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

Abstract

The present application discloses a three-vector speed control method and device for a permanent magnet synchronous motor, relating to the field of motor control technology. The method comprises: determining a composite speed tracking deviation based on an electrical angular speed and an electrical angular speed reference value; establishing a super-local speed-current model based on the composite speed tracking deviation to form inner and outer loop concentrated disturbances, thereby improving the dynamic performance of the permanent magnet synchronous motor speed control method; constructing a composite nonlinear extended state observer based on a composite attenuation function to determine a concentrated disturbance estimate; determining a composite speed tracking deviation prediction value and a current prediction value based on a discretized super-local speed-current model; determining two adjacent effective voltage vectors based on the electrical angle; constructing a cost function to determine the duty cycle of the two adjacent effective voltage vectors and the zero vector to form a drive signal for the inverter. The present application improves the steady-state performance of the permanent magnet synchronous motor speed control method, thereby improving the control accuracy of the electrical angular speed of the permanent magnet synchronous motor.

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 (PMSMs) are widely used in modern electrified transportation, particularly electric vehicles, due to their high efficiency and power density. Speed ​​control of PMSMs is crucial. Field-oriented control and direct torque control are commonly used in the market for real-time control of PMSMs. However, model predictive control (MPC) has recently become a major competitor to these two approaches due to its fast dynamics, straightforward implementation, and ease of adding multivariable constraints. MPC, which eliminates the need for a proportional-integral speed controller, can effectively improve the system's dynamic performance. To further enhance steady-state performance, three-vector MPC has been proposed in recent decades. These three voltage vectors are used throughout the control cycle.

[0003] However, three-vector model-predictive direct speed control (MPC) is subject to both outer-loop and inner-loop disturbances. The outer-loop disturbances include load torque and mechanical parameter mismatches, while the inner-loop disturbances primarily consist of electrical parameter mismatches and other unmodeled unknown disturbances. In most existing MPC systems based on lumped disturbances, these disturbances are typically modeled as outer-loop lumped disturbances and inner-loop lumped disturbances, respectively. Obviously, the characteristics of the inner-loop and outer-loop lumped disturbances differ in terms of amplitude and rate of change. Therefore, the control algorithm must either design two different observers with specific characteristic disturbance ranges or use two observers that accommodate the full disturbance range, which inevitably leads to computational complexity or algorithmic redundancy. Furthermore, to compensate for the inconsistent mechanical and electromagnetic timings, additional control objectives must be added to the cost function, which increases the number of weighting factors to adjust. Although adapting to different speed / current sampling periods can also compensate for their time differences, this can introduce speed overshoot / oscillation in the dynamic response.

[0004] Using a traditional nonlinear disturbance observer to observe lumped disturbances can include rapidly changing disturbances when applying step loads or step velocities. Traditional NESOs, which use a "fal" function as an error decay function, converge poorly under rapidly changing disturbances. Furthermore, the non-smooth, piecewise error decay function structure can lead to jitter in the control response.

[0005] Because the mechanical angular velocity and stator current have different magnitudes and amplitude ranges, appropriate weighting factors must be used to balance the importance of speed and current in three-vector model-predictive direct speed control. In practice, the traditional weighting factor adjustment procedure is often a trial-and-error approach, which is time-consuming. Furthermore, it is subject to operating conditions. The weighting factors selected by this trial-and-error approach may vary 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 includes:

[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 velocity tracking deviation at time k based on 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. According to the stator voltage at time k, the stator current at time k and the composite speed tracking deviation at time k, the discretized composite nonlinear extended state observer is used to determine the concentrated disturbance estimation value at time k and the concentrated disturbance estimation value at time k+1.

[0012] According to the concentrated disturbance estimated 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 estimated value at time k+1, and the candidate voltage vector, a discretized super-local speed-current model is used to determine a composite speed tracking deviation predicted value at time k+2 and a current predicted 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] Determine a reference voltage vector based on the deadbeat control principle according to the composite speed tracking deviation prediction value at time k+2, the current prediction value at time k+2, the composite speed tracking deviation reference value, and the current reference value, and determine two adjacent effective voltage vectors based on the reference voltage vector and the electrical angle at time k;

[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 ratios of two adjacent effective voltage vectors and the zero vector are determined according to the cost function to form a drive signal for 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 is used to collect the stator current, stator voltage, electrical angular speed and electrical angle of the permanent magnet synchronous motor in real time to obtain the stator current, stator voltage, electrical angular speed and electrical angle at time k;

[0017] A composite speed tracking deviation determination module is used to determine the composite speed tracking deviation at time k based on the electrical angular speed at time k and the electrical angular 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 use the discretized composite nonlinear extended state observer to determine the concentrated disturbance estimation value at time k and the concentrated disturbance estimation value at time k+1 according to the stator voltage at time k, the stator current at time k, and the composite speed tracking deviation at time k;

[0019] a composite speed tracking deviation and current prediction module, configured to determine a composite speed tracking deviation prediction value at time k+2 and a current prediction value at time k+2 using a discretized hyperlocal speed-current model based on the concentrated disturbance estimate 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 estimate at time k+1, and the candidate voltage vector; the hyperlocal speed-current model being established based on the composite speed tracking deviation and the stator current;

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

[0021] The electrical angular 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 for the inverter to control the electrical angular 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 centralized disturbance through a super-local speed-current model, while compensating for the difference between the mechanical and electromagnetic time constants. 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 centralized 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, thereby improving 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 the 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 following briefly introduces the drawings required for use in the embodiments. 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 creative work.

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

[0026] Figure 2 This is 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 direct speed control predicted by the traditional three-vector model under step acceleration;

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

[0032] Figure 8 The steady-state response effect diagram of direct speed control based on the three-vector model prediction under parameter mismatch conditions;

[0033] Figure 9 This is a diagram showing the steady-state response of the present application under parameter mismatch conditions;

[0034] Figure 10 Predicted steady-state response of direct speed control based on the three-vector model at 75% load;

[0035] Figure 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 this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0037] In order to make the above-mentioned purposes, 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 includes 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 speed ω[k] at time k and the electrical angular speed reference value ω*.

[0042] Specifically, the composite velocity tracking deviation model is used to determine the composite velocity tracking deviation at time k. The composite velocity 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 angle speed, ω e is the electrical angular speed, 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 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 deviation, 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, such as 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 velocity 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 estimated value of the concentrated disturbance 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; 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 k moment ω [k], the estimated value of the concentrated disturbance at time k+1 and the candidate voltage vector u s , using the discretized hyperlocal speed-current model, the composite speed tracking deviation prediction value z at time k+2 is determined 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 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 estimated value of the concentrated disturbance 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 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 unmodeled unknown disturbances) 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 the 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 composite velocity tracking deviation prediction value at time k+1 and the d-axis current prediction value 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 velocity 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 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 estimated value of the concentrated disturbance 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 d-axis current prediction 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 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:

[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] The steps 103 and 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 time k+2 ω [k+2], the current prediction value i at the k+2 moment 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 effective voltage vectors u of two adjacent s|x and u s|y The process consists of 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 time k+2 d [k+2], composite speed tracking deviation reference value Current reference value The predicted d-axis current value i at time k+1 d [k+1], the composite velocity tracking deviation prediction value 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 velocity tracking deviation prediction value z at the k+2 moment ω [k+2], the d-axis current predicted value i at time k+2 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's 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 where the two adjacent effective voltage vectors u are determined s|x and u s|y , according to the effective voltage vectors u of two adjacent s|x and u s|y , and the zero vector, are 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 velocity tracking deviation prediction value z at the k+2 time ω [k+2], the current prediction value i at the k+2 moment 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 for the inverter to control the electrical angular 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, is the composite speed tracking deviation reference value;

[0086] In this application, the process of determining the duty ratios 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 to determine the duty ratio of two adjacent effective voltage vectors and the 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, an 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 is used to collect the stator current, stator voltage, electrical angular speed and electrical angle of the permanent magnet synchronous motor in real time to obtain the stator current, stator voltage, electrical angular speed and electrical angle at time k;

[0095] A composite speed tracking deviation determination module is used to determine the composite speed tracking deviation at time k based on the electrical angular speed at time k and the electrical angular 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 use the discretized composite nonlinear extended state observer to determine the concentrated disturbance estimation value at time k and the concentrated disturbance estimation value at time k+1 according to the stator voltage at time k, the stator current at time k, and the composite speed tracking deviation at time k;

[0097] a composite speed tracking deviation and current prediction module, configured to determine a composite speed tracking deviation prediction value at time k+2 and a current prediction value at time k+2 using a discretized hyperlocal speed-current model based on the concentrated disturbance estimate 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 estimate at time k+1, and the candidate voltage vector; the hyperlocal speed-current model being established based on the composite speed tracking deviation and the stator current;

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

[0099] The electrical angular 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 for the inverter to control the electrical angular 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 superlocal speed-current model, and transforms outer and inner loop disturbances into a centralized disturbance. A composite nonlinear extended state observer is then designed to estimate the centralized disturbance, significantly improving the dynamic performance and disturbance suppression performance of a three-vector speed control method and device for a permanent magnet synchronous motor. Furthermore, a mathematical method for deriving a value function using a minimum method is used to quickly and easily eliminate weight factors, improving the steady-state performance of the three-vector speed control method and device for a 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 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 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 shows 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 velocity control, the velocity fluctuation is large and the settling time is long. max 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 Where 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 Figure 9 As shown, the parameter mismatch Under these circumstances, the present invention has no current tracking error or speed tracking error. In addition, the present invention has the smallest current ripple and THD (Total Harmonic Distortion).

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

[0109] like Figure 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 can 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 document uses specific examples to illustrate the principles and implementation methods of this application. The description of the above examples is only intended to help understand the method and core concept of this application. At the same time, for those skilled in the art, based on the concept of this application, there may 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 three-vector speed control method of the permanent magnet synchronous motor includes: 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 velocity tracking deviation at time k based on 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. According to the stator voltage at time k, the stator current at time k and the composite speed tracking deviation at time k, the discretized composite nonlinear extended state observer is used to determine the concentrated disturbance estimation value at time k and the concentrated disturbance estimation value at time k+1. According to the concentrated disturbance estimated 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 estimated value at time k+1, and the candidate voltage vector, a discretized super-local speed-current model is used to determine a composite speed tracking deviation predicted value at time k+2 and a current predicted value at time k+2; the super-local speed-current model is established based on the composite speed tracking deviation and the stator current; Determine a reference voltage vector based on the deadbeat control principle according to the composite speed tracking deviation prediction value at time k+2, the current prediction value at time k+2, the composite speed tracking deviation reference value, and the current reference value, and determine two adjacent effective voltage vectors based on the reference voltage vector and the electrical angle at time k; 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 ratios of two adjacent effective voltage vectors and the zero vector are determined according to the cost function to form a drive signal for the inverter to control the electrical angular speed of the permanent magnet synchronous motor.

2. The three-vector speed control method for a permanent magnet synchronous motor according to claim 1, characterized in that: The permanent magnet synchronous motor three-vector speed control method further 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 stator voltage at time k is subjected to coordinate transformation 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 for a permanent magnet synchronous motor according to claim 1, characterized in that: According to the electrical angular speed at time k and the electrical angular speed reference value, the composite velocity tracking deviation at time k is determined, specifically including: According to the electrical angular speed and the electrical angular speed reference value at time k, the 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 angle speed, ω e is the electrical angular speed, and ρ is a positive coefficient.

4. The three-vector speed control method for a permanent magnet synchronous motor according to claim 2, 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 estimated value of the concentrated disturbance 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; is the estimated value of the composite velocity tracking deviation at time k+1.

5. The three-vector speed control method for a permanent magnet synchronous motor according to claim 2, 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 estimated 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 estimated value at time k+1, and the candidate voltage vector, a discretized hyperlocal speed-current model is used to determine a composite speed tracking deviation predicted value at time k+2 and a current predicted value at time k+2, specifically including: Determine a predicted value of the composite speed tracking deviation at time k+1 and a predicted value of the d-axis current at time k+1 using a discretized super-local speed-current model based on the concentrated disturbance estimated value at time k, the d-axis stator voltage at time k, the q-axis stator voltage at time k, the d-axis stator current at time k, and the composite speed tracking deviation at time k; 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 for a permanent magnet synchronous motor according to claim 5, characterized in that: The following formula is used to determine the composite velocity tracking deviation prediction value at time k+1 and the d-axis current prediction value 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 velocity 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 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 estimated value of the concentrated disturbance 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 following formula is used to determine the composite velocity tracking deviation prediction value at time k+2 and the d-axis current prediction value at time k+2: 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 for a permanent magnet synchronous motor according to claim 5, characterized in that: Determining a reference voltage vector based on the deadbeat control principle according to the composite speed tracking deviation predicted value at time k+2, the current predicted value at time k+2, 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: Determining a reference voltage vector based on a deadbeat control principle according to the composite speed tracking deviation predicted value at time k+2, the d-axis current predicted value at time k+2, the composite speed tracking deviation reference value, the current reference value, the d-axis current predicted value at time k+1, the composite speed tracking deviation predicted value at time k+1, and the concentrated disturbance at time k+1; wherein the deadbeat control principle is that the composite speed tracking deviation predicted value at time k+2 is equal to the composite speed tracking deviation reference value, and the d-axis current predicted 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 for a permanent magnet synchronous motor according to claim 6, 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 for a permanent magnet synchronous motor according to claim 8, characterized in that: Determining the duty ratios 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 to determine the duty ratio of two adjacent effective voltage vectors and the 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 is used to collect the stator current, stator voltage, electrical angular speed and electrical angle of the permanent magnet synchronous motor in real time to obtain the stator current, stator voltage, electrical angular speed and electrical angle at time k; A composite speed tracking deviation determination module is used to determine the composite speed tracking deviation at time k based on the electrical angular speed at time k and the electrical angular 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 use the discretized composite nonlinear extended state observer to determine the concentrated disturbance estimation value at time k and the concentrated disturbance estimation value at time k+1 according to the stator voltage at time k, the stator current at time k, and the composite speed tracking deviation at time k; a composite speed tracking deviation and current prediction module, configured to determine a composite speed tracking deviation prediction value at time k+2 and a current prediction value at time k+2 using a discretized hyperlocal speed-current model based on the concentrated disturbance estimate 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 estimate at time k+1, and the candidate voltage vector; the hyperlocal speed-current model being established based on the composite speed tracking deviation and the stator current; an effective voltage vector determining module, configured to determine a reference voltage vector based on the deadbeat control principle according to the composite speed tracking deviation prediction value at time k+2, the current prediction value at time k+2, the composite speed tracking deviation reference value, and the current reference value, and to determine two adjacent effective voltage vectors based on the reference voltage vector and the electrical angle at time k; The electrical angular 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 for the inverter to control the electrical angular speed of the permanent magnet synchronous motor.

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