Motor back electromotive force determination method and device, equipment, storage medium and program product

Abstract

The invention discloses a motor back electromotive force determination method and device, equipment, a storage medium and a program product. The method belongs to the technical field of power electronics, and comprises the following steps: under the condition that a motor is determined to be in a zero-torque operation state, obtaining motor operation electrical parameters and a motor rotation speed; determining a motor running state of the motor based on the motor rotating speed and a preset rotating speed threshold value; and determining the counter electromotive force of the motor according to the motor operation state and the motor operation electrical parameters. According to the embodiment of the invention, the counter electromotive force of the motor can be simply, conveniently and accurately calculated, so that accurate torque control of the motor is realized.

Description

Technical Field

[0001] The present application belongs to the technical field of power electronics, and in particular, relates to a method, device, equipment, storage medium and program product for determining back electromotive force of a motor. Background Art

[0002] Back electromotive force refers to the electromotive force generated by resisting the trend of current change. During the operation of the permanent magnet synchronous motor, the operating current and cooling system of the permanent magnet synchronous motor will cause the rotor temperature to rise, causing the back electromotive force of the permanent magnet synchronous motor to change, thereby affecting the torque control of the permanent magnet synchronous motor.

[0003] In the related art, additional coils are usually added to measure the induced electromotive force of the rotor in the permanent magnet synchronous motor, so as to calculate the back electromotive force of the permanent magnet synchronous motor. However, adding additional coils to measure the back electromotive force of the permanent magnet synchronous motor not only requires placing the permanent magnet synchronous motor on a special test device for measurement, but also the measurement accuracy is affected by the environment, resulting in the calculated back electromotive force being inaccurate, thereby affecting the torque control of the motor. Summary of the invention

[0004] The embodiments of the present application provide a method, device, equipment, storage medium and program product for determining the back electromotive force of a motor, which can easily and accurately calculate the back electromotive force of the motor, thereby achieving precise torque control of the motor.

[0005] On the one hand, an embodiment of the present application provides a method for determining back electromotive force of a motor, the method comprising:

[0006] When it is determined that the motor is in a zero torque operating state, obtaining the motor operating electrical parameters and the motor speed;

[0007] Determining a motor operating state of the motor based on the motor speed and a preset speed threshold;

[0008] The back electromotive force of the motor is determined according to the motor operating state and the motor operating electrical parameters.

[0009] Optionally, the motor operating electrical parameters include stator resistance, electrical angular velocity, first direct-axis inductance, first quadrature-axis inductance and motor operating current; and determining the motor back electromotive force according to the motor operating state and the motor operating electrical parameters includes:

[0010] Determining the direct-axis current and quadrature-axis current of the rotor according to the motor running current;

[0011] determining a direct-axis voltage according to the direct-axis current, the stator resistance, the electrical angular velocity and the first direct-axis inductance;

[0012] Determining a quadrature-axis voltage according to the quadrature-axis current, the stator resistance, the electrical angular velocity and the first quadrature-axis inductance;

[0013] The back electromotive force of the motor is determined according to the direct-axis voltage, the quadrature-axis voltage and the running state of the motor.

[0014] Optionally, determining the motor back electromotive force according to the direct-axis voltage, the quadrature-axis voltage and the motor operating state includes:

[0015] When the motor operating state is determined to be a field weakening region operating state, the quadrature axis voltage is determined to be a motor back electromotive force.

[0016] Optionally, determining the motor back electromotive force according to the direct-axis voltage, the quadrature-axis voltage and the motor operating state includes:

[0017] When the motor operation state is determined to be a non-weakening magnetic field region operation state, determining a rotational electromotive force according to the electrical angular velocity, the quadrature-axis inductance and the quadrature-axis current;

[0018] The motor back electromotive force is determined according to the difference between the quadrature-axis voltage and the rotational electromotive force.

[0019] Optionally, determining the direct-axis current and the quadrature-axis current of the rotor according to the motor operating current includes:

[0020] Performing a clack transformation on the motor running current to obtain a two-phase orthogonal current in an α-β coordinate system;

[0021] Park transformation is performed on the two-phase orthogonal current to obtain a direct-axis current and a quadrature-axis current in a dq coordinate system.

[0022] Optionally, before determining the quadrature-axis voltage according to the direct-axis current, the stator resistance, the electrical angular velocity and the direct-axis inductance, the method further comprises:

[0023] Obtaining historical motor back electromotive force during multiple historical operation cycles of the motor;

[0024] Based on the historical motor back electromotive force, determining the historical quadrature-axis inductance and the corresponding historical quadrature-axis current at multiple temperature intervals;

[0025] determining a quadrature-axis inductance-quadrature-axis current-temperature relationship based on the plurality of temperature intervals, the historical quadrature-axis inductance, and the historical quadrature-axis current;

[0026] Obtaining the first quadrature-axis inductance, including:

[0027] In the quadrature-axis inductance-quadrature-axis current-temperature relationship, searching for a historical quadrature-axis inductance corresponding to the quadrature-axis current;

[0028] The historical quadrature-axis inductance corresponding to the quadrature-axis current is determined as a first quadrature-axis inductance.

[0029] Optionally, after determining the motor back electromotive force according to the motor operating state and the motor operating electrical parameters, the method further includes:

[0030] Compensating the torque output by the motor according to the back electromotive force of the motor to obtain the output torque;

[0031] The motor control electrical parameters are determined according to the output torque, so as to perform torque control on the motor according to the motor control electrical parameters.

[0032] On the other hand, an embodiment of the present application provides a device for determining back electromotive force of a motor, the device comprising:

[0033] An acquisition module, used for acquiring the motor operating electrical parameters and the motor speed when it is determined that the motor is in a zero torque operating state;

[0034] A determination module, configured to determine a motor operating state of the motor based on the motor speed and a preset speed threshold;

[0035] The determination module is also used to determine the motor back electromotive force according to the motor operating state and the motor operating electrical parameters.

[0036] In another aspect, an embodiment of the present application provides an electronic device, the device comprising: a processor and a memory storing computer program instructions;

[0037] When the processor executes the computer program instructions, the method for determining the motor back electromotive force as described in the first aspect is implemented.

[0038] On the other hand, an embodiment of the present application provides a computer storage medium, on which computer program instructions are stored. When the computer program instructions are executed by a processor, the method for determining the motor back electromotive force as described in the first aspect is implemented.

[0039] On the other hand, an embodiment of the present application provides a computer program product. When the instructions in the computer program product are executed by a processor of an electronic device, the electronic device executes the method for determining the motor back electromotive force as described in the first aspect.

[0040] The motor back-electromotive force determination method, device, equipment and computer storage medium of the embodiments of the present application, in the embodiments of the present application, when the torque of the motor is controlled, since the rotor of the motor will generate back-electromotive force during the operation of the motor, affecting the operation of the motor, when the motor is in a zero-torque operating state, the motor operating state can be determined based on the motor speed and a preset speed threshold, and then the motor back-electromotive force can be determined based on the motor operating state and the corresponding motor operating electrical parameters. In the process of determining the motor back-electromotive force, there is no need to place the motor on an additional measuring device for measurement, and the accuracy of the motor back-electromotive force calculation can be guaranteed during the operation of the motor, thereby achieving precise torque control of the motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solution of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0042] Figure 1 is a flow chart of a method for determining back electromotive force of a motor provided by an embodiment of the present application;

[0043] Figure 2 is a flow chart of a method for determining back electromotive force of a motor provided by an embodiment of the present application;

[0044] Figure 3 is a structural schematic diagram of a device for determining back electromotive force of a motor provided by another embodiment of the present application;

[0045] Figure 4 It is a structural schematic diagram of an electronic device provided in yet another embodiment of the present application. DETAILED DESCRIPTION

[0046] The features and exemplary embodiments of various aspects of the present application will be described in detail below. In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain the present application, rather than to limit the present application. For those skilled in the art, the present application can be implemented without the need for some of these specific details. The following description of the embodiments is only to provide a better understanding of the present application by illustrating the examples of the present application.

[0047] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "include..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0048] In order to solve the problems of the prior art, embodiments of the present application provide a method, apparatus, device, storage medium and program product for determining the back electromotive force of a motor.

[0049] In an embodiment of the present application, when the torque of the motor is controlled, since the rotor of the motor will generate back electromotive force during the operation of the motor, which affects the operation of the motor, when the motor is in a zero-torque operating state, the motor operating state can be determined based on the motor speed and a preset speed threshold, and then the motor back electromotive force can be determined based on the motor operating state and the corresponding motor operating electrical parameters. In the process of determining the motor back electromotive force, there is no need to place the motor on an additional measuring device for measurement. The accuracy of the motor back electromotive force calculation can be guaranteed during the operation of the motor, thereby achieving precise torque control of the motor.

[0050] The following first introduces the method for determining the motor back electromotive force provided in the embodiment of the present application.

[0051] Figure 1 FIG. 1 is a flow chart of a method for determining the back electromotive force of a motor provided by an embodiment of the present application. Figure 1 As shown, the method for determining the motor back electromotive force may include S101-S103:

[0052] S101, when it is determined that the motor is in a zero torque operation state, obtaining the motor operation electrical parameters and the motor speed.

[0053] In some embodiments, in order to eliminate the interference of external factors on the calculation of the motor's back electromotive force, it is necessary to ensure that the motor is in a zero-torque operating state for calculation, that is, the zero-torque operating state can be a no-load state or a special torque state. The special torque can maintain the operating state in which the electromagnetic torque generated by the motor is balanced with the load torque.

[0054] In this embodiment, when it is determined that the motor is in a zero torque operating state, the motor operating electrical parameters can be obtained by a sensor and the motor speed can be obtained by a tachometer to calculate the back electromotive force of the motor.

[0055] As an example, the motor in the embodiment of the present application may be a permanent magnet synchronous motor, or other types of motors that can generate back electromotive force, which is not limited here.

[0056] S102, determining a motor operating state of the motor based on the motor speed and a preset speed threshold.

[0057] In an embodiment of the present application, as an example, the motor operating state may include a non-weak magnetic zone operating state and a weak magnetic zone operating state. During the operation of the motor, the motor will experience non-weak magnetic zone operation and weak magnetic zone operation. For different operating states, the back electromotive force of the motor is different, so different operating states need to be determined.

[0058] Specifically, the motor operating state of the motor can be determined by the motor speed. For example, during the operation of the motor, as the motor speed increases, the stator direct-axis current begins to increase negatively and the quadrature-axis component gradually decreases, thereby weakening the magnetic flux intensity generated by the permanent magnet. At this time, the motor is operating in the weak magnetic region, and the motor begins to enter the weak magnetic region operating state. In other words, the motor enters the weak magnetic region operating state. At this time, the motor speed is greater than a preset speed threshold, wherein the preset speed threshold can be the motor base speed. As an example, the preset speed threshold can also be the speed of the motor being measured set by the dynamometer.

[0059] In addition, when the motor speed is less than or equal to the preset speed threshold, the motor is in a non-weakening magnetic zone operating state.

[0060] In some other embodiments, when the torque output by the motor is zero torque, the motor operating state of the motor can also be judged by the direct-axis current and the cross-axis current of the rotor. For example, when the torque output by the motor is zero torque, the direct-axis current and the cross-axis current of the motor rotor are both 0, and it can be determined that the motor operating state of the motor is a non-weak magnetic zone operating state, that is, the motor operates in a non-weak magnetic zone; when the cross-axis current of the motor rotor is 0 and the direct-axis current is not 0, it can be determined that the motor operating state of the motor is a weak magnetic zone operating state, that is, the motor operates in a weak magnetic zone.

[0061] S103, determining the motor back electromotive force according to the motor operating state and the motor operating electrical parameters.

[0062] In some embodiments, the motor operating electrical parameters may include stator resistance, electrical angular velocity, first direct-axis inductance, first quadrature-axis inductance, and motor operating current.

[0063] Reference Figure 2In this embodiment, since the permanent magnet synchronous motor is torque controlled, in order to accurately determine the motor back electromotive force during the motor torque control process, S1031-S1034 may be included before S103:

[0064] S1031, determining the direct-axis current and quadrature-axis current of the rotor according to the motor operating current;

[0065] S1032, determining the direct-axis voltage according to the direct-axis current, the stator resistance, the electrical angular velocity, and the first direct-axis inductance;

[0066] S1033, determining a quadrature-axis voltage according to the quadrature-axis current, the stator resistance, the electrical angular velocity, and the first quadrature-axis inductance;

[0067] S1034, determining the motor back electromotive force according to the direct-axis voltage, the quadrature-axis voltage and the motor operating state.

[0068] In this embodiment, when the permanent magnet synchronous motor is in torque control, since the permanent magnet synchronous motor is a three-phase alternating current, in order to accurately determine the motor back electromotive force, the direct axis current and quadrature axis current of the rotor can be determined according to the motor running current, and then the direct axis voltage can be determined according to the following formula (1):

[0069] <![CDATA[U d =R s *i d -ω e L d *i d ]]> (1)

[0070] Among them, U d is the direct axis voltage, R s is the stator resistance, i d is the direct axis current, ω e is the electrical angular velocity, L d is the first straight-axis inductor.

[0071] In this embodiment, the quadrature axis voltage can be determined according to the following formula (2):

[0072] <![CDATA[U q =R s *i q +ω e (L d *i d )]]> (2)

[0073] Among them, U q is the quadrature axis voltage, R s is the stator resistance, i q is the quadrature axis current, ω e is the electrical angular velocity, L q is the first quadrature-axis inductance.

[0074] It is worth noting that the above quadrature-axis voltage and direct-axis voltage are calculated in the absence of back electromotive force.

[0075] In some other embodiments, the quadrature-axis voltage may also be determined according to the following formula (3):

[0076] <![CDATA[U q =R s *i q +ω e (L d *i d )+U f ]]> (3)

[0077] Among them, U f is the motor back electromotive force.

[0078] When the motor has a back electromotive force, the quadrature-axis voltage can be acquired in real time by a sensor.

[0079] In some embodiments, S1031 may specifically include:

[0080] Perform clack transformation on the motor running current to obtain the two-phase orthogonal current in the α-β coordinate system;

[0081] Perform park transformation on the two-phase orthogonal current to obtain the direct-axis current and quadrature-axis current in the dq coordinate system.

[0082] In this embodiment, since the permanent magnet synchronous motor is FOC torque controlled, when determining the direct-axis current and quadrature-axis current of the motor, the three-phase motor operating current is firstly subjected to a clack transformation to obtain a two-phase orthogonal current in the α-β coordinate system, that is, a two-phase orthogonal current in a two-phase rotating coordinate system. As an example, the two-phase orthogonal current may include an orthogonal current on the α-axis and an orthogonal current on the β-axis. Then, the two-phase orthogonal current is subjected to a park transformation to obtain a direct-axis current and a quadrature-axis current in the dq coordinate system, that is, a direct-axis current and a quadrature-axis current in a two-phase stationary coordinate system.

[0083] Since the motor runs in a zero torque state, the back electromotive force of the motor is determined by the quadrature-axis voltage, the direct-axis voltage and the motor operating state.

[0084] Specifically, S1034 may include:

[0085] When the motor operating state is determined to be a field weakening region operating state, the quadrature axis voltage is determined as the motor back electromotive force.

[0086] In this embodiment, when the motor operating state is determined to be the weak magnetic field operating state, the quadrature-axis current and the direct-axis current are both 0. At this time, the motor back electromotive force of the motor is determined by the quadrature-axis voltage of the motor rotor, that is, the motor back electromotive force of the motor is equal to the quadrature-axis voltage.

[0087] In some other embodiments, S1034 may also include:

[0088] When the motor operation state is determined to be a non-weakening magnetic field region operation state, the rotational electromotive force is determined according to the electrical angular velocity, the quadrature-axis inductance and the quadrature-axis current;

[0089] The motor back EMF is determined based on the difference between the quadrature axis voltage and the rotational EMF.

[0090] In this embodiment, when the motor operating state is determined to be a non-weakening magnetic zone operating state, the motor back electromotive force is determined according to the above formula (3), that is, when the motor operating state is determined to be a non-weakening magnetic zone operating state, the rotating electromotive force can be determined according to the above formula (3), that is, the rotating electromotive force is determined by the product of the electric angular velocity, the first quadrature-axis inductance and the direct-axis current. Since the quadrature-axis current is 0 at this time, the motor back electromotive force at this time is the difference between the quadrature-axis voltage and the rotating electromotive force.

[0091] As an example, the quadrature-axis voltage and direct-axis current at this time are calculated by the method described above, and the electrical angular velocity can be obtained by acquisition, which will not be elaborated here.

[0092] In this embodiment, in order to calculate the back electromotive force of the motor more quickly and accurately, before S1032, the method may further include:

[0093] Obtain the historical motor back electromotive force in multiple historical operation cycles of the motor;

[0094] Based on the historical motor back electromotive force, determine the historical quadrature-axis inductance and its corresponding historical quadrature-axis current at multiple temperature intervals;

[0095] determining a quadrature-axis inductance-quadrature-axis current-temperature relationship based on a plurality of temperature intervals, the historical quadrature-axis inductance, and the historical quadrature-axis current;

[0096] Obtaining the first quadrature-axis inductance, including:

[0097] In the quadrature-axis inductance-quadrature-axis current-temperature relationship, find the historical quadrature-axis inductance corresponding to the quadrature-axis current;

[0098] A historical quadrature-axis inductance corresponding to the quadrature-axis current is determined as a first quadrature-axis inductance.

[0099] As an example, the temperature interval may be set to 5°C.

[0100] Specifically, in the present embodiment, since the first cross-axis inductance is affected by the cross-axis current and the temperature of the motor operation, it is necessary to calculate it through the historical motor operation parameters of the motor in multiple historical operation cycles, that is, the historical cross-axis inductance and its corresponding historical cross-axis current at a temperature interval are determined through the historical motor back electromotive force, and the temperature at which the historical cross-axis inductance and its corresponding historical cross-axis current are read can be recorded to determine the relationship between the temperature interval, the historical cross-axis inductance and the historical cross-axis current, and obtain the cross-axis inductance-cross-axis current-temperature relationship, that is, the intrinsic relationship is determined through a large number of historical experiments, and when the motor is currently running, the cross-axis inductance corresponding to the cross-axis current and temperature can be found in the cross-axis inductance-cross-axis current-temperature relationship, which is more convenient and quick.

[0101] In some embodiments, after S103, the method may further include:

[0102] The torque output by the motor is compensated according to the back electromotive force of the motor to obtain the output torque;

[0103] The motor control electrical parameters are determined according to the output torque, so as to control the torque of the motor according to the motor control electrical parameters.

[0104] In this embodiment, after accurately calculating the motor back electromotive force, it is also necessary to compensate the torque output by the motor according to the calculated motor back electromotive force to obtain the output torque. Specifically, the output torque can be adjusted by adjusting the direct-axis current and the quadrature-axis current to achieve compensation for the back electromotive force, thereby achieving precise control of the torque accuracy.

[0105] In some other embodiments, according to the above formulas (1) to (3), when these parameters are not obtained by calculation, the temperature, quadrature-axis current, direct-axis current, first quadrature-axis inductance and first direct-axis inductance can be calibrated through the historical operating parameters of the motor to determine the various parameters under multiple temperature conditions, thereby realizing the calculation of the motor back electromotive force.

[0106] Reference Figure 3 The embodiment of the present application further provides a motor back electromotive force determination device 300, and the motor back electromotive force determination device 300 may include:

[0107] The acquisition module 301 is used to acquire the motor operating electrical parameters and the motor speed when it is determined that the motor is in a zero torque operating state;

[0108] A determination module 302, configured to determine a motor operating state of the motor based on a motor speed and a preset speed threshold;

[0109] The determination module 302 is further configured to determine the back electromotive force of the motor according to the motor operation state and the motor operation electrical parameters.

[0110] As an optional implementation manner, the motor operating electrical parameters include stator resistance, electrical angular velocity, first direct-axis inductance, first quadrature-axis inductance and motor operating current; the determination module 302 may also be used to:

[0111] According to the motor running current, determine the direct axis current and quadrature axis current of the rotor;

[0112] Determine the direct-axis voltage according to the direct-axis current, the stator resistance, the electrical angular velocity and the first direct-axis inductance;

[0113] Determining the quadrature-axis voltage according to the quadrature-axis current, the stator resistance, the electrical angular velocity and the first quadrature-axis inductance;

[0114] The motor back electromotive force is determined based on the direct-axis voltage, quadrature-axis voltage and motor operating status.

[0115] As an optional implementation, the determination module 302 may also be used to:

[0116] When the motor operating state is determined to be a field weakening region operating state, the quadrature axis voltage is determined as the motor back electromotive force.

[0117] As an optional implementation, the determination module 302 may also be used to:

[0118] When the motor operation state is determined to be a non-weakening magnetic field region operation state, the rotational electromotive force is determined according to the electrical angular velocity, the quadrature-axis inductance and the quadrature-axis current;

[0119] The motor back EMF is determined based on the difference between the quadrature axis voltage and the rotational EMF.

[0120] As an optional implementation, the determination module 302 may also be used to:

[0121] Perform clack transformation on the motor running current to obtain the two-phase orthogonal current in the α-β coordinate system;

[0122] Perform park transformation on the two-phase orthogonal current to obtain the direct-axis current and quadrature-axis current in the dq coordinate system.

[0123] As an optional implementation, the determination module 302 may also be used to:

[0124] Obtain the historical motor back electromotive force in multiple historical operation cycles of the motor;

[0125] Based on the historical motor back electromotive force, determine the historical quadrature-axis inductance and its corresponding historical quadrature-axis current at multiple temperature intervals;

[0126] determining a quadrature-axis inductance-quadrature-axis current-temperature relationship based on a plurality of temperature intervals, the historical quadrature-axis inductance, and the historical quadrature-axis current;

[0127] The acquisition module 301 may also be used for:

[0128] In the quadrature-axis inductance-quadrature-axis current-temperature relationship, find the historical quadrature-axis inductance corresponding to the quadrature-axis current;

[0129] A historical quadrature-axis inductance corresponding to the quadrature-axis current is determined as a first quadrature-axis inductance.

[0130] As an optional implementation, the determination module 302 may also be used to:

[0131] The torque output by the motor is compensated according to the back electromotive force of the motor to obtain the output torque;

[0132] The motor control electrical parameters are determined according to the output torque, so as to control the torque of the motor according to the motor control electrical parameters.

[0133] Figure 4 A schematic diagram of the hardware structure of an electronic device provided in an embodiment of the present application is shown.

[0134] The electronic device may include a processor 401 and a memory 502 storing computer program instructions.

[0135] Specifically, the processor 401 may include a central processing unit (CPU), or an application specific integrated circuit (ASIC), or may be configured to implement one or more integrated circuits of the embodiments of the present application.

[0136] The memory 402 may include a large capacity memory for data or instructions. By way of example and not limitation, the memory 402 may include a hard disk drive (HDD), a floppy disk drive, a flash memory, an optical disk, a magneto-optical disk, a magnetic tape, or a universal serial bus (USB) drive or a combination of two or more of these. In one example, the memory 402 may include a removable or non-removable (or fixed) medium, or the memory 402 is a non-volatile solid-state memory. The memory 402 may be inside or outside the integrated gateway disaster recovery device.

[0137] In one example, the memory 402 may be a read-only memory (ROM). In one example, the ROM may be a mask-programmed ROM, a programmable ROM (PROM), an erasable PROM (EPROM), an electrically erasable PROM (EEPROM), an electrically rewritable ROM (EAROM), or a flash memory, or a combination of two or more of these.

[0138] The memory 402 may include a read-only memory (ROM), a random access memory (RAM), a magnetic disk storage medium device, an optical storage medium device, a flash memory device, an electrical, optical or other physical / tangible memory storage device. Thus, typically, the memory includes one or more tangible (non-transitory) computer-readable storage media (e.g., a memory device) encoded with software including computer-executable instructions, and when the software is executed (e.g., by one or more processors), it is operable to perform the operations described with reference to the motor back electromotive force determination method according to the first aspect of the present disclosure.

[0139] The processor 401 reads and executes the computer program instructions stored in the memory 402 to implement Figure 1 A method for determining back electromotive force of a motor in the illustrated embodiment.

[0140] In one example, the electronic device may further include a communication interface 403 and a bus 404. Figure 4 As shown, the processor 401, the memory 402, and the communication interface 403 are connected via a bus 404 and communicate with each other.

[0141] The communication interface 403 is mainly used to implement communication between various modules, devices, units and / or equipment in the embodiments of the present application.

[0142] Bus 404 includes hardware, software or both, and the parts of electronic equipment are coupled to each other. For example, but not limitation, bus may include accelerated graphics port (Accelerated Graphics Port, AGP) or other graphics bus, enhanced industry standard architecture (Extended Industry Standard Architecture, EISA) bus, front side bus (Front Side Bus, FSB), hypertransmission (Hyper Transport, HT) interconnection, industry standard architecture (IndustryStandard Architecture, ISA) bus, infinite bandwidth interconnection, low pin count (LPC) bus, memory bus, micro channel architecture (MCA) bus, peripheral component interconnection (PCI) bus, PCI-Express (PCI-X) bus, serial advanced technology attachment (SATA) bus, video electronics standard association local (VLB) bus or other suitable bus or two or more of these combinations. In appropriate cases, bus 404 may include one or more buses. Although the present application embodiment describes and shows a specific bus, the application considers any suitable bus or interconnection.

[0143] The electronic device can execute the video query method in the embodiment of the present application, thereby realizing the combination Figure 1-Figure 3 A method and device for determining the back electromotive force of a motor are described.

[0144] In addition, in combination with the motor back electromotive force determination method in the above embodiment, the embodiment of the present application can provide a computer storage medium for implementation. The computer storage medium stores computer program instructions; when the computer program instructions are executed by the processor, any one of the motor back electromotive force determination methods in the above embodiment is implemented.

[0145] In an optional embodiment, in combination with the motor back electromotive force determination method in the above-mentioned embodiment, the embodiment of the present application can provide a computer program product for implementation, and the instructions in the computer program product are executed by a processor of an electronic device, so that the electronic device can implement any one of the motor back electromotive force determination methods in the above-mentioned embodiments.

[0146] It should be clear that the present application is not limited to the specific configuration and processing described above and shown in the figures. For the sake of simplicity, a detailed description of the known method is omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of the present application is not limited to the specific steps described and shown, and those skilled in the art can make various changes, modifications and additions, or change the order between the steps after understanding the spirit of the present application.

[0147] The functional blocks shown in the above block diagram can be implemented as hardware, software, firmware or a combination thereof. When implemented in hardware, it can be, for example, an electronic circuit, an application specific integrated circuit (ASIC), appropriate firmware, a plug-in, a function card, etc. When implemented in software, the elements of the present application are programs or code segments that are used to perform the required tasks. The program or code segment can be stored in a machine-readable medium, or transmitted on a transmission medium or a communication link by a data signal carried in a carrier wave. "Machine-readable medium" can include any medium capable of storing or transmitting information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, ROM, flash memory, erasable ROM (EROM), floppy disks, CD-ROMs, optical disks, hard disks, optical fiber media, radio frequency (RF) links, etc. The code segment can be downloaded via a computer network such as the Internet, an intranet, etc.

[0148] It should also be noted that the exemplary embodiments mentioned in this application describe some methods or systems based on a series of steps or devices. However, this application is not limited to the order of the above steps, that is, the steps can be performed in the order mentioned in the embodiment, or in a different order from the embodiment, or several steps can be performed simultaneously.

[0149] Aspects of the present disclosure are described above with reference to the flowchart and / or block diagram of the method, device (system) and computer program product according to the embodiment of the present disclosure. It should be understood that each box in the flowchart and / or block diagram and the combination of each box in the flowchart and / or block diagram can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device to produce a machine so that these instructions executed by the processor of the computer or other programmable data processing device enable the implementation of the function / action specified in one or more boxes of the flowchart and / or block diagram. Such a processor can be, but is not limited to, a general-purpose processor, a special-purpose processor, a special application processor, or a field programmable logic circuit. It can also be understood that each box in the block diagram and / or flowchart and the combination of boxes in the block diagram and / or flowchart can also be implemented by dedicated hardware that performs a specified function or action, or can be implemented by a combination of dedicated hardware and computer instructions.

[0150] The above are only specific implementation methods of the present application. Those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working processes of the systems, modules and units described above can refer to the corresponding processes in the aforementioned method embodiments, and will not be repeated here. It should be understood that the protection scope of the present application is not limited to this. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in this application, and these modifications or replacements should be included in the protection scope of this application.

Claims

1. A method for determining back electromotive force of a motor, characterized in that: include: When it is determined that the motor is in a zero torque operating state, obtaining the motor operating electrical parameters and the motor speed; Determining a motor operating state of the motor based on the motor speed and a preset speed threshold; The back electromotive force of the motor is determined according to the motor operating state and the motor operating electrical parameters.

2. The method according to claim 1, characterized in that The motor operating electrical parameters include stator resistance, electrical angular velocity, first direct-axis inductance, first quadrature-axis inductance and motor operating current; Determining the motor back electromotive force according to the motor operating state and the motor operating electrical parameters comprises: Determining the direct-axis current and quadrature-axis current of the rotor according to the motor running current; determining a direct-axis voltage according to the direct-axis current, the stator resistance, the electrical angular velocity and the first direct-axis inductance; Determining a quadrature-axis voltage according to the quadrature-axis current, the stator resistance, the electrical angular velocity and the first quadrature-axis inductance; The back electromotive force of the motor is determined according to the direct-axis voltage, the quadrature-axis voltage and the running state of the motor.

3. The method according to claim 2, characterized in that The step of determining the motor back electromotive force according to the direct-axis voltage, the quadrature-axis voltage and the motor operation state comprises: When the motor operating state is determined to be a field weakening region operating state, the quadrature axis voltage is determined to be a motor back electromotive force.

4. The method according to claim 2, characterized in that: The method of determining the motor back electromotive force according to the direct-axis voltage, the quadrature-axis voltage and the motor running state comprises: When the motor operation state is determined to be a non-weakening magnetic field region operation state, determining a rotational electromotive force according to the electrical angular velocity, the quadrature-axis inductance and the quadrature-axis current; The motor back electromotive force is determined according to the difference between the quadrature-axis voltage and the rotational electromotive force.

5. The method according to any one of claims 2 to 4, characterized in that: The step of determining the direct-axis current and the quadrature-axis current of the rotor according to the motor operating current comprises: Performing a clack transformation on the motor running current to obtain a two-phase orthogonal current in an α-β coordinate system; Park transformation is performed on the two-phase orthogonal current to obtain a direct-axis current and a quadrature-axis current in a dq coordinate system.

6. The method according to any one of claims 2 to 4, characterized in that: Before determining the quadrature-axis voltage according to the direct-axis current, the stator resistance, the electrical angular velocity and the direct-axis inductance, the method further includes: Obtaining historical motor back electromotive force during multiple historical operation cycles of the motor; Based on the historical motor back electromotive force, determining the historical quadrature-axis inductance and the corresponding historical quadrature-axis current at multiple temperature intervals; determining a quadrature-axis inductance-quadrature-axis current-temperature relationship based on the plurality of temperature intervals, the historical quadrature-axis inductance, and the historical quadrature-axis current; Obtaining the first quadrature-axis inductance, including: In the quadrature-axis inductance-quadrature-axis current-temperature relationship, searching for a historical quadrature-axis inductance corresponding to the quadrature-axis current; The historical quadrature-axis inductance corresponding to the quadrature-axis current is determined as a first quadrature-axis inductance.

7. The method according to any one of claims 2 to 4, characterized in that: After determining the motor back electromotive force according to the motor operating state and the motor operating electrical parameters, the method further includes: Compensating the torque output by the motor according to the back electromotive force of the motor to obtain the output torque; The motor control electrical parameters are determined according to the output torque, so as to perform torque control on the motor according to the motor control electrical parameters.

8. A device for determining back electromotive force of a motor, characterized in that: The device comprises: An acquisition module, used for acquiring the motor operating electrical parameters and the motor speed when it is determined that the motor is in a zero torque operating state; A determination module, configured to determine a motor operating state of the motor based on the motor speed and a preset speed threshold; The determination module is also used to determine the motor back electromotive force according to the motor operating state and the motor operating electrical parameters.

9. An electronic device, characterized in that: The device comprises: a processor and a memory storing computer program instructions; When the processor executes the computer program instructions, the method for determining the motor back electromotive force as described in any one of claims 1-7 is implemented.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer program instructions, and when the computer program instructions are executed by a processor, the method for determining the motor back electromotive force according to any one of claims 1 to 7 is implemented.

11. A computer program product, characterized in that When the instructions in the computer program product are executed by a processor of an electronic device, the electronic device executes the method for determining the motor back electromotive force as described in any one of claims 1 to 7.

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