Motor control method and device and electronic equipment

Abstract

The invention relates to the technical field of motor control, and provides a motor control method and device and electronic equipment, and the motor control method comprises the steps: judging whether a vector control motor is in a driving state or a power generation state, and obtaining a first judgment result; judging whether the vector control motor is in a deep flux weakening state to obtain a second judgment result; according to the first judgment result and the second judgment result, a voltage limiting strategy is selected, and the voltage limiting strategy comprises a voltage limiting strategy preferentially meeting the q-axis voltage or a voltage limiting strategy preferentially meeting the d-axis voltage; generating a limited d-axis voltage instruction and a limited q-axis voltage instruction according to the selected voltage limiting strategy; and controlling the vector control motor based on the limited d-axis voltage command and the limited q-axis voltage command. According to the method, the voltage utilization rate of the bus can be improved while the current control stability is ensured, so that the system efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of motor control, and in particular to a motor control method, device and electronic equipment. Background Art

[0002] In modern electric vehicles and industrial drive systems, vector control motors are widely used due to their high efficiency and excellent control performance. Vector control technology achieves efficient drive and power generation of motors by precisely controlling the magnetic field and torque of the motor.

[0003] However, existing control methods for vector controlled motors usually adopt a fixed voltage limiting strategy without considering the actual operating state of the motor, resulting in challenges to the stability and efficiency of motor control. Summary of the invention

[0004] The present invention provides a motor control method, device and electronic device to solve the defects of the prior art that the stability and efficiency of motor control are challenged due to the use of a fixed voltage limiting strategy. It can improve the voltage utilization of the bus while ensuring the stability of current control, thereby improving system efficiency.

[0005] The present invention provides a method for controlling a motor, comprising: determining whether a vector-controlled motor is in a driving state or a power generation state to obtain a first determination result; determining whether the vector-controlled motor is in a deep magnetic weakening state to obtain a second determination result; selecting a voltage limiting strategy according to the first determination result and the second determination result, the voltage limiting strategy comprising a voltage limiting strategy that preferentially satisfies a q-axis voltage or a voltage limiting strategy that preferentially satisfies a d-axis voltage; generating a limited d-axis voltage instruction and a limited q-axis voltage instruction according to the selected voltage limiting strategy; and controlling the vector-controlled motor based on the limited d-axis voltage instruction and the limited q-axis voltage instruction.

[0006] According to the control method of the motor provided by the present invention, the voltage limiting strategy is selected according to the first judgment result and the second judgment result, including: when the first judgment result indicates that the vector controlled motor is in a driving state, and the second judgment result indicates that the vector controlled motor is in a deep magnetic weakening state, or the first judgment result indicates that the vector controlled motor is in a power generation state, and the second judgment result indicates that the vector controlled motor is in a non-deep magnetic weakening state, selecting a voltage limiting strategy that gives priority to the q-axis voltage; when the first judgment result indicates that the vector controlled motor is in a power generation state, and the second judgment result indicates that the vector controlled motor is in a deep magnetic weakening state, or the first judgment result indicates that the vector controlled motor is in a driving state, and the second judgment result indicates that the vector controlled motor is in a non-deep magnetic weakening state, selecting a voltage limiting strategy that gives priority to the d-axis voltage.

[0007] According to the control method of the motor provided by the present invention, the voltage limiting strategy that gives priority to the q-axis voltage includes setting the voltage limit of the q-axis voltage according to the maximum value of the fundamental wave amplitude of the output phase voltage, and the voltage limiting strategy that gives priority to the d-axis voltage includes setting the voltage limit of the d-axis voltage according to the maximum value of the fundamental wave amplitude of the output phase voltage.

[0008] According to the control method of the motor provided by the present invention, the vector control motor is controlled based on the limited d-axis voltage command and the limited q-axis voltage command, including: converting the limited d-axis voltage command and the limited q-axis voltage command into voltage commands on a stationary coordinate system to obtain an α-axis voltage command and a β-axis voltage command; processing the α-axis voltage command and the β-axis voltage command by a pre-constructed overmodulation algorithm to generate a pulse width modulation signal of an inverter; and controlling the vector control motor based on the pulse width modulation signal.

[0009] According to the control method of the motor provided by the present invention, the α-axis voltage command and the β-axis voltage command are processed by a pre-constructed overmodulation algorithm to generate a pulse width modulation signal of the inverter, including: determining a reference voltage vector according to the α-axis voltage command and the β-axis voltage command; calculating the reference action time of two adjacent non-zero voltages according to the reference voltage vector; if the reference voltage vector is located in the overmodulation area, and the sum of half of one reference action time and the other reference action time among the reference action times is not greater than the switching period of the three-phase inverter, then the reference action time is proportionally reduced to obtain the actual action time, and the sum of the actual action times is not greater than the switching period; and the pulse width modulation signal of the three-phase inverter is generated according to the actual action time.

[0010] According to the control method of the motor provided by the present invention, before generating the pulse width modulation signal of the inverter according to the actual voltage vector, the method also includes: if the reference voltage vector is located in the overmodulation area, and the sum of half of one reference action time among the reference action times and the other reference action time is greater than the switching period of the three-phase inverter, then the larger reference action time among the reference action times is retained, and the smaller reference action time among the reference action times is modified to zero to obtain the actual action time.

[0011] According to the control method of the motor provided by the present invention, the reference voltage vector is determined according to the α-axis voltage command and the β-axis voltage command, including: synthesizing the voltage vector to be corrected according to the α-axis voltage command and the β-axis voltage command; calculating a reference modulation index according to the voltage vector to be corrected; determining an actual modulation index corresponding to the reference modulation index according to a pre-established modulation index table; and correcting the voltage vector to be corrected according to the actual modulation index to obtain the reference voltage vector.

[0012] The present invention also provides a control device for a motor, including: a first judgment module, configured to judge whether the vector-controlled motor is in a driving state or a power generation state to obtain a first judgment result; a second judgment module, configured to judge whether the vector-controlled motor is in a deep magnetic weakening state to obtain a second judgment result; a selection module, configured to select a voltage limiting strategy according to the first judgment result and the second judgment result, the voltage limiting strategy including a voltage limiting strategy that preferentially satisfies the q-axis voltage or a voltage limiting strategy that preferentially satisfies the d-axis voltage; a generation module, configured to generate a limited d-axis voltage instruction and a limited q-axis voltage instruction according to the selected voltage limiting strategy; a control module, configured to control the vector-controlled motor based on the limited d-axis voltage instruction and the limited q-axis voltage instruction.

[0013] The present invention also provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, any of the above-mentioned motor control methods is implemented.

[0014] The present invention also provides a non-transitory computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the control method of the motor as described above is implemented.

[0015] The present invention also provides a computer program product, comprising a computer program, wherein when the computer program is executed by a processor, the computer program implements any of the above-mentioned motor control methods.

[0016] The motor control method, device and electronic device provided by the present invention select a voltage limiting strategy that gives priority to the q-axis voltage or a voltage limiting strategy that gives priority to the d-axis voltage according to the state of the motor, and control the vector controlled motor based on the selected voltage limiting strategy. It can improve the voltage utilization rate of the bus while ensuring the stability of current control, thereby improving system efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 It is a flow chart of the motor control method provided by the present invention.

[0019] Figure 2 It is a schematic diagram of the motor control system provided by the present invention.

[0020] Figure 3 It is a schematic diagram of the voltage vector distribution of the first sector in the αβ coordinate system provided by the present invention.

[0021] Figure 4 It is a flow chart of the overmodulation algorithm provided by the present invention.

[0022] Figure 5 It is a schematic diagram of the modulation index table provided by the present invention.

[0023] Figure 6 It is a structural schematic diagram of the control device of the motor provided by the present invention.

[0024] Figure 7 It is a structural schematic diagram of the electronic device provided by the present invention. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] Unless otherwise defined, the technical terms or scientific terms used in the present invention should be understood by people with ordinary skills in the field to which the present invention belongs. The words "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, words such as "one", "one" or "the" do not indicate a quantitative limitation, but indicate the existence of at least one. Words such as "include" or "comprise" mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect.

[0027] The following is a brief explanation of the terms involved in the present invention.

[0028] Combine the following Figure 1-Figure 7 The invention describes a motor control method, a motor control device and an electronic device.

[0029] Figure 1 is a flow chart of the motor control method provided by the present invention, such as Figure 1 As shown, the method includes the following: Step 101: determine whether the vector-controlled motor is in a driving state or a generating state to obtain a first determination result.

[0030] In this embodiment, vector control (also known as field oriented control, i.e., field vector control) is an advanced control strategy for three-phase AC motors (especially permanent magnet synchronous motors and asynchronous motors). Vector control achieves precise control of AC motors by imitating the control method of DC motors. Vector controlled motors may include permanent magnet synchronous motors, switched reluctance motors, and synchronous reluctance motors. Specifically, the driving and generating state of the motor can be determined based on the motor speed and the actual value of the q-axis current, or the electromagnetic torque of the motor can be estimated by measuring the current and voltage of the motor, or the electric power input and output of the motor can be measured to determine whether the vector controlled motor is in a driving state or a generating state.

[0031] Step 102: Determine whether the vector-controlled motor is in a deep field weakening state to obtain a second determination result.

[0032] In this embodiment, determining whether the motor is in a deep field weakening state generally involves monitoring parameters such as the motor's speed, flux, and voltage. Field weakening control, also known as field increase control, refers to the process of reducing the flux in order to maintain a constant power output after the motor exceeds the rated speed. The deep field weakening state refers to a state in which the motor operates at a speed far exceeding its rated speed and needs to significantly reduce the flux to achieve further speed increase.

[0033] Specifically, the sign of the q-axis voltage can be used to determine whether the motor is in a deep field weakening state. Taking a permanent magnet synchronous motor as an example, its steady-state voltage equation is as follows:

[0034] in, U d represents the d-axis voltage, U q represents the q-axis voltage, L d represents the d-axis inductance, L q represents the q-axis inductance, I d represents the d-axis current, I q represents the q-axis current, ω represents the electrical angular velocity of the motor, R s represents the resistance of the motor winding, Represents the magnetic flux. When it is assumed that the magnetic field is weak at a deep level and the influence of resistance is ignored, it can be simplified to When it is considered to have entered deep magnetic weakening.

[0035] In addition, the motor speed, flux current and control system strategy can be combined to comprehensively determine whether the motor is in a deep magnetic weakening state.

[0036] Step 103: Select a voltage limiting strategy according to the first judgment result and the second judgment result.

[0037] In this embodiment, the voltage limiting strategy includes a voltage limiting strategy that gives priority to the q-axis voltage or a voltage limiting strategy that gives priority to the d-axis voltage. The voltage limiting strategy that gives priority to the q-axis voltage is mainly focused on meeting the torque demand because the q-axis voltage is directly related to the torque generated by the motor. In some applications, such as those requiring fast response or high dynamic performance, it is crucial to maintain sufficient torque output. The voltage limiting strategy that gives priority to the d-axis voltage is more focused on maintaining the magnetic flux of the motor because the d-axis voltage is directly related to the magnetic flux control. In some applications that need to maintain constant magnetic flux, such as weak magnetic control or maintaining efficiency at a specific speed, this strategy is more appropriate.

[0038] Step 104 : Generate a limited d-axis voltage command and a limited q-axis voltage command according to the selected voltage limiting strategy.

[0039] In this embodiment, according to the voltage limiting strategy that gives priority to the q-axis voltage or the voltage limiting strategy that gives priority to the d-axis voltage, the voltage limit value may be determined to generate a limited d-axis voltage command and a limited q-axis voltage command.

[0040] Step 105 : Control the vector controlled motor based on the limited d-axis voltage command and the limited q-axis voltage command.

[0041] In this embodiment, according to the actual motor control system, the control of the vector controlled motor may include coordinate transformation, PWM signal generation, current closed-loop control and other parts. In order to improve the system efficiency, SVPWM (space vector pulse width modulation) or other pulse width modulation technologies may also be used to calculate the on-time and off-time of each switch of the inverter according to the voltage command.

[0042] The motor control method provided by the present invention selects a voltage limiting strategy that prioritizes the q-axis voltage or a voltage limiting strategy that prioritizes the d-axis voltage according to the state of the motor, and controls the vector controlled motor based on the selected voltage limiting strategy. It can improve the voltage utilization rate of the bus while ensuring the stability of current control, thereby improving system efficiency.

[0043] Taking the motor control of electric vehicles as an example, for pure electric vehicle drive systems, an embedded permanent magnet synchronous motor system is generally used. The bus voltage in the motor control of electric vehicles is constrained by the power battery, resulting in an upper limit on the AC voltage that the inverter can actually output. Weak magnetic operation is required when the motor runs at high speed. The lower the voltage utilization rate, the greater the weak magnetic current, which reduces system efficiency and affects endurance. Improving the voltage utilization rate of the bus can effectively reduce the weak magnetic current, and the improvement of voltage utilization is generally achieved through overmodulation technology. However, increasing the voltage utilization rate of the bus will cause insufficient current control margin and saturation problems, resulting in system out of control, causing safety problems. The present invention can improve the system efficiency of the pure electric vehicle drive system by selecting a voltage limiting strategy that preferentially satisfies the q-axis voltage or a voltage limiting strategy that preferentially satisfies the d-axis voltage through the state of the motor.

[0044] In some optional implementations, a voltage limiting strategy is selected based on the first judgment result and the second judgment result, including: when the first judgment result indicates that the vector-controlled motor is in a driving state and the second judgment result indicates that the vector-controlled motor is in a deep magnetic weakening state, or the first judgment result indicates that the vector-controlled motor is in a generating state and the second judgment result indicates that the vector-controlled motor is in a non-deep magnetic weakening state, selecting a voltage limiting strategy that prioritizes the q-axis voltage; when the first judgment result indicates that the vector-controlled motor is in a generating state and the second judgment result indicates that the vector-controlled motor is in a deep magnetic weakening state, or the first judgment result indicates that the vector-controlled motor is in a driving state and the second judgment result indicates that the vector-controlled motor is in a non-deep magnetic weakening state, selecting a voltage limiting strategy that prioritizes the d-axis voltage.

[0045] In addition, the correspondence between the first judgment result and the second judgment result and the voltage limiting strategy can be set according to actual needs, and other additional information can also be added. For example, during startup and low-speed operation, a larger torque output is usually required, so a strategy of giving priority to the q-axis voltage may be selected to ensure sufficient torque. When a system fault or abnormality is detected (such as overheating, overcurrent, etc.), it may be necessary to select a strategy of giving priority to the q-axis or d-axis voltage according to the fault type to protect the motor and inverter.

[0046] In some optional implementations, the voltage limiting strategy that gives priority to the q-axis voltage includes setting the voltage limit of the q-axis voltage according to the maximum value of the output phase voltage fundamental amplitude, and the voltage limiting strategy that gives priority to the d-axis voltage includes setting the voltage limit of the d-axis voltage according to the maximum value of the output phase voltage fundamental amplitude. The maximum value of the output phase voltage fundamental amplitude can be directly set as the voltage limit of the q-axis or d-axis, or a proportional value can be pre-set according to the actual situation of the motor control system, for example, 0.95 times the maximum value of the output phase voltage fundamental amplitude is set as the voltage limit of the q-axis voltage, and then the voltage limit of the d-axis is set according to the actual q-axis voltage.

[0047] Taking the permanent magnet synchronous motor as an example, when the PWM overmodulation module adopts the SVPWM modulation mode, the maximum amplitude of the fundamental wave of the output phase voltage of the control system is 2 U dc / π, where U dc is the DC bus voltage. Among them, the voltage limit value of the q-axis and the voltage limit value of the d-axis that give priority to the voltage limit strategy of the q-axis voltage can be: ; The voltage limit value of the q-axis and the voltage limit value of the d-axis that preferentially satisfies the voltage limiting strategy of the d-axis voltage can be: ; in, U d represents the d-axis voltage before limiting, U q represents the q-axis voltage before limiting, U dLmt represents the voltage limit of the d-axis, U qLmt Indicates the voltage limit of the q-axis.

[0048] In some optional implementations, the vector control motor is controlled based on the limited d-axis voltage command and the limited q-axis voltage command, including: converting the limited d-axis voltage command and the limited q-axis voltage command into voltage commands on a stationary coordinate system to obtain an α-axis voltage command and a β-axis voltage command; processing the α-axis voltage command and the β-axis voltage command by a pre-built overmodulation algorithm to generate a pulse width modulation signal of an inverter; and controlling the vector control motor based on the pulse width modulation signal. In this implementation, the system performance can be further improved by processing with a pre-built overmodulation algorithm.

[0049] See also Figure 2 , Figure 2 is a schematic diagram of a motor control system provided by the present invention, Figure 2 The input of the current command acquisition module 1 is the torque command TRef, and the output is the D-axis current reference value IdRef and the Q-axis current reference value IqRef. Specifically, the D-axis current reference value and the Q-axis current reference value corresponding to the torque command can be obtained according to the pre-established offline current table. The current loop PI module 2 determines the D-axis voltage command and the Q-axis voltage command according to the difference between the D-axis current reference value and the Q-axis current reference value and the actual current. The input of the voltage vector limitation module 3 is the DQ-axis voltage command, and the output is the DQ-axis voltage command after limitation. The input of the Ipark transformation module 4 is the DQ-axis voltage command, and the output is the αβ-axis voltage command, that is, the voltage command on the rotating coordinate system is converted into the voltage command on the stationary coordinate system. The input of the overmodulation module 5 is the αβ-axis voltage command, and the output is the three-phase PWM duty cycle command. The specific implementation method is the proposed PWM overmodulation module. The input of the Clark / Park transformation module 8 is the feedback of the three-phase current and the motor angle of the motor, and the output is the feedback of the DQ-axis current, which converts the three-phase current in the stationary coordinate system into the two-phase current in the rotating coordinate system.

[0050] In some optional implementations, the α-axis voltage command and the β-axis voltage command are processed by a pre-built overmodulation algorithm to generate a pulse width modulation signal of the inverter, including: determining a reference voltage vector according to the α-axis voltage command and the β-axis voltage command; calculating the reference action time of two adjacent non-zero voltages according to the reference voltage vector; if the reference voltage vector is located in the overmodulation area, and the sum of half of one reference action time and the other reference action time in the reference action time is not greater than the switching period of the three-phase inverter, then the reference action time is proportionally reduced to obtain the actual action time, and the sum of the actual action time is not greater than the switching period; and the pulse width modulation signal of the three-phase inverter is generated according to the actual action time. Among them, the overmodulation area can be determined according to the pre-set area boundary parameters.

[0051] As an example, the reference action time of two adjacent non-zero voltages can be calculated by the following formula: ,

[0052] ; in, T S represents the switching cycle, T 1. T 2 represents the reference action time of adjacent non-zero voltages, U S represents the reference voltage vector, θ Represents the angle of the reference voltage vector.

[0053] In addition, when calculating the reference action time of two adjacent non-zero voltages, the system error can also be considered by adding an error term to the formula.

[0054] In some optional implementations, before generating the pulse width modulation signal of the inverter according to the actual voltage vector, the method further includes: if the reference voltage vector is located in the overmodulation area, and the sum of half of one reference action time and another reference action time in the reference action time is greater than the switching period of the three-phase inverter, then the larger reference action time in the reference action time is retained, and the smaller reference action time in the reference action time is modified to zero to obtain the actual action time. In addition, if the reference voltage vector is located outside the overmodulation area, it can stay at the six vertices of the hexagon for 1 / 6 of a cycle in sequence, that is, a six-step mode is adopted.

[0055] Combine the following Figure 3 The modulation process is explained with an example. Figure 3 It is a schematic diagram of the voltage vector distribution of the first sector in the αβ coordinate system provided by the present invention. In the αβ coordinate system, the inverter can generate seven basic voltage vectors (including one zero vector and six non-zero vectors), which form a regular hexagon. Each non-zero vector corresponds to a specific switch state combination of the inverter. The regular hexagon composed of six non-zero vectors is the voltage vector output capacity boundary, and the vectors inside the hexagon can be synthesized by activating these switch states in time proportion. For example, to synthesize a vector located between two vertices, it can be achieved by activating the switch states corresponding to the two vertices in a certain proportion within a certain time.

[0056] When the reference voltage vector amplitude is and When the reference voltage vector is between the inscribed circle and the circumscribed circle of the regular hexagon, the reference voltage vector is between OADG and OBEH. When the reference voltage vector is inside the hexagon, the actual voltage vector is equal to the reference voltage vector; when the reference voltage vector is outside the hexagon, the phase angle can be kept unchanged and the amplitude can be reduced so that the actual voltage vector falls on the edge of the hexagon, that is, Figure 3 The line in BDH.

[0057] The specific implementation method can be to proportionally reduce the action time of the two non-zero vectors through the following formula: T 1. T 2:

[0058] When the reference voltage vector amplitude reaches When , the actual voltage vector trajectory is BDHJ, which is the boundary between the overmodulation zone 1 and the overmodulation zone 2 in the traditional overmodulation method. However, in this implementation, different modulation methods are not set based on the overmodulation zone 1 and the overmodulation zone 2, but the overmodulation zone 1 and the overmodulation zone 2 algorithms are unified, which reduces the amount of calculation and is easier to implement in a microcontroller unit.

[0059] When the reference voltage vector amplitude is and When the reference voltage vector is between OBEH and OCFI, the processing method can be: When the trajectory of the reference voltage vector is within the right triangle OBF and OHF, the processing method is the same as that of the overmodulation zone 1, keeping the phase angle unchanged and reducing the amplitude so that the actual voltage vector falls on the edge of the hexagon. The specific implementation method is the same as the above formula.

[0060] When the trajectory of the reference voltage vector is in the CBF region, the actual voltage vector is kept at OB and remains unchanged; when the trajectory of the reference voltage vector is in the IHF region, the actual voltage vector is kept at OH and remains unchanged.

[0061] When the reference voltage vector amplitude reaches When Figure 3 The actual voltage vector trajectory can stay at the six vertices of the hexagon for 1 / 6 cycle in sequence. At this time, it is a six-step mode, which is the boundary of the overmodulation area. Through the six-step mode overmodulation control, the bus voltage utilization rate can be further improved.

[0062] See also Figure 4 , Figure 4 It is a flow chart of the overmodulation algorithm provided by the present invention. Figure 4 middle T 1. T 2 and T S The relationship can be corresponded to Figure 3 For example, Can correspond Figure 3 Line BF in Can correspond Figure 3 The line HF, Can correspond Figure 3 The line OF, Can correspond Figure 3The line BDH in the triangle is also the side of the regular hexagon. Can be expressed in Figure 3 Stop at point B. Can be expressed in Figure 3 Stay at point H.

[0063] In some optional implementations, determining the reference voltage vector according to the α-axis voltage command and the β-axis voltage command includes: synthesizing the voltage vector to be corrected according to the α-axis voltage command and the β-axis voltage command; calculating the reference modulation index according to the voltage vector to be corrected; determining the actual modulation index corresponding to the reference modulation index according to a pre-established modulation index table; and correcting the voltage vector to be corrected according to the actual modulation index to obtain the reference voltage vector. Figure 5 , Figure 5 It is a schematic diagram of the modulation index table provided by the present invention, which reflects the overmodulation gain characteristics of the motor.

[0064] In this implementation, the modulation index M It can be used to describe the ratio of the inverter output voltage vector to the bus voltage. As an example, it can be calculated by the following formula: ; in, U 1 is the voltage vector to be corrected, U dc is the bus voltage. In addition, modulation partitioning can be performed through the modulation index. This implementation method corrects the actual modulation index and compensates the voltage gain so that the overmodulation area still has a linear voltage gain.

[0065] The control device of the motor provided by the present invention is described below. The control device of the motor described below and the control method of the motor described above can be referred to each other.

[0066] Figure 6 A schematic diagram of the structure of the motor control device provided in the embodiment of the present application, such as Figure 6 As shown, it specifically includes: a first judgment module 601, which is configured to judge whether the vector-controlled motor is in a driving state or a power generation state to obtain a first judgment result; a second judgment module 602, which is configured to judge whether the vector-controlled motor is in a deep magnetic weakening state to obtain a second judgment result; a selection module 603, which is configured to select a voltage limiting strategy according to the first judgment result and the second judgment result, and the voltage limiting strategy includes a voltage limiting strategy that gives priority to satisfying the q-axis voltage or a voltage limiting strategy that gives priority to satisfying the d-axis voltage; a generation module 604, which is configured to generate a limited d-axis voltage command and a limited q-axis voltage command according to the selected voltage limiting strategy; a control module 605, which is configured to control the vector-controlled motor based on the limited d-axis voltage command and the limited q-axis voltage command.

[0067] In some optional implementations, the selection module 603 is further configured to: when the first judgment result indicates that the vector-controlled motor is in a driving state and the second judgment result indicates that the vector-controlled motor is in a deep magnetic weakening state, or the first judgment result indicates that the vector-controlled motor is in a power generation state and the second judgment result indicates that the vector-controlled motor is in a non-deep magnetic weakening state, select a voltage limiting strategy that gives priority to the q-axis voltage; when the first judgment result indicates that the vector-controlled motor is in a power generation state and the second judgment result indicates that the vector-controlled motor is in a deep magnetic weakening state, or the first judgment result indicates that the vector-controlled motor is in a driving state and the second judgment result indicates that the vector-controlled motor is in a non-deep magnetic weakening state, select a voltage limiting strategy that gives priority to the d-axis voltage.

[0068] In some optional implementations, the voltage limiting strategy that gives priority to the q-axis voltage includes setting the voltage limit of the q-axis voltage according to the maximum value of the output phase voltage fundamental amplitude, and the voltage limiting strategy that gives priority to the d-axis voltage includes setting the voltage limit of the d-axis voltage according to the maximum value of the output phase voltage fundamental amplitude.

[0069] In some optional implementations, the control module 605 is further configured to: convert the limited d-axis voltage command and the limited q-axis voltage command into voltage commands on a stationary coordinate system to obtain α-axis voltage commands and β-axis voltage commands; process the α-axis voltage command and the β-axis voltage command through a pre-built overmodulation algorithm to generate a pulse width modulation signal of the inverter; and control the vector control motor based on the pulse width modulation signal.

[0070] In some optional implementations, the control module 605 is further configured to: determine a reference voltage vector based on the α-axis voltage command and the β-axis voltage command; calculate the reference action time of two adjacent non-zero voltages based on the reference voltage vector; if the reference voltage vector is located in the overmodulation area, and the sum of half of one reference action time and the other reference action time is not greater than the switching period of the three-phase inverter, then the reference action time is proportionally reduced to obtain the actual action time, and the sum of the actual action time is not greater than the switching period; and generate a pulse width modulation signal of the three-phase inverter based on the actual action time.

[0071] In some optional implementations, the control module 605 is further configured to: if the reference voltage vector is in the overmodulation region, and the sum of half of one reference action time in the reference action time and the other reference action time is greater than the switching period of the three-phase inverter, then the larger reference action time in the reference action time is retained, and the smaller reference action time in the reference action time is modified to zero to obtain the actual action time.

[0072] In some optional implementations, the control module 605 is further configured to: synthesize the voltage vector to be corrected according to the α-axis voltage command and the β-axis voltage command; calculate the reference modulation index according to the voltage vector to be corrected; determine the actual modulation index corresponding to the reference modulation index according to a pre-established modulation index table; and correct the voltage vector to be corrected according to the actual modulation index to obtain the reference voltage vector.

[0073] The control device for the motor provided by the present invention selects a voltage limiting strategy that gives priority to the q-axis voltage or a voltage limiting strategy that gives priority to the d-axis voltage according to the state of the motor, and controls the vector controlled motor based on the selected voltage limiting strategy. It can improve the voltage utilization rate of the bus while ensuring the stability of current control, thereby improving system efficiency.

[0074] Figure 7 An example of a physical structure diagram of an electronic device is shown in FIG. Figure 7 As shown, the electronic device may include: a processor 710, a communication interface 720, a memory 730 and a communication bus 740, wherein the processor 710, the communication interface 720 and the memory 730 communicate with each other through the communication bus 740. The processor 710 may call the logic instructions in the memory 730 to execute the motor control method, the method comprising: determining whether the vector control motor is in a driving state or a power generation state to obtain a first determination result; determining whether the vector control motor is in a deep magnetic weakening state to obtain a second determination result; selecting a voltage limiting strategy according to the first determination result and the second determination result, the voltage limiting strategy including a voltage limiting strategy that preferentially satisfies the q-axis voltage or a voltage limiting strategy that preferentially satisfies the d-axis voltage; generating a limited d-axis voltage command and a limited q-axis voltage command according to the selected voltage limiting strategy; and controlling the vector control motor based on the limited d-axis voltage command and the limited q-axis voltage command.

[0075] In addition, the logic instructions in the above-mentioned memory 730 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on this understanding, the technical solution of the present invention can be essentially or partly embodied in the form of a software product that contributes to the prior art. The computer software product is stored in a storage medium, including several instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc. Various media that can store program codes.

[0076] On the other hand, the present invention also provides a computer program product, which includes a computer program. The computer program can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the motor control method provided by the above-mentioned methods, and the method includes: judging whether the vector-controlled motor is in a driving state or a power generation state to obtain a first judgment result; judging whether the vector-controlled motor is in a deep magnetic weakening state to obtain a second judgment result; selecting a voltage limiting strategy based on the first judgment result and the second judgment result, the voltage limiting strategy including a voltage limiting strategy that prioritizes the q-axis voltage or a voltage limiting strategy that prioritizes the d-axis voltage; generating a limited d-axis voltage command and a limited q-axis voltage command based on the selected voltage limiting strategy; and controlling the vector-controlled motor based on the limited d-axis voltage command and the limited q-axis voltage command.

[0077] On the other hand, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, is implemented to execute the motor control method provided by the above-mentioned methods, the method comprising: determining whether the vector-controlled motor is in a driving state or a power generation state to obtain a first judgment result; determining whether the vector-controlled motor is in a deep magnetic weakening state to obtain a second judgment result; selecting a voltage limiting strategy based on the first judgment result and the second judgment result, the voltage limiting strategy comprising a voltage limiting strategy that preferentially satisfies the q-axis voltage or a voltage limiting strategy that preferentially satisfies the d-axis voltage; generating a limited d-axis voltage command and a limited q-axis voltage command based on the selected voltage limiting strategy; and controlling the vector-controlled motor based on the limited d-axis voltage command and the limited q-axis voltage command.

[0078] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0079] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0080] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for controlling a motor, characterized in that: include: Determine whether the vector-controlled motor is in a driving state or a generating state to obtain a first determination result; Determining whether the vector controlled motor is in a deep field weakening state to obtain a second determination result; According to the first judgment result and the second judgment result, a voltage limiting strategy is selected, wherein the voltage limiting strategy includes a voltage limiting strategy that gives priority to the q-axis voltage or a voltage limiting strategy that gives priority to the d-axis voltage; According to the selected voltage limiting strategy, a limited d-axis voltage command and a limited q-axis voltage command are generated; The vector controlled motor is controlled based on the limited d-axis voltage command and the limited q-axis voltage command.

2. The motor control method according to claim 1, characterized in that: The selecting a voltage limiting strategy according to the first judgment result and the second judgment result includes: When the first judgment result indicates that the vector controlled motor is in a driving state, and the second judgment result indicates that the vector controlled motor is in a deep magnetic weakening state, or the first judgment result indicates that the vector controlled motor is in a generating state, and the second judgment result indicates that the vector controlled motor is in a non-deep magnetic weakening state, a voltage limiting strategy that preferentially satisfies the q-axis voltage is selected; When the first judgment result indicates that the vector controlled motor is in a power generation state and the second judgment result indicates that the vector controlled motor is in a deep magnetic weakening state, or the first judgment result indicates that the vector controlled motor is in a driving state and the second judgment result indicates that the vector controlled motor is in a non-deep magnetic weakening state, a voltage limiting strategy that prioritizes the d-axis voltage is selected.

3. The motor control method according to claim 1, characterized in that: The voltage limiting strategy that gives priority to the q-axis voltage includes setting the voltage limit of the q-axis voltage according to the maximum value of the output phase voltage fundamental amplitude, and the voltage limiting strategy that gives priority to the d-axis voltage includes setting the voltage limit of the d-axis voltage according to the maximum value of the output phase voltage fundamental amplitude.

4. The motor control method according to claim 1, characterized in that: The controlling the vector controlled motor based on the limited d-axis voltage command and the limited q-axis voltage command comprises: Converting the limited d-axis voltage command and the limited q-axis voltage command into voltage commands on a stationary coordinate system to obtain an α-axis voltage command and a β-axis voltage command; Processing the α-axis voltage command and the β-axis voltage command by a pre-built overmodulation algorithm to generate a pulse width modulation signal of an inverter; The vector controlled motor is controlled based on the pulse width modulation signal.

5. The motor control method according to claim 4, characterized in that: The α-axis voltage command and the β-axis voltage command are processed by a pre-built overmodulation algorithm to generate a pulse width modulation signal of the inverter, including: Determine a reference voltage vector according to the α-axis voltage command and the β-axis voltage command; Calculate the reference action time of two adjacent non-zero voltages according to the reference voltage vector; If the reference voltage vector is located in the overmodulation region, and the sum of half of one reference action time and the other reference action time among the reference action times is not greater than the switching period of the three-phase inverter, the reference action time is proportionally reduced to obtain the actual action time, and the sum of the actual action time is not greater than the switching period; A pulse width modulation signal of the three-phase inverter is generated according to the actual action time.

6. The motor control method according to claim 5, characterized in that: Before generating a pulse width modulation signal of an inverter according to the actual voltage vector, the method further includes: If the reference voltage vector is located in the overmodulation area, and the sum of half of one of the reference action times and the other reference action time is greater than the switching period of the three-phase inverter, the larger reference action time of the reference action times is retained, and the smaller reference action time of the reference action times is modified to zero to obtain the actual action time.

7. The method according to claim 5, characterized in that The determining of the reference voltage vector according to the α-axis voltage command and the β-axis voltage command comprises: synthesizing a voltage vector to be corrected according to the α-axis voltage command and the β-axis voltage command; Calculating a reference modulation index according to the voltage vector to be corrected; Determining an actual modulation index corresponding to the reference modulation index according to a pre-established modulation index table; The voltage vector to be corrected is corrected according to the actual modulation index to obtain the reference voltage vector.

8. A control device for a motor, characterized in that: include: A first judgment module is configured to judge whether the vector-controlled motor is in a driving state or a generating state to obtain a first judgment result; A second judgment module is configured to judge whether the vector-controlled motor is in a deep magnetic weakening state to obtain a second judgment result; A selection module is configured to select a voltage limiting strategy according to the first judgment result and the second judgment result, wherein the voltage limiting strategy includes a voltage limiting strategy that preferentially satisfies the q-axis voltage or a voltage limiting strategy that preferentially satisfies the d-axis voltage; A generating module configured to generate a limited d-axis voltage command and a limited q-axis voltage command according to a selected voltage limiting strategy; The control module is configured to control the vector controlled motor based on the limited d-axis voltage command and the limited q-axis voltage command.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the method for controlling the motor according to any one of claims 1 to 7 is implemented.

10. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the control method of the motor according to any one of claims 1 to 7 is implemented.

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