Three-vector speed control method and device for permanent magnet synchronous motor

Abstract

The invention discloses a three-vector speed control method and device for a permanent magnet synchronous motor, and relates to the technical field of motor control, and the method comprises the steps: determining a composite speed tracking deviation according to an electrical angle rotating speed and an electrical angle rotating speed reference value, building a super-local rotating speed-current model according to the composite speed tracking deviation, forming inner and outer ring centralized disturbance, and obtaining a three-vector speed of the permanent magnet synchronous motor; the dynamic performance of the speed control method of the permanent magnet synchronous motor is improved, a composite nonlinear extended state observer is constructed based on a composite attenuation function, a concentrated disturbance estimated value is determined, a composite speed tracking deviation predicted value and a current predicted value are determined based on a discretized super-local rotating speed-current model, and the speed of the permanent magnet synchronous motor is controlled. And determining two adjacent effective voltage vectors according to the electrical angle, constructing a cost function, determining duty ratios of the two adjacent effective voltage vectors and a zero vector, and forming a driving signal of the inverter. The steady-state performance of the speed control method of the permanent magnet synchronous motor is improved, and then the control precision of the electrical angle rotating speed of the permanent magnet synchronous motor is improved.

Description

Technical Field

[0001] The present application relates to the field of motor control technology, and in particular to a three-vector speed control method and device for a permanent magnet synchronous motor. Background Art

[0002] Permanent magnet synchronous motors have been widely used in modern electrified transportation, especially electric vehicles, due to their high efficiency and power density. Among them, the speed control of permanent magnet synchronous motors is crucial. In the market, field-oriented control and direct torque control are generally used to control permanent magnet synchronous motors in real time; however, in recent years, model predictive control has become the main competitor of field-oriented control and direct torque control due to its fast dynamics, direct implementation, and easy addition of multivariable constraints. There is no proportional-integral speed controller in model predictive direct speed control, which can effectively improve the dynamic performance of the system. In order to further improve the steady-state performance, a three-vector based model predictive direct speed control has been proposed in recent decades, using three voltage vectors to act during the entire control cycle.

[0003] However, there are outer-loop disturbances and inner-loop disturbances in the three-vector based model predictive direct speed control, where the outer-loop disturbances include load torque and mechanical parameter mismatch, while the inner-loop disturbances are mainly composed of electrical parameter mismatch and other unknown disturbances that are not modeled. In most existing model predictive direct speed controls based on lumped disturbances, they are usually established as outer-loop concentrated disturbances and inner-loop concentrated disturbances, respectively. Obviously, the characteristics of the inner-loop and outer-loop concentrated disturbances are different in amplitude and rate of change. Therefore, it is necessary to design two different observers with specific characteristic disturbance ranges in the control algorithm, or use two observers that adapt to the full disturbance range, which inevitably leads to computational complexity or algorithm redundancy. On the other hand, in order to compensate for the inconsistent mechanical and electromagnetic times, more control objectives must be added to the cost function, which will increase the adjustment of more weighting factors. Although adapting to different speed / current sampling periods can also compensate for their time difference, this will bring speed overshoot / oscillation in the dynamic response.

[0004] Using a conventional nonlinear disturbance observer to observe lumped disturbances, it contains fast step-changing disturbances when a step load or step velocity is applied. Conventional NESO using the “fal” function as the error decay function has a poor convergence rate under fast-changing disturbances. In addition, the non-smooth piecewise error decay function structure may cause jitter in the control response.

[0005] Since the mechanical angular velocity and stator current have different sizes and amplitude ranges, appropriate weighting factors must be used to balance the importance of speed and current in three-vector based model predictive direct speed control. In practice, the traditional weighting factor adjustment procedure is usually a trial and error choice, which is time-consuming. In addition, it is also limited by the operating conditions. The weighting factors selected by this trial and error method may be different under different motor operating conditions, making it impossible to achieve optimal control under all operating conditions. Summary of the invention

[0006] The purpose of this application is to provide a three-vector speed control method and device for a permanent magnet synchronous motor, which can improve the dynamic performance, steady-state performance and anti-interference performance of the three-vector speed control process of the permanent magnet synchronous motor, thereby improving the control accuracy of the electrical angular speed of the permanent magnet synchronous motor.

[0007] To achieve the above objectives, this application provides the following solutions:

[0008] In a first aspect, the present application provides a three-vector speed control method for a permanent magnet synchronous motor, wherein the permanent magnet synchronous motor is connected to an inverter, and the three-vector speed control method for the permanent magnet synchronous motor comprises:

[0009] The stator current, stator voltage, electrical angular speed and electrical angle of the permanent magnet synchronous motor are collected in real time to obtain the stator current, stator voltage, electrical angular speed and electrical angle at time k;

[0010] Determine the composite speed tracking deviation at time k according to the electrical angular speed at time k and the electrical angular speed reference value;

[0011] A composite nonlinear extended state observer is constructed based on the composite attenuation function, and the concentrated disturbance estimation value at time k and the concentrated disturbance estimation value at time k+1 are determined by using the discretized composite nonlinear extended state observer according to the stator voltage at time k, the stator current at time k and the composite speed tracking deviation at time k.

[0012] According to the concentrated disturbance estimation value at time k, the stator voltage at time k, the stator current at time k, the composite speed tracking deviation at time k, the concentrated disturbance estimation value at time k+1 and the candidate voltage vector, a discretized super-local speed-current model is used to determine the composite speed tracking deviation prediction value at time k+2 and the current prediction value at time k+2; the super-local speed-current model is established based on the composite speed tracking deviation and the stator current;

[0013] According to the composite speed tracking deviation prediction value at the k+2 moment, the current prediction value at the k+2 moment, the composite speed tracking deviation reference value and the current reference value, based on the deadbeat control principle, a reference voltage vector is determined, and two adjacent effective voltage vectors are determined according to the reference voltage vector and the electrical angle at the k moment;

[0014] A cost function is established based on the composite speed tracking deviation prediction value at the k+2 moment, the current prediction value at the k+2 moment, the composite speed tracking deviation reference value, the current reference value and the candidate voltage vector, and the duty cycle of two adjacent effective voltage vectors and the zero vector is determined according to the cost function to form a drive signal of the inverter to control the electrical angular speed of the permanent magnet synchronous motor.

[0015] In a second aspect, the present application further provides a three-vector speed control device for a permanent magnet synchronous motor, the three-vector speed control device for a permanent magnet synchronous motor comprising:

[0016] A data acquisition module, used for real-time acquisition of the stator current, stator voltage, electrical angular speed and electrical angle of the permanent magnet synchronous motor, so as to obtain the stator current, stator voltage, electrical angular speed and electrical angle at time k;

[0017] A composite speed tracking deviation determination module, used to determine the composite speed tracking deviation at time k according to the electrical angle speed at time k and the electrical angle speed reference value;

[0018] The concentrated disturbance estimation module is used to construct a composite nonlinear extended state observer based on the composite attenuation function, and determine the concentrated disturbance estimation value at the time k and the concentrated disturbance estimation value at the time k+1 by using the discretized composite nonlinear extended state observer according to the stator voltage at the time k, the stator current at the time k and the composite speed tracking deviation at the time k;

[0019] A composite speed tracking deviation and current prediction module, for determining a composite speed tracking deviation prediction value at time k+2 and a current prediction value at time k+2 by using a discretized super-local speed-current model according to the concentrated disturbance estimation value at time k, the stator voltage at time k, the stator current at time k, the composite speed tracking deviation at time k, the concentrated disturbance estimation value at time k+1 and the candidate voltage vector; the super-local speed-current model is established based on the composite speed tracking deviation and the stator current;

[0020] an effective voltage vector determination module, for determining a reference voltage vector based on the deadbeat control principle according to the composite speed tracking deviation prediction value at the k+2 moment, the current prediction value at the k+2 moment, the composite speed tracking deviation reference value and the current reference value, and determining two adjacent effective voltage vectors according to the reference voltage vector and the electrical angle at the k moment;

[0021] The electrical angle speed control module is used to establish a cost function based on the composite speed tracking deviation prediction value at the k+2 moment, the current prediction value at the k+2 moment, the composite speed tracking deviation reference value, the current reference value and the candidate voltage vector, and determine the duty cycle of two adjacent effective voltage vectors and the zero vector according to the cost function to form a drive signal of the inverter to control the electrical angle speed of the permanent magnet synchronous motor.

[0022] According to the specific embodiments provided in this application, this application discloses the following technical effects:

[0023] The present application provides a three-vector speed control method and device for a permanent magnet synchronous motor. First, the outer loop disturbance and the inner loop disturbance are derived into a concentrated disturbance through a super-local speed-current model, and the difference between the mechanical and electromagnetic time constants is compensated. Secondly, by designing a composite attenuation function with faster convergence speed and higher estimation accuracy, a composite nonlinear extended state observer is constructed to determine the estimated value of the concentrated disturbance, thereby improving the dynamic performance of the three-vector speed control method for a permanent magnet synchronous motor. Furthermore, by establishing a cost function, the duty cycle of two adjacent effective voltage vectors and a zero vector is determined to improve the steady-state performance of the three-vector speed control method for a permanent magnet synchronous motor. The present application improves the control accuracy of the electrical angular speed of a permanent magnet synchronous motor by improving the dynamic performance and steady-state performance of the three-vector speed control method for a permanent magnet synchronous motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 A control block diagram of a three-vector speed control method for a permanent magnet synchronous motor provided in this application;

[0026] Figure 2 A flow chart of a three-vector speed control method for a permanent magnet synchronous motor provided in this application;

[0027] Figure 3 This is the model block diagram corresponding to the composite nonlinear extended state observer in this application;

[0028] Figure 4 The dynamic response effect diagram of the traditional three-vector-based model predicting direct speed control under step acceleration;

[0029] Figure 5 This is a dynamic response effect diagram of this application under step acceleration;

[0030] Figure 6 The dynamic response effect diagram of the traditional three-vector-based model predicting direct speed control under step load;

[0031] Figure 7 This is a dynamic response effect diagram of the present application under step load;

[0032] Figure 8 The steady-state response effect diagram of direct speed control predicted by the three-vector model under the condition of parameter mismatch;

[0033] Fig. 9 It is a steady-state response effect diagram of the present application under the condition of parameter mismatch;

[0034] Fig.10 The steady-state response of direct speed control predicted by the three-vector based model at 75% load;

[0035] Fig.11 This is a diagram showing the steady-state response of the present application at 75% load. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0037] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0038] like Figure 1 and Figure 2 As shown, the three-vector speed control method of the permanent magnet synchronous motor provided by the present application comprises the following steps:

[0039] Step 101: Real-time acquisition of the stator current i of the permanent magnet synchronous motor abc , stator voltage u abc , electrical angular speed ω and electrical angle θ, to obtain the stator current i at time k abc [k], stator voltage u abc [k], electrical angular rotation speed ω[k] and electrical angle θ[k].

[0040] For the stator current i at time k abc [k] performs coordinate transformation to obtain the d-axis stator current i at time k d [k] and the q-axis stator current i at time k q[k]; stator voltage u at time k abc [k] performs coordinate transformation to obtain the d-axis stator voltage u at time k d [k] and the q-axis stator voltage u at time k q [k].

[0041] Step 102: Determine the composite velocity tracking deviation z[k] at time k based on the electrical angular velocity ω[k] at time k and the electrical angular velocity reference value ω*.

[0042] Specifically, a composite speed tracking deviation model is used to determine the composite speed tracking deviation at time k. The composite speed tracking deviation model is:

[0043]

[0044] Among them, z ω is the composite velocity tracking deviation, t is the time, is the electrical angular velocity tracking error, is the reference value of electrical angular speed, ω e is the electrical angular speed, and ρ is a positive coefficient. ω When it is controlled to 0, the electrical angular velocity tracking error and its differential control are simultaneously controlled to decay to 0. And by reasonably adjusting the ρ coefficient, the system can achieve low speed overshoot / fluctuation and obtain a better dynamic performance.

[0045] Step 103: Construct a composite nonlinear extended state observer based on the composite attenuation function, and calculate the stator voltage u at time k. d [k] and u q [k], stator current i at time k d [k] and i q [k] and the composite velocity tracking deviation z[k] at time k, and the estimated value of the concentrated disturbance at time k is determined by using a discretized composite nonlinear extended state observer and the estimated value of the concentrated disturbance at time k+1 The composite nonlinear extended state observer is:

[0046]

[0047] Where x is the state variable matrix, i d is the d-axis stator current, z ω is the composite velocity tracking deviation, is the estimated state variable matrix, is the estimated value of the d-axis stator current, is the composite velocity tracking bias estimate, is the first-order derivative of the estimated state variable matrix, is the estimated concentrated perturbation matrix, is the estimated value of the concentrated disturbance of the stator current, is the concentrated disturbance estimate of the composite velocity tracking error, is the first-order derivative of the estimated concentrated disturbance matrix, e is the observation error matrix, e = [e c ,e z ] T , e c is the error between the actual value and the estimated value of the stator current, e z is the error between the actual value and the estimated value of the composite speed tracking deviation, u is the stator voltage matrix, u=[u d ,u q ] T ,u d is the d-axis stator voltage, u q is the q-axis stator voltage, A is the stator voltage coefficient matrix, A=[a c ,a z ] T , a c is the d-axis stator voltage coefficient, a z is the q-axis stator voltage coefficient, β1=2ω0, ω0 is the bandwidth of the composite nonlinear extended state observer, φ(e) is the composite attenuation function φ(e) = k1e+(k2+a |e| )|e| b sign(e), e is the observation error matrix, and the value of e is e c [k] or e z [k], k1, k2, a, b are all positive coefficients, sign(e) is the switching function. φ(e)=[φ(e c ),φ(e z )] T It is the core of the composite nonlinear extended state observer, which determines the convergence speed and estimation accuracy of the system under the same bandwidth. c ) is the error composite attenuation function between the actual value and the estimated value of the stator current, φ(e z ) is the composite attenuation function of the error between the actual value and the estimated value of the composite velocity tracking deviation.

[0048] Among them, Figure 3 As shown, the discretized composite nonlinear extended state observer includes a current disturbance observer and a speed disturbance observer.

[0049] The current disturbance observer is:

[0050]

[0051] The speed disturbance observer is:

[0052]

[0053] Among them, e c [k] is the error between the actual value and the estimated value of the d-axis stator current at time k, e z [k] is the error between the actual value and the estimated value of the composite velocity tracking deviation at time k, i d [k] is the d-axis stator current at time k, is the estimated value of the d-axis stator current at time k, is the estimated value of the d-axis stator current at time k+1, T s For the cycle, is the estimated value of the concentrated disturbance at time k, include and is the estimated value of the concentrated disturbance of the stator current at time k, is the concentrated disturbance estimate of the composite velocity tracking deviation at time k, is the estimated value of the concentrated disturbance at time k+1, include and is the estimated value of the concentrated disturbance of the stator current at time k+1, is the concentrated disturbance estimate of the composite velocity tracking deviation at time k+1, a c is the d-axis stator voltage coefficient, a z is the q-axis stator voltage coefficient, u d [k] is the d-axis stator voltage at time k, u q [k] is the q-axis stator voltage at time k, β1=2ω0, ω0 is the bandwidth of the composite nonlinear extended state observer, φ(e) is the composite attenuation function φ(e) = k1e+(k2+a |e| )|e| b sign(e), e is the observation error matrix, and the value of e is e c [k] or e z [k], k1, k2, a, b are all positive coefficients, sign(e) is the switching function, z ω [k] is the composite velocity tracking deviation at time k, is the estimated value of the composite velocity tracking deviation at time k; It is the estimated value of the composite velocity tracking deviation at time k+1.

[0054] Step 104: Based on the estimated value of the concentrated disturbance at the k moment Stator voltage u at time k d [k] and u q [k], stator current i at time k d[k] and i q [k], the composite velocity tracking deviation z at the time k ω [k], the estimated value of the concentrated disturbance at the k+1 moment and the candidate voltage vector u s , using the discretized super-local speed-current model, determine the composite speed tracking deviation prediction value z at time k+2 ω [k+2] and the current prediction value i at time k+2 d [k+2].

[0055] Specifically, based on the composite velocity tracking deviation z ω and the stator current i d A super-local speed-current model is established, specifically:

[0056]

[0057] Among them, a c is the d-axis stator voltage coefficient, a z is the q-axis stator voltage coefficient, is the nameplate value of the stator inductance, is the nameplate value of the permanent magnet, is the nameplate value of the moment of inertia, P is the number of pole pairs, is the estimated value of the concentrated disturbance of the stator current at time k, is the concentrated disturbance estimate of the composite velocity tracking deviation at time k, ψ f is the permanent magnet, J is the moment of inertia, R is the stator resistance, L is the stator inductance, T l is the load torque. According to the above formula, the outer loop disturbance (including load torque and mechanical parameter mismatch) and the inner loop disturbance (including electrical parameter mismatch and other unknown disturbances not modeled) are pushed into a concentrated disturbance f z .

[0058] The current prediction value at time k+2 is the d-axis current prediction value i at time k+2 d [k+2]; Step 104 specifically includes the following two steps:

[0059] Step 1: Based on the estimated value of the concentrated disturbance at the k moment The d-axis stator voltage u at time k d [k], q-axis stator voltage u at the time k q [k], the d-axis stator current i at the time k d [k] and the composite velocity tracking deviation z at the time k ω[k], using the discretized super-local speed-current model to determine the composite speed tracking deviation prediction value z at time k+1 ω [k+1] and the predicted d-axis current value i at time k+1 d [k+1].

[0060] Specifically, the following formula is used to determine the predicted value of the composite speed tracking deviation at time k+1 and the predicted value of the d-axis current at time k+1:

[0061]

[0062] Among them, i d [k+1] is the predicted value of the d-axis current at time k+1; z ω [k+1] is the predicted value of the composite speed tracking deviation at time k+1; i d [k] is the d-axis stator current at time k; z ω [k] is the composite velocity tracking deviation at time k; T s is the cycle; a c is the d-axis stator voltage coefficient, a z is the q-axis stator voltage coefficient; is the estimated value of the concentrated disturbance of the stator current at time k, is the concentrated disturbance estimate of the composite velocity tracking deviation at time k; u d [k] is the d-axis stator voltage at time k, u q [k] is the q-axis stator voltage at time k.

[0063] Step 2: Track the deviation prediction value z according to the composite velocity at time k+1 ω [k+1], the predicted d-axis current value i at the k+1 time d [k+1], the estimated value of the concentrated disturbance at the k+1 moment With the candidate voltage vector u s , the discretized super-local speed-current model is used to determine the composite speed tracking deviation prediction value z at time k+2 ω [k+2] and the predicted d-axis current value i at time k+2 d [k+2].

[0064] Specifically, the composite speed tracking deviation prediction value at time k+2 and the d-axis current prediction value at time k+2 are determined using the following formula:

[0065]

[0066] Among them, i d [k+2] is the predicted value of the d-axis current at time k+2; z ω[k+2] is the predicted value of the composite velocity tracking deviation at time k+2; u d [k+1] is the candidate voltage vector of the d-axis at time k+1, u q [k+1] is the candidate voltage vector of the q-axis at time k+1; is the estimated value of the concentrated disturbance of the stator current at time k+1, is the concentrated disturbance estimate of the composite velocity tracking deviation at time k+1.

[0067] Step 103 and step 104 are as follows: Figure 1 The robust predictive controller shown is implemented in

[0068] Step 105: Track the deviation prediction value z according to the composite velocity at the k+2 time ω [k+2], the current prediction value i at the k+2 time d [k+2], composite speed tracking deviation reference value With current reference value Based on the deadbeat control principle, the reference voltage vector u is determined s , and according to the reference voltage vector u s The electrical angle θ[k] at time k determines the two adjacent effective voltage vectors u s|x and u s|y The specific steps include the following two steps:

[0069] Step 1: Track the deviation prediction value u according to the composite velocity at time k+2 s|x and u s|y , the predicted d-axis current value i at the time k+2 d [k+2], composite speed tracking deviation reference value Current reference value The predicted value of d-axis current at time k+1 is i d [k+1], the predicted value of the composite speed tracking deviation z at time k+1 ω [k+1] and the concentrated disturbance at time k+1 Based on the deadbeat control principle, the reference voltage vector u is determined s ; The deadbeat control principle is the composite speed tracking deviation prediction value z at the k+2 moment ω [k+2], the predicted d-axis current value i at the k+2 time d [k+2] and composite speed tracking deviation reference value Current reference value Equal, that is:

[0070] The reference voltage vector is expressed as:

[0071]

[0072] in, is the d-axis reference voltage vector, is the q-axis reference voltage vector, a c is the d-axis stator voltage coefficient, a z is the q-axis stator voltage coefficient, T s It is a cycle. is the composite speed tracking deviation reference value, is the current reference value, i d [k+1] is the predicted value of the d-axis current at time k+1, is the estimated value of the concentrated disturbance of the stator current at time k+1, is the concentrated disturbance estimate of the composite velocity tracking deviation at time k+1.

[0073] Step 2: Based on the reference voltage vector u s and the electrical angle θ[k] to calculate a reference electrical angle θ*, and determine the sector where the reference voltage vector is located according to the reference electrical angle θ*;

[0074] The reference electrical angle θ* can be expressed as:

[0075]

[0076] According to the reference voltage vector u s The sector determines the two adjacent effective voltage vectors u s|x and u s|y , according to the two adjacent effective voltage vectors u s|x and u s|y , and the zero vector, synthesized as candidate voltage vectors, as follows:

[0077] u s =d x u s|x +d y u s|y ;

[0078] u s|x is the first effective voltage vector, d x is the duty cycle of the first effective voltage vector, u s|y is the second effective voltage vector, d y is the duty cycle of the second effective voltage vector, u s is the reference voltage vector.

[0079] Step 106: Based on the composite speed tracking deviation prediction value z at the k+2 time ω [k+2], the current prediction value i at the k+2 time d[k+2], the composite speed tracking deviation reference value The current reference value With the candidate voltage vector u s A cost function g is established, and the duty ratios of two adjacent effective voltage vectors and a zero vector are determined according to the cost function g to form a drive signal of the inverter to control the electrical angle speed of the permanent magnet synchronous motor.

[0080] The cost function g is:

[0081]

[0082] Among them, u s|x is the first effective voltage vector, u s|y is the second effective voltage vector, d x is the duty cycle of the first effective voltage vector, d y is the duty cycle of the first effective voltage vector, u d|x [k+1] is the d-axis effective voltage vector of the first effective voltage vector at time k+1, u q|x [k+1] is the q-axis effective voltage vector of the first effective voltage vector at time k+1, u d|y [k+1] is the d-axis effective voltage vector of the second effective voltage vector at time k+1, u q|y [k+1] is the q-axis effective voltage vector of the second effective voltage vector at time k+1; λ c is the d-axis voltage weight factor, λ z is the q-axis voltage weight factor, m and n are intermediate variables;

[0083]

[0084]

[0085] is the d-axis stator current reference value, It is the composite speed tracking deviation reference value;

[0086] In the present application, the process of determining the duty ratio of two adjacent effective voltage vectors and a zero vector according to the cost function specifically includes:

[0087] Based on the cost function, a minimization method is used to eliminate the d-axis voltage weight factor and the q-axis voltage weight factor in the cost function, and determine the duty cycle of two adjacent effective voltage vectors and a zero vector; the minimization method is specifically as follows:

[0088] The duty cycle of the first effective voltage vector is:

[0089]

[0090] The duty cycle of the second effective voltage vector is:

[0091]

[0092] The duty cycle of the zero vector is: d0=1-(d x +d y ), where d0 is the duty cycle of the zero vector.

[0093] Based on the same inventive concept, the embodiment of the present application further provides a three-vector speed control device for a permanent magnet synchronous motor, the three-vector speed control device for a permanent magnet synchronous motor comprising:

[0094] A data acquisition module, used for real-time acquisition of the stator current, stator voltage, electrical angular speed and electrical angle of the permanent magnet synchronous motor, so as to obtain the stator current, stator voltage, electrical angular speed and electrical angle at time k;

[0095] A composite speed tracking deviation determination module, used to determine the composite speed tracking deviation at time k according to the electrical angle speed at time k and the electrical angle speed reference value;

[0096] The concentrated disturbance estimation module is used to construct a composite nonlinear extended state observer based on the composite attenuation function, and determine the concentrated disturbance estimation value at the time k and the concentrated disturbance estimation value at the time k+1 by using the discretized composite nonlinear extended state observer according to the stator voltage at the time k, the stator current at the time k and the composite speed tracking deviation at the time k;

[0097] A composite speed tracking deviation and current prediction module, for determining a composite speed tracking deviation prediction value at time k+2 and a current prediction value at time k+2 by using a discretized super-local speed-current model according to the concentrated disturbance estimation value at time k, the stator voltage at time k, the stator current at time k, the composite speed tracking deviation at time k, the concentrated disturbance estimation value at time k+1 and the candidate voltage vector; the super-local speed-current model is established based on the composite speed tracking deviation and the stator current;

[0098] an effective voltage vector determination module, for determining a reference voltage vector based on the deadbeat control principle according to the composite speed tracking deviation prediction value at the k+2 moment, the current prediction value at the k+2 moment, the composite speed tracking deviation reference value and the current reference value, and determining two adjacent effective voltage vectors according to the reference voltage vector and the electrical angle at the k moment;

[0099] The electrical angle speed control module is used to establish a cost function based on the composite speed tracking deviation prediction value at the k+2 moment, the current prediction value at the k+2 moment, the composite speed tracking deviation reference value, the current reference value and the candidate voltage vector, and determine the duty cycle of two adjacent effective voltage vectors and the zero vector according to the cost function to form a drive signal of the inverter to control the electrical angle speed of the permanent magnet synchronous motor.

[0100] Wherein, the inverter is a three-phase two-level inverter.

[0101] This application proposes a composite speed tracking deviation model, derives a super-local speed-current model, pushes the outer loop disturbance and the inner loop disturbance into a centralized disturbance, and designs a composite nonlinear extended state observer to estimate the centralized disturbance, which greatly improves the dynamic performance and disturbance suppression performance of the three-vector speed control method and device of the permanent magnet synchronous motor. In addition, a mathematical method of deriving the value function by the minimum method is used to quickly and simply eliminate the weight factor, thereby improving the steady-state performance of the three-vector speed control method and device of the permanent magnet synchronous motor.

[0102] like Figure 4 As shown in the figure, under the condition of no load torque, the permanent magnet synchronous motor accelerates from the initial reference speed of static to the speed of 2500 revolutions per minute (r / min). Where: n is the electrical angular speed of the permanent magnet synchronous motor, Δn overshoot is the overshoot of the electrical angle speed of the permanent magnet synchronous motor, Δn overshoot =438rpm, indicating that the electrical angle speed of the permanent magnet synchronous motor is 438 revolutions per minute, rpm is the number of revolutions per minute, i d is the d-axis stator current, i q is the q-axis stator current, and div is a division or scale unit on the display. In the traditional three-vector based model predictive direct speed control, there is a large speed overshoot during the acceleration process.

[0103] like Figure 5 As shown, the present application exhibits excellent performance in terms of speed overshoot and settling time.

[0104] like Figure 6 As shown in Figure 2, when using the traditional three-vector based model to predict direct speed control, the speed fluctuation is large and the settling time is long. max It is the maximum value of the electrical angle speed fluctuation of the permanent magnet synchronous motor.

[0105] like Figure 7 As shown, the present application can reduce velocity fluctuations and shorten settling time.

[0106] like Figure 8 As shown, the parameter mismatch In this case, the traditional three-vector based model predictive direct speed control has a d-axis current tracking error of 0.7A and a speed tracking error of 144pm. Figure 8 In which, n* is the speed reference value, Δn is the speed tracking error, Δi d is the d-axis current tracking error, i q_rip is the q-axis current ripple, i d_rip is the d-axis current ripple, is the d-axis stator current reference value, i a is the a-phase current, and THD is the total harmonic distortion.

[0107] like Fig. 9 As shown, the parameter mismatch Under such circumstances, the present application has no current tracking error or speed tracking error. In addition, the current ripple and THD (Total Harmonic Distortion) of the present application are minimal.

[0108] like Fig.10 As shown, the traditional three-vector based model predictive direct speed control has a large d-axis current ripple, which is 0.141A.

[0109] like Fig.11 As shown, under precise parameters, the d-axis current ripple of the present application is 0.108 A. Similarly, the method provided by the present application can provide a lower current THD.

[0110] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0111] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. At the same time, for those skilled in the art, according to the ideas of this application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. A three-vector speed control method for a permanent magnet synchronous motor, wherein the permanent magnet synchronous motor is connected to an inverter, characterized in that: The permanent magnet synchronous motor three-vector speed control method comprises: The stator current, stator voltage, electrical angular speed and electrical angle of the permanent magnet synchronous motor are collected in real time to obtain the stator current, stator voltage, electrical angular speed and electrical angle at time k; Determine the composite speed tracking deviation at time k according to the electrical angular speed at time k and the electrical angular speed reference value; A composite nonlinear extended state observer is constructed based on the composite attenuation function, and the concentrated disturbance estimation value at time k and the concentrated disturbance estimation value at time k+1 are determined by using the discretized composite nonlinear extended state observer according to the stator voltage at time k, the stator current at time k and the composite speed tracking deviation at time k. According to the concentrated disturbance estimation value at time k, the stator voltage at time k, the stator current at time k, the composite speed tracking deviation at time k, the concentrated disturbance estimation value at time k+1 and the candidate voltage vector, a discretized super-local speed-current model is used to determine the composite speed tracking deviation prediction value at time k+2 and the current prediction value at time k+2; the super-local speed-current model is established based on the composite speed tracking deviation and the stator current; According to the composite speed tracking deviation prediction value at the k+2 moment, the current prediction value at the k+2 moment, the composite speed tracking deviation reference value and the current reference value, based on the deadbeat control principle, a reference voltage vector is determined, and two adjacent effective voltage vectors are determined according to the reference voltage vector and the electrical angle at the k moment; A cost function is established based on the composite speed tracking deviation prediction value at the k+2 moment, the current prediction value at the k+2 moment, the composite speed tracking deviation reference value, the current reference value and the candidate voltage vector, and the duty cycle of two adjacent effective voltage vectors and the zero vector is determined according to the cost function to form a drive signal of the inverter to control the electrical angular speed of the permanent magnet synchronous motor.

2. The three-vector speed control method of a permanent magnet synchronous motor according to claim 1 is characterized in that: The permanent magnet synchronous motor three-vector speed control method also includes: Perform coordinate transformation on the stator current at time k to obtain the d-axis stator current at time k and the q-axis stator current at time k; The coordinate transformation of the stator voltage at time k is performed to obtain the d-axis stator voltage at time k and the q-axis stator voltage at time k.

3. The three-vector speed control method of a permanent magnet synchronous motor according to claim 1 is characterized in that: According to the electrical angular speed at time k and the electrical angular speed reference value, the composite speed tracking deviation at time k is determined, specifically including: According to the electrical angular speed at time k and the electrical angular speed reference value, a composite speed tracking deviation at time k is determined using a composite speed tracking deviation model; the composite speed tracking deviation model is: Among them, z ω is the composite velocity tracking deviation, t is the time, is the electrical angular velocity tracking error, is the reference value of electrical angular speed, ω e is the electrical angular speed, and ρ is a positive coefficient.

4. The three-vector speed control method of a permanent magnet synchronous motor according to claim 2 is characterized in that: The discretized composite nonlinear extended state observer is: Among them, e c [k] is the error between the actual value and the estimated value of the d-axis stator current at time k, e z [k] is the error between the actual value and the estimated value of the composite velocity tracking deviation at time k, i d [k] is the d-axis stator current at time k, is the estimated value of the d-axis stator current at time k, is the estimated value of the d-axis stator current at time k+1, T s For the cycle, is the estimated value of the concentrated disturbance at time k, include and is the estimated value of the concentrated disturbance of the stator current at time k, is the concentrated disturbance estimate of the composite velocity tracking deviation at time k, is the estimated value of the concentrated disturbance at time k+1, include and is the estimated value of the concentrated disturbance of the stator current at time k+1, is the concentrated disturbance estimate of the composite velocity tracking deviation at time k+1, a c is the d-axis stator voltage coefficient, a z is the q-axis stator voltage coefficient, u d [k] is the d-axis stator voltage at time k, u q [k] is the q-axis stator voltage at time k, β1=2ω0, ω0 is the bandwidth of the composite nonlinear extended state observer, φ(e) is the composite attenuation function φ(e) = k1e+(k2+a |e| )|e| b sign(e), e is the observation error matrix, and the value of e is e c [k] or e z [k], k1, k2, a, b are all positive coefficients, sign(e) is the switching function, z ω [k] is the composite velocity tracking deviation at time k, is the estimated value of the composite velocity tracking deviation at time k; It is the estimated value of the composite velocity tracking deviation at time k+1.

5. The three-vector speed control method of a permanent magnet synchronous motor according to claim 2 is characterized in that: The current prediction value at time k+2 is the d-axis current prediction value at time k+2; According to the concentrated disturbance estimation value at time k, the stator voltage at time k, the stator current at time k, the composite speed tracking deviation at time k, the concentrated disturbance estimation value at time k+1 and the candidate voltage vector, a discretized super-local speed-current model is used to determine the composite speed tracking deviation prediction value at time k+2 and the current prediction value at time k+2, specifically including: According to the concentrated disturbance estimation value at the time k, the d-axis stator voltage at the time k, the q-axis stator voltage at the time k, the d-axis stator current at the time k and the composite speed tracking deviation at the time k, a discretized super-local speed-current model is used to determine the composite speed tracking deviation prediction value at the time k+1 and the d-axis current prediction value at the time k+1; According to the composite speed tracking deviation prediction value at time k+1, the d-axis current prediction value at time k+1, the concentrated disturbance estimation value at time k+1 and the candidate voltage vector, a discretized super-local speed-current model is used to determine the composite speed tracking deviation prediction value at time k+2 and the d-axis current prediction value at time k+2.

6. The three-vector speed control method of a permanent magnet synchronous motor according to claim 5 is characterized in that: The following formula is used to determine the predicted value of the composite speed tracking deviation at time k+1 and the predicted value of the d-axis current at time k+1: Among them, i d [k+1] is the predicted value of the d-axis current at time k+1, z ω [k+1] is the predicted value of the composite speed tracking deviation at time k+1, i d [k] is the d-axis stator current at time k, z ω [k] is the composite velocity tracking error at time k, T s is the period, a c is the d-axis stator voltage coefficient, a z is the q-axis stator voltage coefficient, is the estimated value of the concentrated disturbance of the stator current at time k, is the concentrated disturbance estimate of the composite velocity tracking deviation at time k, u d [k] is the d-axis stator voltage at time k, u q [k] is the q-axis stator voltage at time k; The composite velocity tracking deviation prediction value at time k+2 and the d-axis current prediction value at time k+2 are determined using the following formula: Among them, i d [k+2] is the predicted value of the d-axis current at time k+2, z ω [k+2] is the predicted value of the composite velocity tracking deviation at time k+2, u d [k+1] is the candidate voltage vector of the d-axis at time k+1, u q [k+1] is the candidate voltage vector of the q-axis at time k+1, is the estimated value of the concentrated disturbance of the stator current at time k+1, is the concentrated disturbance estimate of the composite velocity tracking deviation at time k+1.

7. The three-vector speed control method of a permanent magnet synchronous motor according to claim 5, characterized in that: Determine a reference voltage vector based on the deadbeat control principle according to the composite speed tracking deviation prediction value at the k+2 moment, the current prediction value at the k+2 moment, the composite speed tracking deviation reference value and the current reference value; Determining two adjacent effective voltage vectors according to the reference voltage vector and the electrical angle specifically includes: According to the composite speed tracking deviation prediction value at time k+2, the d-axis current prediction value at time k+2, the composite speed tracking deviation reference value, the current reference value, the d-axis current prediction value at time k+1, the composite speed tracking deviation prediction value at time k+1 and the concentrated disturbance at time k+1, based on the deadbeat control principle, a reference voltage vector is determined; the deadbeat control principle is that the composite speed tracking deviation prediction value at time k+2 is equal to the composite speed tracking deviation reference value, and the d-axis current prediction value at time k+2 is equal to the current reference value; Calculating a reference electrical angle according to the reference voltage vector and the electrical angle, and determining a sector where the reference voltage vector is located according to the reference electrical angle; Two adjacent effective voltage vectors are determined according to the sector where the reference voltage vector is located.

8. The three-vector speed control method of a permanent magnet synchronous motor according to claim 6 is characterized in that: The cost function is: Among them, g is the cost function value, u s|x is the first effective voltage vector, u s|y is the second effective voltage vector, d x is the duty cycle of the first effective voltage vector, d y is the duty cycle of the second effective voltage vector, u d|x [k+1] is the d-axis effective voltage vector of the first effective voltage vector at time k+1, u q|x [k+1] is the q-axis effective voltage vector of the first effective voltage vector at time k+1, u d|y [k+1] is the d-axis effective voltage vector of the second effective voltage vector at time k+1, u q|y [k+1] is the q-axis effective voltage vector of the second effective voltage vector at time k+1, λ c is the d-axis voltage weight factor, λ z is the q-axis voltage weight factor, m and n are intermediate variables, is the d-axis stator current reference value, It is the composite speed tracking deviation reference value.

9. The three-vector speed control method of a permanent magnet synchronous motor according to claim 8, characterized in that: Determining the duty cycle of two adjacent effective voltage vectors and a zero vector according to the cost function specifically includes: Based on the cost function, a minimization method is used to eliminate the d-axis voltage weight factor and the q-axis voltage weight factor in the cost function, and determine the duty cycle of two adjacent effective voltage vectors and a zero vector; the minimization method is specifically as follows: The duty cycle of the first effective voltage vector is: The duty cycle of the second effective voltage vector is: The duty cycle of the zero vector is: d0=1-(d x +d y ), where d0 is the duty cycle of the zero vector.

10. A three-vector speed control device for a permanent magnet synchronous motor, applied to the three-vector speed control method for a permanent magnet synchronous motor according to any one of claims 1 to 9, characterized in that: The three-vector speed control device of the permanent magnet synchronous motor comprises: A data acquisition module, used for real-time acquisition of the stator current, stator voltage, electrical angular speed and electrical angle of the permanent magnet synchronous motor, so as to obtain the stator current, stator voltage, electrical angular speed and electrical angle at time k; A composite speed tracking deviation determination module, used to determine the composite speed tracking deviation at time k according to the electrical angle speed at time k and the electrical angle speed reference value; The concentrated disturbance estimation module is used to construct a composite nonlinear extended state observer based on the composite attenuation function, and determine the concentrated disturbance estimation value at the time k and the concentrated disturbance estimation value at the time k+1 by using the discretized composite nonlinear extended state observer according to the stator voltage at the time k, the stator current at the time k and the composite speed tracking deviation at the time k; A composite speed tracking deviation and current prediction module, for determining a composite speed tracking deviation prediction value at time k+2 and a current prediction value at time k+2 by using a discretized super-local speed-current model according to the concentrated disturbance estimation value at time k, the stator voltage at time k, the stator current at time k, the composite speed tracking deviation at time k, the concentrated disturbance estimation value at time k+1 and the candidate voltage vector; the super-local speed-current model is established based on the composite speed tracking deviation and the stator current; an effective voltage vector determination module, for determining a reference voltage vector based on the deadbeat control principle according to the composite speed tracking deviation prediction value at the k+2 moment, the current prediction value at the k+2 moment, the composite speed tracking deviation reference value and the current reference value, and determining two adjacent effective voltage vectors according to the reference voltage vector and the electrical angle at the k moment; The electrical angle speed control module is used to establish a cost function based on the composite speed tracking deviation prediction value at the k+2 moment, the current prediction value at the k+2 moment, the composite speed tracking deviation reference value, the current reference value and the candidate voltage vector, and determine the duty cycle of two adjacent effective voltage vectors and the zero vector according to the cost function to form a drive signal of the inverter to control the electrical angle speed of the permanent magnet synchronous motor.

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