Control method of synchronous reluctance motor and related assembly

Abstract

The invention discloses a control method of a synchronous reluctance motor and related components, and relates to the field of motor control, the direct-axis current of the synchronous reluctance motor is used as torque current, the quadrature-axis current is used as excitation current, and the torque current of the synchronous reluctance motor is adjusted according to the actual motor rotating speed and the given motor rotating speed of the synchronous reluctance motor; when the synchronous reluctance motor is in a constant-torque operation area, the absolute value of the excitation current is adjusted to be equal to that of the current torque current of the synchronous reluctance motor, the maximum torque current ratio control is achieved, it is guaranteed that the output voltage is smaller on the premise that the working condition is not affected, and control over the motor is more efficient and saves more energy; when the synchronous reluctance motor is in the weak magnetic operation area, the absolute value of the exciting current is adjusted to be equal to the absolute value of the current torque current of the synchronous reluctance motor, the current torque current of the synchronous reluctance motor is reduced, and the high dynamic response performance of the motor in the weak magnetic operation area is achieved.

Description

Technical Field

[0001] The present invention relates to the field of motor control, and in particular to a control method for a synchronous reluctance motor and related components. Background Art

[0002] Synchronous reluctance motor is an AC motor that follows the closed principle of the minimum reluctance path and generates magnetic pull (i.e. reluctance torque) through the reluctance changes caused by the rotor at different positions to drive the motor to rotate. It has been widely used in related fields due to its simple structure, wide speed regulation range and low cost. However, there are few mature and stable control strategies for synchronous reluctance motors on the market. Summary of the invention

[0003] The purpose of the present invention is to provide a control method and related components of a synchronous reluctance motor, which can achieve stable control of the synchronous reluctance motor, and realize maximum torque-to-current ratio control of the synchronous reluctance motor in a constant torque operating area, and high dynamic response performance in a weak magnetic operating area.

[0004] In order to solve the above technical problems, the present invention provides a control method of a synchronous reluctance motor, comprising:

[0005] adjusting the torque current of the synchronous reluctance motor according to the actual motor speed of the synchronous reluctance motor and the given motor speed, wherein the torque current is the direct-axis current of the synchronous reluctance motor;

[0006] When the synchronous reluctance motor is in a constant torque operation area, adjusting the excitation current of the synchronous reluctance motor to a current equal to the absolute value of the current torque current of the synchronous reluctance motor, wherein the excitation current is the quadrature axis current of the synchronous reluctance motor;

[0007] When the synchronous reluctance motor is in a weak magnetic field operation region, the excitation current is adjusted to be a current equal to an absolute value of a current torque current of the synchronous reluctance motor, and the current torque current of the synchronous reluctance motor is reduced.

[0008] Preferably, when the synchronous reluctance motor is in the constant torque operation area, before adjusting the excitation current of the synchronous reluctance motor to a current equal to the absolute value of the current torque current of the synchronous reluctance motor, the method further includes:

[0009] Determining whether the absolute value of the current torque current of the synchronous reluctance motor is less than a first preset signal-to-noise ratio optimization current;

[0010] If yes, adjusting the excitation current of the synchronous reluctance motor to the first preset signal-to-noise ratio optimized current;

[0011] If not, the process proceeds to a step of adjusting the excitation current of the synchronous reluctance motor to a current equal to the absolute value of the current torque current of the synchronous reluctance motor.

[0012] Preferably, the first preset signal-to-noise ratio optimized current is the product of a preset adjustable gain value and a rated current of the synchronous reluctance motor, wherein the preset adjustable gain value is a positive number less than 1.

[0013] Preferably, reducing the current torque current of the synchronous reluctance motor includes:

[0014] Obtaining an actual voltage output value of a frequency converter corresponding to the synchronous reluctance motor;

[0015] Subtracting the actual voltage output value from the maximum voltage output value of the frequency converter to obtain a voltage difference;

[0016] When the voltage difference is a negative number, a torque current increment is obtained based on the voltage difference, wherein the positive and negative signs of the torque current increment are opposite to the positive and negative signs of the current torque current of the synchronous reluctance motor;

[0017] The torque current increment is superimposed on the current torque current of the synchronous reluctance resistor.

[0018] Preferably, obtaining the torque current increment based on the voltage difference includes:

[0019] Obtaining an initial torque current increment based on the voltage difference using a voltage regulator algorithm;

[0020] Obtaining a value of a sign function, wherein the value of the sign function is 1 when the current torque current of the synchronous reluctance motor is positive, and the value of the sign function is -1 when the current torque current of the synchronous reluctance motor is negative;

[0021] The product of the initial torque current increment and the value of the sign function is used as the torque current increment.

[0022] Preferably, after obtaining the initial torque current increment based on the voltage difference using a voltage regulator algorithm, the method further comprises:

[0023] When the initial torque current increment is less than the current amplitude limit value of the synchronous reluctance motor, the current amplitude limit value is used as the initial torque current increment.

[0024] Preferably, it also includes:

[0025] When the synchronous reluctance motor is in a no-load running state and a position sensorless algorithm is used to determine the actual motor speed of the synchronous reluctance motor, the excitation current of the synchronous reluctance motor is increased to a second preset signal-to-noise ratio optimized current.

[0026] In order to solve the above technical problems, the present invention also provides a control device for a synchronous reluctance motor, comprising:

[0027] Memory for storing computer programs;

[0028] A processor is used to implement the steps of any of the above-mentioned methods for controlling a synchronous reluctance motor when executing the computer program.

[0029] In order to solve the above technical problems, the present invention also provides a control system for a synchronous reluctance motor, comprising:

[0030] a torque current regulating unit, configured to regulate the torque current of the synchronous reluctance motor according to the actual motor speed of the synchronous reluctance motor and the given motor speed, wherein the torque current is the direct-axis current of the synchronous reluctance motor;

[0031] a first excitation current regulating unit, configured to regulate the excitation current of the synchronous reluctance motor to a current equal to an absolute value of a current torque current of the synchronous reluctance motor when the synchronous reluctance motor is in a constant torque operation zone, wherein the excitation current is a quadrature axis current of the synchronous reluctance motor;

[0032] The second excitation current regulating unit is used to regulate the excitation current to a current equal to the absolute value of the current torque current of the synchronous reluctance motor and reduce the current torque current of the synchronous reluctance motor when the synchronous reluctance motor is in the weak magnetic field operation area.

[0033] In order to solve the above technical problem, the present invention also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of any of the above-mentioned control methods for synchronous reluctance motors are implemented.

[0034] The beneficial effects of the present invention are as follows: the present invention provides a control method and related components for a synchronous reluctance motor, wherein the direct-axis current of the synchronous reluctance motor is used as the torque current, and the quadrature-axis current is used as the excitation current, and the torque current of the synchronous reluctance motor is adjusted according to the actual motor speed and the given motor speed of the synchronous reluctance motor; when the synchronous reluctance motor is in the constant torque operation area, the excitation current is adjusted to be equal to the absolute value of the current torque current of the synchronous reluctance motor, so as to realize maximum torque current ratio control, and ensure a smaller output voltage without affecting the working conditions, so as to make the control of the motor more efficient and energy-saving; when the synchronous reluctance motor is in the weak magnetic operation area, the excitation current is adjusted to be equal to the absolute value of the current torque current of the synchronous reluctance motor, and the current torque current of the synchronous reluctance motor is reduced, so as to realize the high dynamic response performance of the motor in the weak magnetic operation area. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the prior art and the drawings required for use in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0036] Figure 1 A flow chart of a control method for a synchronous reluctance motor provided by the present invention;

[0037] Figure 2 A first control block diagram of a control method for a synchronous reluctance motor provided by the present invention;

[0038] Figure 3 A second control block diagram of a control method for a synchronous reluctance motor provided by the present invention;

[0039] Figure 4 A main circuit topology diagram of a frequency converter-driven synchronous reluctance motor provided by the present invention;

[0040] Figure 5 A block diagram of the synchronous reluctance motor rotor field oriented vector control provided by the present invention;

[0041] Figure 6 A schematic structural diagram of a control device for a synchronous reluctance motor provided by the present invention;

[0042] Figure 7 A schematic structural diagram of a control system of a synchronous reluctance motor provided by the present invention. DETAILED DESCRIPTION

[0043] The core of the present invention is to provide a control method and related components of a synchronous reluctance motor, which can achieve stable control of the synchronous reluctance motor, and realize the maximum torque-to-current ratio control of the synchronous reluctance motor in the constant torque operation area, and high dynamic response performance in the weak magnetic operation area.

[0044] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments 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.

[0045] Please refer to Figure 1 , Figure 1 A flow chart of a control method of a synchronous reluctance motor provided by the present invention, the control method of the synchronous reluctance motor comprising:

[0046] S1: adjusting the torque current of the synchronous reluctance motor according to the actual motor speed of the synchronous reluctance motor and the given motor speed, wherein the torque current is the direct axis current of the synchronous reluctance motor;

[0047] S2: When the synchronous reluctance motor is in the constant torque operation area, adjusting the excitation current of the synchronous reluctance motor to a current equal to the absolute value of the current torque current of the synchronous reluctance motor, wherein the excitation current is the quadrature axis current of the synchronous reluctance motor;

[0048] S3: When the synchronous reluctance motor is in the weak magnetic field operation area, the excitation current is adjusted to be equal to the absolute value of the current torque current of the synchronous reluctance motor, and the current torque current of the synchronous reluctance motor is reduced.

[0049] In the present invention, controlling the synchronous reluctance motor mainly refers to controlling the torque current and excitation current of the synchronous reluctance motor. The torque current can control the magnitude of the electromagnetic torque of the synchronous reluctance motor, and the excitation current can control the strength of the magnetic field of the synchronous reluctance motor.

[0050] For a synchronous reluctance motor, in a synchronous rotating coordinate system, its steady-state voltage equation is as follows:

[0051]

[0052] Among them, u d is the direct axis voltage in the synchronous rotating coordinate system, u q is the quadrature axis voltage in the synchronous rotating coordinate system, R is the stator resistance, i d is the direct axis current, i q is the quadrature axis current, ω e is the synchronous angular frequency, L q is the quadrature-axis inductance, L d is the direct-axis inductor.

[0053] The electromagnetic torque equation of the synchronous reluctance motor is as follows:

[0054]

[0055] Among them, T e is the electromagnetic torque, N p is the pole pair number, L q is the quadrature-axis inductance, L d is the direct-axis inductance, i d is the direct axis current, i q is the quadrature axis current.

[0056] Since permanent magnets are not used in synchronous reluctance motors, the steady-state voltage equation of synchronous reluctance motors does not contain the permanent magnet back EMF term, and the direct-axis current i dand the quadrature axis current i q can be used as excitation current or torque current. However, in this application, it is further considered that due to the structural characteristics of the synchronous reluctance motor, the direct axis inductance L d Much larger than the quadrature axis inductance L q (Usually the direct-axis inductance is more than four times the quadrature-axis inductance). When the synchronous reluctance motor runs at high speed, ω e *L d *i d will become the dominant term of the inverter output voltage. d As the excitation current, when the synchronous reluctance motor is running at high speed and no-load, a very high output voltage is required to maintain the excitation current, which occupies the adjustment space of the torque current and reduces the load capacity and speed regulation range of the synchronous reluctance motor. Therefore, the present application uses the quadrature axis current of the synchronous reluctance motor as the excitation current to ensure that the output voltage of the synchronous reluctance motor is smaller and more energy-efficient. Based on the above reasons, in the present invention, the direct axis current i of the synchronous reluctance motor is used as the excitation current. d As the torque current, the quadrature axis current i of the synchronous reluctance motor is q as the excitation current.

[0057] On this basis, the present invention adjusts the torque current of the synchronous reluctance motor according to the actual motor speed of the synchronous reluctance motor and the given motor speed. Figure 5 , Figure 5 The synchronous reluctance motor rotor magnetic field oriented vector control block diagram provided by the present invention is as follows: Figure 5 Medium * is the given motor speed, f is the actual motor speed, is the ideal torque current, i d is the torque current of the synchronous reluctance motor. Figure 5 The ASR (Automatic Speed ​​Regulator) obtains the ideal torque current of the synchronous reluctance motor based on the difference between the given motor speed and the actual motor speed, and adjusts the torque current of the synchronous reluctance motor to the ideal torque current.

[0058] In order to reduce motor losses and improve operating efficiency when the synchronous reluctance motor is in the constant torque operating area, the maximum torque current ratio control of the synchronous reluctance motor in the constant torque operating area is implemented in the present invention. Specifically, the excitation current of the synchronous reluctance motor is adjusted to be a current equal to the absolute value of the current torque current of the synchronous reluctance motor. Considering that the direct-axis current of the synchronous reluctance motor, that is, the torque current in the present invention, can be positive or negative, but the excitation current is required to be positive during the actual operation of the synchronous reluctance motor, the excitation current is therefore a current equal to the absolute value of the current torque current of the synchronous reluctance motor.

[0059] In order to prevent the output voltage from being saturated when the synchronous reluctance motor is in the weak magnetic operation area, and to improve the dynamic response capability of the motor control and the load capacity of the motor, in this application, while adjusting the excitation current to a current equal to the absolute value of the current torque current of the synchronous reluctance motor, the current torque current of the synchronous reluctance motor is reduced. It can be seen from the steady-state voltage equation of the synchronous reluctance motor that when the torque current of the synchronous reluctance motor is reduced, the ω in the quadrature axis voltage e *L d *i d The value of the term will decrease, thereby completing the weak magnetic field control of the synchronous reluctance motor.

[0060] It can be seen that the present invention does not need to obtain motor parameters such as resistance, inductance and back-EMF of the synchronous reluctance motor when realizing control of the synchronous reluctance motor. Therefore, the control accuracy of the synchronous reluctance motor is not affected by whether the motor parameters are accurate, which makes the control method of the synchronous reluctance motor provided by the present invention have good adaptability and robustness.

[0061] It should also be noted that the control method for a synchronous reluctance motor provided by the present invention is applicable not only to the case where the synchronous reluctance motor is in a motoring operation state, but also to the case where the synchronous reluctance motor is in a generating operation state.

[0062] In summary, the present invention starts from the principle of the synchronous reluctance motor, and after fully analyzing the output voltage-to-output ratio of the synchronous reluctance motor during operation, proposes a control scheme that uses the direct-axis current of the synchronous reluctance motor as the torque current and the quadrature-axis current as the excitation current. The direct-axis current is used as the torque current to control the size of the motor magnetic field, and the quadrature-axis current is used as the excitation current to control the size of the motor output. On this basis, the maximum torque-to-current ratio control and weak magnetic control methods of the synchronous reluctance motor are proposed, which can achieve efficient and energy-saving control of the synchronous reluctance motor and improve the dynamic response performance of the synchronous reluctance motor when it is in a high-speed operating state.

[0063] Based on the above embodiments:

[0064] As a preferred embodiment, when the synchronous reluctance motor is in the constant torque operation area, before adjusting the excitation current of the synchronous reluctance motor to a current equal to the absolute value of the current torque current of the synchronous reluctance motor, it also includes:

[0065] Determining whether the absolute value of the current torque current of the synchronous reluctance motor is less than a first preset signal-to-noise ratio optimization current;

[0066] If yes, adjusting the excitation current of the synchronous reluctance motor to a first preset signal-to-noise ratio optimized current;

[0067] If not, the process proceeds to a step of adjusting the excitation current of the synchronous reluctance motor to a current equal to the absolute value of the current torque current of the synchronous reluctance motor.

[0068] Considering that the actual motor speed of the synchronous reluctance motor needs to be collected when controlling the synchronous reluctance motor, when using the position sensorless algorithm to determine the actual motor speed, the actual motor speed is mainly calculated by collecting the voltage and current of the synchronous reluctance motor. Therefore, when the excitation current of the synchronous reluctance motor is too small, the proportion of sampling noise will increase, affecting the calculated value of the actual motor speed.

[0069] To this end, in the present embodiment, before adjusting the excitation current to a current equal to the absolute value of the current torque current, it is first determined whether the absolute value of the current torque current of the synchronous reluctance motor is less than the first preset signal-to-noise ratio optimization current. If so, it may cause a deviation in the actual motor speed calculation value. Therefore, in the present embodiment, the excitation current of the synchronous reluctance motor is adjusted to the first preset signal-to-noise ratio optimization current; if not, the excitation current of the synchronous reluctance motor will still be adjusted to a current equal to the absolute value of the current torque current of the synchronous reluctance motor.

[0070] The present invention does not impose any special limitation on the specific value of the first preset signal-to-noise ratio optimization current, and can be adjusted according to actual needs. For example, the first preset signal-to-noise ratio optimization current is the product of a preset adjustable gain value and a rated current of the synchronous reluctance motor, wherein the preset adjustable gain value is a positive number less than 1.

[0071] As a preferred embodiment, reducing the current torque current of the synchronous reluctance motor includes:

[0072] Obtain the actual voltage output value of the inverter corresponding to the synchronous reluctance motor;

[0073] Subtract the actual voltage output value from the maximum voltage output value of the inverter to obtain the voltage difference;

[0074] When the voltage difference is a negative number, a torque current increment is obtained based on the voltage difference, wherein the positive and negative signs of the torque current increment are opposite to the positive and negative signs of the current torque current of the synchronous reluctance motor;

[0075] The torque current increment is added to the current torque current of the synchronous reluctance resistor.

[0076] In order to control the synchronous reluctance motor in the weak magnetic field operation area in the present invention, it is necessary to reduce the torque current of the synchronous reluctance motor. In this embodiment, a specific implementation method for reducing the torque current of the synchronous reluctance motor is provided.

[0077] Specifically, first obtain the actual voltage output value of the inverter corresponding to the synchronous reluctance motor (the inverter is used to drive the synchronous reluctance motor), and then subtract the actual voltage output value from the maximum voltage output value to obtain the voltage difference. Weakening magnetic control is only required when the voltage difference is negative. Therefore, when the voltage difference is negative, the torque current increment is obtained based on the voltage difference. Weakening magnetic control requires reducing the voltage of the synchronous reluctance motor. e *L d *i d The value of the term, in this embodiment, is to weaken the torque current of the synchronous reluctance motor by the torque current increment, so the positive and negative signs of the torque current increment are opposite to the positive and negative signs of the current torque current of the synchronous reluctance motor. Finally, the torque current increment is superimposed on the current torque current of the synchronous reluctance motor to achieve magnetic weakening control of the synchronous reluctance motor, and the control method is simple.

[0078] As a preferred embodiment, obtaining the torque current increment based on the voltage difference includes:

[0079] An initial torque current increment is obtained based on the voltage difference using a voltage regulator algorithm;

[0080] Obtain the value of the sign function. When the current torque current of the synchronous reluctance motor is positive, the value of the sign function is 1. When the current torque current of the synchronous reluctance motor is negative, the value of the sign function is -1.

[0081] The product of the initial torque current increment and the value of the sign function is taken as the torque current increment.

[0082] In this embodiment, the torque current increment based on the voltage difference is obtained by using a voltage regulator and a sign function. The voltage regulator is a virtual unit running a voltage regulator algorithm. First, the voltage difference is input into the voltage regulator to obtain the initial torque current increment. Since the torque current needs to be weakened by the torque current increment, the value of the sign function is opposite to the positive and negative signs of the current torque current of the synchronous reluctance motor. When the current torque current of the synchronous reluctance motor is positive, the value of the sign function is 1, and when the current torque current of the synchronous reluctance motor is negative, the value of the sign function is -1. The product of the initial torque current increment and the value of the sign function is the torque current increment, and the implementation method is simple.

[0083] As a preferred embodiment, after obtaining the initial torque current increment based on the voltage difference using a voltage regulator algorithm, the method further includes:

[0084] When the initial torque current increment is less than the current limit value of the synchronous reluctance motor, the current limit value is used as the initial torque current increment.

[0085] In order to ensure the safe operation of the synchronous reluctance motor, the torque current needs to be maintained within a certain range. Therefore, in this embodiment, when the initial torque current increment is too small, that is, the size of the initial torque current increment is too large, the current limit value is used as the initial torque current increment. Whether the current limit value needs to be used as the initial torque current increment is determined by judging whether the initial torque current increment is less than the current limit value of the synchronous reluctance motor. The specific value of the current limit value can be adjusted according to actual conditions, such as the opposite of the rated current, etc. Selecting the judgment value as the opposite of the rated current of the synchronous reluctance motor can not only ensure the safety of the synchronous reluctance motor, but also ensure the value range of the torque current increment.

[0086] Please refer to Figure 3 , Figure 3 A first control block diagram of a control method for a synchronous reluctance motor provided by the present invention, Figure 3 middle u α is the stator voltage component of the synchronous reluctance motor under the α axis, u β is the stator voltage component of the synchronous reluctance motor under the β axis, u s is the ideal voltage output value of the inverter, u max is the maximum voltage output value of the inverter, is the ideal torque current, Sign is the sign function, Δi d is the torque current increment.

[0087] exist Figure 3 In the process, after obtaining the voltage difference obtained by subtracting the actual voltage output value from the maximum voltage output value of the inverter, the voltage difference is input into the AVR (Automation Voltage Regulator) to obtain the initial torque current increment. The limiting unit is used to ensure that the subsequent step of obtaining the torque current increment based on the voltage difference can only be performed when the voltage difference is negative. The limiting unit is used to limit the value of the torque current increment of the synchronous reluctance motor to within the rated current of the synchronous reluctance motor, thereby ensuring the safety and reliability of the synchronous reluctance motor.

[0088] As a preferred embodiment, it also includes:

[0089] When the synchronous reluctance motor is in a no-load running state and a position sensorless algorithm is used to determine the actual motor speed of the synchronous reluctance motor, the excitation current of the synchronous reluctance motor is increased to a second preset signal-to-noise ratio optimized current.

[0090] Considering that the actual motor speed of the synchronous reluctance motor needs to be collected when controlling the synchronous reluctance motor, when using the position sensorless algorithm to determine the actual motor speed, the actual motor speed is mainly calculated by collecting the voltage and current of the synchronous reluctance motor. When the synchronous reluctance motor is in a no-load running state, the excitation current of the motor is usually very small. If the excitation current is too small, the proportion of sampling noise will increase, affecting the calculated value of the actual motor speed.

[0091] To this end, in this embodiment, when the synchronous reluctance motor is in a no-load running state and the position sensorless algorithm is used to determine the actual motor speed of the synchronous reluctance motor, the excitation current of the synchronous reluctance motor is increased to the second preset signal-to-noise ratio optimized current. The second preset signal-to-noise ratio optimized current can be equal to the first preset signal-to-noise ratio optimized current, so the strategy for controlling the excitation current of the synchronous electromagnetic motor can be integrated as follows Figure 2 The second control block diagram shown. Figure 2 middle is the ideal torque current, k is the preset adjustable gain, i n is the rated current of the synchronous reluctance motor, MAX is the maximum value operation, is the ideal excitation current.

[0092] Please refer to Figure 4 and Figure 5 , Figure 4 The main circuit topology diagram of the inverter-driven synchronous reluctance motor provided by the present invention is as follows: Figure 5 This is a block diagram of the synchronous reluctance motor rotor field oriented vector control provided by the present invention. Figure 5 For the medium-weak magnetic controller, please refer to Figure 3 , Figure 3 A second control block diagram of a control method for a synchronous reluctance motor provided by the present invention; Figure 5 in i q The calculation part can be referred to Figure 2 , Figure 2 This is a first control block diagram of a control method for a synchronous reluctance motor provided by the present invention. Figure 4 The circuits on the left side of the synchronous reluctance motor SymRM are all inverters, which are used to drive the synchronous reluctance motor.

[0093] In addition, when the second preset signal-to-noise ratio optimization current is equal to the first preset signal-to-noise ratio optimization current, and both are equal to the product of the preset adjustable gain value and the rated current of the synchronous reluctance motor, when the actual motor speed is directly measured by the sensor using encoded vector control, there is no need to consider the influence of the acquisition noise on the calculated value of the actual motor speed. In this case, the preset adjustable gain value k can be set to 0.

[0094] Please refer to Figure 6 , Figure 6 A schematic diagram of the structure of a control device for a synchronous reluctance motor provided by the present invention, the control device for the synchronous reluctance motor comprises:

[0095] A memory 21, used for storing computer programs;

[0096] The processor 22 is used to implement the steps of any of the above-mentioned synchronous reluctance motor control methods when executing a computer program.

[0097] For a detailed introduction to the control device of the synchronous reluctance motor provided by the present invention, please refer to the embodiment of the control method of the synchronous reluctance motor, which will not be described in detail here.

[0098] Please refer to Figure 7 , Figure 7 A schematic diagram of the structure of a control system of a synchronous reluctance motor provided by the present invention, the control system of the synchronous reluctance motor comprises:

[0099] a torque current regulating unit 31, for regulating the torque current of the synchronous reluctance motor according to the actual motor speed of the synchronous reluctance motor and the given motor speed, wherein the torque current is the direct axis current of the synchronous reluctance motor;

[0100] A first excitation current regulating unit 32 is used to regulate the excitation current of the synchronous reluctance motor to a current equal to the absolute value of the current torque current of the synchronous reluctance motor when the synchronous reluctance motor is in a constant torque operation area, wherein the excitation current is the quadrature axis current of the synchronous reluctance motor;

[0101] The second excitation current regulating unit 33 is used to regulate the excitation current to a current equal to the absolute value of the current torque current of the synchronous reluctance motor when the synchronous reluctance motor is in the weak magnetic field operation area, and reduce the current torque current of the synchronous reluctance motor.

[0102] For a detailed introduction to the control system of the synchronous reluctance motor provided by the present invention, please refer to the embodiment of the control method of the synchronous reluctance motor, which will not be described in detail here.

[0103] Based on the above embodiments:

[0104] As a preferred embodiment, it also includes:

[0105] A judgment unit, used for judging whether the absolute value of the current torque current of the synchronous reluctance motor is less than a first preset signal-to-noise ratio optimization current before adjusting the excitation current of the synchronous reluctance motor to a current equal to the absolute value of the current torque current of the synchronous reluctance motor when the synchronous reluctance motor is in a constant torque operation area; if so, triggering the signal-to-noise ratio optimization unit; if not, triggering the first excitation current adjustment unit 32;

[0106] The signal-to-noise ratio optimization unit is used to adjust the excitation current of the synchronous reluctance motor to a first preset signal-to-noise ratio optimized current.

[0107] As a preferred embodiment, the first preset signal-to-noise ratio optimized current is the product of a preset adjustable gain value and a rated current of the synchronous reluctance motor, wherein the preset adjustable gain value is a positive number less than 1.

[0108] As a preferred embodiment, reducing the current torque current of the synchronous reluctance motor includes:

[0109] Obtain the actual voltage output value of the inverter corresponding to the synchronous reluctance motor;

[0110] Subtract the actual voltage output value from the maximum voltage output value of the inverter to obtain the voltage difference;

[0111] When the voltage difference is a negative number, a torque current increment is obtained based on the voltage difference, wherein the positive and negative signs of the torque current increment are opposite to the positive and negative signs of the current torque current of the synchronous reluctance motor;

[0112] The torque current increment is added to the current torque current of the synchronous reluctance resistor.

[0113] As a preferred embodiment, obtaining the torque current increment based on the voltage difference includes:

[0114] An initial torque current increment is obtained based on the voltage difference using a voltage regulator algorithm;

[0115] Obtain the value of the sign function. When the current torque current of the synchronous reluctance motor is positive, the value of the sign function is 1. When the current torque current of the synchronous reluctance motor is negative, the value of the sign function is -1.

[0116] The product of the initial torque current increment and the value of the sign function is taken as the torque current increment.

[0117] As a preferred embodiment, it also includes:

[0118] The lower limit unit is used to use the current limit value as the initial torque current increment after obtaining the initial torque current increment using the voltage regulator algorithm based on the voltage difference, when the initial torque current increment is less than the current limit value of the synchronous reluctance motor.

[0119] As a preferred embodiment, it also includes:

[0120] The no-load operation control unit is used to increase the excitation current of the synchronous reluctance motor to a second preset signal-to-noise ratio optimized current when the synchronous reluctance motor is in a no-load operation state and a position sensorless algorithm is used to determine the actual motor speed of the synchronous reluctance motor.

[0121] The present invention also provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the steps of any of the above-mentioned control methods for a synchronous reluctance motor are implemented.

[0122] For a detailed introduction to the computer-readable storage medium provided by the present invention, please refer to the embodiment of the control method of the synchronous reluctance motor, which will not be described in detail here.

[0123] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0124] It should also be noted that in this specification, the terms "include", "comprises" or any other variations 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, an element defined by the sentence "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

[0125] The professionals may further realize that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented by electronic hardware, computer software or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the components and steps of each example have been generally described in terms of function in the above description. The professionals may use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present invention.

Claims

1. A control method for a synchronous reluctance motor, characterized in that: include: adjusting the torque current of the synchronous reluctance motor according to the actual motor speed of the synchronous reluctance motor and the given motor speed, wherein the torque current is the direct-axis current of the synchronous reluctance motor; When the synchronous reluctance motor is in a constant torque operation area, adjusting the excitation current of the synchronous reluctance motor to a current equal to the absolute value of the current torque current of the synchronous reluctance motor, wherein the excitation current is the quadrature axis current of the synchronous reluctance motor; When the synchronous reluctance motor is in a weak magnetic field operation region, the excitation current is adjusted to be a current equal to an absolute value of a current torque current of the synchronous reluctance motor, and the current torque current of the synchronous reluctance motor is reduced.

2. The control method of the synchronous reluctance motor according to claim 1, characterized in that: When the synchronous reluctance motor is in a constant torque operation area, before adjusting the excitation current of the synchronous reluctance motor to a current equal to the absolute value of the current torque current of the synchronous reluctance motor, the method further includes: Determining whether the absolute value of the current torque current of the synchronous reluctance motor is less than a first preset signal-to-noise ratio optimization current; If yes, adjusting the excitation current of the synchronous reluctance motor to the first preset signal-to-noise ratio optimized current; If not, the process proceeds to a step of adjusting the excitation current of the synchronous reluctance motor to a current equal to the absolute value of the current torque current of the synchronous reluctance motor.

3. The control method of the synchronous reluctance motor according to claim 2, characterized in that: The first preset signal-to-noise ratio optimized current is a product of a preset adjustable gain value and a rated current of the synchronous reluctance motor, wherein the preset adjustable gain value is a positive number less than 1.

4. The control method of a synchronous reluctance motor according to claim 1, characterized in that: Reducing the current torque current of the synchronous reluctance motor includes: Obtaining an actual voltage output value of a frequency converter corresponding to the synchronous reluctance motor; Subtracting the actual voltage output value from the maximum voltage output value of the frequency converter to obtain a voltage difference; When the voltage difference is a negative number, a torque current increment is obtained based on the voltage difference, wherein the positive and negative signs of the torque current increment are opposite to the positive and negative signs of the current torque current of the synchronous reluctance motor; The torque current increment is superimposed on the current torque current of the synchronous reluctance resistor.

5. The control method of the synchronous reluctance motor according to claim 4, characterized in that: The torque current increment is obtained based on the voltage difference, including: Obtaining an initial torque current increment based on the voltage difference using a voltage regulator algorithm; Obtaining a value of a sign function, wherein the value of the sign function is 1 when the current torque current of the synchronous reluctance motor is positive, and the value of the sign function is -1 when the current torque current of the synchronous reluctance motor is negative; The product of the initial torque current increment and the value of the sign function is used as the torque current increment.

6. The control method of the synchronous reluctance motor according to claim 5, characterized in that: After obtaining the initial torque current increment based on the voltage difference by using a voltage regulator algorithm, the method further includes: When the initial torque current increment is less than the current amplitude limit value of the synchronous reluctance motor, the current amplitude limit value is used as the initial torque current increment.

7. The control method of a synchronous reluctance motor according to any one of claims 1 to 6, characterized in that: Also includes: When the synchronous reluctance motor is in a no-load running state and a position sensorless algorithm is used to determine the actual motor speed of the synchronous reluctance motor, the excitation current of the synchronous reluctance motor is increased to a second preset signal-to-noise ratio optimized current.

8. A control device for a synchronous reluctance motor, characterized in that: include: Memory for storing computer programs; A processor, configured to implement the steps of the method for controlling a synchronous reluctance motor as claimed in any one of claims 1 to 7 when executing the computer program.

9. A control system for a synchronous reluctance motor, characterized in that: include: a torque current regulating unit, configured to regulate the torque current of the synchronous reluctance motor according to the actual motor speed of the synchronous reluctance motor and the given motor speed, wherein the torque current is the direct-axis current of the synchronous reluctance motor; a first excitation current regulating unit, configured to regulate the excitation current of the synchronous reluctance motor to a current equal to an absolute value of a current torque current of the synchronous reluctance motor when the synchronous reluctance motor is in a constant torque operation zone, wherein the excitation current is a quadrature axis current of the synchronous reluctance motor; The second excitation current regulating unit is used to regulate the excitation current to a current equal to the absolute value of the current torque current of the synchronous reluctance motor and reduce the current torque current of the synchronous reluctance motor when the synchronous reluctance motor is in the weak magnetic field operation area.

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

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