suitable component, such as a Schmitt trigger. A timing element (e.g., an RC element) can also be provided, which only issues the emergency signal EC after a specified time. This ensures that only an actual error is recognized as an error and avoids triggering an unnecessary reaction.

[0023] In the event that the monitoring device 10 detects a failure or drop in the supply voltage, an emergency signal EC is issued and the electric motor EM (preferably) or the accumulator (high-voltage storage device) of the at least partially electrically powered motor vehicle is connected to the driver board as an additional energy source. Fig. Figure 2 shows an example in which the electric motor EM is connected as a power source to the driver 3 of the driver board to supply it. In this case, a voltage divider R1, R2 is also advantageously provided, which is connected to the driver 3. Even when the power is supplied via the accumulator, a voltage divider R1, R2 is advantageously provided, which serves to provide a lower voltage than the high voltage to the driver 3.

[0024] In order to provide the driver board with a redundant power supply (EM or accumulator), a circuit arrangement with a switching element 5 is provided. In the event that the supply voltage of a component of the driver board (in the embodiment shown, the driver 3) fails or drops and an emergency signal EC is issued, this switching element electrically connects the accumulator or the electric motor EM to the component, here the driver 3, and thus supplies it with power. The switching element 5 is normally open, i.e. when no power is supplied via the accumulator or the electric motor EM, and is closed when the accumulator or the electric motor EM is to be used as a power supply, in order to provide the energy flow. The same principle is applied to all components for which it is detected that their power supply fails or drops.

[0025] In case the electric motor EM serves as the energy source, the energy supply of the component(s) can be provided via one or more of the AC phases U, V, W of the electric motor EM. Fig. Figure 2 shows the case where the power supply is via a single phase, here AC phase V is selected as an example. For this purpose, a diode D1 is additionally provided as a rectifier between the switching element 5 and the AC phase V used by the electric motor EM. Diode D1 is connected with its anode to the AC phase V and with its cathode to the switching element 5. The switching element 5 receives its signal to use the electric motor EM or the accumulator as an energy source simultaneously from the EC signal. Thus, the driver supply is supplied with energy from the rotating machine and can supply the component(s) with energy again.

[0026] For example, in the case of a defective power semiconductor 2, the remaining power semiconductors 1 can be returned to the conductive state by the driver 3 in order to support the defective topological switch.

[0027] If two or more phases U, V, and W are used, a suitable diode rectifier, e.g., a three-phase one, can be used instead of a single diode D1, tailored to the driver requirements. The voltage divider R1, R2 is connected downstream of the diode D1 or a diode rectifier.

[0028] The power electronic circuit is part of an electronic module (power electronic module). An electronic module within the scope of this invention serves to operate an electric drive of a vehicle, in particular an electric vehicle and / or a hybrid vehicle, and / or electrified axles. The electronic module comprises a DC / AC inverter. It can also comprise or be part of an AC / DC rectifier, a DC / DC converter, a transformer, and / or another electrical converter or a part of such a converter. In particular, the electronic module serves to supply current to an electric machine, for example, an electric motor and / or a generator. A DC / AC inverter preferably serves to generate a multi-phase alternating current from a direct current generated by means of a DC voltage from an energy source, such as a battery. List of reference symbols 1 power semiconductor (transistor) 2 defective power semiconductors (transistors) 3 drivers 4 Last 5 Switching element 10 Monitoring device 100 topological switches R_gate gate resistance R1, R2 voltage divider D1 diode EM electric motor U, V, W AC phases U1 voltage EC emergency signal

Claims

[1] Energy supply system for a power electronic circuit of an at least partially electrically driven motor vehicle, comprising an accumulator and an electric motor (EM) with at least one phase (U, V, W), wherein - a driver board is provided with components arranged thereon which are designed to control the power electronic circuit, wherein predetermined components of the driver board are supplied with a supply voltage, and wherein furthermore - at least one monitoring device (10) is provided which is designed to monitor the supply voltage, and - a circuit arrangement with a switching element (5) which is arranged between at least one phase (U, V, W) of the electric motor (EM) and the driver board in such a way that it can provide a power supply from the electric motor (EM) for one or more components of the driver board, wherein in the event that the monitoring device (10) detects a failure or a reduction in the supply voltage of one or more components of the driver board, the switching element (5) is switched by the monitoring device (10) from an open state in which it provides no power supply to the electric motor (EM) for one or more components of the driver board, to a closed state in which it provides a power supply from the electric motor (EM) for one or more components of the driver board for which the supply voltage has failed or dropped. [2] Power supply system according to claim 1, wherein the monitoring device (10), in the event that it detects a failure or a reduction in the supply voltage, outputs an emergency signal (EC) to the switching element (5), which is arranged to change its state thereupon. [3] Energy supply system according to claim 1 or 2, wherein the power electronic circuit comprises a topological switch (100) with at least two power semiconductors (1, 2) connected in parallel to one another, and at least one driver (3) supplied with a supply voltage, which is designed to control the power semiconductors (1, 2). [4] Energy supply system according to one of the preceding claims, wherein a voltage divider (R1, R2) and at least one diode (D1) as well as the switching element (5) are arranged between the electric motor (EM) and the driver (3). [5] Energy supply system according to one of the preceding claims, which is part of an electronic module of the motor vehicle. [6] Motor vehicle comprising an energy supply system according to one of the preceding claims. [7] Method for providing an energy supply for a power electronic circuit of an at least partially electrically driven motor vehicle, comprising an accumulator and an electric motor (EM) with at least one phase (U, V, W), wherein a driver board is provided with components arranged thereon which are designed to control the power electronic circuit, wherein predetermined components of the driver board are supplied with a supply voltage, wherein in the event that a failure or a reduction in the supply voltage of one or more components of the driver board is detected, an energy supply is provided by the electric motor (EM) for the one or more components of the driver board for which the supply voltage has failed or dropped.

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