Method for providing safe operation state of motor without demagnetization of rotor magnet

Abstract

The invention relates to a method for providing a safe operating state for an electric machine (200) in a vehicle upon detection of a fault signal of the vehicle, the electric machine (200) being energized by means of a converter (10, 110) having a phase for each of a plurality of coil windings of the electric machine (200), the phase having a plurality of power switches (12a-c, 14a-c), the invention relates to a method for detecting a vehicle fault signal, comprising a plurality of power switches forming a half-bridge having a high-side device and a low-side device and being switchable by a pulsed mode to generate a phase current (ia-c) based on a DC input voltage (vdc), the method comprising:-receiving a detected vehicle fault signal; -establishing a predefined intermediate operating point of the electric machine (200) by means of a predictive control scheme, preferably by means of a deadbeat control scheme, in response to the received fault signal; switching the electric machine (200) from the predefined intermediate operating point to a safe operating state (e.g. AKS).

Description

TECHNICAL FIELD

[0001] The present invention relates to a method of establishing a safe operating state of an electric machine, in particular a synchronous electric machine, without de-excitation of the rotor upon detection of a fault signal, a corresponding controller, a corresponding computer-readable storage medium, and an at least partially electrified vehicle having the controller or the computer-readable storage medium. BACKGROUND

[0002] Pure electric vehicles and hybrid vehicles are known from the prior art, which are driven by one or more electric machines as drive assemblies, either exclusively or in addition. In order to supply the electric machines of such electric vehicles or hybrid vehicles with electrical energy, the electric vehicles and hybrid vehicles comprise an electrical energy store, in particular a rechargeable battery or secondary battery. These batteries are configured as a direct voltage source, but the electric machines usually require an alternating voltage. Therefore, a power electronics with a so-called DC / AC inverter is usually connected between the battery of the electric vehicle or hybrid vehicle and the electric machine (E-Maschine) in order to convert the DC input voltage into an AC output voltage for powering the electric machine.

[0003] Such inverters set a predetermined voltage on the strands or phases of the electric machine or, respectively, the rotating field machine (Drehfeldmaschine) by means of half-bridges. In each half-bridge, two semiconductor-based power switches (high-side power switch and low-side power switch) are connected in series between different potentials of an intermediate circuit voltage. At the point where the two power switches are connected to each other, the associated phase is contacted. If the two power switches are alternately opened and closed with a predetermined duty cycle, the desired voltage is established on the phase.

[0004] It is known from the prior art that, in addition to a rapid discharge unit (English: rapid discharge unit, RDU) for the vehicle drive battery, specific switching combinations of the power switches are also known in order to establish an electric machine safe operating state in response to a fault event, in particular a crash with, for example, other objects or vehicles. In particular, all high-side power switches can be opened and all low-side power switches can be closed, or all high-side power switches can be closed and all low-side power switches can be opened, in order to induce an active short circuit (AKS) of the power electronics. In both cases, the voltage transmission from the inverter to the electric machine is suppressed and, as a result, the continued operation of the electric machine is suppressed. In this way, further negative effects, such as a fire in the vehicle, can be prevented in the event of a crash. Alternatively, a so-called inverter blockage (WRS) is known, which is implemented without cutting off the voltage transmission from the inverter to the electric machine and provides for the high-side power switches and the low-side power switches to be opened.

[0005] However, existing methods for establishing an AKS in a motor have drawbacks, namely, that the transition to AKS can result in excessively severe overshoot of the phase current in the motor windings. In some cases, this severe, and sometimes even excessive, current overshoot can demagnetize the permanent magnets mounted in the motor rotor, which can permanently impair the motor's torque and power transmission, and thus permanently damage the vehicle's operation. Summary of the Invention

[0006] The purpose of this invention is to provide a method for providing a safe operating state for a motor, particularly a synchronous motor, especially an AKS when a fault signal is detected, in which the demagnetization of the rotor magnets is avoided.

[0007] According to the invention, this objective is achieved by the method, apparatus, computer-readable storage medium, and at least partially electrified vehicle having the apparatus or the computer-readable storage medium as described in the independent claims. Advantageous designs and modifications of the invention are derived from the dependent claims.

[0008] In a first aspect, the present invention relates to a method for providing a safe operating state of a motor after a fault signal of a motor or vehicle is detected.

[0009] The motor is preferably configured as a rotating field motor, which can be controlled by field-oriented adjustment. Field-oriented adjustment allows for the decoupling of the components forming the field and the components forming the torque, also known as the d-component and q-component, wherein the detected stator variable is transformed into a rotating coordinate system. The transformation angle required for this can be detected by a mechanical sensor (i.e., a so-called "generator"), which can be designed, for example, as an optical increment generator or resolver. Alternatively, the transformation angle can be determined using the electrical variable of the motor instead of using a generator.

[0010] To energize a motor with multiple coil windings, a DC / AC converter is connected in the regulating circuit. This converter is particularly used to convert a DC input voltage provided by a vehicle drive battery into an AC output voltage. For this purpose, the converter has an intermediate circuit (i.e., a commutation circuit) with an intermediate circuit capacitor across which an intermediate circuit voltage is applied. The intermediate circuit capacitor may comprise a single capacitor or an assembly of multiple capacitor modules. The converter also has a phase for each coil winding of the motor. The converter can be single-phase, i.e., having a single phase, or preferably multi-phase, i.e., having multiple phases. Each phase includes multiple semiconductor-based power switches forming a half-bridge. In each half-bridge, a high-voltage side device and a low-voltage side device are connected in series between different potentials of the intermediate circuit voltage. The high-voltage side device is formed by one or more power switches connected in parallel (high-voltage side power switches), and the low-voltage side device is formed by one or more power switches connected in parallel (low-voltage side power switches). Where the high-voltage side device and the low-voltage side device are connected to each other, the associated phases are in contact. If the high-voltage side power switch and the low-voltage side power switch are alternately opened and closed with a predetermined duty cycle, the desired voltage (converter voltage) is generated on the phase, which is transmitted to the associated coil winding.

[0011] A switching signal generator unit that controls the converter to switch the power switch provides a predetermined duty cycle in order to preferably implement so-called pulse width modulation (PWM) of the power switch. For example, and preferably, in the normal operation of the vehicle, PWM can be used for asynchronous or synchronous modulation of the power switch.

[0012] When a fault signal is received from one or more vehicle status sensors, such as an electronic control unit (ECU), the motor should be operated to bring it into a safe state as soon as possible, such as AKS or WRS.

[0013] According to the present invention, instead of directly putting the motor into a safe operating state, particularly the AKS state, a predefined intermediate operating point of the motor is first established. This can be achieved through a predictive (or model-predictive) control scheme, preferably a deadbeat control scheme. Alternative methods can also be used to reach the intermediate operating point. Once the predefined intermediate operating point is reached, or the predefined time for reaching the predefined intermediate operating point has elapsed, the motor switches from that predefined intermediate operating point to the safe operating state, particularly the AKS state.

[0014] The predefined intermediate operating point is preferably defined by the phase currents present in the motor coil windings in the safe operating state to be reached (preferably the AKS state). Specifically, the predefined intermediate operating point corresponds to the d-components and q-components (i.e., d-current and q-current) of the phase currents in the motor's AKS state, where these d / q components are obtained by Park-Transformation of the three- or multi-component phase currents of the motor. This means that before the motor switches to the safe operating state or the AKS state, it has entered an operating point where the d-current and q-current are substantially equal to or at least close to the d / q currents (AKS current) actually present in the AKS state (AKS steady state).

[0015] This method allows for safe operation, particularly AKS (Advanced Kinematics State), starting from a predefined intermediate operating point of the motor. Since the motor is already in a state where the d-current and q-current are approximately equal to or close to the AKS current after establishing the predefined intermediate operating point, the AKS state can be established with reduced (preferably reduced to zero) instantaneous phase current overshoot compared to immediate switching upon detection or receipt of a fault signal (known as "hard AKS"), and without uncontrolled demagnetization of the rotor magnets. This prevents permanent damage to the motor's torque and power transmission, and thus prevents permanent damage to the vehicle.

[0016] Simultaneously, using predictive control schemes, particularly deadbeat control schemes, enables the motor to enter a safe operating state or AKS state with higher or greater fault robustness and signal quality. Furthermore, predictive or deadbeat control schemes can be configured to establish a predefined intermediate operating point of the motor within a predetermined time interval (or a predetermined sampling period). By appropriately selecting the predetermined time interval, the switching time to enter the motor's safe operating state or AKS state can be further minimized. Alternatively or additionally, the predictive control scheme, preferably a deadbeat control scheme, is configured to optionally extend the predetermined time interval if the time interval exceeds the period during which the motor is controlled to enter the predefined intermediate operating point. This measure ensures that the motor reaches the predefined intermediate operating point with higher fault robustness. This is particularly advantageous if the vehicle drive battery has been disconnected in the event of a fault, and the available intermediate circuit voltage changes significantly.

[0017] According to one embodiment, a method for establishing a predefined intermediate operating point includes the steps of: providing a target voltage space vector previously determined by a deadbeat control scheme, which can establish a predefined intermediate operating point for the motor; and generating a switching signal for controlling the converter based on the provided voltage space vector to control the motor to enter the predefined intermediate operating point. The voltage space vector is a representation of a voltage vector on a space vector diagram, preferably having d-voltage components and q-voltage components. Alternatively, the voltage vector may be represented in an alternative coordinate system. The switching signal (particularly a gate signal) for controlling the converter is generated by a switching signal generator unit and applied to control terminals (particularly gate terminals) of a power switch installed in the converter, wherein the switching signal generator unit is electrically connected to a control unit that provides the voltage space vector. The converter converts the switching signal, taking into account intermediate circuit voltages, to provide a converter voltage or phase current to the motor's coil windings corresponding to the predefined intermediate operating point, thereby establishing the predefined intermediate operating point.

[0018] A predefined voltage space vector can be determined based on one or more of the following variables: - The phase current (or d current / q current) before the fault signal appears. - The current (or d current / q current) predicted or known for the safe operating condition of the motor, preferably for the AKS condition. - The rotor position angle measured or estimated before the fault signal occurred; - Intermediate circuit voltage; - A predetermined time interval used to control the motor to enter a predefined intermediate operating point.

[0019] According to a preferred embodiment, the current voltage space vector is continuously determined using a predictive control scheme or a deadbeat-free control scheme before a fault signal occurs, preferably during motor operation, in order to continuously generate multiple candidate voltage space vectors (the current voltage space vector). The generated candidate voltage space vectors can also be continuously stored so that they can be directly recalled when a fault occurs. In this way, when a vehicle fault event (such as a collision) occurs, a predefined voltage space vector can be immediately selected from the generated and stored candidate voltage space vectors. Alternatively, candidate voltage space vectors can be determined outside of motor operation (i.e., offline).

[0020] According to another preferred embodiment, the predefined voltage space vector is a candidate voltage space vector corresponding to the electrical input variables of the motor detected at the time of the fault signal, particularly the phase current signal and / or rotor position angle signal. One or more phase currents and rotor position angles are determined in real time within the framework of field-oriented regulation and (partially after Parker transformation to d / q components) fed back to the regulator unit. The detection of the phase current signal or rotor position angle signal occurs over a certain time period, during which the corresponding current voltage space vector can be determined and recorded. In this way, an associated candidate voltage space vector is generated at each detection time of the phase current signal and / or rotor position angle signal. Thus, when a fault event (collision event) occurs, the phase current or rotor position angle present in the motor at the time of the fault event is applied, and the associated candidate voltage space vector (i.e., determined based on the phase current signal and / or rotor position angle signal detected at the time of the fault event) is selected as the predefined voltage space vector. Alternatively, especially when no phase current signal or rotor position angle signal is detected at the time of the fault event, the candidate voltage space vector corresponding to the last detected phase current signal and / or rotor position angle signal before the time of the fault signal can be defined as a predefined voltage space vector.

[0021] The present invention also relates to an apparatus for providing a safe operating state for a motor in a vehicle upon detection of a fault signal. The apparatus preferably includes a control unit for establishing a predefined intermediate operating point of the motor in response to a received motor fault signal, using a predictive (especially model predictive) control scheme, preferably a deadbeat control scheme. The apparatus further includes a switching signal generator unit electrically connected to the control unit for generating an associated switching signal, and includes a converter for controlling the motor based on the switching signal.

[0022] According to a preferred embodiment, the device includes a regulator unit for field-oriented regulation of the motor. This regulator unit is electrically connected to a switching signal generator unit via a switching module, preferably such that the switching signal generator unit can be optionally electrically connected to either a control unit or the regulator unit. The switching module is configured to immediately switch the electrical connection from the regulator unit to the control unit in response to a received motor / vehicle fault signal (or upon detecting a fault event). For this purpose, the switching module has multiple signal inputs for inputting regulation signals from the regulator unit and control signals from the control unit. Simultaneously, the switching module has at least one signal output for outputting either the regulation signal or the control signal. Preferably, the switching module has two first signal inputs for inputting d-voltage signals and q-voltage signals from the regulator unit, and two second signal inputs for inputting d-voltage signals and q-voltage signals from the control unit. The switching module also preferably has two signal outputs for outputting either the two voltage signals from the regulator unit or the two voltage signals from the control unit. The two voltage signals from the control unit form components of a predefined voltage space vector, which is determined by a predictive control scheme (or deadbeat control scheme) of the control unit being executed.

[0023] According to another preferred embodiment, the control unit is also configured to determine, in particular continuously determine, the aforementioned candidate voltage space vector based on electrical input variables of the motor, such as phase current signals and / or rotor position angle signals, and preferably continuously record or store them.

[0024] The present invention also relates to a computer-readable (storage) medium comprising instructions that, when executed by a computer, cause the computer to perform steps of a method according to one embodiment of the present invention. Furthermore, the present invention relates to a vehicle that is at least partially electrified, the vehicle including an electric motor, a device according to the present invention, or a computer-readable storage medium according to the present invention, the vehicle carrying a computer. Thus, the advantages already described in conjunction with the method according to the present invention also apply to the device according to the present invention, the (storage) medium according to the present invention, and the at least partially electrified vehicle. Attached Figure Description

[0025] The invention is explained below by way of example with reference to the embodiments shown in the accompanying drawings. Figure 1 A schematic circuit diagram of a multiphase converter, such as a three-phase converter, is shown for energizing a motor. Figure 2 A schematic diagram of the voltage space vector on the space vector diagram is shown; Figure 3 A schematic diagram of a device for providing a safe operating condition for a motor is shown; Figures 4 to 6Several graphs are shown, which plot voltage or current data recorded both during hard AKS and during the method according to the invention for providing AKS status (Ping-AKS). Detailed Implementation

[0026] In all the accompanying drawings, the same objects, functional units, and comparable parts are labeled with the same reference numerals. Unless otherwise expressly or implied in the specification, these objects, functional units, and comparable parts are of the same design in terms of their technical features.

[0027] Figure 1 A schematic circuit diagram of a multiphase, here purely exemplary, three-phase DC / AC converter (inverter) 10 for energizing motor 200 is shown, wherein... Figure 3 The diagram schematically and purely illustratively illustrates a motor 200 and a device 100 for providing a safe operating state for the motor 200. The converter 10 includes power electronics composed of multiple half-bridges, each half-bridge having high-voltage side devices and low-voltage side devices. Figure 1 In the exemplary embodiment shown, the high-voltage side device and the low-voltage side device are respectively composed of high-voltage side power switches 12a-c or low-voltage side power switches 14a-c. However, the present invention is not limited thereto; on the contrary, the high-voltage side device and / or the low-voltage side device may each include multiple power switches. A DC input voltage V generated by the DC voltage supply unit 16 is applied to the input side of the power electronic device. dc (The internal resistance 18 of the DC voltage supply section 16 is also shown here), and this DC input voltage is fed into the power electronics. At the node between the high-side and low-side devices of the corresponding half-bridge, AC phase output sections 20a-c are provided to obtain the AC phase current i. a i b i c The AC phase current is based on the fed DC input voltage V. dc This is generated by switching power switches 12A-C and 14A-C according to a pulse pattern, particularly by pulse width modulation (PWM). Phase current i a i b i c And the related phase voltage (converter voltage) v a v b v c The electric vehicle axle drive is fed into the relevant coil windings of the motor 200 to energize the motor and thereby operate the vehicle.

[0028] To control the converter 10, the controller 120 is used (in Figure 3The switching signal generated (illustrated schematically and purely exemplarily) preferably includes multiple high-voltage side switching voltages u for the high-voltage side power switches 12a-c. a-c and multiple low-voltage side switching voltages u' for low-voltage side power switches 14a-c a-c Switching signal or switching voltage u a-c 、u' a-c By switching signal generator unit 108 (see Figure 3 This is generated based on the voltage space vector, which is generated by the regulator unit 102 (see...). Figure 3 ) generated. In Figure 2 The voltage space vector shown schematically and exemplarily in the diagram (see the voltage vector in Region III, which is the superposition of two components along the v3 or v4 axis) is the form of a vector representation of multiphase voltage in the complex plane, called a space vector diagram.

[0029] Figure 3 A schematic diagram of a device 100 for providing a safe operating state for a motor 200 is shown. The device 100 is used to control the motor 200 based on field-oriented regulation (FOR), and for this purpose includes a regulator unit 102 and a switching signal generator unit 108 that can be electrically connected to the regulator unit 102. The regulator unit 102 is configured to obtain the d current component i from the conversion device 115. d and q current component i q (dq current). The conversion device 115 is further configured to continuously detect the phase current i by the current sensor 112 on the output side of the converter 110. a i b i c Transform the d-current component i into dq representation d and q current component i q The dq current i obtained from this is d i q This represents the motor's current operating point (actual operating point). Additionally, other electrical input variables, such as the rotor position angle φ, can be used. m and the angular velocity ω obtained through the differentiation unit 117 m The input is fed into regulator unit 102. Regulator unit 102 is also configured to acquire the additional dq current i. * d i * q As input, these additional dq currents represent the desired operating point (target operating point) of the motor 200. The regulator unit 102 processes the aforementioned input variable i through an adjustment method, preferably PI regulation, and inverse transformation. d i q i *d i * q φ m ω m And thus generate the d voltage component u. d and q voltage component u q As a control signal, these voltage components form a voltage space vector as the dp voltage. The dq voltage u d u q The signal is transmitted to the switching signal generator unit 108 via the switching module 106, thereby generating a signal generator unit 108 that includes three switching voltages u. a-c The switching signal is used to control the converter 110. The switching signal generator unit 108 is preferably a so-called discrete switch state generation unit, and more preferably configured as a space vector modulator, for generating a modulated, particularly pulse-width modulated, switching voltage u. a-c After a switching signal is applied to the power switches 12a-c and 14a-c of the converter 110, these power switches will switch accordingly. The detected electrical input variable i d i q φ m ω m Feedback is sent to regulator unit 102 via feedback lines 114, 116, 118, and 119 for field-oriented regulation. The main circuit includes regulator unit 102, switching signal generator unit 108, and converter 110. This main circuit and feedback lines 114, 116, 118, and 119 together form a regulation loop. Through this regulation loop, after a certain number of feedback cycles (or iterations), the target operating point of motor 200 is generated.

[0030] In device 100, a control unit 104 is also connected in parallel with the regulator unit 102. This control unit is configured to provide a predefined intermediate operating point for the motor 200. The regulator unit 102, control unit 104, switching module 106, and switching signal generator unit 108 together form a controller for operating the converter 110. Upon detecting or receiving a fault signal (e.g., a collision signal), the motor 200 is not immediately switched to a safe operating state, particularly the AKS state. Instead, the motor 200 is first controlled to enter the predefined intermediate operating point. This is achieved through a predictive (or model-predicted) control scheme, preferably a deadbeat control scheme. Only when the predefined intermediate operating point is reached does the motor 200 switch from that predefined intermediate operating point to the safe operating state, particularly the AKS state.

[0031] The predefined intermediate operating point is preferably defined by the phase current present in the coil windings of motor 200 in the safe operating state to be achieved (preferably AKS state). Specifically, the predefined intermediate operating point is defined by the d-components and q-components (i.e., d-current and q-current) of the phase current in the AKS state of the motor. This means that before switching motor 200 to the safe operating state or AKS state, the motor has already entered an operating point where the d-current and q-current are substantially equal to or at least close to the d / q current (AKS current) actually present in motor 200 in the AKS state (AKS steady state).

[0032] In this way, a safe operating state, particularly the AKS state, can be achieved starting from a predefined intermediate operating point of the motor 200. Since the motor 200 is already in a state where the d current and q current are approximately equal to or close to the AKS current after establishing the predefined intermediate operating point, the AKS state can be established with reduced instantaneous overshoot of the phase current and thus avoids uncontrolled demagnetization of the rotor magnets, compared to a hard AKS. This prevents permanent damage to the torque and power transmission of the motor 200, and thus prevents permanent damage to the vehicle.

[0033] Predictive control schemes or deadbeat control schemes are preferably configured to establish a predefined intermediate operating point of motor 200 within a predetermined time interval. By appropriately selecting the predetermined time interval, the switching time for motor 200 to enter a safe operating state or AKS state can also be minimized. Alternatively or additionally, the predictive control scheme, preferably a deadbeat control scheme, is configured to automatically extend the predetermined time interval if the predetermined time interval is exceeded during the process of controlling motor 200 to enter the predetermined intermediate operating point. This measure ensures that motor 200 reaches the predetermined intermediate operating point with higher fault robustness.

[0034] Control unit 104 is configured to provide a voltage space vector as an adjustment signal, which is previously determined by a deadbeat control scheme and corresponds to a predefined intermediate operating point of motor 200. The voltage space vector, or voltage vector, is determined by the voltage component u. Ping d and q voltage component u Ping q Definition. This predefined voltage space vector (or dq voltage u) Ping d u Ping q The determination can preferably be based on one or more of the following electrical input variables: - When the fault signal occurs, the phase current i of motor 200 a-c (or d / q current i)d i q ); - For the safe operating condition of motor 200, the current (or d / q current i) predicted by the preferred AKS state. AKS d i AKS q ); - Rotor position angle φ when the fault signal occurs m ; - Intermediate circuit voltage v dc ; - A predetermined time interval used to control the motor 200 to enter a predefined intermediate operating point or AKS state.

[0035] Preferably, during the operation of the motor 200 (e.g., during driving), before a fault signal is detected, the current voltage space vector is continuously determined by the control unit 104 using a predictive control scheme or a deadbeat control scheme. This generates multiple candidate voltage space vectors that can be continuously recorded and recalled when needed. In the event of a vehicle malfunction (e.g., a collision), a predefined voltage space vector can be selected from the generated and recorded candidate voltage space vectors. In addition to determining candidate voltage space vectors online, offline determination is also possible.

[0036] Preferably, the candidate voltage space vector corresponds to one or more electrical input variables detected by the motor 200 at the time of the fault signal. The detection of the electrical input variables is performed over a certain time period, during which the corresponding current voltage space vector can be determined and recorded by the control unit 104. In this way, a corresponding candidate voltage space vector is generated at each detection moment of the electrical input variable, thus generating a series of current voltage space vectors. In the event of a fault (collision event), the candidate voltage space vector related to the time of the fault event is selected as the predefined voltage space vector. Alternatively, particularly when no electrical input variable is detected at the time of the fault event, the candidate voltage space vector corresponding to the last detected electrical input variable before the time of the fault signal can be defined as the predefined voltage space vector.

[0037] Using the switching module 106, the switching signal generator unit 108 can be selectively electrically connected to the regulator unit 102 (for normal operation of the motor 200) or to the control unit 104 (for providing a safe operating state or AKS state after detecting a fault signal / collision signal). Therefore, the switching module 106 can, in response to a received fault signal from the motor 200 / vehicle, directly switch its electrical connection from the regulator unit 102 to the control unit 104. For this purpose, the switching module 106 preferably has a dq voltage u for inputting to the regulator unit 102. d u q The two first signal input sections, and the predefined dq voltage u for input control unit 104. Ping d u Ping q The two second signal input sections. By switching the two switches of the switching module 106, the dq voltage u of the regulator unit 102 can be adjusted. d u q Or the predefined dq voltage u of control unit 104 Ping d u Ping q The output is sent to the switching signal generator unit 108.

[0038] Figures 4 to 6 Several graphs are shown, plotting voltage or current data, which are recorded both for hard AKS and for the method according to the invention used to provide AKS status (Ping-AKS). Figure 4 In the figure, the voltage or current data of two methods (hard AKS and Ping-AKS) are plotted as a function of time t using curves. Ping-AKS is established first, and hard AKS is established after a certain period of time. Figure 5 The voltage or current data of the hard AKS can be seen in the image, while... Figure 6 The voltage or current data according to the Ping-AKS of the present invention can be seen. Figures 4 to 6 In all three sets of graphs, the dq voltage u is plotted in the corresponding upper curve (A). d u q The voltage data changes with time t, and the current i is plotted in the corresponding intermediate curve (B). d i q The current data varies with time t, and the phase current i is plotted in the corresponding curve (C) below. a、b、c The change over time t. Figure 5 and Figure 6In the diagram, voltage or current data is plotted for two time windows (the curve on the left represents the larger time window, while the curve on the right represents the smaller time window contained within the larger time window). The predetermined time interval used to control motor 200 to enter a predefined intermediate operating point is, for example, 500 μs (see [reference]). Figure 6 (Times t1 and t2 in the data). Figure 4 As shown, compared to hard AKS, the dq current i is achieved in the case of Ping-AKS. d i q and phase current i a、b、c The overshoot was significantly reduced. (Comparison) Figure 5 The local curve diagram on the right side of B and Figure 6 The local curve on the right side of B also clearly shows this difference. And in the case of Ping-AKS, as... Figure 6 As shown in Figure B, at the end of a predetermined time interval t2 or after the end of a deadbeat control scheme, the dq current i d i q It is already very close to the AKS current (i.e., the dq current under AKS steady state), and only slight current oscillations can be observed thereafter, while the dq current i at time t2... d i q The current dq was significantly different from that under steady-state conditions in AKS, and much more violent current oscillations were subsequently recorded. List of reference numerals in the attached diagram: 10, 110 DC / AC converters 12a-12c High-voltage side power switch 14a-14c Low-voltage side power switch 16 DC Voltage Supply Department 18 Internal Resistance 20a-20c AC phase output section 100 devices 102 Regulator Unit 104 Control unit for intermediate steps (Ping-AKS) 106 Switch Module 108 Switching Signal Generator Unit 112 Current Sensor Feedback lines: 114, 116, 118, 119 115 Converter Unit 117 Differentiation 120 controller 200 motor.

Claims

1. A method for providing a safe operating state for a motor (200) in a vehicle after detecting a fault signal in the vehicle, wherein, The motor (200) is energized via converters (10, 110) having phases for each of a plurality of coil windings of the motor (200), wherein each phase has a plurality of power switches (12a-c, 14a-c) forming a half-bridge with high-voltage side devices and low-voltage side devices, and is capable of switching via pulse mode based on the DC input voltage (V). dc ) generates phase current (i a-c The method includes: - Receive the fault signal of the vehicle; - In response to the received fault signal, a predefined intermediate operating point of the motor (200) is established through a predictive control scheme, preferably through a deadbeat control scheme; - Switch the motor (200) from the predefined intermediate operating point to the safe operating state.

2. The method according to claim 1, characterized in that, The predictive control scheme is preferably a deadbeat control scheme.

3. The method according to at least one of claims 1 or 2, characterized in that, The method steps for establishing the predefined intermediate working point include: - Provide a voltage space vector previously determined by the control scheme, which establishes a predefined intermediate operating point for the motor (200); - Based on the provided voltage space vector, a switching signal is generated to control the converters (10, 110) so as to control the motor (200) to enter the predefined intermediate operating point.

4. The method according to claim 3, wherein, Before the fault signal is detected, preferably during the operation of the motor (200), the target voltage space vector is continuously determined in order to continuously generate a plurality of candidate voltage space vectors for the predefined voltage space vector, and preferably the candidate voltage space vectors are also continuously recorded.

5. The method according to claim 4, wherein, The predefined voltage space vector is a candidate voltage space vector corresponding to the electrical input variables, particularly the phase current signal and / or rotor position angle signal, that were last detected by the motor (200) at the time of the fault signal or before the time of the fault signal.

6. The method according to any one of claims 3 to 5, wherein, The predefined voltage space vector is determined based on one or more of the following variables: - The effective phase current (i) before the fault signal appears a-c ); - For the safe operating state of the motor, preferably for the active short circuit AKS, a predefined current or AKS current (i) is defined. AKS d i AKS q ); - The rotor position angle (φ) before the fault signal appeared m ); - Intermediate circuit voltage (V) dc ); - A predetermined time interval for controlling the motor (200) to enter the predefined intermediate working point.

7. The method according to any one of claims 1 to 6, wherein, The predictive control scheme, preferably the deadbeat control scheme, is configured to control the motor (200) to enter the predefined intermediate operating point within a predetermined time interval starting from the moment the fault signal is detected.

8. The method according to any one of claims 1 to 6, wherein, The predictive control scheme, preferably the deadbeat control scheme, is configured to automatically extend the predetermined time interval if the time interval exceeds the predetermined time interval during the control of the motor (200) to enter the predetermined intermediate operating point.

9. A device (100) for providing a safe operating state for a motor (200) in a vehicle after detecting a fault signal in the vehicle, wherein, The apparatus (100) is configured to perform the method according to any one of the preceding claims.

10. The apparatus (100) according to claim 9, comprising a control unit (104), a converter (110), and a switching signal generator unit (108), wherein the control unit is configured to establish a predefined intermediate operating point of the motor (200) in response to a received fault signal of the motor (200) through a predictive control scheme, preferably through a deadbeat control scheme, the converter is configured to energize the motor (200) based on a switching signal, and the switching signal generator unit is configured to generate the switching signal.

11. The apparatus (100) according to claim 10, wherein, The device (100) includes a regulator unit (102) for field orientation regulation of the motor (200). The regulator unit is electrically connected to the switching signal generator unit (108) via a switching module (106). Preferably, the switching signal generator unit (108) can be optionally electrically connected to the control unit (104) or the regulator unit (102).

12. A computer-readable storage medium comprising instructions that, when executed by a computer, cause the computer to perform the steps of the method according to any one of claims 1 to 7.

13. Vehicles that are at least partially electrified, including: - Motor (200); - The apparatus (100) according to any one of claims 8 to 11, or the computer-readable storage medium according to claim 12.

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