Synchronous motor control method and device, electronic equipment and storage medium

Abstract

The invention discloses a synchronous motor control method and device, electronic equipment and a storage medium, and the method comprises the steps: obtaining the switching state of an inverter of a permanent magnet linear synchronous motor according to a preset period when the permanent magnet linear synchronous motor is in an operation state, and determining an output voltage vector plane according to the switching state of the inverter; dividing the output voltage vector plane according to preset division times to obtain each divided virtual voltage vector; obtaining operation parameters of the permanent magnet linear synchronous motor, and obtaining an optimal voltage vector according to the operation parameters, each virtual voltage vector and a predetermined current prediction model; and controlling the permanent magnet linear synchronous motor based on the optimal voltage vector. The method has the advantages that the flexibility and adaptability of motor control are improved, and different motor operation states can be better coped with.

Description

Technical Field

[0001] Embodiments of the present invention relate to the technical field of linear motor control, and in particular to a synchronous motor control method, device, electronic device and storage medium. Background Art

[0002] Permanent magnet linear synchronous motor is a rotating permanent magnet motor that is flattened along the radial direction. It can directly generate thrust in the linear direction, eliminating the need for intermediate mechanical transmission devices. It has many advantages such as small size, simple structure, and easy maintenance. It is widely used in industrial servo, rail transportation, aerospace and other fields. It is a green and efficient drive option. At present, the model predictive control method is generally used to control the operation of permanent magnet linear synchronous motor. The model predictive control method does not require the current inner loop and its parameter setting and hysteresis regulator, does not require pulse width modulation, and is easy to handle system constraints or add other control targets. It has the advantages of simple structure, fast dynamic response and easy expansion.

[0003] However, current model predictive control methods mostly use only one basic voltage vector to control the motor in a single control cycle. However, the basic voltage vector is not necessarily the optimal voltage vector. In fact, the error between the basic voltage vector and the optimal vector is large, resulting in large current harmonics and thrust fluctuations, which reduces the working performance of the permanent magnet linear synchronous motor. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a synchronous motor control method, device, electronic device and storage medium that can accurately determine the optimal voltage vector from multiple voltage vectors, thereby improving the working performance of a permanent magnet linear synchronous motor.

[0005] In order to solve the above technical problems, the technical solution proposed by the present invention is:

[0006] A synchronous motor control method, comprising:

[0007] When the permanent magnet linear synchronous motor is in a running state, a switching state of an inverter of the permanent magnet linear synchronous motor is obtained according to a preset cycle, and an output voltage vector plane is determined according to the switching state of the inverter;

[0008] Dividing the output voltage vector plane according to a preset number of divisions to obtain virtual voltage vectors after division;

[0009] Acquiring operating parameters of the permanent magnet linear synchronous motor, and obtaining an optimal voltage vector according to the operating parameters, each virtual voltage vector and a predetermined current prediction model;

[0010] The permanent magnet linear synchronous motor is controlled based on the optimal voltage vector.

[0011] As a further improvement of the above technical solution:

[0012] The output voltage vector plane includes an α-axis plane and a β-axis plane; the output voltage vector plane is divided according to a preset number of divisions to obtain virtual voltage vectors after division, including:

[0013] Dividing the α-axis of the voltage vector plane to obtain division points of the α-axis, and dividing the β-axis of the voltage vector plane to obtain division points of the β-axis;

[0014] The α-axis vertical lines corresponding to the division points of the α-axis and the β-axis vertical lines corresponding to the division points of the β-axis are determined, and the intersection points of the α-axis vertical lines and the β-axis vertical lines are determined as the virtual voltage vectors.

[0015] The α-axis of the voltage vector plane is divided to obtain the division points of the α-axis, including:

[0016] Determine the midpoint of the α-axis of the voltage vector plane as the α-axis dividing point, and divide the α-axis into two equal parts based on the α-axis dividing point to obtain a first α-sub-axis and a second α-sub-axis;

[0017] Taking the first α sub-axis and the second α sub-axis as the current α sub-axis respectively, determining the trisection division point of the current α sub-axis, and performing a first trisection division on the current α sub-axis based on the trisection division point of the current α sub-axis to obtain three α trisection axes corresponding to the current α sub-axis;

[0018] When the number of times the current α sub-axis is divided into three equal parts does not reach the preset number of times, the three α trisection axes are respectively used as the current α sub-axis, and the step of determining the trisection points of the current α sub-axis is repeated until the current α sub-axis is divided into three equal parts for the preset number of times to obtain the division points of the α axis.

[0019] Obtaining an optimal voltage vector according to the operating parameters, the virtual voltage vectors and a predetermined current prediction model, including:

[0020] Screening all virtual voltage vectors to obtain candidate voltage vectors from all virtual voltage vectors;

[0021] An optimal voltage vector is obtained according to the operating parameters, each candidate voltage vector and a predetermined current prediction model.

[0022] The operating parameters include the actual current and angular velocity of the αβ axes, and the optimal voltage vector is obtained according to the operating parameters, the candidate voltage vectors and a predetermined current prediction model, including:

[0023] Inputting the operating parameters into a predetermined state observer to obtain a back electromotive force observation value corresponding to the operating parameters;

[0024] For each candidate voltage vector, based on the operating parameters, the current candidate voltage vector, the back electromotive force observation value and the current prediction model, an αβ-axis predicted current value corresponding to the current candidate voltage vector is obtained;

[0025] The optimal voltage vector is determined based on the αβ-axis predicted current values ​​corresponding to all candidate voltage vectors.

[0026] Based on the operating parameters, the current candidate voltage vector, the back electromotive force observation value and the current prediction model, the αβ-axis predicted current value corresponding to the current candidate voltage vector is obtained, including:

[0027] Obtaining the αβ-axis reference current of the permanent magnet linear synchronous motor in the current cycle according to the operating parameters and a preset proportional-integral controller;

[0028] Determine a current factor according to the inductance, resistance and the actual current of the αβ axis, and subtract the sum of the current factor and the current candidate voltage vector from the back electromotive force observation value to obtain a prediction factor;

[0029] The ratio of the current cycle to the inductance is multiplied by the prediction factor to obtain the αβ-axis predicted current value corresponding to the current candidate voltage vector.

[0030] Determining the optimal voltage vector based on the αβ-axis predicted current values ​​corresponding to all candidate voltage vectors includes:

[0031] Calculating the α-axis current difference between the α-axis component of the αβ-axis reference current and the α-axis component of the αβ-axis predicted current value corresponding to the current candidate voltage vector; Calculating the β-axis current difference between the β-axis component of the αβ-axis reference current and the β-axis component of the αβ-axis predicted current value corresponding to the current candidate voltage vector;

[0032] Obtaining a cost function value of the current candidate voltage vector based on the α-axis current difference, the β-axis current difference and a preset cost function;

[0033] A candidate voltage vector with the smallest cost function value among all candidate voltage vectors is determined as the optimal voltage vector.

[0034] A synchronous motor control device, comprising:

[0035] A plane determination module, used for obtaining a switching state of an inverter of the permanent magnet linear synchronous motor according to a preset cycle when the permanent magnet linear synchronous motor is in a running state, and determining an output voltage vector plane according to the switching state of the inverter;

[0036] A vector division module, used for dividing the output voltage vector plane according to a preset number of divisions to obtain virtual voltage vectors after division;

[0037] A vector determination module, used for acquiring the operating parameters of the permanent magnet linear synchronous motor, and obtaining an optimal voltage vector according to the operating parameters, the virtual voltage vectors and a predetermined current prediction model;

[0038] A motor control module is used to control the permanent magnet linear synchronous motor based on the optimal voltage vector.

[0039] An electronic device comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor implements a synchronous motor control method as described above when executing the program.

[0040] A computer-readable storage medium stores a computer program, which, when executed by a processor, implements a synchronous motor control method as described above.

[0041] Compared with the prior art, the advantages of the present invention are:

[0042] When the permanent magnet linear synchronous motor is in operation, the present invention obtains the switching state of the inverter of the permanent magnet linear synchronous motor according to a preset cycle, and determines the output voltage vector plane according to the switching state of the inverter; divides the output voltage vector plane according to a preset number of divisions to obtain each virtual voltage vector after division; obtains the operating parameters of the permanent magnet linear synchronous motor, and obtains the optimal voltage vector according to the operating parameters, each virtual voltage vector and a predetermined current prediction model; and controls the permanent magnet linear synchronous motor based on the optimal voltage vector. The method of the embodiment of the present invention, by dividing the output voltage vector plane to obtain each virtual voltage vector, provides more voltage vector options for subsequent motor control, increases the flexibility and adaptability of motor control, and can better cope with different motor operating states. Through the selection of the optimal voltage vector, the problems of current harmonics and large thrust fluctuations in the application of the permanent magnet linear synchronous motor are effectively reduced, and the steady-state control performance of the permanent magnet linear synchronous motor is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The present invention will be described in more detail below based on embodiments and with reference to the accompanying drawings, wherein:

[0044] Figure 1 A first flow chart of a synchronous motor control method provided by an embodiment of the present invention;

[0045] Figure 2A second flow chart of a synchronous motor control method provided by an embodiment of the present invention;

[0046] Figure 3 A schematic diagram of the structure of a synchronous motor control device provided by an embodiment of the present invention;

[0047] Figure 4 A schematic diagram of the structure of an electronic device provided by an embodiment of the present invention.

[0048] The symbols in the figure represent:

[0049] 301. plane determination module; 302. vector division module; 303. vector determination module; 304. motor control module; 12. electronic device; 14. external device; 16. processing unit; 18. bus; 20. network adapter; 22. input / output interface; 24. display; 28. system memory; 30. random access memory; 32. cache memory; 34. storage system; 40. utility tool; 46. program module. DETAILED DESCRIPTION

[0050] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, but the protection scope of the present invention is not limited thereby.

[0051] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0052] Figure 1 This is a first flow chart of a synchronous motor control method provided in an embodiment of the present invention. The method in the embodiment of the present invention can accurately determine the optimal voltage vector from multiple voltage vectors, and use the optimal voltage vector to control the permanent magnet linear synchronous motor, thereby improving the working performance of the permanent magnet linear synchronous motor. The method can be executed by a synchronous motor control device provided in an embodiment of the present invention. The device can be implemented in software and / or hardware. The following embodiments will be described by taking the device integrated in an electronic device as an example. The electronic device can be a server or computer device for implementing a synchronous motor control method. Figure 1 , the method may specifically include the following steps:

[0053] Step 101: When the permanent magnet linear synchronous motor is in operation, a switching state of an inverter of the permanent magnet linear synchronous motor is obtained according to a preset cycle, and an output voltage vector plane is determined according to the switching state of the inverter.

[0054] Among them, the preset cycle is a time interval predetermined based on the domain big data, the performance of the permanent magnet linear synchronous motor and the specific operating environment. The voltage vector is generated by a combination of different switching states of the inverter. The output voltage vector plane of the inverter is a two-dimensional coordinate system used to describe the output voltage state of the inverter, usually represented by the αβ coordinate system. In the output voltage vector plane, each point represents a specific voltage vector.

[0055] Specifically, during the operation of the permanent magnet linear synchronous motor, the switching state and other operating parameters of the inverter can be collected in real time according to a preset cycle. Other operating parameters include but are not limited to: the angular velocity, voltage vector, resistance, inductance, actual current of the αβ axis and motor speed of the permanent magnet linear synchronous motor. In this scheme, the output voltage vector plane is determined according to the space vector pulse width modulation technology. In the space vector pulse width modulation technology, six basic voltage vectors form a regular hexagon, which is divided into six sectors. By judging in which sector the reference voltage vector is located, a suitable basic voltage vector can be selected for synthesis. The reference voltage is determined according to the actual current of the αβ axis and the position information of the motor, and a suitable basic voltage vector is selected for synthesis according to the sector where the reference voltage is located. By reasonably controlling the switching between two adjacent non-zero vectors and the zero vector, the rotating reference vector is approached in each switching cycle, so that the trajectory of the synthetic voltage vector approaches a circle, thereby obtaining the output voltage vector plane.

[0056] Step 102 : Divide the output voltage vector plane according to a preset number of divisions to obtain virtual voltage vectors after division.

[0057] The preset number of divisions is a number predetermined according to the specification information of the permanent magnet linear synchronous motor and field big data, etc. Specifically, the output voltage vector plane is a plane on the αβ axis. After the output voltage vector plane is determined, the α axis and the β axis can be divided according to the preset number of divisions, and each virtual voltage vector is determined according to the division results of the α axis and the β axis.

[0058] In an optional implementation, the midpoint of the α-axis of the voltage vector plane is determined as the α-axis division point, and the α-axis is divided into two equal parts based on the α-axis division point to obtain a first α sub-axis and a second α sub-axis; the first α sub-axis and the second α sub-axis are respectively used as the current α sub-axis, the trisection division point of the current α sub-axis is determined, and the current α sub-axis is divided into three equal parts for the first time based on the trisection division point of the current α sub-axis to obtain three α trisection axes corresponding to the current α sub-axis; when the number of divisions of the current α sub-axis into three equal parts does not reach a preset number of divisions, the three α trisection axes are respectively used as the current α sub-axis, and the step of determining the trisection division point of the current α sub-axis is repeated until the current α sub-axis is divided into three equal parts for the preset number of divisions to obtain the division points of the α axis. The β-axis of the voltage vector plane is divided by the same method to obtain the division points of the β-axis; the α-axis vertical line corresponding to the division points of the α-axis and the β-axis vertical line corresponding to the division points of the β-axis are determined, and the intersection points of the α-axis vertical line and the β-axis vertical line are determined as virtual voltage vectors.

[0059] Step 103: Acquire the operating parameters of the permanent magnet linear synchronous motor, and obtain the optimal voltage vector according to the operating parameters, each virtual voltage vector and a predetermined current prediction model.

[0060] Among them, the operating parameters of the permanent magnet linear synchronous motor include the angular velocity, voltage vector, resistance, inductance, actual current of the αβ axes and motor speed of the permanent magnet linear synchronous motor. The voltage vector is the actual voltage value and direction applied to the stator winding of the motor when the motor is running. The actual current of the αβ axes is the actual current value flowing through the α and β axes of the motor when the motor is running. In this solution, the corresponding operating parameters can be collected by a parameter acquisition device. For example, use tools such as an oscilloscope or a multimeter to measure the phase voltage and phase current of the motor. The speed and position information of the motor are measured in real time through position sensors such as encoders or Hall sensors.

[0061] The current prediction model includes a set of mathematical equations for describing the dynamic behavior of the motor. The current virtual voltage vector and operating parameters are input into the current prediction model, and the current prediction model can calculate them, and obtain the αβ axis predicted current value corresponding to the current virtual voltage vector according to the calculation result. In an optional embodiment, after obtaining the virtual voltage vectors after division, all virtual voltage vectors are screened to obtain candidate voltage vectors among all virtual voltage vectors; the operating parameters are input into a predetermined state observer to obtain the back electromotive force observation value corresponding to the operating parameters; for each candidate voltage vector, the αβ axis reference current of the permanent magnet linear synchronous motor in the current cycle is obtained according to the operating parameters and the preset proportional integral controller; the current factor is determined according to the inductance, resistance and αβ axis actual current, and the sum of the current factor and the current candidate voltage vector is subtracted from the back electromotive force observation value to obtain the prediction factor; the ratio of the current cycle to the inductance is multiplied by the prediction factor to obtain the αβ axis predicted current value corresponding to the current candidate voltage vector. Calculate the α-axis current difference between the α-axis component of the αβ-axis reference current and the α-axis component of the αβ-axis predicted current value corresponding to the current candidate voltage vector; calculate the β-axis current difference between the β-axis component of the αβ-axis reference current and the β-axis component of the αβ-axis predicted current value corresponding to the current candidate voltage vector; obtain the cost function value of the current candidate voltage vector based on the α-axis current difference and the β-axis current difference; determine the candidate voltage vector with the smallest cost function value among all candidate voltage vectors as the optimal voltage vector.

[0062] Step 104: Control the permanent magnet linear synchronous motor based on the optimal voltage vector.

[0063] Among them, the optimal voltage vector refers to the voltage vector that can make the motor operating state closest to the desired state after evaluation by the current prediction model and the cost function. Specifically, after obtaining the optimal voltage vector, the corresponding inverter switching signal is generated according to the optimal voltage vector. The generated inverter switching signal is applied to the inverter. After the inverter receives the switching signal, it can adjust the on-off state of its internal semiconductor switching device according to these signals, thereby changing the amplitude and phase of the output voltage. By precisely controlling the output voltage of the inverter, precise control of the permanent magnet linear synchronous motor can be achieved, including the adjustment of parameters such as speed, position and torque.

[0064] The technical solution of this embodiment is that when the permanent magnet linear synchronous motor is in operation, the switching state of the inverter of the permanent magnet linear synchronous motor is obtained according to a preset cycle, and the output voltage vector plane is determined according to the switching state of the inverter; the output voltage vector plane is divided according to a preset number of divisions to obtain each virtual voltage vector after division; the operating parameters of the permanent magnet linear synchronous motor are obtained, and the optimal voltage vector is obtained according to the operating parameters, each virtual voltage vector and a predetermined current prediction model; the permanent magnet linear synchronous motor is controlled based on the optimal voltage vector. The technical solution of this embodiment provides more voltage vector options for subsequent motor control by dividing the output voltage vector plane, increases the flexibility and adaptability of motor control, and can better cope with different motor operating states. Through the selection of the optimal voltage vector, the problems of current harmonics and large thrust fluctuations in the application of permanent magnet linear synchronous motors are effectively reduced, and the steady-state control performance of permanent magnet linear synchronous motors is improved.

[0065] Figure 2 The second flow chart of the synchronous motor control method provided in the embodiment of the present invention is a refinement of the above embodiment. The specific method can be as follows Figure 2 As shown, the method may include the following steps:

[0066] Step 201 : when the permanent magnet linear synchronous motor is in operation, the switching state of the inverter of the permanent magnet linear synchronous motor is obtained according to a preset cycle, and the output voltage vector plane is determined according to the switching state of the inverter.

[0067] Step 202: Divide the α-axis of the voltage vector plane to obtain division points of the α-axis, and divide the β-axis of the voltage vector plane to obtain division points of the β-axis.

[0068] Specifically, the output voltage vector plane is a plane on the αβ axes. After the output voltage vector plane is determined, the α axis and the β axis can be divided according to a preset number of divisions, and each virtual voltage vector is determined according to the division results of the α axis and the β axis. In the present scheme, optionally, the α-axis of the voltage vector plane is divided to obtain the division points of the α-axis, including: determining the midpoint of the α-axis of the voltage vector plane as the α-axis division point, and dividing the α-axis into two equal parts based on the α-axis division point to obtain a first α sub-axis and a second α sub-axis; using the first α sub-axis and the second α sub-axis as the current α sub-axis, respectively, determining the trisection division point of the current α sub-axis, and performing a first trisection division on the current α sub-axis based on the trisection division point of the current α sub-axis to obtain three α trisection axes corresponding to the current α sub-axis; when the number of divisions of the current α sub-axis into three equal parts does not reach the preset number of divisions, respectively using the three α trisection axes as the current α sub-axis, and repeating the step of determining the trisection division point of the current α sub-axis until the current α sub-axis is divided into three equal parts for the preset number of times to obtain the division points of the α-axis.

[0069] Specifically, the midpoint of the a-axis is first used as the dividing point, and the a-axis is divided into two equal parts according to the dividing point. In the voltage vector plane, the interval of the a-axis is u dc is the DC bus voltage. After the α-axis is divided into two equal parts, the first α-axis and the second α-axis are obtained. At the same time, the first α-axis and the second α-axis are divided into three equal parts for the first time, and the first α-axis and the second α-axis are divided into smaller areas, that is, the first α-axis and the second α-axis are divided into three equal parts for the second time, and then the smaller area is divided into three equal parts again, that is, the first α-axis and the second α-axis are divided into three equal parts for the third time, and the step of dividing into three equal parts is repeated until the first α-axis and the second α-axis are divided into three equal parts for the preset number of times, and the division of the α-axis is completed. The bisection points and all the trisection points of the α-axis are determined as the division points of the α-axis. Assuming that the preset number of divisions is n times, 2×3 n-1 Each division point of the α axis.

[0070] Furthermore, the β axis of the voltage vector plane is divided in the same way. First, the midpoint of the β axis is used as the dividing point for bisection, and the β axis is divided into two equal parts according to the bisection point (the β axis interval is u αoptis the a-axis component of the searched optimal voltage vector). After bisecting the β-axis, the first β-sub-axis and the second β-sub-axis are obtained. At the same time, the first β-sub-axis and the second β-sub-axis are divided into three equal parts for the first time, and the first β-sub-axis and the second β-sub-axis are divided into smaller areas, that is, the first β-sub-axis and the second β-sub-axis are divided into three equal parts for the first time, and the trisection step is repeated until the first β-sub-axis and the second β-sub-axis are divided into three equal parts for the preset number of times, and the division of the β-axis is completed. The bisection points and all the trisection points of the β-axis are determined as the division points of the β-axis. Assuming that the preset number of divisions is n, 2×3 n-1 Each division point of the β axis.

[0071] By dividing the α-axis and β-axis into multiple sub-axes and further dividing them into three equal parts, more virtual voltage vectors can be obtained, providing more options for motor control, making the motor control more refined, thereby improving control accuracy. By refining the division of the α-axis, the generation of current harmonics can be reduced, the thrust of the motor can be controlled more accurately, thereby reducing thrust fluctuations and improving the stability and efficiency of motor operation.

[0072] Step 203 : Determine the α-axis vertical lines corresponding to the division points of the α-axis and the β-axis vertical lines corresponding to the division points of the β-axis, and determine the intersection points of the α-axis vertical lines and the β-axis vertical lines as virtual voltage vectors.

[0073] Take each division point of the α axis as a vertical point, and make a vertical line perpendicular to the α axis according to each vertical point. Take each division point of the β axis as a vertical point, and make a vertical line perpendicular to the β axis according to each vertical point. Determine each intersection of the vertical line of the α axis and the vertical line of the β axis as each virtual voltage vector. Assuming that the preset number of divisions is n, after the a axis and the b axis are iteratively divided n times, the total number of virtual voltage vectors is: n total =4×3 2n-2 (n≥1); where n total is the total number of virtual voltage vectors, and n is the number of divisions.

[0074] Step 204 : Screen all virtual voltage vectors to obtain candidate voltage vectors from all virtual voltage vectors.

[0075] Specifically, as the number of divisions increases, the number of generated virtual voltage vectors increases exponentially. The total number of virtual voltage vectors is n total =4×3 2n-2(n≥1), if all virtual voltage vectors are evaluated directly, the amount of calculation will become very large. And the preset cycle is generally a very small time interval, so it is necessary to complete the evaluation of the virtual voltage vector in a very short time. Therefore, after all virtual voltage vectors are obtained, all virtual voltage vectors are screened to obtain candidate voltage vectors from all virtual voltage vectors. In this solution, after all virtual voltage vectors are obtained, according to the number of iterations, n total 4n virtual voltage vectors are selected as candidate voltage vectors.

[0076] Step 205 : Acquire the operating parameters of the permanent magnet linear synchronous motor, input the operating parameters into a predetermined state observer, and obtain back electromotive force observation values ​​corresponding to the operating parameters.

[0077] Among them, the state observer is used to calculate the back electromotive force observation value based on the operating parameters. The back electromotive force is the voltage induced in the winding due to the change of the magnetic field when the motor rotates. The back electromotive force observation value is the estimated value of the motor back electromotive force obtained by observation or calculation.

[0078] Exemplarily, the state observer is:

[0079] Among them, t is the time variable, represents the αβ axis observation current, L s Inductance, R s Represents resistance, u αβ represents the voltage vector, i αβ Indicates the actual current of αβ axis, represents the observed value of back EMF, represents the observed value of the intermediate variable, ω r represents the angular velocity, Indicates the αβ axis observation current Relative to the actual current i of the αβ axis αβ The error, λ represents the gain parameter, and λ>0. The operating parameters are input into the state observer, and the state observer can calculate the back electromotive force observation value according to the above formula.

[0080] Step 206 : for each candidate voltage vector, based on the operating parameters, the current candidate voltage vector, the back electromotive force observation value and the current prediction model, obtain the αβ-axis predicted current value corresponding to the current candidate voltage vector.

[0081] The current prediction model includes a set of mathematical equations for describing the dynamic behavior of the motor. The current virtual voltage vector and operating parameters are input into the current prediction model, and the current prediction model can calculate them, and obtain the αβ axis predicted current value corresponding to the current virtual voltage vector according to the calculation result. In this solution, optionally, based on the operating parameters, the current candidate voltage vector, the back electromotive force observation value and the current prediction model, obtaining the αβ axis predicted current value corresponding to the current candidate voltage vector includes the following steps A1-A2:

[0082] Step A1: Obtain the αβ-axis reference current of the current cycle of the permanent magnet linear synchronous motor according to the operating parameters and a preset proportional-integral controller.

[0083] Among them, the proportional-integral (PI) controller is a feedback control strategy, and the PI controller adjusts the control input according to the error between the actual output and the expected output. The PI controller in this scheme is used to adjust the q-axis current reference value through feedback control of the speed error. In an optional implementation, after obtaining the operating parameters, the speed difference between the motor speed in the operating parameters and the preset speed reference value is calculated, and the speed difference is input to the PI controller. After receiving the speed difference, the PI controller performs PI control on the speed difference to obtain the q-axis reference current of the permanent magnet linear synchronous motor.

[0084] The speed difference is proportionally and integrally controlled by a proportional-integral controller to obtain the q-axis reference current of the permanent magnet linear synchronous motor. The preset d-axis reference current and q-axis reference current are converted to the αβ axes according to a predetermined coordinate conversion algorithm to obtain the αβ axis reference current.

[0085] Among them, the speed reference value is a value predetermined according to the performance of the permanent magnet linear synchronous motor and the specific operating environment. The coordinate conversion algorithm is an algorithm for converting the d-axis reference current and the q-axis reference current to the αβ axis. The coordinate conversion algorithm in this scheme can be a Parker transformation algorithm. After obtaining the q-axis current, the Parker transformation is used to convert the preset d-axis reference current and the q-axis reference current to the αβ axis to obtain the αβ axis reference current.

[0086] Step A2: Determine the current factor based on the inductance, resistance and actual current of the αβ axis, and subtract the sum of the current factor and the current candidate voltage vector from the back electromotive force observation value to obtain the prediction factor. Multiply the ratio of the current cycle to the inductance by the prediction factor to obtain the αβ axis predicted current value corresponding to the current candidate voltage vector.

[0087] Among them, the current factor and the prediction factor are part of the equation of the current prediction model, and the current factor and the prediction factor are used to calculate the αβ axis predicted current value corresponding to the current candidate voltage vector. After obtaining the αβ axis reference current, according to the inductance L s , current cycle T, resistance R s and the actual current i of the αβ axis αβ The current factor is obtained as: Where t is the time variable. The current factor and the current candidate voltage vector u αβ The sum of the back EMF observations Subtract and get the predictor: Multiply the ratio of the current cycle to the inductance by the prediction factor to obtain the αβ-axis predicted current value corresponding to the current candidate voltage vector of the next cycle of the current cycle: Among them, i αβ (t+1) is the predicted current value of the αβ axes corresponding to the current candidate voltage vector.

[0088] By obtaining the αβ-axis predicted current value corresponding to the current candidate voltage vector through the current prediction model, we can understand the impact of different low-voltage vectors on the motor performance, and thus select the optimal voltage vector, which provides a basis for subsequently improving the accuracy and efficiency of controlling the permanent magnet linear synchronous motor.

[0089] Step 207 : Determine the optimal voltage vector based on the αβ-axis predicted current values ​​corresponding to all candidate voltage vectors.

[0090] The optimal voltage vector refers to the voltage vector that can make the motor operation state closest to the desired state after evaluation by the current prediction model and the cost function. In this solution, the optimal voltage vector is determined based on the αβ axis predicted current values ​​corresponding to all candidate voltage vectors, including the following steps B1-B2:

[0091] Step B1: Calculate the α-axis current difference between the α-axis component of the αβ-axis reference current and the α-axis component of the αβ-axis predicted current value corresponding to the current candidate voltage vector; Calculate the β-axis current difference between the β-axis component of the αβ-axis reference current and the β-axis component of the αβ-axis predicted current value corresponding to the current candidate voltage vector;

[0092] Specifically, after obtaining the αβ-axis predicted current value, the α-axis component of the αβ-axis reference current is subtracted from the α-axis component of the αβ-axis predicted current value to obtain the α-axis current difference: i αref -i α (t+1); where i αref represents the α-axis component of the αβ-axis reference current, i α (t+1) represents the α-axis component of the αβ-axis predicted current value. Subtract the β-axis component of the αβ-axis reference current from the β-axis component of the αβ-axis predicted current value to obtain the β-axis current difference: iβref -i β (t+1), where i βref represents the β-axis component of the αβ-axis reference current, i β (t+1) represents the β-axis component of the αβ-axis predicted current value.

[0093] Step B2: obtaining a cost function value of the current candidate voltage vector based on the α-axis current difference, the β-axis current difference and a preset cost function; and determining the candidate voltage vector with the smallest cost function value among all candidate voltage vectors as the optimal voltage vector.

[0094] The cost function is a pre-set function used to measure the difference between the model prediction value and the true value. In this solution, after obtaining the cost function value corresponding to each candidate voltage vector, the candidate voltage vector with the smallest cost function value among all candidate voltage vectors can be determined as the optimal voltage vector.

[0095] The cost function in this scheme is: g = [i αref -i α (t+1)] 2 +[i βref -i β (t+1)] 2 ; Wherein, g represents the cost function value. After obtaining the α-axis current difference and the β-axis current difference, the α-axis current difference and the β-axis current difference are substituted into the cost function to obtain the cost function value of the current candidate voltage vector. Further, the cost function values ​​of all candidate voltage vectors are obtained, and the candidate voltage vector with the smallest cost function value among all candidate voltage vectors is determined as the optimal voltage vector.

[0096] By calculating the α-axis current difference and the β-axis current difference, the influence of each candidate voltage vector on the motor current can be evaluated more accurately, which helps to select the most appropriate voltage vector, thereby improving the control accuracy of the motor.

[0097] Step 208: Control the permanent magnet linear synchronous motor based on the optimal voltage vector.

[0098] In the technical solution of this embodiment, when the permanent magnet linear synchronous motor is in operation, the switching state of the inverter of the permanent magnet linear synchronous motor is obtained according to a preset cycle, and the output voltage vector plane is determined according to the switching state of the inverter. The α axis of the voltage vector plane is divided to obtain each division point of the α axis, and the β axis of the voltage vector plane is divided to obtain each division point of the β axis. Determine the α axis vertical line corresponding to each division point of the α axis and the β axis vertical line corresponding to each division point of the β axis, and determine each intersection of the α axis vertical line and the β axis vertical line as each virtual voltage vector. Obtain the operating parameters of the permanent magnet linear synchronous motor, screen all virtual voltage vectors, and obtain candidate voltage vectors among all virtual voltage vectors. Input the operating parameters into a predetermined state observer to obtain the back electromotive force observation value corresponding to the operating parameters. For each candidate voltage vector, based on the operating parameters, the current candidate voltage vector, the back electromotive force observation value and the current prediction model, the αβ axis predicted current value corresponding to the current candidate voltage vector is obtained. Determine the optimal voltage vector based on the αβ axis predicted current values ​​corresponding to all candidate voltage vectors. Control the permanent magnet linear synchronous motor based on the optimal voltage vector. The technical solution of this embodiment determines the virtual voltage vector according to the intersection of the vertical lines dividing the centers of the α-axis and the β-axis, provides more voltage vector options for motor control, increases the flexibility and adaptability of motor control, and can better cope with different motor operating states. By dividing the discrete candidate voltage vectors into regions and performing comparative optimization, the number of voltage vectors involved in online optimization is reduced, thereby reducing the computational burden. The real-time performance of motor control is improved, while the requirements for hardware performance are reduced. In addition, the optimal voltage vector selected in this solution can better achieve a smooth transition of the motor state, reduce the negative impact of mutations, and thus enhance the stability of motor control.

[0099] Figure 3 Schematic diagram of the structure of a synchronous motor control device provided in an embodiment of the present invention, which is suitable for executing a synchronous motor control method provided in an embodiment of the present invention. Figure 3 As shown, the device may specifically include:

[0100] The plane determination module 301 is used to obtain the switching state of the inverter of the permanent magnet linear synchronous motor according to a preset cycle when the permanent magnet linear synchronous motor is in a running state, and determine the output voltage vector plane according to the switching state of the inverter;

[0101] A vector division module 302, configured to divide the output voltage vector plane according to a preset number of divisions to obtain virtual voltage vectors after division;

[0102] A vector determination module 303 is used to obtain the operating parameters of the permanent magnet linear synchronous motor, and obtain an optimal voltage vector according to the operating parameters, each virtual voltage vector and a predetermined current prediction model;

[0103] The motor control module 303 is used to control the permanent magnet linear synchronous motor based on the optimal voltage vector.

[0104] Optionally, the vector division module 302 is specifically configured to: divide the α-axis of the voltage vector plane to obtain each division point of the α-axis, and divide the β-axis of the voltage vector plane to obtain each division point of the β-axis;

[0105] The α-axis vertical lines corresponding to the division points of the α-axis and the β-axis vertical lines corresponding to the division points of the β-axis are determined, and the intersection points of the α-axis vertical lines and the β-axis vertical lines are determined as the virtual voltage vectors.

[0106] Optionally, the vector division module 302 is further configured to: determine the midpoint of the α-axis of the voltage vector plane as an α-axis division point, and divide the α-axis into two equal parts based on the α-axis division point to obtain a first α-sub-axis and a second α-sub-axis;

[0107] Taking the first α sub-axis and the second α sub-axis as the current α sub-axis respectively, determining the trisection division point of the current α sub-axis, and performing a first trisection division on the current α sub-axis based on the trisection division point of the current α sub-axis to obtain three α trisection axes corresponding to the current α sub-axis;

[0108] When the number of times the current α sub-axis is divided into three equal parts does not reach the preset number of times, the three α trisection axes are respectively used as the current α sub-axis, and the step of determining the trisection points of the current α sub-axis is repeated until the current α sub-axis is divided into three equal parts for the preset number of times to obtain the division points of the α axis.

[0109] Optionally, the vector determination module 303 is specifically used to: screen all virtual voltage vectors to obtain candidate voltage vectors among all virtual voltage vectors;

[0110] An optimal voltage vector is obtained according to the operating parameters, each candidate voltage vector and a predetermined current prediction model.

[0111] Optionally, the vector determination module 303 is further used to: input the operating parameter into a predetermined state observer to obtain a back electromotive force observation value corresponding to the operating parameter;

[0112] For each candidate voltage vector, based on the operating parameters, the current candidate voltage vector, the back electromotive force observation value and the current prediction model, an αβ-axis predicted current value corresponding to the current candidate voltage vector is obtained;

[0113] The optimal voltage vector is determined based on the αβ-axis predicted current values ​​corresponding to all candidate voltage vectors.

[0114] Optionally, the vector determination module 303 is further used to: obtain the αβ axis reference current of the permanent magnet linear synchronous motor in the current cycle according to the operating parameters and a preset proportional-integral controller;

[0115] Determine a current factor according to the inductance, resistance and the actual current of the αβ axis, and subtract the sum of the current factor and the current candidate voltage vector from the back electromotive force observation value to obtain a prediction factor;

[0116] The ratio of the current cycle to the inductance is multiplied by the prediction factor to obtain the αβ-axis predicted current value corresponding to the current candidate voltage vector.

[0117] Optionally, the vector determination module 303 is further used to: calculate the α-axis current difference between the α-axis component of the αβ-axis reference current and the α-axis component of the αβ-axis predicted current value corresponding to the current candidate voltage vector; calculate the β-axis current difference between the β-axis component of the αβ-axis reference current and the β-axis component of the αβ-axis predicted current value corresponding to the current candidate voltage vector;

[0118] Obtaining a cost function value of the current candidate voltage vector based on the α-axis current difference, the β-axis current difference and a preset cost function;

[0119] A candidate voltage vector with the smallest cost function value among all candidate voltage vectors is determined as the optimal voltage vector.

[0120] The synchronous motor control device provided in the embodiment of the present invention can execute a synchronous motor control method provided in any embodiment of the present invention, and has the corresponding functional modules and beneficial effects of the execution method. For the contents not described in detail in this embodiment, reference can be made to the description in any method embodiment of the present invention.

[0121] Figure 4 A schematic diagram of the structure of an electronic device provided by an embodiment of the present invention, referring to Figure 4 , Figure 4 The electronic device 12 shown is only an example and should not limit the functions and scope of use of the embodiments of the present application. Figure 4 As shown, the electronic device 12 is in the form of a general purpose computing device. The components of the electronic device 12 may include, but are not limited to: one or more processors or processing units 16, a system memory 28, and a bus 18 that connects various system components (including the system memory 28 and the processing unit 16).

[0122] Bus 18 represents one or more of several types of bus structures, including a memory bus or memory controller, a peripheral bus, an accelerated graphics port, a processor or a local bus using any of a variety of bus architectures. By way of example, these architectures include, but are not limited to, an Industry Standard Architecture (ISA) bus, a Micro Channel Architecture (MAC) bus, an Enhanced ISA bus, a Video Electronics Standards Association (VESA) local bus, and a Peripheral Component Interconnect (PCI) bus.

[0123] The electronic device 12 typically includes a variety of computer system readable media. These media can be any available media that can be accessed by the electronic device 12, including volatile and non-volatile media, removable and non-removable media.

[0124] The system memory 28 may include computer system readable media in the form of volatile memory, such as random access memory (RAM) 30 and / or cache memory 32. The electronic device 12 may further include other removable / non-removable, volatile / non-volatile computer system storage media. By way of example only, the storage system 34 may be used to read and write non-removable, non-volatile magnetic media ( Figure 4 not shown, usually called a "hard drive"). Although Figure 4 Not shown, a disk drive for reading and writing to a removable non-volatile disk (e.g., a "floppy disk"), and an optical drive for reading and writing to a removable non-volatile optical disk (e.g., a CD-ROM, a DVD-ROM, or other optical medium) may be provided. In these cases, each drive may be connected to the bus 18 via one or more data medium interfaces. The memory 28 may include at least one program product having a set (e.g., at least one) of program modules that are configured to perform the functions of the various embodiments of the present application.

[0125] A program / utility 40 having a set (at least one) of program modules 46 may be stored, for example, in the memory 28, such program modules 46 including, but not limited to, an operating system, one or more application programs, other program modules, and program data, each of which or some combination may include an implementation of a network environment. The program modules 46 generally perform the functions and / or methods of the embodiments described herein.

[0126] The electronic device 12 may also communicate with one or more external devices 14 (e.g., keyboards, pointing devices, displays 24, etc.), may communicate with one or more devices that enable a user to interact with the electronic device 12, and / or may communicate with any device that enables the electronic device 12 to communicate with one or more other computing devices (e.g., a network card, a modem, etc.). Such communication may be performed via an input / output (I / O) interface 22. Furthermore, the electronic device 12 may also communicate with one or more networks (e.g., a local area network (LAN), a wide area network (WAN), and / or a public network, such as the Internet) via a network adapter 20. As shown, the network adapter 20 communicates with other modules of the electronic device 12 via the bus 18. It should be understood that although Figure 4 Not shown, other hardware and / or software modules may be used in conjunction with the electronic device 12, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage systems.

[0127] The processing unit 16 executes various functional applications and data processing by running the program stored in the system memory 28, for example, implementing a synchronous motor control method provided in an embodiment of the present invention: when the permanent magnet linear synchronous motor is in operation, the switching state of the inverter of the permanent magnet linear synchronous motor is obtained according to a preset period, and the output voltage vector plane is determined according to the switching state of the inverter; the output voltage vector plane is divided according to a preset number of divisions to obtain each virtual voltage vector after division; the operating parameters of the permanent magnet linear synchronous motor are obtained, and the optimal voltage vector is obtained according to the operating parameters, the virtual voltage vectors and a predetermined current prediction model; the permanent magnet linear synchronous motor is controlled based on the optimal voltage vector.

[0128] An embodiment of the present invention provides a computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, a synchronous motor control method provided by all the embodiments of the present invention is implemented: when the permanent magnet linear synchronous motor is in operation, the switching state of the inverter of the permanent magnet linear synchronous motor is obtained according to a preset period, and the output voltage vector plane is determined according to the switching state of the inverter; the output voltage vector plane is divided according to a preset number of divisions to obtain each virtual voltage vector after division; the operating parameters of the permanent magnet linear synchronous motor are obtained, and the optimal voltage vector is obtained according to the operating parameters, each virtual voltage vector and a predetermined current prediction model; the permanent magnet linear synchronous motor is controlled based on the optimal voltage vector. The computer-readable medium can be a computer-readable signal medium or a computer-readable storage medium. The computer-readable storage medium can be, for example, but not limited to, an electronic device, device or device of electricity, magnetism, light, electromagnetic, infrared, or semiconductor, or any combination thereof. More specific examples of computer-readable storage media (a non-exhaustive list) include: an electrical connection with one or more conductors, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In this document, a computer-readable storage medium can be any tangible medium that contains or stores a program that can be used by or in conjunction with an instruction-executing electronic device, apparatus, or device.

[0129] Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, which carry computer-readable program code. Such propagated data signals may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. Computer-readable signal media may also be any computer-readable medium other than a computer-readable storage medium, which may send, propagate, or transmit a program for use by or in conjunction with an instruction-executing electronic device, apparatus, or device.

[0130] The program code embodied on the computer readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.

[0131] Computer program code for performing the operations of the present invention may be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, C++, and conventional procedural programming languages ​​such as "C" or similar programming languages. The program code may be executed entirely on the user's computer, partially on the user's computer, as a separate software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0132] Although the present invention has been described with reference to preferred embodiments, various modifications may be made thereto and parts thereof may be replaced by equivalents without departing from the scope of the present invention. In particular, the various technical features mentioned in the various embodiments may be combined in any manner as long as there are no structural conflicts. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A synchronous motor control method, characterized in that: The method comprises: When the permanent magnet linear synchronous motor is in a running state, a switching state of an inverter of the permanent magnet linear synchronous motor is obtained according to a preset cycle, and an output voltage vector plane is determined according to the switching state of the inverter; Dividing the output voltage vector plane according to a preset number of divisions to obtain virtual voltage vectors after division; Acquiring operating parameters of the permanent magnet linear synchronous motor, and obtaining an optimal voltage vector according to the operating parameters, each virtual voltage vector and a predetermined current prediction model; The permanent magnet linear synchronous motor is controlled based on the optimal voltage vector.

2. The method according to claim 1, characterized in that The output voltage vector plane includes an α-axis plane and a β-axis plane; the output voltage vector plane is divided according to a preset number of divisions to obtain virtual voltage vectors after division, including: Dividing the α-axis of the voltage vector plane to obtain division points of the α-axis, and dividing the β-axis of the voltage vector plane to obtain division points of the β-axis; The α-axis vertical lines corresponding to the division points of the α-axis and the β-axis vertical lines corresponding to the division points of the β-axis are determined, and the intersection points of the α-axis vertical lines and the β-axis vertical lines are determined as the virtual voltage vectors.

3. The method according to claim 2, characterized in that The α-axis of the voltage vector plane is divided to obtain the division points of the α-axis, including: Determine the midpoint of the α-axis of the voltage vector plane as the α-axis dividing point, and divide the α-axis into two equal parts based on the α-axis dividing point to obtain a first α-sub-axis and a second α-sub-axis; Taking the first α sub-axis and the second α sub-axis as the current α sub-axis respectively, determining the trisection division point of the current α sub-axis, and performing a first trisection division on the current α sub-axis based on the trisection division point of the current α sub-axis to obtain three α trisection axes corresponding to the current α sub-axis; When the number of divisions of the current α sub-axis into three equal parts does not reach the preset number of divisions, the three α trisection axes are respectively used as the current α sub-axes, and the step of determining the trisection points of the current α sub-axis is repeated until the current α sub-axis is divided into three equal parts for the preset number of times to obtain the division points of the α axis.

4. The method according to claim 1, characterized in that: Obtaining an optimal voltage vector according to the operating parameters, the virtual voltage vectors and a predetermined current prediction model, including: Screening all virtual voltage vectors to obtain candidate voltage vectors from all virtual voltage vectors; An optimal voltage vector is obtained according to the operating parameters, each candidate voltage vector and a predetermined current prediction model.

5. The method according to claim 4, characterized in that The operating parameters include the actual current and angular velocity of the αβ axes, and the optimal voltage vector is obtained according to the operating parameters, the candidate voltage vectors and a predetermined current prediction model, including: Inputting the operating parameters into a predetermined state observer to obtain a back electromotive force observation value corresponding to the operating parameters; For each candidate voltage vector, based on the operating parameters, the current candidate voltage vector, the back electromotive force observation value and the current prediction model, an αβ-axis predicted current value corresponding to the current candidate voltage vector is obtained; The optimal voltage vector is determined based on the αβ-axis predicted current values ​​corresponding to all candidate voltage vectors.

6. The method according to claim 5, characterized in that Based on the operating parameters, the current candidate voltage vector, the back electromotive force observation value and the current prediction model, the αβ-axis predicted current value corresponding to the current candidate voltage vector is obtained, including: Obtaining the αβ-axis reference current of the permanent magnet linear synchronous motor in the current cycle according to the operating parameters and a preset proportional-integral controller; Determine a current factor according to the inductance, resistance and the actual current of the αβ axis, and subtract the sum of the current factor and the current candidate voltage vector from the back electromotive force observation value to obtain a prediction factor; The ratio of the current cycle to the inductance is multiplied by the prediction factor to obtain the αβ-axis predicted current value corresponding to the current candidate voltage vector.

7. The method according to claim 6, characterized in that Determining the optimal voltage vector based on the αβ-axis predicted current values ​​corresponding to all candidate voltage vectors includes: Calculating the α-axis current difference between the α-axis component of the αβ-axis reference current and the α-axis component of the αβ-axis predicted current value corresponding to the current candidate voltage vector; Calculating the β-axis current difference between the β-axis component of the αβ-axis reference current and the β-axis component of the αβ-axis predicted current value corresponding to the current candidate voltage vector; Obtaining a cost function value of the current candidate voltage vector based on the α-axis current difference, the β-axis current difference and a preset cost function; A candidate voltage vector with the smallest cost function value among all candidate voltage vectors is determined as the optimal voltage vector.

8. A synchronous motor control device, characterized in that: include: A plane determination module, used for obtaining a switching state of an inverter of the permanent magnet linear synchronous motor according to a preset cycle when the permanent magnet linear synchronous motor is in a running state, and determining an output voltage vector plane according to the switching state of the inverter; A vector division module, used for dividing the output voltage vector plane according to a preset number of divisions to obtain virtual voltage vectors after division; A vector determination module, used for acquiring the operating parameters of the permanent magnet linear synchronous motor, and obtaining an optimal voltage vector according to the operating parameters, the virtual voltage vectors and a predetermined current prediction model; A motor control module is used to control the permanent magnet linear synchronous motor based on the optimal 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 program, the synchronous motor control method according to any one of claims 1 to 7 is implemented.

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

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