CN116572758A

CN116572758A - Safety state control method, device, equipment and medium of motor controller

Info

Publication number: CN116572758A
Application number: CN202310676287.9A
Authority: CN
Inventors: 谭曦; 陈健; 杜长虹
Original assignee: Deep Blue Automotive Technology Co ltd
Current assignee: Deep Blue Automotive Technology Co ltd
Priority date: 2023-06-08
Filing date: 2023-06-08
Publication date: 2023-08-11

Abstract

The application provides a safety state control method, a device, equipment and a medium of a motor controller, wherein the method comprises the following steps: acquiring the current voltage and the current rotating speed of a motor; determining a target switching point representing the safety state of the motor controller according to the current voltage and a preset output torque curve graph; determining a first switching rotation speed corresponding to a target switching point based on a preset output torque curve chart; comparing the current rotation speed with the first switching rotation speed once; and adjusting the current safety state of the motor controller to a target safety state according to the first comparison result, wherein the target safety state comprises an open-circuit protection safety state and an active protection safety state. The target switching point of the safety state is determined in real time through the current voltage and the output torque curve graph, so that the target switching points are different under different voltages, and the target safety state of the motor controller is controlled by combining the current rotating speed, so that the zero torque or the safety braking torque can be ensured, the damage of devices can be avoided, and the safety and the controllability of the vehicle are improved.

Description

Safety state control method, device, equipment and medium of motor controller

Technical Field

The present invention relates to the field of motor control technologies, and in particular, to a method, an apparatus, a device, and a medium for controlling a safety state of a motor controller.

Background

In an electric vehicle, a motor controller can control a running state such as a start operation, a forward and backward speed, a climbing force, and the like of the electric vehicle according to instructions such as a gear, an accelerator, a brake, and the like. When the vehicle breaks down and affects the driving safety, a reasonable control strategy needs to be formulated to enable the vehicle to enter a safety state so as to ensure the safety of the vehicle and personnel on the vehicle, and the safety states of the motor controller are two: active short ASC (Active short circuit) and open protection FW (Freewheeling). The active short circuit ASC has the following characteristics: (1) a significant braking torque is generated in the low speed region; (2) The continuous current generated by the back electromotive force can cause the motor to overheat; (3) the risk of demagnetizing the rotor magnetic steel caused by overheat of the motor; (4) Motor overheating causes the inverter to overheat, resulting in damage to the inverter. The open circuit protection FW has the following characteristics: (1) high-speed region phase current flows through the freewheeling diode; (2) The high counter electromotive force in the high-speed area brings impact hazard to devices on the bus; (3) The motor output in the high speed region generates an unexpectedly large braking torque. Therefore, the control of the safety state of the motor controller seriously affects the performance, safety and service life of the vehicle.

In chinese patent CN114435137a, an active short-circuit control method, apparatus, device and medium for a motor controller are disclosed, where four thresholds, namely, a temperature threshold and three rotation speed thresholds, are set, and the actual rotation speed value, the first rotation speed threshold, the second rotation speed threshold, the third rotation speed threshold, and the actual temperature value and the temperature threshold are compared respectively, so as to optimize the condition that the motor controller enters an ASC state or SPO (Safty Pulse Off) state; in chinese patent CN112787309a, a method and a system for controlling circuit protection of a motor controller are disclosed, where two state switching points are determined by calibrating a safe torque curve, a current rotation speed threshold value is compared with rotation speed threshold values corresponding to the two switching points, and the motor controller is controlled to enter an ASC state or an SPO state according to the comparison result.

Therefore, in the related art, for switching the safety state of the motor controller, the switching point is usually unchanged under different working conditions according to the output torque and the rotation speed, the corresponding rotation speed is a constant value, the switching scene of the safety state is too simple, and the output characteristics of the active protection ASC and the open circuit protection FW under different voltages are ignored, so that unexpected torque is generated, and the safety operation of the motor controller is affected.

Disclosure of Invention

The following presents a simplified summary in order to provide a basic understanding of some aspects of the disclosed embodiments. This summary is not an extensive overview, and is intended to neither identify key/critical elements nor delineate the scope of such embodiments, but is intended as a prelude to the more detailed description that follows.

In view of the above-mentioned drawbacks of the prior art, the present application discloses a method, an apparatus, a device, and a medium for controlling a safety state of a motor controller, which are used for solving the technical problem that the output characteristics of an active protection ASC and an open circuit protection FW under different voltages are not considered to determine a rotation speed threshold value in the related art, which may affect the safety operation of the motor controller.

In a first aspect, the present application provides a method for controlling a safety state of a motor controller, the method comprising: acquiring the current voltage and the current rotating speed of a motor; determining a target switching point representing the safety state of the motor controller according to the current voltage and a preset output torque curve chart; determining a first switching rotation speed corresponding to the target switching point based on the preset output torque curve graph; comparing the current rotation speed with the first switching rotation speed once; and adjusting the current safety state of the motor controller to a target safety state according to a first comparison result, wherein the target safety state comprises an open circuit protection safety state and an active protection safety state.

In an embodiment of the present invention, the obtaining of the preset output torque curve includes: if the motor is in the open-circuit protection safety state, collecting a plurality of first output torques generated by corresponding different motor speeds under different motor voltages so as to obtain a first output torque set formed by the plurality of first output torques; if the motor is in the active short-circuit safety state, calculating a plurality of second output torques generated at different motor speeds to obtain a second output torque set formed by the plurality of second output torques; establishing a motor rotating speed-output torque coordinate system, drawing a first output torque curve of the open-circuit protection safety state according to the first output torque set, and drawing a second output torque curve of the active short-circuit protection state according to the second output torque set, wherein the first output torque curve is a plurality of first output torque curves; and splicing the first output torque curve and the second output torque curve to generate the preset output torque curve.

In an embodiment of the present invention, the determining a target switching point for characterizing a safety state of the motor controller according to the current voltage and in combination with a preset output torque curve comprises: acquiring intersection points of the first output torque curve and the second output torque curve, wherein the number of the intersection points is multiple; taking an intersection point curve formed by the intersection points as a safe output torque curve; quantifying the relation between the safe output torque curve and the motor rotating speed to obtain a safe state switching curve; and acquiring a target intersection point of the first output torque curve corresponding to the current voltage and the safety state switching curve, and determining the target intersection point as the target safety state switching point.

In an embodiment of the present invention, the determining the target switching point for characterizing the safety state of the motor controller according to the current voltage and in combination with a preset output torque curve further includes: if the target intersection points are multiple, calculating a first peak counter-irrigation voltage according to the current counter-electromotive force of the motor and the motor rotating speed corresponding to each target intersection point; performing second comparison on the first peak reverse filling voltage and a preset withstand voltage value; selecting a first target intersection point with higher motor rotation speed from first target intersection points with the first peak reverse filling voltage smaller than the preset withstand voltage value as the target safety state switching point; and selecting a second target intersection point with a lower corresponding motor rotating speed from second target intersection points with the first peak counter-filling voltage larger than the preset withstand voltage value as a safety state switching point.

In an embodiment of the present invention, after selecting the second target intersection point with the lower rotation speed of the corresponding motor as the safety state switching point, the method further includes: calculating a second peak counter-irrigation voltage according to the motor rotating speed corresponding to the second target intersection point with the lower motor rotating speed and the current counter-electromotive force; if the second peak counter-filling voltage is larger than the preset withstand voltage value, taking the preset withstand voltage value as a third peak counter-filling voltage; calculating according to the third peak counter-irrigation voltage and the current counter-electromotive force to obtain a second safety state switching rotating speed; and determining a point corresponding to the second safety state switching rotating speed in the safety state switching curve as the target safety state switching point.

In an embodiment of the present invention, the calculation formula of the second output torque is:wherein T is _e Representing an output torque; p is p _n Representing the pole pair number of the motor; ω represents the mechanical angular velocity; r is R _s A motor stator winding; psi _f Representing rotor flux linkage; l (L) _d Representing d-axis inductance; l (L) _q Representing the q-axis inductance.

In an embodiment of the present invention, before the obtaining the current voltage and the current rotation speed of the vehicle, the method further includes: monitoring the real-time state of the motor controller; generating a drive fault signal based on the drive fault state when the real-time state is determined to be the drive fault state; and responding to the driving fault signal, triggering the motor controller to control the motor to enter a safety protection state.

In an embodiment of the present invention, the adjusting the current state of the motor controller to the target safe state according to the comparison result includes: if the first comparison result is that the current rotating speed is greater than or equal to the first safety state switching rotating speed, the current safety state of the motor controller is adjusted to be the active protection safety state; and if the first comparison result is that the current rotating speed is smaller than the first safety state switching rotating speed, adjusting the current safety state of the motor controller to be the open-circuit protection safety state.

In an embodiment of the present application, the obtaining the current voltage of the motor includes: collecting a first voltage signal in the output signal of the battery pack, a second voltage signal in the output signal of the driving module and a third voltage signal in the output signal of the power module; and processing the first voltage signal, the second voltage signal and the third voltage signal to obtain the current voltage.

In a second aspect, the present application provides a safety state control device for a motor controller, the device comprising: the acquisition module is used for acquiring the current voltage and the current rotating speed of the motor; the switching point determining module is used for determining a target switching point representing the safety state of the motor controller according to the current voltage and a preset output torque curve graph; the switching rotation speed determining module is used for determining a first switching rotation speed corresponding to the target switching point based on the preset output torque curve chart; the comparison module is used for comparing the current rotating speed with the first switching rotating speed once; and the target safety state determining module is used for adjusting the current safety state of the motor controller into a target safety state according to a first comparison result, wherein the target safety state comprises an open circuit protection safety state and an active protection safety state.

In a third aspect, the present application provides an electronic device, comprising: one or more processors; and a storage means for storing one or more programs which, when executed by the one or more processors, cause the electronic device to implement the method of controlling the safety state of the motor controller described in the first aspect.

In a fourth aspect, the present application provides a computer-readable storage medium having stored thereon a computer program which, when executed by a processor of a computer, causes the computer to perform the safety state control method of the motor controller described in the first aspect.

As described above, the method, device, equipment and medium for controlling the safety state of the motor controller provided by the embodiment of the application have the following beneficial effects:

when a vehicle breaks down and affects driving safety, after the vehicle is triggered to enter a safety state, the current voltage and the current rotating speed of a motor are immediately obtained, a target switching point representing the safety state of a motor controller is determined according to the current voltage and a preset output torque curve graph, the voltages under the current working condition are different, the corresponding target switching points are also different, the output characteristics of an active protection ASC and an open circuit protection FW under different voltages are considered, the target switching points can be dynamically adjusted according to the different voltages, then a first switching rotating speed corresponding to the target switching point is determined based on the preset output torque curve graph, the current rotating speed is compared with the first switching rotating speed once, and finally the current safety state of the motor controller is adjusted to be in a target safety state according to a first comparison result. The target switching point of the safety state is determined in real time through the current voltage and the output torque curve graph, so that the target switching points are different under different voltages, the target safety state of the motor controller is reasonably controlled and adjusted by combining the current rotating speed, the generation of unexpected torque is reduced to the maximum extent, the permanent demagnetization of motor magnetic steel is avoided, the service life of the motor is maintained, and the safety and the controllability of the vehicle are improved.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application as claimed.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the application and together with the description, serve to explain the principles of the application. It is evident that the drawings in the following description are only some embodiments of the present application and that other drawings may be obtained from these drawings without inventive effort for a person of ordinary skill in the art. In the drawings:

FIG. 1 is a schematic diagram illustrating the operation of an ASC and FW in accordance with an exemplary embodiment of the present application;

FIG. 2 is a schematic view of an implementation environment of a safety state control device of a motor controller according to an exemplary embodiment of the present application;

FIG. 3 is a flow chart illustrating a method of controlling a safety state of a motor controller according to an exemplary embodiment of the present application;

FIG. 4 is a schematic diagram of a multi-voltage acquisition device according to an exemplary embodiment of the present application;

FIG. 5 is a flow chart of step S220 in the embodiment of FIG. 3 in an exemplary embodiment;

FIG. 6 is a schematic diagram of a three-phase full-bridge passive rectifier shown in an exemplary embodiment of the application;

FIG. 7 is a graph showing ASC output torque versus current as a function of motor speed for an exemplary embodiment of the present application;

FIG. 8 is a schematic diagram of an ASC generated transient three-phase current shown in an exemplary embodiment of the application;

FIG. 9 is a preset output torque profile illustrating an exemplary embodiment of the present application;

FIG. 10 is another preset output torque profile shown in accordance with an exemplary embodiment of the present application;

fig. 11 is a schematic structural view of a safety state control device of a motor controller according to an exemplary embodiment of the present application;

fig. 12 is a block diagram of an information configuration apparatus of a vehicle controller shown in an exemplary embodiment of the present application;

fig. 13 is a schematic structural diagram of an electronic device according to an embodiment of the present application.

Detailed Description

Further advantages and effects of the present application will become readily apparent to those skilled in the art from the disclosure herein, by referring to the accompanying drawings and the preferred embodiments. The application may be practiced or carried out in other embodiments that depart from the specific details, and the details of the present description may be modified or varied from the spirit and scope of the present application. It should be understood that the preferred embodiments are presented by way of illustration only and not by way of limitation.

It should be noted that the illustrations provided in the following embodiments merely illustrate the basic concept of the present application by way of illustration, and only the components related to the present application are shown in the drawings and are not drawn according to the number, shape and size of the components in actual implementation, and the form, number and proportion of the components in actual implementation may be arbitrarily changed, and the layout of the components may be more complicated.

In the following description, numerous details are set forth in order to provide a more thorough explanation of embodiments of the present application, it will be apparent, however, to one skilled in the art that embodiments of the present application may be practiced without these specific details, in other embodiments, well-known structures and devices are shown in block diagram form, rather than in detail, in order to avoid obscuring the embodiments of the present application.

It should be noted that, for the driving system, the implementation of the ASC control or the FW control is actually performed by controlling the power conversion module of the motor controller, taking an insulated gate bipolar transistor (Insulated Gate Bipolar Transistor, IGBT) as an example, please refer to fig. 1, and fig. 1 is a schematic diagram of the operation of the ASC and the FW according to an exemplary embodiment of the present application. As shown in fig. 1 (a), when the upper bridge arm and the lower bridge arm of the IGBT module are both disconnected, the inverter enters a passive rectifying state, and is in a FW safe state; when the three tubes of the upper arm of the IGBT module are turned on and the three tubes of the lower arm are turned off, as shown in fig. 1 (b), or when the three tubes of the upper arm of the IGBT module are turned off and the three tubes of the lower arm are turned on, as shown in fig. 1 (c), the IGBT module is in an ASC safe state. Therefore, the precondition of accurately realizing ASC or FW control is that the on and off of the upper and lower six three-phase bridge arms on the power converter module can be correctly controlled.

The upper and lower bridge arm switch tubes in FW are all disconnected, so that the motor and the motor controller are separated, and the motor can only perform passive rectification through the reverse diode on the inverter bridge under the condition. The FW has the advantage that no significant unintended torque is generated and thus no impact on the driver's handling. However, if FW is performed during the high-speed process of the motor, the motor is in a weak magnetic state at this time, which leads to a higher back electromotive force, and the voltage of the back electromotive force is greater than the battery voltage after the back electromotive force is passively rectified by the reverse diode, so that the DC-Link (capacitor) is charged, the bus voltage is also increased, other electronic components such as IGBTs and the like hanging on the bus are affected, and the risk of failure of the controller is increased.

In ASC, motor stator winding and IGBT of upper/lower bridge arm form closed loop, back electromotive force energy generated by motor is released through stator winding, motor output end generates corresponding braking moment, closed loop is isolated from external voltage, and bus voltage is not affected. For ASC state, the current increases rapidly with the increase of the rotating speed in the low-speed area, and then decreases rapidly with the increase of the rotating speed, and the high-speed area tends to be stable; the output torque of the motor rapidly increases along with the rising of the rotating speed in the ultra-low speed area, then rapidly decreases along with the rising of the rotating speed, and the high speed area tends to be stable. Under the low-speed condition, the ASC can generate larger braking torque for the motor rotor, the braking torque can enable the motor to stop rapidly and enter a safe state, but the torque is unexpected torque, the control of a driver on the vehicle can be influenced, meanwhile, the ASC can generate larger transient high current, the generated temperature rise can influence the thermal safety performance of the vehicle, and meanwhile, the service life of the motor magnetic steel can be influenced.

Therefore, the control of the safety state of the motor controller seriously affects the performance, safety and service life of the vehicle, and for the switching of the safety state of the motor controller, usually, according to the output torque and the rotating speed as the judging points, the switching points are unchanged under different working conditions, the corresponding rotating speed is a constant value, the switching scene of the safety state is too simple, and the output characteristics of the active protection ASC and the open circuit protection FW under different voltages are ignored, so that unexpected torque is generated, thereby affecting the safe operation of the motor controller, and a reasonable control strategy based on different voltages needs to be provided.

Thus, referring to fig. 2, fig. 2 is a schematic view of an implementation environment of a safety state control device of a motor controller according to an exemplary embodiment of the present application. As shown in fig. 2, the implementation environment includes a vehicle 201 and a control device 202, where the control device 202 is embedded in the vehicle 201 to realize control of a safety state of a motor controller, and the control device 202 includes, but is not limited to, a vehicle system, a vehicle-mounted computer, etc., and determines a target switching point of the safety state in real time through a current voltage and a preset output torque curve graph, so that the target switching points are different under different voltages, and then, by combining with the current rotation speed, the target safety state of the motor controller is reasonably controlled and adjusted, thereby maximally reducing generation of unexpected torque, avoiding permanent demagnetization of motor magnetic steel, maintaining the service life of the motor, and improving safety and controllability of the vehicle.

Referring to fig. 3, fig. 3 is a flowchart illustrating a safety state control method of a motor controller according to an exemplary embodiment of the present application. The method may be applied to the implementation environment shown in fig. 2 and specifically executed by the control device in the implementation environment. It should be understood that the method may be adapted to other exemplary implementation environments and be specifically executed by devices in other implementation environments, and the implementation environments to which the method is adapted are not limited by the present embodiment.

As shown in fig. 3, in an exemplary embodiment, the method for controlling the safety state of the motor controller at least includes steps S310 to S350, which are described in detail as follows:

step S310, obtaining the current voltage and the current rotation speed of the motor.

In an embodiment, before acquiring the current voltage and the current rotation speed of the vehicle, the method further includes: monitoring the real-time state of a motor controller; when the real-time state is determined to be a driving fault state, generating a driving fault signal based on the driving fault state; and responding to the driving fault signal, triggering the motor controller to control the motor to enter a safety protection state. That is, only after the vehicle fails and affects the driving safety, the control of the motor controller needs to enter a safe state.

Specifically, acquiring a current voltage of the motor includes: collecting a first voltage signal in the output signal of the battery pack, a second voltage signal in the output signal of the driving module and a third voltage signal in the output signal of the power module; and processing the first voltage signal, the second voltage signal and the third voltage signal to obtain the current voltage.

Referring to fig. 4, fig. 4 is a schematic diagram of a multi-voltage acquisition device according to an exemplary embodiment of the application. As shown in fig. 4, the multi-voltage acquisition device at least comprises a control device, a battery pack and a battery management unit. The battery pack is the power output of the electric vehicle, providing a high voltage input to the control device. The battery management unit is BMS (Battery management system), acquires the battery cell voltage and converts the battery cell voltage into the total voltage, and outputs the total voltage to other modules through communication. The control device refers to a motor controller and at least comprises a micro control unit, a safety state processing unit, a driving control unit and a power module. The micro control unit at least comprises a memory and an actuator, and is used for storing control data information and executing the control of the motor controller; the safety state processing unit is in electrical signal connection with the micro control unit, receives the control signal of the micro control unit and outputs the comprehensive control signal to the drive control unit; the driving control unit is in electric signal connection with the safety state processing unit, receives the comprehensive control signal and controls the power module to enter a safety state ASC or FW; and the power module is connected with the micro-control unit through an electric signal, and the micro-control unit collects the high-voltage input voltage of the power module.

In fig. 4, the micro control unit is electrically connected with the power module, receives the AD sampling signal, and processes the AD sampling signal into a first voltage signal; the driving control unit is electrically connected with the first voltage signal and receives the frequency sampling signal; is communicatively connected to the battery management unit BMS, and receives the third voltage signal. Preferably, the first voltage signal collected by the micro control unit can be a resistor voltage division, and is output to the micro control unit after being isolated and operational amplifier. Preferably, the safety state processing unit further receives signals of other modules, such as a hardware overvoltage signal and a power management signal, for comprehensively judging with the control signals, and outputs the comprehensive control signals to the driving control unit, wherein the safety state processing unit can be in a logic gate circuit, and the driving control unit can be in a driving control chip.

It should be noted that, the above processing the AD sampling signal into the first voltage signal and the frequency sampling signal into the second voltage signal, and specific processing logic is not specifically described in this embodiment, and only the multiple redundant sampling of the current voltage can be implemented by the multiple voltage acquisition device in this embodiment, so as to provide stable, accurate and real-time current voltage (i.e. bus voltage).

Step S320, determining a target switching point representing a safety state of the motor controller according to the current voltage and the preset output torque curve.

It should be noted that the target switching point is a switching point of ASC and FW, and corresponds to a switching rotation speed, that is, when the current rotation speed of the motor reaches a certain rotation speed value after the vehicle enters a safe state, the safe state of the motor controller should be controlled to be ASC or FW. Additionally, the preset output torque profile may be pre-stored in the micro-control assembly.

In an embodiment, please refer to fig. 5, fig. 5 is a flowchart of step S220 in the embodiment shown in fig. 3 in an exemplary embodiment. As shown in fig. 5, the obtaining of the preset output torque curve graph includes at least steps S510 to S540, as follows: step S510, if the motor is in an open-circuit protection safety state, collecting a plurality of first output torques generated by corresponding different motor speeds under different motor voltages to obtain a first output torque set formed by the plurality of first output torques; step S520, if the motor is in an active short-circuit safety state, calculating a plurality of second output torques generated at different motor speeds to obtain a second output torque set formed by the plurality of second output torques; step S530, a motor rotating speed-output torque coordinate system is established, a first output torque curve of an open-circuit protection safety state is drawn according to a first output torque set, and a second output torque curve of an active short-circuit protection state is drawn according to a second output torque set, wherein the first output torque curve is a plurality of output torque curves; step S540, the first output torque curve and the second output torque curve are spliced to generate a preset output torque curve graph.

It should be noted that, the first output torques generated by corresponding to different motor speeds under different motor voltages are collected, for example, the first output torques generated by corresponding to different motor speeds under 235V are collected, then the first output torques generated by corresponding to different motor speeds under 315V are collected, or the first output torques generated by corresponding to different motor speeds under 350V are collected, so that a plurality of first output torque curves can be obtained based on different voltages, and in addition, the value range of the voltages is in accordance with the range of the motor voltages.

As shown in fig. 6, fig. 6 is a schematic diagram of three-phase full-bridge passive rectification shown in an exemplary embodiment of the present application. As shown in fig. 6, six freewheeling diodes form a three-phase full-bridge rectifying circuit, FW realizes that the controller breaks away from control of the motor by turning off 6 switching tubes of the inverter bridge, and under this condition, the energy measured by the motor can only be passively rectified by the reverse diodes on the inverter bridge. If the effective value of the counter electromotive force does not exceed the bus voltage, the counter electromotive force cannot enable the diode to be conducted, the motor is in a cut-off state and runs in an open circuit, and the rotor can only stop by means of mechanical damping. Thus, FW has two states: (1) The back electromotive force is larger than the bus voltage, and the kinetic energy of the motor is discharged through passive rectification; (2) The back electromotive force is less than the busbar voltage, the kinetic energy of the motor is discharged through the ground or mechanical damping, and when the back electromotive force is less than the busbar voltage, 0 torque is output, and the minimum unexpected torque requirement is met.

Referring to fig. 7, fig. 7 is a graph showing ASC output torque versus current as a function of motor speed according to an exemplary embodiment of the present application. As shown in fig. 7, the horizontal axis represents motor rotation speed, the left vertical axis represents current, the right vertical axis represents ASC output torque, wherein the curve with dots is a graph of current versus motor rotation speed, and the curve with squares is a graph of ASC output torque versus motor rotation speed. As can be seen from fig. 7, at low rotational speeds, the ASC will generate a large braking torque on the motor rotor, which braking torque will enable the motor to be stopped quickly, into a safe state, but which is an unintended torque, which will have an impact on the driver's handling of the vehicle. Meanwhile, the ASC generates a large transient heavy current, the generated temperature rise affects the thermal safety performance of the vehicle and affects the service life of the motor magnet steel, referring to fig. 8, fig. 8 is a schematic diagram of a transient three-phase current generated by the ASC according to an exemplary embodiment of the present application, and as shown in fig. 8, a very large transient current is generated when the ASC enters an ASC state, and the transient heavy current mainly has two kinds of hazards, namely, permanent damage to components and parts and irreversible demagnetization to the loaded motor magnet steel are caused, so that the vehicle is reasonably controlled to enter the ASC state.

In addition, the first output torque and the second output torque can be obtained by actually collecting the high-voltage gantry belt product, or can be obtained by performing simulation calculation according to parameters of the motor.

Specifically, in one embodiment, the calculation formula of the second output torque is:wherein T is _e Representing an output torque; p is p _n Representing the pole pair number of the motor; ω represents the mechanical angular velocity; r is R _s A motor stator winding; psi _f Representing rotor flux linkage; l (L) _d Representing d-axis inductance; l (L) _q Representing the q-axis inductance.

In the present embodiment, the calculation formula of the second output torque varies based on the difference in the motor rotation speed, specifically, when the motor rotation speed is low (i.e.) The calculation formula is +.> When the motor speed is high (i.e. +.>) The calculation formula is +.>

Referring to fig. 9, fig. 9 is a preset output torque profile according to an exemplary embodiment of the present application. As shown in fig. 9, the horizontal axis represents motor rotation speed, and the vertical axis represents output torque; curve 1 shows the variation relationship of motor torque with motor speed in ASC state; curve 2 shows the variation of motor torque with motor speed at 235V in FW; curve 3 shows the variation of motor torque with motor speed at 315V in FW; curve 4 shows the variation of motor torque with motor speed at 350V in FW; curve 5 shows the motor torque as a function of motor speed at 410V in FW.

In one embodiment, determining a target switching point indicative of a safe state of the motor controller based on the current voltage and in combination with a preset output torque profile includes: acquiring a plurality of intersection points of the first output torque curve and the second output torque curve; taking an intersection point curve formed by intersection points as a safe output torque curve; quantifying the relation between the safe output torque curve and the motor rotating speed to obtain a safe state switching curve; and acquiring a target intersection point of the first output torque curve corresponding to the current voltage and the safety state switching curve, and determining the target intersection point as a target safety state switching point.

For example, with continued reference to fig. 9, the first output torque curve (curves 2, 3, 4, 5) and the second output torque curve (curve 1) form 4 intersections, which represent the safe state switching points at voltages of 235V, 315V, 350V, 410V, respectively. And taking an intersection curve formed by the 4 intersection points as a safe output torque curve, quantifying the relation between the safe output torque curve and the motor rotating speed, and obtaining a safe state switching curve, wherein the intersection point of the curve 2 and the curve 1 is a target safe state switching point on the assumption that the voltage of the current voltage is 235V.

In another embodiment of the present application, the intersection point of the first output torque curve and the second output torque curve may be increased or decreased according to the actual requirement, so that the switching decision point of the safety state can be dynamically adjusted along with the fluctuation of the voltage under the condition that the output torque characteristics and the safety state under different voltages are in the merits of different rotation speed segments.

Referring to fig. 10, fig. 10 is another preset output torque profile shown in accordance with an exemplary embodiment of the present application. As shown in fig. 10, if output torque data of FW at different voltages of high density is acquired, curves C1, C2, C3...cn; acquiring output torque data of ASC, and obtaining a curve Ck; the intersection point of Ck and any one of the C1-Cn curves forms a safe output torque T (n, V) under the corresponding voltage, n represents the motor rotation speed, and V represents the motor voltage; the intersection points of the curves C1-Cn and the curve Ck are k1, k2 and k3.; quantifying the relation between the safety output torque curve Fx and the motor rotating speed to obtain a safety state switching curve, and writing the safety state switching curve into the micro-control assembly; when the vehicle is triggered to enter a safety state, the multi-voltage acquisition device acquires the current voltage, a switching point of the safety state is dynamically determined according to the current voltage, and if the switching point is k1, the switching rotating speed can be determined to be the rotating speed corresponding to the point n 1.

In one embodiment, determining a target switching point characterizing a safety state of the motor controller based on the current voltage and in combination with the preset output torque profile further comprises: if the target intersection points are multiple, calculating a first peak counter-irrigation voltage according to the current counter-electromotive force of the motor and the motor rotating speed corresponding to each target intersection point; performing second comparison on the first peak reverse filling voltage and a preset withstand voltage value; selecting a first target intersection point with higher motor rotation speed from first target intersection points with the first peak reverse filling voltage smaller than a preset withstand voltage value as a target safety state switching point; and selecting a second target intersection point with a lower corresponding motor rotating speed from second target intersection points with the first peak counter-filling voltage larger than a preset withstand voltage value as a safety state switching point.

It should be noted that, if the density of the motor voltage sampling points is relatively high, n rotation speed switching points (target intersection points) corresponding to the same safety torque may occur, and at this time, the determination of the target switching points may be performed according to the comparison result of the peak reverse charging voltage and the preset withstand voltage value. If an IGBT is taken as an example, the preset withstand voltage is an insulated gate bipolar transistor withstand voltage. In addition, the calculation formula of the peak reverse filling voltage is as follows: peak tank voltage=motor reaction force motor rotation speed 1.4, wherein the motor rotation speed in the formula is the motor rotation speed corresponding to the target intersection point.

Specifically, in an embodiment, after selecting the second target intersection point with the lower corresponding motor rotation speed as the safety state switching point, the method further includes: calculating a second peak counter-current voltage according to the motor rotating speed corresponding to the second target intersection point with the lower motor rotating speed and the current counter-current potential; if the second peak counter-filling voltage is larger than the preset withstand voltage value, taking the preset withstand voltage value as a third peak counter-filling voltage; calculating according to the third peak counter-irrigation voltage and the current counter-electromotive force to obtain a second safety state switching rotating speed; and determining a corresponding point of the second safety state switching rotating speed in the safety state switching curve as a target safety state switching point.

Step S230, determining a first switching rotation speed corresponding to the target switching point based on the preset output torque graph.

Referring to fig. 10, in the preset output torque graph, if k1 is determined as the target switching point, the rotation speed corresponding to the n1 point is the switching rotation speed.

In step S240, the current rotation speed is compared with the first switching rotation speed.

Step S250, the current safety state of the motor controller is adjusted to be a target safety state according to the first comparison result, wherein the target safety state comprises an open circuit protection safety state and an active protection safety state.

Specifically, adjusting the current state of the motor controller to a target safety state according to the comparison result includes: if the first comparison result is that the current rotating speed is greater than or equal to the first safety state switching rotating speed, the current safety state of the motor controller is adjusted to be an active protection safety state; and if the first comparison result is that the current rotating speed is smaller than the first safety state switching rotating speed, the current safety state of the motor controller is adjusted to be an open-circuit protection safety state.

According to the safety state control method of the motor controller, when a vehicle breaks down and affects driving safety, after the motor is triggered to enter a safety state, the current voltage and the current rotating speed of the motor are immediately obtained, the target switching point representing the safety state of the motor controller is determined according to the current voltage and a preset output torque curve graph, the voltage under the current working condition is different, the corresponding target switching point is also different, the output characteristics of the active protection ASC and the open circuit protection FW under different voltages are considered, the target switching point can be dynamically adjusted according to the different voltages, then the first switching rotating speed corresponding to the target switching point is determined based on the preset output torque curve graph, the current rotating speed and the first switching rotating speed are compared once, and finally the current safety state of the motor controller is adjusted to the target safety state according to the first comparison result. The target switching point of the safety state is determined in real time through the current voltage and the output torque curve graph, so that the target switching points are different under different voltages, the target safety state of the motor controller is reasonably controlled and adjusted by combining the current rotating speed, the generation of unexpected torque is reduced to the maximum extent, the permanent demagnetization of motor magnetic steel is avoided, the service life of the motor is maintained, and the safety and the controllability of the vehicle are improved.

Referring to fig. 11, fig. 11 is a schematic structural view of a safety state control device of a motor controller according to an exemplary embodiment of the present application. As shown in fig. 11, the structural schematic diagram includes a battery management controller, a CAN interface, a control module, a driving module, and a power module, which is described in detail as follows:

the battery management controller is an acquisition control unit of a battery pack, is in communication connection with a voltage acquisition unit in the control module through a CAN interface and transmits voltage 1 through a communication network;

the control module comprises a motor control unit and a voltage acquisition unit.

The voltage acquisition unit is in communication connection with the voltage acquisition unit, receives a voltage signal 1 of the battery pack, is in electric signal connection with a driving unit in the driving module, receives a voltage signal 2, preferably, the voltage signal can be a frequency signal, the driving unit acquires the voltage signal to transmit information in a PWM mode, is indirectly and electrically connected with a high-voltage input of the power module, receives a voltage signal 3, preferably, the voltage signal can be an analog sampling signal, and acquires bus voltage through resistor voltage division and sends the bus voltage into the voltage acquisition unit through an isolation operational amplifier.

Preferably, the voltage acquisition unit acquires multiple groups of voltages, redundant sampling is performed, the instantaneity and the accuracy of the voltages are guaranteed, and the early-stage conditions of dynamic control are met. Meanwhile, according to actual configuration, the voltage sampling can be 1 path, 2 paths, 3 paths or more, and bus voltage can be converted through real-time data reverse pushing of the motor.

The motor control unit comprises a micro-control component and a logic processing component. The micro-control component can be specifically regarded as a single-chip microcomputer MCU (Micro Controller Uni, micro-control unit) which internally comprises a memory and an actuator, stores control data information, and executes associated control information and outputs the control information to the logic processing component. The information specifically stored for execution in the embodiment is a voltage signal, safety state control information, or the like. The logic processing component is electrically connected with the micro-control component and receives control information of the micro-control component, in this embodiment, the logic processing component can be specifically regarded as a logic gate circuit, receives various signal inputs to perform logic judgment, and preferably, the logic processing component can also receive the motor rotation speed or the motor voltage and the like, and performs logic judgment in combination with the safety state control signal input of the micro-control component. The logic processing component is electrically connected with a programmable logic device in the driving module, and a safety state control signal after comprehensive judgment is output to the programmable logic device.

The driving module comprises a programmable logic device and a driving unit. The programmable logic device may be a CPLD (Complex Programmable logic device ) programmable logic device, and in other embodiments, may be other types of programmable logic devices. The drive unit may be an IGBT drive unit, and in other embodiments, the drive unit may be another type of drive unit.

The power module comprises 6 IGBTs, the upper bridge arm and the lower bridge arm are respectively composed of 3 IGBTs, control signals of the driving unit are received, and corresponding work of the IGBTs is executed.

Referring to fig. 12, fig. 12 is a block diagram of a safety state control device of a motor controller according to an exemplary embodiment of the present application. The apparatus may be applied to the implementation environment shown in fig. 2, and it should be understood that the apparatus may also be applied to other exemplary implementation environments, and the embodiment is not limited to the implementation environment to which the apparatus is applied.

As shown in fig. 12, in an exemplary embodiment, the safety state control device of the motor controller at least includes an acquisition module 1210, a switching point determination module 1220, a switching rotation speed determination module 1230, and a comparison module 1240, and a target safety state determination module 1250, which will be described in detail below:

an acquisition module 1210, configured to acquire a current voltage and a current rotation speed of the motor;

a switching point determination module 1220 configured to determine a target switching point indicative of a safe state of the motor controller based on the current voltage and the preset output torque profile;

a switching rotation speed determining module 1230, configured to determine a first switching rotation speed corresponding to the target switching point based on the preset output torque graph;

A comparison module 1240 for comparing the current rotation speed with the first switching rotation speed once;

the target safety state determining module 1250 is configured to adjust a current safety state of the motor controller to a target safety state according to the first comparison result, where the target safety state includes an open circuit protection safety state and an active protection safety state.

It should be noted that, the safety state control device of the motor controller provided in the foregoing embodiment and the safety state control method of the motor controller provided in the foregoing embodiment belong to the same concept, where the content of performing the operation by each module has been described in detail in the method embodiment, and is not described herein again.

Referring to fig. 13, fig. 13 is a schematic structural diagram of an electronic device according to an embodiment of the application. Fig. 13 shows a schematic diagram of a computer system suitable for use in implementing an embodiment of the application. It should be noted that, the computer system 1300 of the electronic device shown in fig. 13 is only an example, and should not impose any limitation on the functions and the application scope of the embodiments of the present application.

As shown in fig. 13, the computer system 1300 includes a central processing unit (Central Processing Unit, CPU) 1301 that can perform various appropriate actions and processes, such as performing the methods in the above-described embodiments, according to a program stored in a Read-Only Memory (ROM) 1302 or a program loaded from a storage portion 1308 into a random access Memory (Random Access Memory, RAM) 1303. In the RAM1303, various programs and data required for the system operation are also stored. The CPU1301, ROM 1302, and RAM1303 are connected to each other through a bus 1304. An Input/Output (I/O) interface 1305 is also connected to bus 1304.

The following components are connected to the I/O interface 1305: an input section 1306 including a keyboard, a mouse, and the like; an output portion 1307 including a Cathode Ray Tube (CRT), a liquid crystal display (Liquid Crystal Display, LCD), and the like, a speaker, and the like; a storage portion 1308 including a hard disk or the like; and a communication section 1309 including a network interface card such as a LAN (Local Area Network ) card, a modem, or the like. The communication section 1309 performs a communication process via a network such as the internet. The drive 1313 is also connected to the I/O interface 1305 as needed. Removable media 1311, such as magnetic disks, optical disks, magneto-optical disks, semiconductor memory, and the like, is mounted on drive 1313 as needed so that a computer program read therefrom is mounted to storage portion 1308 as needed.

In particular, according to embodiments of the present application, the processes described above with reference to flowcharts may be implemented as computer software programs. For example, embodiments of the present application include a computer program product comprising a computer program embodied on a computer readable medium, the computer program comprising a computer program for performing the method shown in the flowchart. In such embodiments, the computer program may be downloaded and installed from a network via the communication portion 1309 and/or installed from the removable medium 1311. When executed by a Central Processing Unit (CPU) 1301, performs various functions defined in the system of the present application.

It should be noted that, the computer readable medium shown in the embodiments of the present application may be a computer readable signal medium or a computer readable storage medium, or any combination of the two. The computer readable storage medium may be, for example, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of the computer-readable storage medium may include, but are not limited to: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a Random Access Memory (RAM), a read-Only Memory (ROM), an erasable programmable read-Only Memory (Erasable Programmable Read Only Memory, EPROM), flash Memory, an optical fiber, a portable compact disc read-Only Memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the present application, a computer-readable signal medium may comprise a data signal propagated in baseband or as part of a carrier wave, with a computer-readable computer program embodied therein. Such a propagated data signal may take any of a variety of forms, including, but not limited to, electro-magnetic, optical, or any suitable combination of the foregoing. A computer readable signal medium may also be any computer readable medium that is not a computer readable storage medium and that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device. A computer program embodied on a computer readable medium may be transmitted using any appropriate medium, including but not limited to: wireless, wired, etc., or any suitable combination of the foregoing.

The flowcharts and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods and computer program products according to various embodiments of the present invention. Where each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams or flowchart illustration, and combinations of blocks in the block diagrams or flowchart illustration, can be implemented by special purpose hardware-based systems which perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.

The units involved in the embodiments of the present invention may be implemented by software, or may be implemented by hardware, and the described units may also be provided in a processor. Wherein the names of the units do not constitute a limitation of the units themselves in some cases.

The present invention also provides a computer-readable storage medium having stored thereon a computer program which, when executed by a processor of a computer, causes the computer to perform a safety state control method of a motor controller as described above. The computer-readable storage medium may be included in the electronic device described in the above embodiment or may exist alone without being incorporated in the electronic device.

The above embodiments are merely illustrative of the principles of the present invention and its effectiveness, and are not intended to limit the invention. Modifications and variations may be made to the above-described embodiments by those skilled in the art without departing from the spirit and scope of the invention. It is therefore intended that all equivalent modifications and changes made by those skilled in the art without departing from the spirit and technical spirit of the present invention shall be covered by the appended claims.

Claims

1. A method for controlling a safety state of a motor controller, the method comprising:

acquiring the current voltage and the current rotating speed of a motor;

determining a target switching point representing the safety state of the motor controller according to the current voltage and a preset output torque curve chart;

Determining a first switching rotation speed corresponding to the target switching point based on the preset output torque curve graph;

comparing the current rotation speed with the first switching rotation speed once;

and adjusting the current safety state of the motor controller to a target safety state according to a first comparison result, wherein the target safety state comprises an open circuit protection safety state and an active protection safety state.

2. The method of claim 1, wherein the obtaining of the preset output torque profile comprises:

if the motor is in the open-circuit protection safety state, collecting a plurality of first output torques generated by corresponding different motor speeds under different motor voltages so as to obtain a first output torque set formed by the plurality of first output torques;

if the motor is in the active short-circuit safety state, calculating a plurality of second output torques generated at different motor speeds to obtain a second output torque set formed by the plurality of second output torques;

establishing a motor rotating speed-output torque coordinate system, drawing a first output torque curve of the open-circuit protection safety state according to the first output torque set, and drawing a second output torque curve of the active short-circuit protection state according to the second output torque set, wherein the first output torque curve is a plurality of first output torque curves;

And splicing the first output torque curve and the second output torque curve to generate the preset output torque curve.

3. The method of claim 2, wherein determining a target switching point characterizing a safety state of the motor controller based on the current voltage and in combination with a preset output torque profile comprises:

acquiring intersection points of the first output torque curve and the second output torque curve, wherein the number of the intersection points is multiple;

taking an intersection point curve formed by the intersection points as a safe output torque curve;

quantifying the relation between the safe output torque curve and the motor rotating speed to obtain a safe state switching curve;

and acquiring a target intersection point of the first output torque curve corresponding to the current voltage and the safety state switching curve, and determining the target intersection point as the target safety state switching point.

4. A method of controlling a safety state of a motor controller according to claim 3, wherein said determining a target switching point characterizing the safety state of the motor controller based on the current voltage and in combination with a preset output torque profile further comprises:

If the target intersection points are multiple, calculating a first peak counter-irrigation voltage according to the current counter-electromotive force of the motor and the motor rotating speed corresponding to each target intersection point;

performing second comparison on the first peak reverse filling voltage and a preset withstand voltage value;

selecting a first target intersection point with higher motor rotation speed from first target intersection points with the first peak reverse filling voltage smaller than the preset withstand voltage value as the target safety state switching point;

and selecting a second target intersection point with a lower corresponding motor rotating speed from second target intersection points with the first peak counter-filling voltage larger than the preset withstand voltage value as a safety state switching point.

5. The method for controlling a safe state of a motor controller according to claim 4, further comprising, after selecting the second target intersection point at which the corresponding motor rotation speed is low as the safe state switching point:

calculating a second peak counter-irrigation voltage according to the motor rotating speed corresponding to the second target intersection point with the lower motor rotating speed and the current counter-electromotive force;

if the second peak counter-filling voltage is larger than the preset withstand voltage value, taking the preset withstand voltage value as a third peak counter-filling voltage;

calculating according to the third peak counter-irrigation voltage and the current counter-electromotive force to obtain a second safety state switching rotating speed;

And determining a point corresponding to the second safety state switching rotating speed in the safety state switching curve as the target safety state switching point.

6. The method of claim 4, wherein the second output torque is calculated by the formula:

wherein T is _e Representing an output torque; p is p _n Representing the pole pair number of the motor; ω represents the mechanical angular velocity; r is R _s A motor stator winding; psi _f Representing rotor flux linkage; l (L) _d Representing d-axis inductance; l (L) _q Representing the q-axis inductance.

7. The method for controlling the safety state of the motor controller according to claim 1, characterized by further comprising, before the current voltage and the current rotation speed of the vehicle are acquired:

monitoring the real-time state of the motor controller;

generating a drive fault signal based on the drive fault state when the real-time state is determined to be the drive fault state;

and responding to the driving fault signal, triggering the motor controller to control the motor to enter a safety protection state.

8. The method of claim 1, wherein adjusting the current state of the motor controller to the target safe state according to the comparison result comprises:

If the first comparison result is that the current rotating speed is greater than or equal to the first safety state switching rotating speed, the current safety state of the motor controller is adjusted to be the active protection safety state;

and if the first comparison result is that the current rotating speed is smaller than the first safety state switching rotating speed, adjusting the current safety state of the motor controller to be the open-circuit protection safety state.

9. The method of controlling a safety state of a motor controller according to any one of claims 1 to 8, wherein the acquiring the current voltage of the motor includes:

collecting a first voltage signal in the output signal of the battery pack, a second voltage signal in the output signal of the driving module and a third voltage signal in the output signal of the power module;

and processing the first voltage signal, the second voltage signal and the third voltage signal to obtain the current voltage.

10. A safety state control device of a motor controller, the device comprising:

the acquisition module is used for acquiring the current voltage and the current rotating speed of the motor;

the switching point determining module is used for determining a target switching point representing the safety state of the motor controller according to the current voltage and a preset output torque curve graph;

The switching rotation speed determining module is used for determining a first switching rotation speed corresponding to the target switching point based on the preset output torque curve chart;

the comparison module is used for comparing the current rotating speed with the first switching rotating speed once;

and the target safety state determining module is used for adjusting the current safety state of the motor controller into a target safety state according to a first comparison result, wherein the target safety state comprises an open circuit protection safety state and an active protection safety state.

11. An electronic device, comprising:

one or more processors;

storage means for storing one or more programs which, when executed by the one or more processors, cause the electronic device to implement the safety state control method of the motor controller of any one of claims 1 to 9.

12. A computer readable storage medium having stored thereon computer readable instructions which, when executed by a processor of a computer, cause the computer to perform the method of controlling the safety state of a motor controller according to any one of claims 1 to 9.