Motor control method and device based on three-level inversion, computer equipment and storage medium

Abstract

The invention relates to the technical field of circuit control, in particular to a motor control method and device based on three-level inversion, computer equipment and a storage medium. The method comprises the following steps: determining target circuit information corresponding to the current moment of the three-level inverter; performing control parameter analysis on the target circuit information to obtain a control parameter corresponding to the permanent magnet synchronous motor; and performing motor control on the permanent magnet synchronous motor according to the control parameters. According to the invention, while the problem of neutral-point potential imbalance of the three-level inverter is considered, the control precision of the motor can be improved, the current harmonic of the motor can be reduced, and the torque ripple of the motor can be reduced by adopting the three-level inverter, double-vector control, variable-period online calculation and other forms.

Description

Technical Field

[0001] The present application relates to the field of circuit control technology, and in particular to a motor control method, device, computer equipment and storage medium based on three-level inversion. Background Art

[0002] In recent years, model predictive control has been widely used in permanent magnet synchronous motor control due to its advantages such as fast dynamic response and multivariable constraints.

[0003] In the prior art, the motor can be controlled by selecting two voltage vectors within a fixed control period to achieve effective reduction of current harmonics compared to traditional model predictive control. However, compared with the three-level inverter, the difference between the synthetic vector and the expected vector of the two-level inverter is large, which cannot adapt to the development trend of new energy vehicles towards high voltage and large capacity, and cannot meet the current motor control needs. Summary of the invention

[0004] Based on this, it is necessary to provide a motor control method, device, computer equipment and storage medium based on three-level inverter that can meet the current motor control needs in order to solve the above technical problems.

[0005] In a first aspect, the present application provides a motor control method based on three-level inversion. The method comprises:

[0006] Determine the target circuit information corresponding to the three-level inverter at the current moment;

[0007] Performing control parameter analysis on the target circuit information to obtain control parameters corresponding to the permanent magnet synchronous motor;

[0008] The permanent magnet synchronous motor is controlled according to the control parameters.

[0009] In one embodiment, the control parameter parsing of the target circuit information to obtain the control parameters corresponding to the permanent magnet synchronous motor includes:

[0010] Determining a candidate voltage vector set based on preset constraints and the target circuit information;

[0011] Performing control parameter analysis on the candidate voltage vector set to obtain control parameters corresponding to the permanent magnet synchronous motor;

[0012] The constraint condition is used to remove voltage vectors that generate a large common mode voltage, reducing the number of candidate voltage vectors to 19.

[0013] The constraints are as follows:

[0014]

[0015] Among them, uo is the common mode voltage of the inverter; uao, ubo and uco are the phase voltages of motor phase A, phase B and phase C respectively; Udc is the bus voltage.

[0016] In one embodiment, the performing control parameter analysis on the candidate voltage vector set to obtain control parameters corresponding to the permanent magnet synchronous motor includes:

[0017] Based on the candidate voltage vector set, determine the voltage across the two capacitors of the inverter at the next moment corresponding to the first initial voltage vector, and the voltage across the two capacitors of the inverter at the next moment corresponding to the second initial voltage vector;

[0018] According to the voltage across two capacitors of the inverter at the next moment corresponding to the first initial voltage vector and the voltage across two capacitors of the inverter at the next moment corresponding to the second initial voltage vector, a cost function analysis is performed on the candidate voltage vector set to obtain control parameters corresponding to the permanent magnet synchronous motor;

[0019] The value function is as follows:

[0020]

[0021] Among them, λ1 refers to the weight coefficient of the midpoint potential balance of the first voltage vector control; v'c1(k+1) and v'c2(k+1) are the voltages across the two capacitors of the inverter at the next moment corresponding to the first voltage vector; λ2 refers to the weight coefficient of the midpoint potential balance of the second voltage vector control, and λ1>λ2; v"c1(k+1) and v"c2(k+1) are the voltages across the two capacitors of the inverter at the next moment corresponding to the second voltage vector;

[0022] The calculation formulas for v”c1(k+1) and v”c2(k+1) are as follows:

[0023]

[0024] Wherein, i”c1(k) and i”c2(k) are the currents flowing through the two capacitors of the three-level inverter when the second voltage vector acts;

[0025] Obtain the optimal mathematical calculation results of the calculation formulas of v”c1(k+1) and v”c2(k+1) to determine the corresponding control parameters of the permanent magnet synchronous motor;

[0026] The mathematical calculation process is as follows:

[0027]

[0028] Wherein, T is a variable control period; the action time is reallocated online according to the time interval of t1 and t2: when T<=0.5Ts, t1=0.5Ts and t2=0 are given; when T>=1.5Ts, t1=1.5Ts and t2=0 are given; when 0.5Ts<=T<=1.5Ts, t1=1.5Ts and t2=0 are given; Ts is a fixed sampling period set according to actual work requirements.

[0029] In one embodiment, the control parameters include a first voltage vector corresponding to the first initial voltage vector, a second voltage vector corresponding to the second initial voltage vector, a first action time corresponding to the first voltage vector, and a second action time corresponding to the second voltage vector.

[0030] In one of the embodiments, determining the target circuit information corresponding to the three-level inverter at the current moment includes:

[0031] Obtaining initial circuit information corresponding to the three-level inverter;

[0032] Parameters of the three-level inverter are analyzed according to the initial circuit information to obtain target circuit information corresponding to the three-level inverter.

[0033] In one embodiment, the target circuit information includes the actual speed of the permanent magnet synchronous motor, the reference current corresponding to the permanent magnet synchronous motor, the voltage of two capacitors on the DC side of the permanent magnet synchronous motor, and the DC side current corresponding to the permanent magnet synchronous motor. In a second aspect, the present application also provides a motor control device. The device includes:

[0034] A determination module, used to determine target circuit information corresponding to the three-level inverter at the current moment;

[0035] An analysis module is used to perform control parameter analysis on the target circuit information to obtain control parameters corresponding to the permanent magnet synchronous motor;

[0036] A control module is used to control the permanent magnet synchronous motor according to the control parameters.

[0037] In a third aspect, the present application further provides a computer device. The computer device includes a memory and a processor, the memory stores a computer program, and the processor implements the following steps when executing the computer program:

[0038] Determine the target circuit information corresponding to the three-level inverter at the current moment;

[0039] Performing control parameter analysis on the target circuit information to obtain control parameters corresponding to the permanent magnet synchronous motor;

[0040] The permanent magnet synchronous motor is controlled according to the control parameters.

[0041] In a fourth aspect, the present application further provides a computer-readable storage medium. The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the following steps are implemented:

[0042] Determine the target circuit information corresponding to the three-level inverter at the current moment;

[0043] Performing control parameter analysis on the target circuit information to obtain control parameters corresponding to the permanent magnet synchronous motor;

[0044] The permanent magnet synchronous motor is controlled according to the control parameters.

[0045] In a fifth aspect, the present application further provides a computer program product. The computer program product includes a computer program, and when the computer program is executed by a processor, the following steps are implemented:

[0046] Determine the target circuit information corresponding to the three-level inverter at the current moment;

[0047] Performing control parameter analysis on the target circuit information to obtain control parameters corresponding to the permanent magnet synchronous motor;

[0048] The permanent magnet synchronous motor is controlled according to the control parameters.

[0049] The motor control method, device, computer equipment and storage medium based on three-level inverter, by determining the target circuit information and performing control parameter analysis on the target circuit information, the control parameters corresponding to the permanent magnet synchronous motor are obtained, and then, the permanent magnet synchronous motor is controlled according to the control parameters. According to the above content, it can be known that in the process of controlling the permanent magnet synchronous motor, the present application will predetermine the target circuit information corresponding to the three-level inverter at the current moment, and then, according to the target circuit information, determine the control parameters corresponding to the permanent magnet synchronous motor, so as to achieve the improvement of the motor control accuracy, the reduction of motor current harmonics, and the reduction of motor torque pulsation by adopting three-level inverter, dual vector control and variable cycle online calculation while considering the problem of unbalanced midpoint potential of the three-level inverter. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 An application environment diagram of a motor control method based on three-level inversion provided in an embodiment of the present application;

[0051] Figure 2 A schematic flow chart of a first motor control method based on three-level inversion provided in an embodiment of the present application;

[0052] Figure 3 A schematic flow chart of a second motor control method based on three-level inversion provided in an embodiment of the present application;

[0053] Figure 4 A spatial voltage vector diagram provided by an embodiment of the present application;

[0054] Figure 5 A schematic flow chart of a third motor control method based on three-level inversion provided in an embodiment of the present application;

[0055] Figure 6 A schematic flow chart of a fourth motor control method based on three-level inverter provided in an embodiment of the present application;

[0056] Figure 7 A structural block diagram of a first motor control device provided in an embodiment of the present application;

[0057] Figure 8 FIG. 4 is a diagram showing the internal structure of a computer device in one embodiment. DETAILED DESCRIPTION

[0058] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0059] It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application. In the description of the present application, the description of the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms is not necessarily for the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples without contradicting each other.

[0060] The motor control method based on three-level inversion provided in the embodiment of the present application can be applied to Figure 1In the application environment shown. Among them, the terminal 102 communicates with the server 104 through the network. The data storage system can store the data that the server 104 needs to process. The data storage system can be integrated on the server 104, or it can be placed on the cloud or other network servers. By determining the target circuit information and parsing the control parameters of the target circuit information, the control parameters corresponding to the permanent magnet synchronous motor are obtained, and then, according to the control parameters, the permanent magnet synchronous motor is controlled. Among them, the terminal 102 can be but is not limited to various personal computers, laptops, smart phones, tablets, Internet of Things devices and portable wearable devices. The Internet of Things devices can be smart speakers, smart TVs, smart air conditioners, smart car-mounted devices, etc. Portable wearable devices can be smart watches, smart bracelets, head-mounted devices, etc. The server 104 can be implemented with an independent server or a server cluster consisting of multiple servers.

[0061] In one embodiment, Figure 2 As shown, a motor control method based on three-level inverter is provided, and the method is applied to Figure 1 The terminal 102 in the example is used as an example to illustrate, and the following steps are included:

[0062] S201, determining target circuit information corresponding to the three-level inverter at the current moment.

[0063] It should be noted that the target circuit information includes the actual speed of the permanent magnet synchronous motor, the reference current corresponding to the permanent magnet synchronous motor, the two capacitor voltages on the DC side of the permanent magnet synchronous motor, and the DC side current corresponding to the permanent magnet synchronous motor. In one embodiment of the present application, when it is necessary to obtain the target circuit information corresponding to the three-level inverter at the current moment, a sampling circuit can be set in the three-level inverter to achieve the acquisition of the target circuit information corresponding to the three-level inverter at the current moment through the sampling circuit.

[0064] Furthermore, since the target circuit information may include parameter information that cannot be directly read through the acquisition circuit, before determining the target circuit information, the initial circuit information corresponding to the three-level inverter at the current moment may be obtained in advance through the sampling circuit; wherein the initial circuit information may include the target circuit information that can be directly obtained, as well as the basic information for calculating the target circuit information.

[0065] S202, performing control parameter analysis on the target circuit information to obtain control parameters corresponding to the permanent magnet synchronous motor.

[0066] In one embodiment of the present application, in the process of performing control parameter analysis on the target circuit information, a candidate voltage vector set can be determined through the target circuit information; then, by performing control parameter analysis on the candidate voltage vector set, control parameters corresponding to the permanent magnet synchronous motor can be obtained.

[0067] S203, controlling the permanent magnet synchronous motor according to the control parameters.

[0068] It should be noted that the control parameters may include: a voltage vector, and the action time of the voltage vector; specifically, when the permanent magnet synchronous motor is controlled according to the control parameters, the specific action of the dual-vector variable period model predictive current control algorithm is determined according to the control parameters, and then the control signal obtained by the dual-vector variable period model predictive current control algorithm is transmitted to the three-level inverter to control the permanent magnet synchronous motor.

[0069] The above-mentioned motor control method based on three-level inverter determines the target circuit information and performs control parameter analysis on the target circuit information to obtain the control parameters corresponding to the permanent magnet synchronous motor, and then, according to the control parameters, the permanent magnet synchronous motor is controlled. According to the above content, it can be known that in the process of controlling the permanent magnet synchronous motor, the present application will predetermine the target circuit information corresponding to the three-level inverter at the current moment, and then, according to the target circuit information, determine the control parameters corresponding to the permanent magnet synchronous motor, so as to achieve the improvement of motor control accuracy, reduction of motor current harmonics, and reduction of motor torque pulsation by adopting three-level inverter, dual vector control and variable period online calculation while considering the problem of unbalanced midpoint potential of the three-level inverter.

[0070] In one embodiment, if Figure 3 As shown, when it is necessary to perform control parameter analysis on the target circuit information to obtain the control parameters corresponding to the permanent magnet synchronous motor, the following contents may be specifically included:

[0071] S301, determining a candidate voltage vector set based on preset constraint conditions and target circuit information.

[0072] It should be noted that, because each phase bridge arm has three switching states, there are a total of 27 switching states for the three-phase bridge arm. The corresponding three-level inverter (such as NPC type three-level inverter) space voltage vector diagram is as follows: Figure 4 As shown, the voltage vectors in the 27 natural coordinate systems are transformed into voltage vectors in 27 dq-axis (Direct Axis flux axis and Quadrature Axis torque axis) rotation coordinate systems as candidate voltage vector sets for predictive current control of the permanent magnet synchronous motor model.

[0073] To further illustrate, constraints may include the following:

[0074] By removing the voltage vectors that generate large common-mode voltages, the number of candidate voltage vectors is reduced to 19, which are calculated using formula (1):

[0075]

[0076] Among them, u o is the common mode voltage of the inverter; u ao 、u bo and u co are the phase voltages of motor phase A, phase B and phase C respectively; U dc is the bus voltage;

[0077] To avoid inverter phase voltage jump, the calculation formula (2) is used:

[0078]

[0079] Among them, s x (k) is the inverter switch state at the current sampling moment, x is a, b, c; s x '(k+1) is the inverter switch state corresponding to the first voltage vector at the next moment, x is a, b, c; s x "(k+1) is the inverter switch state corresponding to the second voltage vector at the next moment, and x is a, b, c.

[0080] The second voltage vector cannot be the same as the first voltage vector, and is specifically calculated using formula (3):

[0081] s″ x (k+1)≠s′ x (k+1) (3)

[0082] In summary, taking the first voltage vectors as PNN, PON, and POO as examples, the second voltage vectors corresponding to the first voltage vectors are shown in the following table:

[0083]

[0084] S302, performing control parameter analysis on the candidate voltage vector set to obtain control parameters corresponding to the permanent magnet synchronous motor.

[0085] It should be noted that when it is necessary to perform control parameter analysis on the candidate voltage vector set to obtain the control parameters corresponding to the permanent magnet synchronous motor, it may include the following contents: based on the candidate voltage vector set, determine the voltage across the two capacitors of the inverter at the next moment corresponding to the first initial voltage vector, and the voltage across the two capacitors of the inverter at the next moment corresponding to the second initial voltage vector; perform a value function analysis on the candidate voltage vector set according to the voltage across the two capacitors of the inverter at the next moment corresponding to the first initial voltage vector, and the voltage across the two capacitors of the inverter at the next moment corresponding to the second initial voltage vector, to obtain the control parameters corresponding to the permanent magnet synchronous motor.

[0086] The control parameters include a first voltage vector corresponding to the first initial voltage vector, a second voltage vector corresponding to the second initial voltage vector, a first action time corresponding to the first voltage vector, and a second action time corresponding to the second voltage vector.

[0087] In one embodiment of the present application, according to the above description, when it is necessary to determine the control parameters corresponding to the permanent magnet synchronous motor, the present application may include the following contents:

[0088] According to the PMSM (Permanent Magnet Synchronous Motor) stator voltage equation in the synchronous rotating coordinate system, the d-axis stator current and q-axis stator current differential calculation formula (4) are obtained as follows:

[0089]

[0090] Among them, u d 、u q are the dq axis components of the stator voltage, i d 、i q They are the dq axis components of the stator current, R s is the stator resistance, ψ f is the permanent magnet flux, ω e is the electrical angular velocity, L d , L q They are the dq axis component inductances respectively.

[0091] Assuming that each variable is sampled at the current moment at time k, the predicted current model of PMSM is obtained according to the discrete differential formula as shown in calculation formula (5):

[0092]

[0093] Among them, T s It is a fixed sampling period set according to actual work needs.

[0094] Using the voltage vector u corresponding to the inverter switching state at the previous moment d (k) and u q (k) and the current prediction model perform one-beat delay compensation on the current sampled at the current moment, and the compensated current is used as the current initial condition for predicting the current at the next moment. The candidate voltage vector sets of the first voltage vector are respectively substituted into the calculation formula (4) to obtain the corresponding current prediction values, and then substituted into the calculation formula (5) of the first voltage vector, and finally the voltage vector corresponding to the minimum value function g1 is selected as the first voltage vector u'.

[0095] The above process is shown in the calculation formula (6):

[0096]

[0097] Wherein, λ1 refers to the weight coefficient of the midpoint potential balance selected by the first voltage vector control; v' c1 (k+1), v' c2 (k+1) are the voltages at both ends of the two capacitors of the inverter corresponding to the first voltage vector at the next moment, and the corresponding calculation formula (7) is as follows:

[0098]

[0099] Among them, i' c1 (k), i' c2 (k) are the currents flowing through the two capacitors of the three-level inverter when the first voltage vector acts, and the corresponding calculation formula (8) is as follows:

[0100]

[0101] Among them, when the state is "1", that is, when the two switches of the upper bridge arm are turned on, G x =1, other states G x =0; when the state is "-1", that is, when the two switches of the lower bridge arm are turned on, H x =1, other states H x =0.

[0102] According to calculation formula (4) and calculation formula (5), the predicted current model at the next moment is obtained as shown in calculation formula (9):

[0103]

[0104] Among them, u' d and u' q are the dq axis components of the first voltage vector u', u" d and u' ’q are the dq axis components of the second voltage vector u″ respectively; t1 and t2 are the action times of the first voltage vector u′ and the second voltage vector u″ respectively.

[0105] The cost function of the first voltage vector and the second voltage vector acting simultaneously is shown in the calculation formula (10):

[0106]

[0107] Wherein, λ2 refers to the weight coefficient for selecting the midpoint potential balance of the second voltage vector control, and λ1>λ2; v" c1 (k+1),v” c2(k+1) are the voltages at both ends of the two capacitors of the inverter corresponding to the second voltage vector at the next moment, and the corresponding calculation formula (11) is as follows:

[0108]

[0109] Among them, i” c1 (k), i” c2 (k) are the currents flowing through the two capacitors of the three-level inverter when the second voltage vector acts. The calculation is similar to equation (8) and will not be repeated here.

[0110] The optimal solution of calculation formula (11) is mathematically calculated, and the calculation process is shown in calculation formula (12).

[0111]

[0112] Where T is the variable control period; the action time is redistributed online according to the time interval between t1 and t2: when T<=0.5T s When t1=0.5T is given s , t2=0; when T>=1.5T s When t1=1.5T is given s , t2=0; when 0.5T s <=T<=1.5T s When t1=1.5T is given s , t2=0; T s It is a fixed sampling period set according to actual work needs.

[0113] The above-mentioned motor control method based on three-level inverter determines a candidate voltage vector set based on pre-set constraints and target circuit information; then, the control parameters of the candidate voltage vector set are analyzed to obtain the control parameters corresponding to the permanent magnet synchronous motor, thereby ensuring that the subsequent motor control operations on the permanent magnet synchronous motor can be smoothly performed according to the control parameters corresponding to the permanent magnet synchronous motor, thereby ensuring the smooth progress of the subsequent process.

[0114] In one embodiment, if Figure 5 As shown, when it is necessary to determine the target circuit information corresponding to the three-level inverter at the current moment, the following contents may be specifically included:

[0115] S501: Acquire initial circuit information corresponding to a three-level inverter.

[0116] It should be noted that the initial circuit information may include but is not limited to: the rotor position θ of the permanent magnet synchronous motor; and the instantaneous values ​​of the three-phase stator currents ia(k), ib(k), and ic(k).

[0117] S502: Analyze parameters of the three-level inverter according to the initial circuit information to obtain target circuit information corresponding to the three-level inverter.

[0118] The target circuit information includes the actual rotation speed of the permanent magnet synchronous motor, the reference current corresponding to the permanent magnet synchronous motor, the voltages of two capacitors on the DC side of the permanent magnet synchronous motor, and the DC side current corresponding to the permanent magnet synchronous motor.

[0119] In one embodiment of the present application, when it is necessary to perform parameter analysis on the three-level inverter according to the initial circuit information, the following contents may be included: differentiating the rotor position of the permanent magnet synchronous motor to obtain the actual speed of the permanent magnet synchronous motor; performing difference calculation between the given speed and the actual speed, and inputting the difference calculation result into the controller to obtain the reference current of the q-axis; performing coordinate transformation according to the instantaneous value of the three-phase stator current of the permanent magnet synchronous motor to obtain the two capacitor voltages on the DC side of the permanent magnet synchronous motor in the two-phase rotating coordinate system, and obtaining the DC side current corresponding to the permanent magnet synchronous motor.

[0120] The above-mentioned motor control method based on three-level inverter obtains the initial circuit information corresponding to the three-level inverter; implements parameter analysis of the three-level inverter according to the initial circuit information to obtain the target circuit information corresponding to the three-level inverter; provides a data basis for the subsequent determination of the control parameters corresponding to the permanent magnet synchronous motor, and ensures the smooth progress of the subsequent process.

[0121] In one embodiment, if Figure 6 As shown, when it is necessary to control the permanent magnet synchronous motor, the following contents may be specifically included:

[0122] S601: Acquire initial circuit information corresponding to a three-level inverter.

[0123] S602: Analyze parameters of the three-level inverter according to the initial circuit information to obtain target circuit information corresponding to the three-level inverter.

[0124] S603, determining a candidate voltage vector set based on pre-set constraint conditions and target circuit information.

[0125] S604, based on the candidate voltage vector set, determine the voltage across two capacitors of the inverter at the next moment corresponding to the first initial voltage vector and the voltage across two capacitors of the inverter at the next moment corresponding to the second initial voltage vector.

[0126] S605, performing a cost function analysis on the candidate voltage vector set according to the voltage across the two capacitors of the inverter at the next moment corresponding to the first initial voltage vector and the voltage across the two capacitors of the inverter at the next moment corresponding to the second initial voltage vector, to obtain control parameters corresponding to the permanent magnet synchronous motor.

[0127] S606: Control the permanent magnet synchronous motor according to the control parameters.

[0128] The above-mentioned motor control method based on three-level inverter determines the target circuit information and performs control parameter analysis on the target circuit information to obtain the control parameters corresponding to the permanent magnet synchronous motor, and then, according to the control parameters, the permanent magnet synchronous motor is controlled. According to the above content, it can be known that in the process of controlling the permanent magnet synchronous motor, the present application will predetermine the target circuit information corresponding to the three-level inverter at the current moment, and then, according to the target circuit information, determine the control parameters corresponding to the permanent magnet synchronous motor, so as to achieve the improvement of motor control accuracy, reduction of motor current harmonics, and reduction of motor torque pulsation by adopting three-level inverter, dual vector control and variable period online calculation while considering the problem of unbalanced midpoint potential of the three-level inverter.

[0129] It should be understood that, although the steps in the flowcharts involved in the above embodiments are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps is not strictly limited in order, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above embodiments may include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the steps or stages in other steps.

[0130] Based on the same inventive concept, the embodiment of the present application also provides a motor control device for implementing the motor control method based on three-level inverter. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme recorded in the above method, so the specific limitations in one or more motor control device embodiments provided below can refer to the limitations of the motor control method based on three-level inverter above, and will not be repeated here.

[0131] In one embodiment, Figure 7 As shown, a motor control device is provided, comprising: a determination module 10, an analysis module 20 and a control module 30, wherein:

[0132] The determination module 10 is used to determine the target circuit information corresponding to the three-level inverter at the current moment.

[0133] The analysis module 20 is used to perform control parameter analysis on the target circuit information to obtain control parameters corresponding to the permanent magnet synchronous motor.

[0134] The control module 30 is used to control the permanent magnet synchronous motor according to the control parameters.

[0135] In one embodiment, a candidate voltage vector set is determined based on pre-set constraints and target circuit information;

[0136] The control parameters of the candidate voltage vector set are analyzed to obtain the control parameters corresponding to the permanent magnet synchronous motor.

[0137] In one embodiment, based on the candidate voltage vector set, the voltage across two capacitors of the inverter at the next moment corresponding to the first initial voltage vector and the voltage across two capacitors of the inverter at the next moment corresponding to the second initial voltage vector are determined;

[0138] According to the voltage across the two capacitors of the inverter at the next moment corresponding to the first initial voltage vector and the voltage across the two capacitors of the inverter at the next moment corresponding to the second initial voltage vector, a value function analysis is performed on the candidate voltage vector set to obtain control parameters corresponding to the permanent magnet synchronous motor.

[0139] In one embodiment, the control parameters include a first voltage vector corresponding to the first initial voltage vector, a second voltage vector corresponding to the second initial voltage vector, a first action time corresponding to the first voltage vector, and a second action time corresponding to the second voltage vector.

[0140] In one embodiment, initial circuit information corresponding to the three-level inverter is obtained;

[0141] Parameters of the three-level inverter are parsed according to the initial circuit information to obtain target circuit information corresponding to the three-level inverter.

[0142] In one embodiment, the target circuit information includes the actual speed of the permanent magnet synchronous motor, the reference current corresponding to the permanent magnet synchronous motor, the voltages of two capacitors on the DC side of the permanent magnet synchronous motor, and the DC side current corresponding to the permanent magnet synchronous motor.

[0143] The above-mentioned motor control device obtains the control parameters corresponding to the permanent magnet synchronous motor by determining the target circuit information and performing control parameter analysis on the target circuit information, and then, according to the control parameters, the permanent magnet synchronous motor is controlled. According to the above content, the present application will predetermine the target circuit information corresponding to the three-level inverter at the current moment in the process of controlling the permanent magnet synchronous motor, and then, according to the target circuit information, determine the control parameters corresponding to the permanent magnet synchronous motor, so as to achieve the improvement of the motor control accuracy, the reduction of motor current harmonics, and the reduction of motor torque pulsation by adopting the three-level inverter, dual vector control and variable period online calculation while considering the problem of unbalanced midpoint potential of the three-level inverter.

[0144] Each module in the above motor control device can be implemented in whole or in part by software, hardware or a combination thereof. Each module can be embedded in or independent of a processor in a computer device in the form of hardware, or can be stored in a memory in a computer device in the form of software, so that the processor can call and execute the operations corresponding to each module.

[0145] In one embodiment, a computer device is provided. The computer device may be a terminal, and its internal structure diagram may be as follows: Figure 8 As shown. The computer device includes a processor, a memory, an input / output interface, a communication interface, a display unit and an input device. Among them, the processor, the memory and the input / output interface are connected through a system bus, and the communication interface, the display unit and the input device are connected to the system bus through the input / output interface. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The input / output interface of the computer device is used to exchange information between the processor and the external device. The communication interface of the computer device is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner can be implemented through WIFI, a mobile cellular network, NFC (near field communication) or other technologies. When the computer program is executed by the processor, a motor control method based on three-level inversion is implemented. The display unit of the computer device is used to form a visually visible picture, which can be a display screen, a projection device or a virtual reality imaging device. The display screen can be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer device can be a touch layer covering the display screen, or a button, trackball or touchpad set on the computer device shell, or an external keyboard, touchpad or mouse.

[0146] Those skilled in the art will understand that Figure 8 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0147] In one embodiment, a computer device is provided, including a memory and a processor, wherein a computer program is stored in the memory, and when the processor executes the computer program, the following steps are implemented:

[0148] Determine the target circuit information corresponding to the three-level inverter at the current moment;

[0149] Analyze the control parameters of the target circuit information to obtain the control parameters corresponding to the permanent magnet synchronous motor;

[0150] The permanent magnet synchronous motor is controlled according to the control parameters.

[0151] In one embodiment, when the processor executes the computer program, the processor further implements the following steps:

[0152] Determine a candidate voltage vector set based on pre-set constraints and target circuit information;

[0153] The control parameters of the candidate voltage vector set are analyzed to obtain the control parameters corresponding to the permanent magnet synchronous motor.

[0154] In one embodiment, when the processor executes the computer program, the processor further implements the following steps:

[0155] Based on the candidate voltage vector set, determine the voltage across the two capacitors of the inverter at the next moment corresponding to the first initial voltage vector, and the voltage across the two capacitors of the inverter at the next moment corresponding to the second initial voltage vector;

[0156] According to the voltage across the two capacitors of the inverter at the next moment corresponding to the first initial voltage vector and the voltage across the two capacitors of the inverter at the next moment corresponding to the second initial voltage vector, a value function analysis is performed on the candidate voltage vector set to obtain control parameters corresponding to the permanent magnet synchronous motor.

[0157] In one embodiment, when the processor executes the computer program, the processor further implements the following steps:

[0158] The control parameters include a first voltage vector corresponding to the first initial voltage vector, a second voltage vector corresponding to the second initial voltage vector, a first action time corresponding to the first voltage vector, and a second action time corresponding to the second voltage vector.

[0159] In one embodiment, when the processor executes the computer program, the processor further implements the following steps:

[0160] Obtaining initial circuit information corresponding to the three-level inverter;

[0161] Parameters of the three-level inverter are parsed according to the initial circuit information to obtain target circuit information corresponding to the three-level inverter.

[0162] In one embodiment, when the processor executes the computer program, the processor further implements the following steps:

[0163] The target circuit information includes the actual speed of the permanent magnet synchronous motor, the reference current corresponding to the permanent magnet synchronous motor, the voltages of two capacitors on the DC side of the permanent magnet synchronous motor, and the DC side current corresponding to the permanent magnet synchronous motor.

[0164] In one embodiment, a computer readable storage medium is provided, on which a computer program is stored, and when the computer program is executed by a processor, the following steps are implemented:

[0165] Determine the target circuit information corresponding to the three-level inverter at the current moment;

[0166] Analyze the control parameters of the target circuit information to obtain the control parameters corresponding to the permanent magnet synchronous motor;

[0167] The permanent magnet synchronous motor is controlled according to the control parameters.

[0168] In one embodiment, when the computer program is executed by a processor, the following steps are also implemented:

[0169] Determine a candidate voltage vector set based on pre-set constraints and target circuit information;

[0170] The control parameters of the candidate voltage vector set are analyzed to obtain the control parameters corresponding to the permanent magnet synchronous motor.

[0171] In one embodiment, when the computer program is executed by a processor, the following steps are also implemented:

[0172] Based on the candidate voltage vector set, determine the voltage across the two capacitors of the inverter at the next moment corresponding to the first initial voltage vector, and the voltage across the two capacitors of the inverter at the next moment corresponding to the second initial voltage vector;

[0173] According to the voltage across the two capacitors of the inverter at the next moment corresponding to the first initial voltage vector and the voltage across the two capacitors of the inverter at the next moment corresponding to the second initial voltage vector, a value function analysis is performed on the candidate voltage vector set to obtain control parameters corresponding to the permanent magnet synchronous motor.

[0174] In one embodiment, when the computer program is executed by a processor, the following steps are also implemented:

[0175] The control parameters include a first voltage vector corresponding to the first initial voltage vector, a second voltage vector corresponding to the second initial voltage vector, a first action time corresponding to the first voltage vector, and a second action time corresponding to the second voltage vector.

[0176] In one embodiment, when the computer program is executed by a processor, the following steps are also implemented:

[0177] Obtaining initial circuit information corresponding to the three-level inverter;

[0178] Parameters of the three-level inverter are parsed according to the initial circuit information to obtain target circuit information corresponding to the three-level inverter.

[0179] In one embodiment, when the computer program is executed by a processor, the following steps are also implemented:

[0180] The target circuit information includes the actual speed of the permanent magnet synchronous motor, the reference current corresponding to the permanent magnet synchronous motor, the voltages of two capacitors on the DC side of the permanent magnet synchronous motor, and the DC side current corresponding to the permanent magnet synchronous motor.

[0181] In one embodiment, a computer program product is provided, comprising a computer program, which, when executed by a processor, implements the following steps:

[0182] Determine the target circuit information corresponding to the three-level inverter at the current moment;

[0183] Analyze the control parameters of the target circuit information to obtain the control parameters corresponding to the permanent magnet synchronous motor;

[0184] The permanent magnet synchronous motor is controlled according to the control parameters.

[0185] In one embodiment, when the computer program is executed by a processor, the following steps are also implemented:

[0186] Determine a candidate voltage vector set based on pre-set constraints and target circuit information;

[0187] The control parameters of the candidate voltage vector set are analyzed to obtain the control parameters corresponding to the permanent magnet synchronous motor.

[0188] In one embodiment, when the computer program is executed by a processor, the following steps are also implemented:

[0189] Based on the candidate voltage vector set, determine the voltage across the two capacitors of the inverter at the next moment corresponding to the first initial voltage vector, and the voltage across the two capacitors of the inverter at the next moment corresponding to the second initial voltage vector;

[0190] According to the voltage across the two capacitors of the inverter at the next moment corresponding to the first initial voltage vector and the voltage across the two capacitors of the inverter at the next moment corresponding to the second initial voltage vector, a value function analysis is performed on the candidate voltage vector set to obtain control parameters corresponding to the permanent magnet synchronous motor.

[0191] In one embodiment, when the computer program is executed by a processor, the following steps are also implemented:

[0192] The control parameters include a first voltage vector corresponding to the first initial voltage vector, a second voltage vector corresponding to the second initial voltage vector, a first action time corresponding to the first voltage vector, and a second action time corresponding to the second voltage vector.

[0193] In one embodiment, when the computer program is executed by a processor, the following steps are also implemented:

[0194] Obtaining initial circuit information corresponding to the three-level inverter;

[0195] Parameters of the three-level inverter are parsed according to the initial circuit information to obtain target circuit information corresponding to the three-level inverter.

[0196] In one embodiment, when the computer program is executed by a processor, the following steps are also implemented:

[0197] The target circuit information includes the actual speed of the permanent magnet synchronous motor, the reference current corresponding to the permanent magnet synchronous motor, the voltages of two capacitors on the DC side of the permanent magnet synchronous motor, and the DC side current corresponding to the permanent magnet synchronous motor.

[0198] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant laws, regulations and standards of relevant countries and regions.

[0199] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiments can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchains, etc., but are not limited thereto. The processors involved in each embodiment provided in this application may be general-purpose processors, central processing units, graphics processors, digital signal processors, programmable logic devices, data processing logic devices based on quantum computing, etc., but are not limited thereto.

[0200] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0201] The above embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A motor control method based on three-level inversion, characterized in that: The method comprises: Determine the target circuit information corresponding to the three-level inverter at the current moment; Performing control parameter analysis on the target circuit information to obtain control parameters corresponding to the permanent magnet synchronous motor; The permanent magnet synchronous motor is controlled according to the control parameters.

2. The method according to claim 1, characterized in that The control parameter analysis of the target circuit information to obtain the control parameters corresponding to the permanent magnet synchronous motor includes: Determining a candidate voltage vector set based on preset constraints and the target circuit information; Performing control parameter analysis on the candidate voltage vector set to obtain control parameters corresponding to the permanent magnet synchronous motor; The constraint condition is used to remove voltage vectors that generate a large common mode voltage, reducing the number of candidate voltage vectors to 19. The constraints are as follows: Among them, uo is the common mode voltage of the inverter; uao, ubo and uco are the phase voltages of motor phase A, phase B and phase C respectively; Udc is the bus voltage.

3. The method according to claim 2, characterized in that The step of performing control parameter analysis on the candidate voltage vector set to obtain control parameters corresponding to the permanent magnet synchronous motor includes: Based on the candidate voltage vector set, determine the voltage across the two capacitors of the inverter at the next moment corresponding to the first initial voltage vector, and the voltage across the two capacitors of the inverter at the next moment corresponding to the second initial voltage vector; Performing a cost function analysis on the candidate voltage vector set according to the voltage across two capacitors of the inverter at the next moment corresponding to the first initial voltage vector and the voltage across two capacitors of the inverter at the next moment corresponding to the second initial voltage vector; The value function is as follows: Wherein, λ1 refers to the weight coefficient for the midpoint potential balance of the first voltage vector control; v'c1(k+1) and v'c2(k+1) are the voltages across the two capacitors of the inverter at the next moment corresponding to the first voltage vector; λ2 refers to the weight coefficient for the midpoint potential balance of the second voltage vector control, and λ1>λ2; v”c1(k+1) and v”c2(k+1) are the voltages across the two capacitors of the inverter at the next moment corresponding to the second voltage vector; The calculation formulas for v”c1(k+1) and v”c2(k+1) are as follows: Wherein, i”c1(k) and i”c2(k) are the currents flowing through the two capacitors of the three-level inverter when the second voltage vector acts; Obtain the optimal mathematical calculation results of the calculation formulas of v”c1(k+1) and v”c2(k+1) to determine the corresponding control parameters of the permanent magnet synchronous motor; The mathematical calculation process is as follows: Wherein, T is a variable control period; the action time is reallocated online according to the time interval of t1 and t2: when T<=0.5Ts, t1=0.5Ts and t2=0 are given; when T>=1.5Ts, t1=1.5Ts and t2=0 are given; when 0.5Ts<=T<=1.5Ts, t1=1.5Ts and t2=0 are given; Ts is a fixed sampling period set according to actual work requirements.

4. The method according to claim 3, characterized in that The control parameters include a first voltage vector corresponding to the first initial voltage vector, a second voltage vector corresponding to the second initial voltage vector, a first action time corresponding to the first voltage vector, and a second action time corresponding to the second voltage vector.

5. The method according to claim 1, characterized in that The determining of target circuit information corresponding to the three-level inverter at the current moment includes: Obtaining initial circuit information corresponding to the three-level inverter; Parameters of the three-level inverter are analyzed according to the initial circuit information to obtain target circuit information corresponding to the three-level inverter.

6. The method according to claim 5, characterized in that The target circuit information includes the actual rotation speed of the permanent magnet synchronous motor, the reference current corresponding to the permanent magnet synchronous motor, the voltages of two capacitors on the DC side of the permanent magnet synchronous motor, and the DC side current corresponding to the permanent magnet synchronous motor.

7. A motor control device, characterized in that: The device comprises: A determination module, used to determine target circuit information corresponding to the three-level inverter at the current moment; An analysis module is used to perform control parameter analysis on the target circuit information to obtain control parameters corresponding to the permanent magnet synchronous motor; A control module is used to control the permanent magnet synchronous motor according to the control parameters.

8. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 6 are implemented.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

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