Dual three-phase motor control method, system and equipment based on virtual vector and medium

Abstract

The invention relates to the technical field of motor control, and provides a dual three-phase motor control method, system and device based on a virtual vector, and a medium, and the method comprises the steps: determining a level output state and a space voltage vector of a target motor; obtaining a first space voltage vector distribution diagram and a second space voltage vector distribution diagram, performing fitting to obtain a first voltage vector loop system and a second voltage vector loop system so as to obtain virtual vectors, and synthesizing a reference voltage vector through the virtual vectors; sampling to obtain motor operation parameters, obtaining a continuous model of a target motor, discretizing to obtain a voltage expected value of the target motor, and determining a target reference voltage vector; constructing a cost function, obtaining a state matrix, constructing a quadratic programming equation, determining initial parameters of the quadratic programming equation, extracting initial input from the quadratic programming equation, and performing iterative solution on the quadratic programming equation to obtain vector action time; and controlling the target motor. According to the invention, the motor control efficiency is effectively improved.

Description

Technical Field

[0001] The present invention relates to the field of motor control technology, and in particular to a dual three-phase motor control method, system, device and medium based on a virtual vector. Background Art

[0002] Compared with traditional three-phase motors, multi-phase motors have the advantages of low voltage and high power output, small torque pulsation amplitude, and strong fault tolerance. Dual three-phase motors have received more attention due to their close relationship with traditional three-phase motors. For the inverter in the dual three-phase motor, the three-level voltage source inverter has the advantages of low voltage stress of switching devices, small voltage change rate, and small output voltage harmonic content. It is particularly suitable for medium voltage and high power applications. Its three-level six-phase voltage source inverter outputs three levels per phase, so the entire inverter has 3 6 There are 729 state combinations, namely 729 space voltage vectors, which is very complicated for designing space vector modulation strategy.

[0003] For the decoupled model, the vector space decoupling modeling method is usually used to map the motor variables to the α-β subspace related to electromechanical energy conversion and other subspaces unrelated to electromechanical energy conversion, where only the current in the α-β subspace participates in torque generation, while the components in the xy subspace increase the harmonic disturbance. Therefore, choosing a suitable vector is the key to eliminating harmonics in dual three-phase permanent magnet synchronous motors. For the control methods of dual three-phase motors, traditional control methods include field-oriented control and direct torque control. However, the PI parameter tuning process of field-oriented control is relatively cumbersome and involves fine adjustment of multiple variables. Although direct torque control has certain advantages in torque response, its steady-state performance is poor, especially in the precise control of torque and current. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the related art. To this end, the present invention provides a dual three-phase motor control method, system, device and medium based on virtual vector to achieve efficient control of the dual three-phase motor.

[0005] The present invention provides a dual three-phase motor control method based on a virtual vector, comprising: S1: determining a target motor, and determining a spatial voltage vector of the target motor according to a level output state of the target motor; S2: obtaining a first space voltage vector distribution diagram and a second space voltage vector distribution diagram through the space voltage vector, performing discrete point fitting in the first space voltage vector distribution diagram and the second space voltage vector distribution diagram, respectively obtaining a first voltage vector loop system and a second voltage vector loop system in sequence, obtaining a virtual vector through the first voltage vector loop system and the second voltage vector loop system, and synthesizing a reference voltage vector through the virtual vector on the first space voltage vector distribution diagram; S3: sampling the target motor to obtain motor operating parameters, obtaining a continuous model through the motor operating parameters, discretizing the continuous model to obtain a voltage expected value, and determining a target reference voltage vector through the voltage expected value and a reference voltage vector; S4: constructing a cost function, obtaining a state matrix of the target motor through the discretized continuous model, and constructing a quadratic programming equation through the state matrix and the cost function; S5: determining initial parameters of the quadratic programming equation, extracting initial input from the quadratic programming equation, and iteratively solving the quadratic programming equation using the quasi-Newton method through the initial parameters and the initial input to obtain the vector action time; S6: Controlling the target motor through the vector action time and the target reference voltage vector.

[0006] According to the dual three-phase motor control method based on virtual vector provided by the present invention, in step S1, the target motor is a dual three-phase motor, and the target motor has six bridge arms, and each bridge arm has three level output states.

[0007] According to the dual three-phase motor control method based on virtual vector provided by the present invention, step S2 specifically includes: S21: projecting the space voltage vector onto the α-β space to obtain the first space voltage vector distribution diagram, and projecting the space voltage vector onto the xy space to obtain the second space voltage vector distribution diagram; S22: performing discrete point fitting according to the distribution of the space voltage vector in the second space voltage vector distribution diagram to obtain a plurality of closed curves as the second voltage vector loop system, and projecting the second voltage vector loop system onto the first space voltage vector distribution diagram to obtain the first voltage vector loop system; S23: Select a first voltage vector set in the first voltage vector loop system, select a second voltage vector set in the second voltage vector loop system based on the first voltage vector set, use the second voltage vector set as the virtual vector, and synthesize a reference voltage vector based on the volt-second balance principle and through the virtual vector.

[0008] According to the dual three-phase motor control method based on virtual vector provided by the present invention, in step S23, when synthesizing the reference voltage vector, the first space voltage vector distribution diagram is divided into a large sector, a medium sector and a small sector, and after the virtual vector is projected onto the first space voltage vector distribution diagram, the projected virtual vector is divided into a large virtual vector, a medium virtual vector and a small virtual vector, in the small sector, a small voltage vector is obtained by synthesizing two of the small virtual vectors, in the medium sector, a medium voltage vector is obtained by synthesizing two of the medium virtual vectors and one of the small virtual vectors, and in the large sector, a large voltage vector is obtained by synthesizing two of the large virtual vectors and one of the medium virtual vectors, and the small voltage vector, the medium voltage vector and the large voltage vector are used as the reference voltage vector.

[0009] According to the dual three-phase motor control method based on virtual vector provided by the present invention, step S3 specifically includes: S31: Sampling the target motor to obtain motor operating parameters, where the motor operating parameters include motor phase current, motor phase voltage and electrical angle; S32: performing coordinate transformation on the motor phase current and the motor phase voltage to obtain a plane shaft current and a plane shaft voltage, constructing an initial operation matrix of the target motor, and obtaining a continuous model of the target motor through the initial operation matrix, the plane shaft current and the plane shaft voltage; S33: Discretize the continuous model to obtain a discrete prediction model, obtain the expected voltage value of the target motor through the discretized prediction model, calculate the target position of the expected voltage value in the first spatial voltage vector distribution diagram, and select the target reference voltage vector through the reference voltage vector and the target position.

[0010] According to the dual three-phase motor control method based on virtual vector provided by the present invention, step S4 specifically includes: S41: construct a cost function, extract the state matrix of the target motor from the discretization prediction model, and the cost function of the kth operation cycle The expression is: in, is the actual value of the dq axis current in the k+1th operating cycle, is the theoretical value of the dq axis current in the k+1th operating cycle, Indicates taking the Euclidean norm; S42: rewriting the cost function through the state matrix, and constructing the quadratic programming equation through the rewritten cost function.

[0011] According to the dual three-phase motor control method based on virtual vector provided by the present invention, step S5 specifically includes: S51: setting an initial solution, a similar inverse matrix, constraints and Lagrange multipliers through the target reference voltage vector, and using the initial solution, the similar inverse matrix, the constraints and the Lagrange multipliers as the initial parameters, extracting an initial input matrix and an initial input vector from the quadratic programming equation, and using the initial input matrix and the initial input vector as the initial input; S52: Calculate a gradient through the Lagrange multiplier, the initial input and the initial parameter, calculate a search direction through the similarity inverse matrix and the gradient, and calculate a step size through the search direction; S53: Under the constraint of the constraint condition, the initial solution is iterated by the step size, and the Lagrange multipliers, the gradient and the similarity inverse matrix are iterated until the iteration end condition is reached, and the vector action time is obtained by the iterated initial solution.

[0012] The present invention also provides a dual three-phase motor control system based on virtual vector, comprising: Space voltage vector module: used to determine the target motor, and determine the space voltage vector of the target motor according to the level output state of the target motor; Reference voltage vector module: used to obtain a first space voltage vector distribution diagram and a second space voltage vector distribution diagram through a space voltage vector, perform discrete point fitting in the first space voltage vector distribution diagram and the second space voltage vector distribution diagram, respectively obtain a first voltage vector loop system and a second voltage vector loop system in sequence, obtain a virtual vector through the first voltage vector loop system and the second voltage vector loop system, and synthesize a reference voltage vector through the virtual vector on the first space voltage vector distribution diagram; Target reference voltage vector module: used to sample the target motor to obtain the motor operating parameters, obtain the continuous model through the motor operating parameters, discretize the continuous model to obtain the expected voltage value, and determine the target reference voltage vector through the expected voltage value and the reference voltage vector; Loss function module: used to construct a cost function, obtain the state matrix of the target motor through the discretized continuous model, and construct a quadratic programming equation through the state matrix and the cost function; Vector action time module: used to determine the initial parameters of the quadratic programming equation, extract the initial input from the quadratic programming equation, iteratively solve the quadratic programming equation using the quasi-Newton method through the initial parameters and the initial input, and obtain the vector action time; Motor control module: used for controlling the target motor through the vector action time and the target reference voltage vector.

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

[0014] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of any of the above-described dual three-phase motor control methods based on virtual vectors.

[0015] The above one or more technical solutions in the embodiments of the present invention have at least one of the following technical effects: The dual three-phase motor control method, system, device and medium based on virtual vector provided by the present invention obtains virtual vector through the first voltage vector loop system and the second voltage vector loop system, and re-divides the first space voltage vector distribution diagram to obtain reference voltage vector, effectively considering the characteristics of different positions in the space voltage vector distribution diagram, then selects the target reference voltage vector from the reference voltage vector, and predicts the action time of each vector in the control cycle by solving the quadratic programming problem, selects two or three virtual vectors to act on the dual three-phase motor in one control cycle, effectively suppresses harmonic current, and improves the control effect on the motor. Thus, efficient and simple control of the dual three-phase motor is achieved.

[0016] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0018] Figure 1 It is a flow chart of a dual three-phase motor control method based on virtual vector provided by the present invention.

[0019] Figure 2 It is a topological diagram of the target motor of the dual three-phase motor control method based on virtual vector provided by the present invention.

[0020] Figure 3 It is a schematic diagram of a first voltage vector loop system and a second voltage vector loop system of a dual three-phase motor control method based on a virtual vector provided by the present invention.

[0021] Figure 4 It is a schematic diagram of sector division of the dual three-phase motor control method based on virtual vector provided by the present invention.

[0022] Figure 5 It is a schematic diagram of experimental verification results of the dual three-phase motor control method based on virtual vector provided by the present invention.

[0023] Figure 6 It is a structural schematic diagram of a dual three-phase motor control system based on virtual vector provided by the present invention.

[0024] Figure 7 It is a structural schematic diagram of a dual three-phase motor control device based on virtual vector provided by the present invention.

[0025] Reference numerals: 100. Space voltage vector module; 200. Reference voltage vector module; 300. Target reference voltage vector module; 400. Loss function module; 500. Vector action time module; 600. Motor control module; 1. Large sector; 2. Medium sector; 3. Small sector; 810. Processor; 820. Communication interface; 830. Memory; 840. Communication bus. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical scheme and advantages of the present invention clearer, the technical scheme in the present invention will be clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention. The following embodiments are used to illustrate the present invention, but cannot be used to limit the scope of the present invention.

[0027] In the description of the embodiments of the present invention, it should be noted that the terms “first”, “second” and “third” are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0028] In the description of this specification, the description with reference to the 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 embodiment of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0029] Combine the following Figures 1 to 7 Describe the specific embodiments of the present invention: Figure 1 It is a flow chart of a dual three-phase motor control method based on virtual vector provided by the present invention, including first determining a target motor and determining a spatial voltage vector of the target motor; then obtaining a first spatial voltage vector distribution schematic diagram and a second spatial voltage vector distribution schematic diagram, thereby synthesizing a reference voltage vector, and then obtaining a continuous operation model and a discretized voltage expectation value, thereby determining a target reference voltage vector; then constructing a cost function, obtaining a state matrix, thereby obtaining a quadratic programming equation; then determining initial parameters and initial inputs, using a quasi-Newton method to iteratively solve the quadratic programming equation, and obtaining a vector action time; finally, controlling the target motor through the vector action time and the target reference voltage vector.

[0030] The dual three-phase motor control method based on virtual vector provided by the present invention comprises: S1: determining a target motor, and determining a spatial voltage vector of the target motor according to a level output state of the target motor; Furthermore, the purpose of this stage is to obtain the spatial voltage vector of the target motor. Specifically, in step S1, the target motor is a dual three-phase motor, and the target motor has six bridge arms, and each bridge arm has three level output states. For the above steps, the specific implementation method in this embodiment is as follows: First, a dual three-phase motor is selected as the target motor. Figure 2 This is the topology diagram of the dual three-phase motor. It can be seen that the dual three-phase motor has six bridge arms, namely A phase, B phase, C phase, U phase, V phase and W phase. Each bridge arm corresponds to one phase and can output three output states: positive level, 0 level and negative level. The total number of the six phases is There are 729 kinds of spatial voltage vectors for the target motor.

[0031] S2: obtaining a first space voltage vector distribution diagram and a second space voltage vector distribution diagram through the space voltage vector, performing discrete point fitting in the first space voltage vector distribution diagram and the second space voltage vector distribution diagram, respectively obtaining a first voltage vector loop system and a second voltage vector loop system in sequence, obtaining a virtual vector through the first voltage vector loop system and the second voltage vector loop system, and synthesizing a reference voltage vector through the virtual vector on the first space voltage vector distribution diagram; Furthermore, the purpose of this stage is to obtain the first voltage vector loop system and the second voltage vector loop system by fitting, and then obtain the virtual vector, and finally synthesize the reference voltage vector through the virtual vector. Specifically, step S2 specifically includes: S21: projecting the space voltage vector onto the α-β space to obtain the first space voltage vector distribution diagram, and projecting the space voltage vector onto the xy space to obtain the second space voltage vector distribution diagram; S22: performing discrete point fitting according to the distribution of the space voltage vector in the second space voltage vector distribution diagram to obtain a plurality of closed curves as the second voltage vector loop system, and projecting the second voltage vector loop system onto the first space voltage vector distribution diagram to obtain the first voltage vector loop system; S23: Select a first voltage vector set in the first voltage vector loop system, select a second voltage vector set in the second voltage vector loop system based on the first voltage vector set, use the second voltage vector set as the virtual vector, and synthesize a reference voltage vector based on the volt-second balance principle and through the virtual vector.

[0032] In step S23, when synthesizing the reference voltage vector, the first space voltage vector distribution diagram is divided into a large sector, a medium sector and a small sector, and after the virtual vector is projected into the first space voltage vector distribution diagram, the projected virtual vector is divided into a large virtual vector, a medium virtual vector and a small virtual vector, in the small sector, a small voltage vector is synthesized by two of the small virtual vectors, in the medium sector, a medium voltage vector is synthesized by two of the medium virtual vectors and one of the small virtual vectors, and in the large sector, a large voltage vector is synthesized by two of the large virtual vectors and one of the medium virtual vectors, and the small voltage vector, the medium voltage vector and the large voltage vector are used as the reference voltage vector.

[0033] With respect to the above steps, the specific implementation methods in this embodiment are as follows: First, the space voltage vector is projected onto the α-β plane to obtain the distribution of the space voltage vector in the α-β plane, i.e., the first space voltage vector distribution diagram, and the space voltage vector is projected onto the xy plane to obtain the distribution of the space voltage vector in the xy plane, i.e., the second space voltage vector distribution diagram.

[0034] Then, several groups of space voltage vectors with the smallest amplitude are selected from the second space voltage vector distribution diagram for discrete point fitting. Here, the least square fitting algorithm is used for fitting to obtain multiple closed curves as the second voltage vector loop system. In this embodiment, there are five closed curves, namely , , , , The second voltage vector ring system is projected onto the first space voltage vector distribution diagram to obtain the first voltage vector ring system, which are , , , , , Figure 3 (a) is a schematic diagram of the first voltage vector loop system. Figure 3 (b) is a schematic diagram of the second voltage vector loop system.

[0035] Next, a first voltage vector set is selected from the first voltage vector loop system, that is, several groups of closed curves are selected from the first voltage vector loop system, and the space voltage vectors on each group of closed curves can be connected to form the first voltage vector set. In this embodiment, there should be another closed curve between a group of closed curves, so and , and as well as and The connection lines of the space voltage vectors on these three groups of closed curves constitute the first voltage vector set. The connection line between two space voltage vectors is called a first voltage vector, and each first voltage vector does not pass through the origin of the first space voltage vector distribution diagram, but its reverse extension line passes through the origin of the first space voltage vector distribution diagram. Correspondingly, several groups of closed curves are selected in the second voltage vector ring system, and the space voltage vectors on each group of closed curves can be connected to form a second voltage vector set. The closed curves selected in the second voltage vector ring system need to correspond to the closed curves selected in the first voltage vector ring system, so the selected and , and as well as and The connection lines of the space voltage vectors on the three groups of closed curves constitute a second voltage vector set, the connection line between two space voltage vectors is called a second voltage vector, and each second voltage vector passes through the origin of the second space voltage vector distribution diagram. The second voltage vector set is taken as a virtual vector.

[0036] In the virtual vector, according to the volt-second balance principle, each second voltage vector in the virtual vector needs to follow the following relationship: Wherein, Q is the space voltage vector corresponding to one end of the second voltage vector, and P is the space voltage vector corresponding to the other end of the second voltage vector. is the action time of Q, is the action time of P, is the length of one operating cycle of the target motor.

[0037] When synthesizing the reference voltage vector, the first space voltage vector distribution diagram is divided into a large sector 1, a medium sector 2 and a small sector 3, and after the virtual vector is projected onto the first space voltage vector distribution diagram, the projected virtual vector is divided into a large virtual vector, a medium virtual vector and a small virtual vector. Figure 4 This is a schematic diagram of sector division. Here, and The space voltage vector connection between them is called the large virtual vector, and The space voltage vector connection between them is called the virtual vector, and The space voltage vector connection line between is called a small virtual vector. In the small sector 3, a small voltage vector is synthesized by two small virtual vectors, in the medium sector 2, a medium voltage vector is synthesized by two medium virtual vectors and a small virtual vector, and in the large sector 1, a large voltage vector is synthesized by two large virtual vectors and a medium virtual vector. The small voltage vector, the medium voltage vector and the large voltage vector are used as the reference voltage vector.

[0038] S3: sampling the target motor to obtain motor operating parameters, obtaining a continuous model through the motor operating parameters, discretizing the continuous model to obtain a voltage expected value, and determining a target reference voltage vector through the voltage expected value and a reference voltage vector; Furthermore, the purpose of this stage is to calculate the expected voltage value of the target motor, and determine the target reference voltage vector through the expected voltage value and the reference voltage vector. Specifically, step S3 specifically includes: S31: Sampling the target motor to obtain motor operating parameters, where the motor operating parameters include motor phase current, motor phase voltage and electrical angle; S32: performing coordinate transformation on the motor phase current and the motor phase voltage to obtain a plane shaft current and a plane shaft voltage, constructing an initial operation matrix of the target motor, and obtaining a continuous model of the target motor through the initial operation matrix, the plane shaft current and the plane shaft voltage; S33: Discretize the continuous model to obtain a discrete prediction model, obtain the expected voltage value of the target motor through the discretized prediction model, calculate the target position of the expected voltage value in the first spatial voltage vector distribution diagram, and select the target reference voltage vector through the reference voltage vector and the target position.

[0039] With respect to the above steps, the specific implementation methods in this embodiment are as follows: First, the operating data of the target motor is sampled to obtain the motor operating parameters, which include the current of each phase of the target motor, i.e., the motor phase current, the voltage of each phase of the target motor, i.e., the motor phase voltage, and the electrical angle. Then, the motor phase current and motor phase voltage are transformed by coordinates, here by Clarke transformation and Park transformation, decoupled to the dq plane and xy plane, and the components of the motor phase current on the d-axis are obtained. , the component of the motor phase current on the q axis , the component of the motor phase current on the x-axis and the components of the motor phase current on the y-axis The plane shaft current; the component of the motor phase voltage on the d axis can also be obtained , the component of the motor phase voltage on the q axis , the component of the motor phase voltage on the x-axis and the component of the motor phase voltage on the y-axis The plane shaft voltage is obtained, and then the initial operation matrix including the first initial operation matrix F, the second initial operation matrix G and the third initial operation matrix W is obtained to construct the continuous model of the target motor: in, for The derivative of for The derivative of for The derivative of for The derivative of is the stator resistance of the target motor, is the component of the winding inductance on the d-axis, is the component of the winding inductance on the q axis, is the electrical angle of the target motor, is the component of the winding inductance in the xy plane, is the flux amplitude generated by the permanent magnet.

[0040] Then the continuous model is discretized to obtain the discretized prediction model: in, is the discretized first initial operation matrix, To discretize the initial second operation matrix, is the discretized initial third operation matrix, I is the identity matrix, is the target motor in the kth operation cycle, that is, , is the target motor in the kth operation cycle , is the target motor in the kth operation cycle , is the target motor in the kth operation cycle , is the target motor in the kth operation cycle , is the target motor in the kth operation cycle , is the target motor in the kth operation cycle , is the target motor in the kth operation cycle , is the target motor in the k+1th operation cycle, that is, in the next operation cycle , is the target motor in the k+1th operation cycle , is the target motor in the k+1th operation cycle , is the target motor in the k+1th operation cycle .

[0041] The expected voltage value can be obtained by using the discretization prediction model. The expected voltage value includes , , and : in, is the target motor in the k+1th operation cycle, that is, in the next operation cycle , is the target motor in the k+1th operation cycle , is the target motor in the k+1th operation cycle , The target motor is , M is the target initial first operation matrix, N is the target initial second operation matrix, P is the target initial third operation matrix, is the inverse matrix of the discretized initial second operation matrix.

[0042] Then, by performing an inverse Park transform on the expected voltage value, we can obtain the position of the expected voltage value in the α-β plane: in, For Parker's counter-transformation, is the component of the motor phase voltage on the α-axis in the k+1th operating cycle of the target motor, is the component of the motor phase voltage on the β axis in the k+1th operating cycle of the target motor, is the amplitude of the target reference voltage vector in the first space voltage vector distribution diagram, is the angle of the target reference voltage vector in the first space voltage vector distribution diagram. The target position can be obtained by the aforementioned amplitude and angle. According to the sector in which the target position is located in the first space voltage vector distribution diagram, the target reference voltage vector can be synthesized by the reference voltage vector. For example, when the target position is located in the middle sector, the reference voltage vector is a medium voltage vector. The medium voltage vector synthesized by two medium virtual vectors and a small virtual vector in the projected virtual vector can be selected as the target reference voltage vector.

[0043] S4: constructing a cost function, obtaining a state matrix of the target motor through the discretized continuous model, and constructing a quadratic programming equation through the state matrix and the cost function; Furthermore, the purpose of this stage is to construct a quadratic programming equation through a cost function after determining the target reference voltage vector, so as to obtain the action time of the virtual vector after the projection participating in synthesizing the target reference voltage vector. Specifically, step S4 specifically includes: S41: construct a cost function, extract the state matrix of the target motor from the discretization prediction model, and the cost function of the kth operation cycle The expression is: in, is the actual value of the dq axis current in the k+1th operating cycle, is the theoretical value of the dq axis current in the k+1th operating cycle, Indicates taking the Euclidean norm; S42: rewriting the cost function through the state matrix, and constructing the quadratic programming equation through the rewritten cost function.

[0044] With respect to the above steps, the specific implementation methods in this embodiment are as follows: First, construct the cost function. The cost function of the kth operation cycle The expression is: in, is the actual value of the dq axis current in the k+1th operating cycle, is the theoretical value of the dq axis current in the k+1th operating cycle, which includes the components of the current on the d axis and the q axis, Indicates taking the Euclidean norm; Then, for and , the state matrix of the target motor is extracted from the discretized prediction model, including the first state matrix , the second state matrix and the third state matrix : , , Then the cost function can be rewritten as: in, is the Park transformation matrix, is the vector magnitude matrix, is the dq axis current value of the kth operation cycle, It is the vector action time of the kth operation cycle, including the action time of the projected virtual vector participating in the synthesis of the target reference voltage vector to be solved. For example, when the target position is located in the middle sector, two middle virtual vectors and one small virtual vector participating in the projected virtual vector of the synthesized target reference voltage vector have their own action time.

[0045] Construct the first auxiliary variable r, and , construct the second auxiliary variable ,and ,but: in, is the transpose of r, for The transpose of for Here, since r is a 2×1 matrix, is a 2×3 matrix, is a 3×1 matrix, so is a 1×1 matrix, that is, a scalar, is also a 1×1 matrix, i.e. a scalar, so the two scalars can be combined to get , at this time, the cost function can be transformed into a quadratic programming problem, and the quadratic programming equation can be constructed: Where H is the initial input matrix, and , f is the initial input vector, is the transpose of f, and , min() means finding the minimum value in the brackets, b means the linear constraint value of the quadratic programming equation, taking the case where the target position is in the middle sector as an example, is the first action time, is the second action time, is the third action time, , and It represents the action time of the virtual vector after the projection of the target reference voltage vector to be solved. For example, when the target position is located in the middle sector, the action time of the small virtual vector in the reference voltage vector participating in the synthesis of the target reference voltage vector is , of the two virtual vectors, the action time of one virtual vector is , the other action time is .

[0046] S5: determining initial parameters of the quadratic programming equation, extracting initial input from the quadratic programming equation, and iteratively solving the quadratic programming equation using the quasi-Newton method through the initial parameters and the initial input to obtain the vector action time; Furthermore, the purpose of this stage is to use the quasi-Newton method to iteratively solve the quadratic programming equation to obtain the vector action time. Specifically, step S5 specifically includes: S51: setting an initial solution, a similar inverse matrix, constraints and Lagrange multipliers through the target reference voltage vector, and using the initial solution, the similar inverse matrix, the constraints and the Lagrange multipliers as the initial parameters, extracting an initial input matrix and an initial input vector from the quadratic programming equation, and using the initial input matrix and the initial input vector as the initial input; S52: Calculate a gradient through the Lagrange multiplier, the initial input and the initial parameter, calculate a search direction through the similarity inverse matrix and the gradient, and calculate a step size through the search direction; S53: Under the constraint of the constraint condition, the initial solution is iterated by the step size, and the Lagrange multipliers, the gradient and the similarity inverse matrix are iterated until the iteration end condition is reached, and the vector action time is obtained by the iterated initial solution.

[0047] With respect to the above steps, the specific implementation methods in this embodiment are as follows: First, the initial solution is set by the target reference voltage vector. Here, when the target position corresponding to the target reference voltage vector is located in a small sector, since only two small virtual vectors participate in synthesizing the target reference voltage vector, the initial solution is Set as , otherwise the initial solution is set to Then set the linear constraint value b, and b= , set the similarity inverse matrix And set the Lagrange multiplier based on experience , where the similar inverse matrix is ​​set to be the identity matrix with the same matrix dimension as H, and the constraint condition is that when the target position is located in a small sector, the third value of the initial solution is always 0. The initial solution, similar inverse matrix, constraint condition and Lagrange multiplier are used as initial parameters, and the initial input matrix H and initial input vector f are extracted from the quadratic programming equation, and the initial input matrix and initial input vector are used as initial input.

[0048] Then the gradient is calculated by the Lagrange multiplier, the initial input and the initial parameters : Where T represents the transpose, and the search direction is calculated by similarity inverse matrix and gradient : Calculate the step size by searching the direction : in, for The transpose of for The transpose of .

[0049] Under the constraints of the constraints, the initial solution is iterated by the step size to obtain the iterative solution : In this embodiment, the constraint condition can be implemented by dividing the third value of the iterative solution by 2 when the third value of the iterative solution is not 0, and then adding the result to the first value and the second value of the iterative solution, respectively, and making the third value of the iterative solution 0. Iterate the Lagrange multiplier to obtain the iterative Lagrange multiplier : in, is a proportional factor constant set based on experience, and in this embodiment, it is taken as 0.1. is the first value of the initial solution, is the second value of the initial solution, is the third value of the initial solution.

[0050] Iterate the gradient to get the iterative gradient : Then calculate the first update value and the second updated value , the similar inverse matrix is ​​iterated by the first update value and the second update value to obtain the iterative similar inverse matrix : Final Order , , , , and recalculate for iteration, guiding to reach the iteration end condition, that is, the gradient is less than the iteration threshold set according to experience, or the number of iterations reaches the upper limit of the number of iterations, then the initial solution at this time is used as the target solution, and the vector action time is obtained from the target solution, that is, the first value, the second value and the third value in the target solution are used as the action time of the three projected virtual vectors participating in the synthesis of the target reference voltage vector, if only two projected virtual vectors participate in the synthesis of the target reference voltage vector, then only the first value and the second value are taken as the vector action time.

[0051] S6: Controlling the target motor through the vector action time and the target reference voltage vector.

[0052] Furthermore, after obtaining the vector action time in this stage, the action time of each projected virtual vector can be obtained, so as to complete the synthesis of the target reference voltage vector in combination with the target reference voltage vector to control the target motor.

[0053] In order to verify the effectiveness of the present invention, the dual three-phase motor control method based on virtual vector proposed in the present invention is experimentally verified on a dual three-phase motor drive experimental platform. In terms of phase current, taking the current of phase A as an example, Figure 5 As shown, Figure 5 (a) is a schematic diagram of the phase current changing with time, with the horizontal axis in seconds. is the phase current of phase A, is the phase current of phase B, is the phase current of phase C, is the phase current of phase U, is the phase current of phase V, is the phase current of phase W, Figure 5 The experimental data shown in (a) is input into the MATLAB tool for analysis, and the THD (Total Harmonic Distortion) of the phase current of phase A is 6.11%. Figure 5 (b) is a schematic diagram of the x-axis and y-axis current changes with time. Figure 5 The experimental data shown in (b) is input into the MATLAB tool for analysis, and it can be obtained that the current ripple amplitude does not exceed 2.1A. Figure 5 (c) is a schematic diagram of the speed change of the dual three-phase motor over time, n is the actual speed value of the target motor, n* is the theoretical speed value, and it can be seen that in terms of speed following, the speed following is good in the stable state. The unit of speed is rpm, that is, revolutions per minute, and the unit of time is seconds. Figure 5 The error in the experiment is mainly due to the delay between the control command to the target motor and the actual operating condition of the motor, which leads to the fluctuation of the operating state of the target motor.

[0054] The following is a description of a dual three-phase motor control device based on a virtual vector provided by the present invention. The dual three-phase motor control device based on a virtual vector described below and the dual three-phase motor control method based on a virtual vector described above can be referred to each other.

[0055] Figure 6 The structural diagram of the dual three-phase motor control system based on virtual vector is shown as an example. Figure 6 As shown, the method for executing the dual three-phase motor control method based on virtual vector as described above includes: The space voltage vector module 100 is used to determine a target motor, and determine the space voltage vector of the target motor according to the level output state of the target motor; A reference voltage vector module 200 is used to obtain a first space voltage vector distribution diagram and a second space voltage vector distribution diagram through a space voltage vector, perform discrete point fitting in the first space voltage vector distribution diagram and the second space voltage vector distribution diagram, respectively obtain a first voltage vector loop system and a second voltage vector loop system in sequence, obtain a virtual vector through the first voltage vector loop system and the second voltage vector loop system, and synthesize a reference voltage vector through the virtual vector on the first space voltage vector distribution diagram; The target reference voltage vector module 300 is used to sample the target motor to obtain the motor operating parameters, obtain the continuous model through the motor operating parameters, discretize the continuous model to obtain the voltage expected value, and determine the target reference voltage vector through the voltage expected value and the reference voltage vector; Loss function module 400: used to construct a cost function, obtain the state matrix of the target motor through the discretized continuous model, and construct a quadratic programming equation through the state matrix and the cost function; Vector action time module 500: used to determine initial parameters of the quadratic programming equation, extract initial input from the quadratic programming equation, iteratively solve the quadratic programming equation using the quasi-Newton method through the initial parameters and initial input, and obtain the vector action time; The motor control module 600 is used to control the target motor through the vector action time and the target reference voltage vector.

[0056] on the other hand, Figure 7 An example of a physical structure diagram of an electronic device is shown in FIG. Figure 7 As shown, the electronic device may include: a processor 810, a communication interface 820, a memory 830 and a communication bus 840, wherein the processor 810, the communication interface 820, and the memory 830 communicate with each other through the communication bus 840. The processor 810 may call the logic instructions in the memory 830 to execute a dual three-phase motor control method based on a virtual vector, the method comprising: S1: determining a target motor, and determining a spatial voltage vector of the target motor according to a level output state of the target motor; S2: obtaining a first space voltage vector distribution diagram and a second space voltage vector distribution diagram through the space voltage vector, performing discrete point fitting in the first space voltage vector distribution diagram and the second space voltage vector distribution diagram, respectively obtaining a first voltage vector loop system and a second voltage vector loop system in sequence, obtaining a virtual vector through the first voltage vector loop system and the second voltage vector loop system, and synthesizing a reference voltage vector through the virtual vector on the first space voltage vector distribution diagram; S3: sampling the target motor to obtain motor operating parameters, obtaining a continuous model through the motor operating parameters, discretizing the continuous model to obtain a voltage expected value, and determining a target reference voltage vector through the voltage expected value and a reference voltage vector; S4: constructing a cost function, obtaining a state matrix of the target motor through the discretized continuous model, and constructing a quadratic programming equation through the state matrix and the cost function; S5: determining initial parameters of the quadratic programming equation, extracting initial input from the quadratic programming equation, and iteratively solving the quadratic programming equation using the quasi-Newton method through the initial parameters and the initial input to obtain the vector action time; S6: Controlling the target motor through the vector action time and the target reference voltage vector.

[0057] In addition, the logic instructions in the above-mentioned memory 830 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on this understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art or the part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program codes.

[0058] In another aspect, the present invention further provides a non-transitory computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the dual three-phase motor control method based on virtual vector provided by the above methods is implemented, and the method includes: S1: determining a target motor, and determining a spatial voltage vector of the target motor according to a level output state of the target motor; S2: obtaining a first space voltage vector distribution diagram and a second space voltage vector distribution diagram through the space voltage vector, performing discrete point fitting in the first space voltage vector distribution diagram and the second space voltage vector distribution diagram, respectively obtaining a first voltage vector loop system and a second voltage vector loop system in sequence, obtaining a virtual vector through the first voltage vector loop system and the second voltage vector loop system, and synthesizing a reference voltage vector through the virtual vector on the first space voltage vector distribution diagram; S3: sampling the target motor to obtain motor operating parameters, obtaining a continuous model through the motor operating parameters, discretizing the continuous model to obtain a voltage expected value, and determining a target reference voltage vector through the voltage expected value and a reference voltage vector; S4: constructing a cost function, obtaining a state matrix of the target motor through the discretized continuous model, and constructing a quadratic programming equation through the state matrix and the cost function; S5: determining initial parameters of the quadratic programming equation, extracting initial input from the quadratic programming equation, and iteratively solving the quadratic programming equation using the quasi-Newton method through the initial parameters and the initial input to obtain the vector action time; S6: Controlling the target motor through the vector action time and the target reference voltage vector.

[0059] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0060] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0061] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A dual three-phase motor control method based on virtual vector, characterized in that: include: S1: determining a target motor, and determining a spatial voltage vector of the target motor according to a level output state of the target motor; S2: obtaining a first space voltage vector distribution diagram and a second space voltage vector distribution diagram through the space voltage vector, performing discrete point fitting in the first space voltage vector distribution diagram and the second space voltage vector distribution diagram, respectively obtaining a first voltage vector loop system and a second voltage vector loop system in sequence, obtaining a virtual vector through the first voltage vector loop system and the second voltage vector loop system, and synthesizing a reference voltage vector through the virtual vector on the first space voltage vector distribution diagram; S3: sampling the target motor to obtain motor operating parameters, obtaining a continuous model through the motor operating parameters, discretizing the continuous model to obtain a voltage expected value, and determining a target reference voltage vector through the voltage expected value and a reference voltage vector; S4: constructing a cost function, obtaining a state matrix of the target motor through the discretized continuous model, and constructing a quadratic programming equation through the state matrix and the cost function; S5: determining initial parameters of the quadratic programming equation, extracting initial input from the quadratic programming equation, and iteratively solving the quadratic programming equation using the quasi-Newton method through the initial parameters and the initial input to obtain the vector action time; S6: Controlling the target motor through the vector action time and the target reference voltage vector.

2. The dual three-phase motor control method based on virtual vector according to claim 1, characterized in that: In step S1, the target motor is a dual three-phase motor, and the target motor has six bridge arms, and each bridge arm has three level output states.

3. The dual three-phase motor control method based on virtual vector according to claim 1, characterized in that: Step S2 specifically includes: S21: projecting the space voltage vector onto the α-β space to obtain the first space voltage vector distribution diagram, and projecting the space voltage vector onto the xy space to obtain the second space voltage vector distribution diagram; S22: performing discrete point fitting according to the distribution of the space voltage vector in the second space voltage vector distribution diagram to obtain a plurality of closed curves as the second voltage vector loop system, and projecting the second voltage vector loop system onto the first space voltage vector distribution diagram to obtain the first voltage vector loop system; S23: Select a first voltage vector set in the first voltage vector loop system, select a second voltage vector set in the second voltage vector loop system based on the first voltage vector set, use the second voltage vector set as the virtual vector, and synthesize a reference voltage vector based on the volt-second balance principle and through the virtual vector.

4. The dual three-phase motor control method based on virtual vector according to claim 3 is characterized in that: In step S23, when synthesizing the reference voltage vector, the first space voltage vector distribution diagram is divided into a large sector, a medium sector and a small sector, and after the virtual vector is projected into the first space voltage vector distribution diagram, the projected virtual vector is divided into a large virtual vector, a medium virtual vector and a small virtual vector, in the small sector, a small voltage vector is synthesized by two of the small virtual vectors, in the medium sector, a medium voltage vector is synthesized by two of the medium virtual vectors and one of the small virtual vectors, and in the large sector, a large voltage vector is synthesized by two of the large virtual vectors and one of the medium virtual vectors, and the small voltage vector, the medium voltage vector and the large voltage vector are used as the reference voltage vector.

5. The dual three-phase motor control method based on virtual vector according to claim 1, characterized in that: Step S3 specifically includes: S31: Sampling the target motor to obtain motor operating parameters, where the motor operating parameters include motor phase current, motor phase voltage and electrical angle; S32: performing coordinate transformation on the motor phase current and the motor phase voltage to obtain a plane shaft current and a plane shaft voltage, constructing an initial operation matrix of the target motor, and obtaining a continuous model of the target motor through the initial operation matrix, the plane shaft current and the plane shaft voltage; S33: Discretize the continuous model to obtain a discrete prediction model, obtain the expected voltage value of the target motor through the discretized prediction model, calculate the target position of the expected voltage value in the first spatial voltage vector distribution diagram, and select the target reference voltage vector through the reference voltage vector and the target position.

6. The dual three-phase motor control method based on virtual vector according to claim 1, characterized in that: Step S4 specifically includes: S41: construct a cost function, extract the state matrix of the target motor from the discretization prediction model, and the cost function of the kth operation cycle The expression is: in, is the actual value of the dq axis current in the k+1th operating cycle, is the theoretical value of the dq axis current in the k+1th operating cycle, Indicates taking the Euclidean norm; S42: rewriting the cost function through the state matrix, and constructing the quadratic programming equation through the rewritten cost function.

7. The dual three-phase motor control method based on virtual vector according to claim 1, characterized in that: Step S5 specifically includes: S51: setting an initial solution, a similar inverse matrix, constraints and Lagrange multipliers through the target reference voltage vector, and using the initial solution, the similar inverse matrix, the constraints and the Lagrange multipliers as the initial parameters, extracting an initial input matrix and an initial input vector from the quadratic programming equation, and using the initial input matrix and the initial input vector as the initial input; S52: Calculate a gradient through the Lagrange multiplier, the initial input and the initial parameter, calculate a search direction through the similarity inverse matrix and the gradient, and calculate a step size through the search direction; S53: Under the constraint of the constraint condition, the initial solution is iterated by the step size, and the Lagrange multiplier, the gradient and the similarity inverse matrix are iterated until the iteration end condition is reached, and the vector action time is obtained by the iterated initial solution.

8. A dual three-phase motor control system based on virtual vector, used to execute the dual three-phase motor control method based on virtual vector according to any one of claims 1 to 7, characterized in that: include: Space voltage vector module: used to determine the target motor, and determine the space voltage vector of the target motor according to the level output state of the target motor; Reference voltage vector module: used to obtain a first space voltage vector distribution diagram and a second space voltage vector distribution diagram through a space voltage vector, perform discrete point fitting in the first space voltage vector distribution diagram and the second space voltage vector distribution diagram, respectively obtain a first voltage vector loop system and a second voltage vector loop system in sequence, obtain a virtual vector through the first voltage vector loop system and the second voltage vector loop system, and synthesize a reference voltage vector through the virtual vector on the first space voltage vector distribution diagram; Target reference voltage vector module: used to sample the target motor to obtain the motor operating parameters, obtain the continuous model through the motor operating parameters, discretize the continuous model to obtain the expected voltage value, and determine the target reference voltage vector through the expected voltage value and the reference voltage vector; Loss function module: used to construct a cost function, obtain the state matrix of the target motor through the discretized continuous model, and construct a quadratic programming equation through the state matrix and the cost function; Vector action time module: used to determine the initial parameters of the quadratic programming equation, extract the initial input from the quadratic programming equation, iteratively solve the quadratic programming equation using the quasi-Newton method through the initial parameters and the initial input, and obtain the vector action time; Motor control module: used for controlling the target motor through the vector action time and the target reference voltage vector.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the steps of the dual three-phase motor control method based on virtual vector as described in any one of claims 1 to 7 are implemented.

10. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the dual three-phase motor control method based on virtual vector as claimed in any one of claims 1 to 7 are implemented.

Images