WO2019162016A1

WO2019162016A1 - Setting a specific operating state of an electrical machine of a vehicle

Info

Publication number: WO2019162016A1
Application number: PCT/EP2019/051482
Authority: WO
Inventors: Alexander BIRK; Manuel Schwab
Original assignee: Zf Friedrichshafen Ag
Priority date: 2018-02-22
Filing date: 2019-01-22
Publication date: 2019-08-29
Also published as: DE102018202662A1

Abstract

The invention presents an apparatus (110) for setting a specific operating state of an electrical machine (115) of a vehicle (100), wherein the apparatus (110) has an inverter (130) for supplying electrical energy which is provided by a high-voltage electrical system (120) of the vehicle (100) to the electrical machine (115). The apparatus (110) further comprises an actuating unit (155) for applying a control signal (160, 160') to at least one switch (135, 135') of the inverter (130) in order to move the switch (135, 135') of the inverter (130) to a switching state which corresponds to the specific operating state of the electrical machine (115), wherein the actuating unit (155) is coupled to a low-voltage electrical system (150) and to the high-voltage electrical system (120), and wherein the actuating unit (155) is designed in order to generate the control signal (160, 160') using energy directly from the high-voltage electrical system (120).

Description

Setting a specific operating state

an electric machine of a vehicle

The present invention relates to an apparatus and a method for setting a predetermined operating state of an electric machine of a vehicle according to the main claims.

An inverter-driven electric machine, especially a PSM (PSM = permanent-magnet synchronous machine), as used in hybrid and electric vehicles, should reach a safe state as a safety-critical subsystem in the event of a fault. This is typically an operating point where the electric machine generates a reduced torque that can not destabilize the vehicle. The safe state of a permanent-magnet synchronous machine (PSM), depending on the operating point, an active short-circuit mode or an inverter lock. In the active short-circuit mode, usually at least two, but more favorably all motor windings are short-circuited with the electrical switches of the inverter. This mode represents the safe system state for a PSM and can be established with different switch positions of the inverter. In the inverter lock, the switches of the inverter (all) are opened, so that the motor windings of the electrical machine are not energized by the inverter.

As a rule, a B6 bridge circuit is used for the inverter. As a switch of such a bridge circuit, for example, an IGBT diode combination or a MOSFET can be used. The active short-circuit mode (AKS), also known as active short-circuit, is typically produced by simultaneously closing all high-side switches (HS) or alternatively all low-side switches (LS). The switches of the respective opposite side remain open. This mode is then also called three-phase or in a multiphase system full-phase short-circuit mode.

Usually, only one of the two switch positions is used for the active short-circuit mode. This can be implemented very easily by hardware. Alternatively, a changing active short-circuit mode can be used. This is regularly changed between two possible switch positions by means of a corresponding control of the switch.

In order to achieve the safe state even in the event of a failure of the electrical system of the vehicle, which is usually designed as a low-voltage network with an operating voltage of, for example, 12 volts, usually a voltage converter is used. This converts a voltage available in a high voltage network and makes it available to the electrical system. Such a voltage converter continues to supply the low-voltage network with voltage even when the vehicle electrical system drops. The high voltage network is provided here primarily as an energy source for an electric traction motor of the vehicle and has a voltage of, for example, several hundred volts in order to provide the traction motor with sufficiently high electrical energy to propel the vehicle can.

Against this background, the present invention provides an improved apparatus and an improved method for setting a (pre-) certain operating state of an electric machine of a vehicle according to the main claims. Advantageous embodiments will become apparent from the dependent claims and the description below.

With the approaches suggested here, a device for setting a specific operating state of an electric machine of a vehicle is presented, in particular a predetermined operating state. The device has the following features:

An inverter for supplying an electric power supplied from a high-voltage network of the vehicle to the electric machine.

A drive unit for applying at least one switch of the inverter with a control signal to bring the switch in a (pre) certain operating state of the electric machine corresponding switching state. The control unit is equipped with a low-voltage network and the high-voltage network coupled. The drive unit is in this case designed to generate the control signal using energy directly from the high-voltage network.

In the present case, a switch may, for example, be understood as a subelement of a bridge or a half bridge of the inverter. As a switch, for example, an IGBT or a MOSFET can be used.

Under a (pre-) certain operating state of the electric machine is understood in particular a predetermined safe state of the electric machine. Such a (pre-) certain operating state of the electrical machine can therefore be understood to mean either an active short circuit of windings / phases of the electrical machine (active short circuit mode, AKS), or a separation of the (all) windings / phases of the electric machine from one Energy source to be understood, or an inverter lock (opening all switches of the inverter) are understood. Under such a (pre-) certain operating condition can thus be understood a desired operating condition. Which possible specific operating state is to be set is decided in particular as a function of the current operating state of the device (actual operating state) and / or an error.

In particular, a switching state means a closed state of the switch (i.e., a state in which the switch is conductive) or an open state of the switch (i.e., a state in which the switch is not conductive).

In the present case, a low-voltage network can be understood to be an electrical network in which a lower voltage level exists than in the high-voltage network. For example, the low-voltage network can be used to transmit sensor and / or control signals. In contrast, the high voltage network can be used to supply electrical energy that is converted by the inverter and thus provided to the electrical machine for its operation. For example, the high-voltage network may have a voltage of several hundred volts and be connected to a (high-voltage) battery or a corresponding accumulator. In particular, the high voltage network and the low-voltage network so separated from each other electrically that damage to components of the low-voltage network is prevented by the electrical voltage present in the high-voltage network.

The approach presented here is based on the knowledge that the at least one switch of the inverter can be controlled by the drive unit using energy directly from the high-voltage network, without the use of electrical energy from the low-voltage network is required for this purpose. The drive unit is therefore connected directly to the high-voltage network.

The direct connection of the drive unit to the high-voltage network ensures that even if a failure or when starting the vehicle electrical system, which usually forms the low-voltage network, the at least one switch of the inverter can be brought into a specific switching state very quickly. As a result, the electric machine can be brought into a safe state as a result. By using the energy directly from the high-voltage network, which is usually available continuously and stably, it is thus possible to design an operation of the electrical machine safely even in borderline situations. In this way it can also be avoided that in case of failure or startup of the low-voltage network, an undefined switching state of the switch of the inverter is present, which can lead to a critical operating state of the electrical machines.

The device for setting the specific operating state of the electric machine may be an electrical device which processes electrical signals, for example sensor signals, and outputs control signals in dependence thereon. The device may have one or more suitable interfaces, which may be formed in hardware and / or software. For example, in a hardware configuration, the interfaces may be part of an integrated circuit in which functions of the device are implemented. The interfaces may also be their own integrated circuits or at least partially consist of discrete components. In the case of a software training, the editing may be software modules that are present for example on a microcontroller in addition to other software modules. The same applies to the drive unit.

The device for setting the specific operating state can be designed to generate the specific operating state in the event of an error. Accordingly, the drive unit is then designed to generate the control signal in the event of a fault using energy directly from the high-voltage network. Such an error case can be, for example, an unsuitable operation of the electrical machine and / or the low-voltage network, such as, for example, a (complete or partial) failure of a vehicle electrical system designed as a low-voltage network. Such an error case is therefore outside normal operation. The criteria for the existence of such an error case may have been specified in advance. A normal operation is understood to mean, in particular, a designated field-oriented control (FOS) or a field-oriented control (FOR) of the electrical machine by means of the inverter.

The device for setting the specific operating state may have a further (second) drive unit, which serves for controlling the at least one switch of the inverter in normal operation. This further drive unit is preferably designed conventionally. It therefore does not need to be discussed in more detail on this further drive unit. The energy for controlling the at least one switch in normal operation is then taken in particular directly from the low-voltage network.

It can therefore be provided that the at least one switch of the inverter is driven in normal operation by signals from the low-voltage network. Accordingly, it can be provided that the aforementioned (first) drive unit for setting the specific operating state of the electrical machine is used only outside of normal operation, that is, for example, in certain emergency situations. Then it is necessary to insert the (pre-) specific operating state. The aforementioned (first) drive unit is accordingly designed as an emergency drive unit. The device for setting the specific operating state may include or be a control device of the inverter. Such a control device may have the aforementioned (first) drive unit. Such a control unit can also have the further (second) drive unit for normal operation.

An embodiment in which the drive unit has a linear regulator and / or a voltage divider for converting energy from the high-voltage network to provide the control signal is advantageous. Such an embodiment offers the advantage of being able to provide the corresponding control signal for actuating the switch of the inverter with technically simple means and very quickly.

Also, according to a further embodiment, the inverter comprises a bridge circuit, in particular a B6 bridge circuit, wherein the switch controlled by the drive unit then forms a subsection of the bridge circuit. Such an embodiment offers the advantage of advantageously combining already existing components with one another in order to be able to quickly implement the safety function for the electrical machine.

According to a further embodiment, the inverter may have at least one second switch in addition to the aforementioned (first) switch. The drive unit is designed to act on the at least one second switch of the inverter with a second control signal to bring the second switch in a (pre) certain operating state corresponding switching state. The drive unit is designed to also generate the second control signal using energy directly from the high-voltage network. Here, the switching state of the second switch may correspond to the switching state of the aforementioned (first) switch. For example, the switching states may be the same or they may be inverted to each other. Such an embodiment offers the advantage of being able to ensure the safety function for the electric machine quickly and reliably by means of the corresponding activation of the second switch. The first switch and the second switch may form a half-bridge of the inverter. One of the first and second switches then forms a high-side switch and the other of the first and second switches then forms a low-side switch. The device may be configured to control, analogously to the described procedure, also other or all switches of the inverter for setting the specific operating state of the electrical machine.

In one embodiment, the drive unit is designed to also generate the control signal (s) in dependence on a voltage level present in the low-voltage network. In particular, the drive unit is designed to generate the control signal (s) when the voltage level in the low-voltage network falls below a predefined low-voltage level (= error case). For example, the control signal (s) may be provided when the voltage level in the low voltage network is less than five volts, for example, zero volts. Thus, it can be ensured that the at least one switch of the inverter is brought into a defined switching state in the event of failure of the vehicle electrical system designed as a low-voltage network and thus does not permit safety-critical operation of the electrical machine.

According to a further embodiment, the drive unit may be designed to generate the control signal or signals in dependence on a voltage level of the high-voltage network. Such an embodiment offers the advantage of being able to set a specific switching state of the switch as a function of a currently present voltage level of the high-voltage network. Thus, for example, depending on the voltage level of the high-voltage network, a selection of one of several safety functions for the operation of the electrical machine is possible. In this way, a very flexible adjustment of the safety function of the electrical machine in dependence on the existing voltage level of the high-voltage network can be achieved.

Particularly advantageous is an embodiment in which the drive unit is designed to generate the control signal or signals in such a way that the at least one Switch is closed when the voltage level in the high voltage network is greater than a first high voltage level (= first error case). Alternatively or additionally, the drive unit is designed to generate the control signal or signals such that the at least one switch is open when the voltage level in the high-voltage network is less than a second high-voltage level (= second fault case). In particular, the first high voltage level is greater than the second high voltage level.

Such an embodiment offers the advantage of being able to specify an active short circuit of the windings / phases of the electrical machine when the voltage of the high-voltage network is greater than a certain level (first high-voltage level). In such a case, sufficient energy can be present in the high-voltage network in order to be able to bring the electrical machine into certain critical operating states. However, if the voltage level in the high voltage network is low compared to the level mentioned above (second high voltage level), it may be assumed that there is also a fault in the high voltage network. The energy in this high-voltage network may then no longer be sufficient to bring the electrical machine into a safety-critical state. In this case, it may be sufficient to switch the inverter into the switching state of the inverter lock and accordingly to open the at least one switch.

In accordance with another embodiment, the drive unit may be configured to block drive signals from the low voltage grid to control the switch when the control signal is generated using energy directly from the high voltage grid. Such blocking may, for example, be non-forwarding. Such control signals come in particular from the above-mentioned further (second) drive unit, which is used for normal operation. Such an embodiment offers the advantage of possibly suppressing incorrectly determined drive signals from the low-voltage network. Thus, the control of the at least one switch is not hindered in the corresponding switching state and ensures reliability of the electrical machine. The above-mentioned advantages can also be realized in one embodiment as a method for setting a predetermined operating state of an electric machine of a vehicle. This is done using the device presented here. The method comprises the following steps:

• Supply of electrical energy from the high-voltage network to the drive unit.

Generating a control signal for driving the switch of the inverter using the energy supplied directly from the high-voltage network to bring the switch of the inverter in a (pre) certain operating state of the electric machine corresponding switching state.

A computer program product with program code which can be stored on a machine-readable carrier such as a semiconductor memory, a hard disk memory or an optical memory and is used to carry out the method according to one of the embodiments described above if the program is installed on a computer or a device is also of advantage is performed.

The invention will be described by way of example with reference to the accompanying drawings. Show it:

Figure 1 is a schematic representation of a vehicle in which an electrical system with a device and an electric machine is arranged.

FIG. 2 is a block diagram representation of a signal flow; FIG.

3 is a schematic representation of a device according to an embodiment;

4 is a flowchart of a method for setting a predetermined operating state of an electric machine of a vehicle.

In the following description of preferred embodiments of the present invention are for the illustrated in the various figures and similar elements used the same or similar reference numerals, wherein a repeated description of these elements is omitted.

1 shows a schematic representation of a vehicle 100, in detail of a motor vehicle, in which an electrical system 105 with a device 110 according to an exemplary embodiment of the present invention and an electric machine 115 are arranged. The electric machine 115 may be, for example, a traction motor, by means of which the vehicle 100 can be driven, that is, can be moved. For this purpose, the electrical machine 115 is supplied with electrical energy from a high-voltage network 120, which has a high-voltage network energy storage 125, for example a high-voltage battery. For example, the high voltage network energy storage 125 may provide a (DC) voltage of several hundred volts, for example, 600 volts to 800 volts. This is provided to an inverter 130.

The inverter 130 comprises, for example, a bridge circuit with a plurality of switches 135, of which only two are exemplarily provided with a reference symbol in FIG. 1 (reference numerals 135 and 135 '). By appropriate activation of the switches 135, an alternating voltage can be provided on three phase lines 140 from the energy provided by the high-voltage network 120. With this 3-phase AC voltage, the electric machine 115 can now be operated as an electric motor, in particular as a traction motor of the vehicle 100.

Furthermore, electrical energy can be supplied to a voltage converter 145 (for example a switching power supply) from the high-voltage network 120. The voltage converter 145 provides electrical energy to a low-voltage network 150 of the vehicle 100, which has a lower electrical voltage than the electrical voltage in the high-voltage network 120. Specifically, the low-voltage network 150, for example, work as a vehicle electrical system with the voltages of 12 volts, 24 volts or 48 volts used in automotive technology and correspondingly supply electrical energy to microelectronic components, such as integrated circuits, microcontrollers or the like. Usually, the low-voltage network 150 actuates the switches 135, 135 'of the inverter 130 by means of PWM signals 152. These PWM signals 152 are generated by a conventional drive unit, not shown in detail, in the low-voltage network 150, which is used for the normal operation of the device 110 , However, this is particularly problematic when the low-voltage network 150 is not yet supplied by the voltage converter 145 with electrical energy at a sufficient voltage during commissioning of the vehicle 100 or if a defect in the low-voltage network 150 occurs and thus the function of controls of the low-voltage network 150 not more guaranteed (= error case). In this case, for example, one or more of the switches 135, 135 'of the inverter 130 may fall into an undefined switching state, so that possibly the electric machine 115 is subjected to a high electrical power and enters a safety-critical operating state. Then she can, for example, perform an unwanted jerky movement. Although such a case will occur only in very short periods of time, this may be sufficient to put the electric machine 115 and / or the vehicle 100 in the above-mentioned critical operating condition.

In order to avoid such a safety-critical operating state of the electric machine 115, the device 110 has a drive unit 155 which will be described in more detail below. This drive unit 155 is connected between the low-voltage network 150 on the one hand and the inverter 130 or at least one of the switches 135, 135 'of the inverter 130 on the other hand. The drive unit 155 is further connected to the high voltage network 120 to receive high voltage power from the high voltage network 120.

The drive unit 155 is further configured to connect at least one, preferably all, of the switches 135, 135 'using a respective control signal 160,

160 ', which is generated directly using the electrical energy from the high voltage network 120. In this way, in the event of a failure or a state of the low-voltage network 150 which is not yet ready for operation, it can be ensured that the at least one switch 135, 135 'is plugged into a circuit. desired switching state can be brought, which is required for the specific operating condition.

An advantage of the use of electrical energy directly from the high-voltage network 120 is that this energy is usually reliable and stable ready and thus the control signal 160, 160 'is very quickly available. This can be done in the range of microseconds, for example. Thus, a significant time advantage over the use of signals from the low voltage network 150 (PWM signals 152) can be realized.

In particular, the control signal 160 activates the (first) switch 135 and the control signal 160 'activates the (second) switch 135' according to the determined operating state, for example to produce a short circuit (active short-circuit mode) between at least two of the phase lines 140 and thus at least short circuit two windings / phase lines 140 of the electric machine 115.

In summary, it should be noted that with the approach presented here thus a hardware circuit for initiating a safe state in the electric machine 115 is described in the event of an error.

2 shows a block diagram representation of a signal flow to the device 110 for setting the predetermined operating state of the electric machine 115. Here, by means of a motor control unit 200 which is operated with the low-voltage network 150, at least one PWM signal 152 for controlling at least one of the switches 135 , 135 'of the inverter 130. This PWM signal 152, which has the voltage level of the low-voltage network 150, is amplified by a driver unit 210 and transferred to a corresponding input of an interface 215 to the high-voltage network 120.

The PWM signal 152 is converted by the driver unit 210 into an amplified PWM signal 152 'and supplied to a booster unit 220 to obtain a re-amplified PWM signal 152 ". The one supplied by the booster unit 220 and again amplified PWM signal 152 "is then supplied to the device 110. By using the device 110 in the region or at least with energy of the high-voltage network 120, it is not necessary to provide the low-voltage network 150 with voltage in the event of an error.

The again amplified PWM signal 152 "is suppressed, for example, directly after the booster unit 220, in the event of a fault in the low-voltage network 150. The at least one switch 135, 135 'of the inverter 130 (here, by way of example, the switch 135) is then driven using the control signal 160 generated with energy from the high-voltage network 120. For this purpose, the gate or the base of this switch 135 is charged to a defined electrical potential, so that the switch 135 is selectively opened or closed and remains in this switching state. Thus, the specific operating state of the electric machine 115 is generated.

For this purpose, the device 110 is embodied as a hardware circuit (hardware control module). It is fed directly from the high voltage network 120.

The device 110 can realize the following functions: First, a power supply of the device 110 can be realized from the high voltage network 120 with minimum turn-on latency (in the range of a few microseconds), since no voltage converter 145 is required to switch the switch 135 into the switching state for the particular operating state bring. Furthermore, an evaluation of the low-voltage, so the voltage level of the low-voltage network 150. Alternatively or additionally, an evaluation of the high-voltage, that is the voltage level of the high-voltage network 120. Alternatively or additionally, blocking the PWM signals 152, 152 ', 152 " done to avoid an undefined switching state of the switch 135. Also, a certain operating point-dependent safe operating state (short-circuit mode or inverter lock) depending on the voltage level in the high-voltage network 120 and / or low-voltage network 150 can be requested by a corresponding control signal 160. FIG. 3 shows a schematic representation of a device 110 according to one exemplary embodiment. The device 1 10 includes, for example, a voltage converter 300 for the electrical voltage of the control signal 160. This voltage converter 300 may be configured as a linear regulator and / or as a voltage divider. Between a high voltage network input terminal 305 and a first tap point AP1, a voltage divider 310 is provided with six ohmic resistors connected in series. Further, in this voltage converter 300, a series circuit 315 of three switches (exemplified as transistors) is provided. The base terminal of the first switch is connected to a tap point after the first two resistors of the voltage divider 310 (from the high voltage power input terminal 305). The base terminal of the second switch is connected to a tap point after the first four resistors of the voltage divider 310 (viewed from the high voltage power input terminal 305). The base terminal of the third switch is connected via an ohmic resistor to the first tapping point AP1. The controlled output of the third switch of the series circuit 315 provides, via an ohmic resistance, the control signal 160 which is applied to the gate of the switch 135 (exemplified as IGBT). The control signal 160 is further connected via a capacitor and a resistor to a ground terminal. Furthermore, an anode of a diode, whose cathode is connected to the first tap point AP1, is also connected to this ground connection. The switch 135 can be understood with this additional circuit as a switching element 320 of the inverter 130.

In order to be able to carry out the evaluation of the voltage level of the high-voltage network 120, a high-voltage evaluation unit 330 is provided. This high voltage evaluation unit 330 includes an evaluation switch (exemplified as IGBT) connected between the first tap point AP1 and the ground terminal. Furthermore, in the high-voltage evaluation unit 330, a second tap point AP2 is provided, which is coupled via an ohmic resistance of the voltage divider 310 to the first tap point AP1. The second tap point AP2 is coupled via an ohmic resistance to the control terminal of the evaluation switch, wherein a cathode of a diode between see this control terminal of the evaluation switch and the ground terminal is also coupled to the control terminal of the evaluation switch. The second tap point AP2 is further connected via a voltage divider to the ground terminal. Another evaluation switch is coupled in the form of another switch (exemplified as a transistor) between the control terminal of the evaluation switch and the ground terminal. The control terminal of the further evaluation switch is coupled to a tapping point between the resistances of the second tapping point AP2 and the ground terminal. As a result, the voltage level of the high-voltage network 120 can now be evaluated in accordance with the following description, and a corresponding control signal 160 can be output by the device 110.

Furthermore, a low-voltage evaluation unit 340 of the device 110 is also provided. Through these, a voltage level of the PWM signal 152 or 152 'or 152 "can be monitored, or a control signal 160 derived from this voltage level can be generated. For this, the low voltage evaluation unit 340 includes a low voltage evaluation switch (exemplified as IGBT) connected between the first tap point AP1 and the ground terminal. The control terminal of the low-voltage evaluation switch is connected to the ground terminal via an ohmic resistor and a capacitance connected in parallel with it. Furthermore, this control terminal is connected to an input terminal 345 of the low-voltage evaluation unit 340 via a series connection of an ohmic resistor, a diode which is connected in the forward direction to the low-voltage evaluation switch, and a capacitor. At the input terminal 345 is then the PWM signal 152 or 152 'or 152 "on.

The provision of the control signal 160 can thus take place in dependence on a voltage level in the low-voltage network 150 and additionally or alternatively on a voltage level in the high-voltage network 120. In particular, when the control signal 160 is generated, activation or deactivation of the switch 135 with a hysteresis in the device 110 depending on the voltage level of the high-voltage network can be implemented as a function module. Thereby, for example, at a high voltage level less than X, the switch 135 may be opened and kept open to implement an inverter lock. On the other hand, at a high voltage level greater than Y, the switch 135 may be closed and closed to realize an active short-circuit mode. The (high voltage level) values X and Y can be made selectable in order to be able to implement a simple control of the electric machine 115, depending on the type of vehicle 100 and / or the electric machine 115.

It is furthermore advantageous that the at least one switch 135 for an active short-circuit mode (AKS) of the electric machine 115 is closed when both the voltage level in the high-voltage network 120 is above the first high-voltage level Y and the voltage level of the low-voltage network 150 is below a threshold value (FIG. of, for example, 5 volts), in particular at 0 volts. Such an embodiment may be technically very easily imaged by the use of an AND gate. In the case of the AND gate, for example, a comparator output of a comparator is present as the first input for comparing whether the voltage level in the high-voltage network 120 is above the first high-voltage threshold value Y. And in the case of the AND gate, a negated voltage value of the low-voltage network 150 is present as the second input. It is assumed here that the active short-circuit mode (AKS) should then be set if in the low-voltage network actually only a voltage value of 0 volts is present, otherwise a comparator with a corresponding wiring of the inputs would also have to be used here.

Alternatively, or in addition, the switch 130, 135 'may be opened for an inverter lockout of the inverter 130 when both the voltage level in the high voltage grid 120 is less than the second high voltage level X and the voltage level of the low voltage grid 150 is below a threshold (eg, 5 volts) ), in particular at 0 volts. Such an embodiment may be technically very easily imaged by the use of an AND gate. In the AND gate is then as the first input, for example, a comparator output of a comparator, for comparing whether the Voltage level in the high voltage network 120 is below the second high voltage threshold X. And in the case of the AND gate, a negated voltage value of the low-voltage network 150 is present as the second input. In this case, it is assumed that the inverter blocking should then be set if in the low-voltage network actually only one voltage value of 0 volt is present, otherwise a comparator with a corresponding wiring of the inputs would also have to be used here.

4 shows a flowchart of an embodiment of the method 400 presented here for setting the predetermined operating state of the electric machine 1 15 using the device 1 10 presented here. The method 400 comprises a step 410 of supplying electrical energy from the high-voltage network 120 to the Drive unit 155. And the method 400 includes a step 420 of generating the control signal 160 to drive the switch 135 of the inverter 130 using the power supplied directly from the high voltage network 120 to switch the switch 135 to a predetermined operating state of the electric machine 1 15 To bring switching state.

If an exemplary embodiment comprises a "and / or" link between a first feature and a second feature, this can be read so that the embodiment according to one embodiment, both the first feature and the second feature and according to another embodiment, either only the first Feature or only the second feature.

REFERENCE CHARACTERS

100 vehicle

105 electrical system

110 device

115 electric machine

120 high voltage network

125 high voltage network energy storage

130 inverters

135, 135 'switch

140 phase lines

145 voltage transformers

150 low voltage grid

152, 152 ', 152 "PWM signal

155 control unit

160, 160 'control signal

200 engine control unit

210 driver unit

215 interface

220 booster unit

300 voltage transformers

305 high voltage power input connector

310 voltage divider

315 series connection

320 switching element

330 high voltage evaluation unit

340 low-voltage evaluation unit

345 Input connection of the low voltage evaluation unit

AP1 first tap point

AP2 second tap point 400 A method for setting a predetermined operating state of an electric machine of a vehicle

410 step of delivering

420 step of creating

Claims

claims

A device (110) for setting a specific operating state of an electric machine (115) of a vehicle (100), the device (110) having the following features:

an inverter (130) for supplying electrical power supplied from a high voltage network (120) of the vehicle (100) to the electric machine (115); and

a drive unit (155) for supplying at least one switch (135) of the inverter (130) with a control signal (160) for switching the switch (135) of the inverter (130) to a switching state corresponding to the determined operating state of the electrical machine (115) bring,

wherein the drive unit (155) is coupled to a low voltage network (150) and the high voltage network (120), and

wherein the drive unit (155) is configured to generate the control signal (160) using power directly from the high voltage network (120).

2. Device (110) according to claim 1, characterized in that the drive unit (155) has a linear regulator for converting energy from the high-voltage network (120) for providing the control signal (160).

3. Device (110) according to one of the preceding claims, characterized in that the inverter (130) comprises a bridge circuit, wherein the driven by the drive unit (155) switch (135) forms a portion of the bridge circuit.

4. Device (110) according to one of the preceding claims, characterized in that the inverter (130) has at least one second switch (135 ') and wherein the drive unit (155) for acting on the at least second switch (135') of the inverter ( 130) is formed with a second control signal (160 ') in order to bring the second switch (135') of the inverter (130) into a switching state corresponding to the predetermined operating state of the electric machine (115), and wherein the drive unit (155) is deactivated. is formed to generate the second control signal (160 ') using energy directly from the high voltage network (120).

5. Device (1 10) according to one of the preceding claims, characterized in that the drive unit (155) is designed to generate the control signal (160, 160 ') further in response to a present in the low voltage network (150) voltage level, in particular generate the control signal (160, 160 ') when the voltage level in the low voltage network (150) falls below a predefined low voltage level or is equal to zero.

6. Device (1 10) according to one of the preceding claims, characterized in that the drive unit (155) is designed to generate the control signal (160, 160 ') in response to a voltage level of the high voltage network (120).

7. Device (1 10) according to claim 6, characterized in that the drive unit (155) is formed,

• to generate the control signal (160, 160 ') such that the switch (135, 135') is closed when the voltage level in the high voltage network (120) is greater than a first high voltage level (Y), and / or

• to generate the control signal (160, 160 ') such that the switch (135, 135') is opened when the voltage level in the high voltage network (120) is less than a second high voltage level (X),

in particular, wherein the first high voltage level (Y) is greater than the second high voltage level (X).

8. Device (1 10) according to one of the preceding claims, characterized in that the drive unit (155) is designed to block drive signals (152) from the low-voltage network (150) for controlling the switch (135) when the control signal ( 160, 160 ') is generated using energy directly from the high voltage network (120).

An electrical system (105) for a vehicle (100) comprising a device (110) according to any one of the preceding claims and an electrical machine (115) coupled to the device (110).

10. A method for setting a predetermined operating state of an electric machine of a vehicle using a device according to claim 1, wherein the method comprises the following steps:

Supplying (410) electrical energy from the high voltage network (1209 to the drive unit (155);

Generating (420) a control signal (160, 160 ') for driving the switch (135, 135') of the inverter (130) using the energy supplied directly from the high voltage network (120) to switch the switch (135, 135 ') of the Inverter (130) to bring in a certain operating state of the electrical machine (115) corresponding switching state.

A computer program product with program code for performing the method (400) of claim 10 when the program is executed on a computer or device (110).