CN102969968A

CN102969968A - Permanent magnet synchronous motor control method

Info

Publication number: CN102969968A
Application number: CN201210461889.4A
Authority: CN
Inventors: 尹忠刚; 李东; 钟彦儒
Original assignee: Xian University of Technology
Current assignee: Xian University of Technology
Priority date: 2012-11-15
Filing date: 2012-11-15
Publication date: 2013-03-13
Anticipated expiration: 2032-11-15
Also published as: CN102969968B

Abstract

A permanent magnet synchronous motor control method, using a vector control system, the vector control system includes two parts of the speed outer loop and the current inner loop, the PI controller of the speed loop is replaced by a two-degree-of-freedom high-order non-singular terminal sliding mode controller; two The input of the high-order non-singular terminal sliding mode controller with degrees of freedom is the difference between the given speed w ^* of the motor and the actual feedback speed w of the motor, and the error between the given speed and the feedback speed is judged. When the speed error is less than ξ, the output The excitation current i _q ^* is calculated by a simple high-order sliding mode non-singular terminal controller; when the speed error is greater than ξ, the output of the two-degree-of-freedom high-order non-singular terminal sliding mode control is a high-order non-singular terminal sliding mode The output i _q ^* of the control is the sum of the output of the high-order non-singular terminal sliding mode and the compensation gain; where the size of ξ can be set according to the actual situation and demand. The invention improves the control precision of the system, realizes the rapid convergence of the motor speed, and has strong robustness to load disturbance.

Description

A method for controlling a permanent magnet synchronous motor

技术领域technical field

本发明涉及一种永磁同步电机控制方法。The invention relates to a control method of a permanent magnet synchronous motor.

背景技术Background technique

永磁同步电机（Permanent Magnet Synchronous Motor缩写为PMSM）具有低惯性、快响应、高功率密度、低损耗、高效率等优点。并且随着永磁材料性能的大幅度提高,其在工业生产自动化领域中的应用将越来越广泛。但因永磁同步电机是一个高阶、非线性、强耦合的多变量系统，同时也存在着参数摄动、负载扰动等不确定性，因此要对其进行高性能的控制比较困难。目前针对PMSM的控制方法有很多被提出来，如自适应控制、模糊控制、神经网络、自抗扰控制等。但这些因算法比较复杂很少有应用在实际的工程中。Permanent Magnet Synchronous Motor (Permanent Magnet Synchronous Motor abbreviated as PMSM) has the advantages of low inertia, fast response, high power density, low loss, and high efficiency. And with the substantial improvement of the performance of permanent magnet materials, its application in the field of industrial production automation will become more and more extensive. However, since the permanent magnet synchronous motor is a high-order, nonlinear, strongly coupled multivariable system, and there are uncertainties such as parameter perturbation and load disturbance, it is difficult to control it with high performance. At present, many control methods for PMSM have been proposed, such as adaptive control, fuzzy control, neural network, active disturbance rejection control and so on. But these are rarely used in actual engineering because of the complexity of the algorithm.

滑模变结构因其对系统参数不确定性和外部扰动具有良好的不变性，在电机调速领域已经开始被广泛应用，滑模变结构控制具有鲁棒性强、实现简单的优点，在电机参数变化及出现扰动时，仍然保证满意的性能，因而受到越来越多的国内外学者的重视。但是由于其控制作用的不连续性，很容易使系统产生抖振，大大影响了实际控制中的应用。高频切换控制会在扰动和模型参数摄动的作用下导致抖振现象。而抖振的幅值与扰动和模型参数摄动的幅度成比例关系。在电机控制系统中，抖振会产生脉动推力，影响系统的平稳性和定位精度，增加能量损耗。近几年提出的非奇异终端滑模能够使系统状态在有限时间内到达平衡点，稳态跟踪精度高，但仍存在抖振。应用饱和函数代替开关函数，仿真表明其在一定程度上削弱了抖振，但同时也减弱了系统的鲁棒性。应用观测器观测负载扰动并加以补偿，该方法通过减小非线性项，能较好地减小抖振，但因增加了观测器而增加了系统设计的复杂性，而且系统抖振的存在影响观测精度，实际难以达到理想的改善效果。Because of its good invariance to system parameter uncertainty and external disturbance, sliding mode variable structure has been widely used in the field of motor speed regulation. Sliding mode variable structure control has the advantages of strong robustness and simple implementation. When parameters change and disturbance occurs, satisfactory performance is still guaranteed, so more and more domestic and foreign scholars pay attention to it. However, due to the discontinuity of its control effect, it is easy to cause chattering in the system, which greatly affects the application in actual control. High-frequency switching control can lead to chattering phenomenon under the action of disturbance and perturbation of model parameters. The magnitude of chattering is proportional to the magnitude of disturbance and perturbation of model parameters. In the motor control system, buffeting will generate pulsating thrust, which will affect the stability and positioning accuracy of the system and increase energy loss. The non-singular terminal sliding mode proposed in recent years can make the system state reach the equilibrium point in a limited time, and the steady-state tracking accuracy is high, but chattering still exists. The saturation function is used instead of the switch function, and the simulation shows that it weakens chattering to a certain extent, but at the same time weakens the robustness of the system. The observer is used to observe the load disturbance and compensate it. This method can reduce the chattering by reducing the nonlinear term, but the complexity of the system design is increased due to the increase of the observer, and the existence of system chattering affects Observation accuracy, it is difficult to achieve the ideal improvement effect in practice.

发明内容Contents of the invention

本发明的目的在于提供一种永磁同步电机控制方法，以提高电机控制系统的鲁棒性和动态响应速度。The purpose of the present invention is to provide a permanent magnet synchronous motor control method to improve the robustness and dynamic response speed of the motor control system.

本发明的目的是这样实现的，一种永磁同步电机控制方法，采用矢量控制系统，矢量控制系统包括速度外环和电流内环两部分，转速环的PI控制器采用二自由度高阶非奇异终端滑模控制器取代；二自由度高阶非奇异终端滑模控制器的输入为电机的给定转速w^*与电机的实际反馈转速w之差，判断给定转速与反馈转速的误差大小，当转速误差小于ξ时，输出的励磁电流i_q ^*是通过单纯的高阶滑模非奇异终端控制器计算实现的；当转速误差大于ξ时二自由度高阶非奇异终端滑模控制的输出为高阶非奇异终端滑模控制的输出i_q ^*为高阶非奇异终端滑模的输出与补偿增益之和；其中ξ的大小可根据实际情况和需求设定。The object of the present invention is achieved in this way. A permanent magnet synchronous motor control method adopts a vector control system. The vector control system includes two parts: the speed outer loop and the current inner loop. The singular terminal sliding mode controller is replaced; the input of the two-degree-of-freedom high-order non-singular terminal sliding mode controller is the difference between the given speed w ^* of the motor and the actual feedback speed w of the motor, and the error between the given speed and the feedback speed is judged , when the speed error is less than ξ, the output excitation current i _q ^* is calculated by a simple high-order sliding mode non-singular terminal controller; when the speed error is greater than ξ, the two-degree-of-freedom high-order non-singular terminal sliding mode control The output is the output of the high-order non-singular terminal sliding mode control. i _q ^* is the sum of the output of the high-order non-singular terminal sliding mode and the compensation gain; where the size of ξ can be set according to the actual situation and demand.

本发明具有如下有益效果：The present invention has following beneficial effects:

1、本发明通过采用将转速环中的PI控制器用二自由度高阶滑模非奇异终端控制取代，将传统滑模控制方法中的切换项加在终端滑模控制方法的导数上，因此，有效的降低了滑模变结构在系统控制过程中的抖振问题，从而也提高了系统控制精度，使得转速能可有效的收敛在平衡点附近。1. The present invention replaces the PI controller in the rotating speed loop with two-degree-of-freedom high-order sliding mode non-singular terminal control, and adds the switching item in the traditional sliding mode control method to the derivative of the terminal sliding mode control method. Therefore, It effectively reduces the chattering problem of the sliding mode variable structure in the system control process, thereby also improving the system control accuracy, so that the speed can effectively converge near the equilibrium point.

2、本发明提出基于二自由度高阶滑模非奇异终端的永磁同步电机转速控制方法，在消除控制量抖振的同时，实现了电机转速的快速收敛，并且对负载扰动具有较强的鲁棒性。2. The present invention proposes a permanent magnet synchronous motor speed control method based on a two-degree-of-freedom high-order sliding mode non-singular terminal, which realizes rapid convergence of the motor speed while eliminating chattering of the control variable, and has strong resistance to load disturbances robustness.

附图说明Description of drawings

图1是永磁同步电机控制矢量方法框图；Fig. 1 is a block diagram of a permanent magnet synchronous motor control vector method;

图2是本发明二自由度高阶滑模非奇异终端控制框图；Fig. 2 is a non-singular terminal control block diagram of a two-degree-of-freedom high-order sliding mode of the present invention;

图3为本发明二自由度高阶滑模控制的电机仿真转速波形曲线；Fig. 3 is the motor simulation rotational speed waveform curve of the two-degree-of-freedom high-order sliding mode control of the present invention;

图4为传统PI控制的电机仿真转速波形曲线。Fig. 4 is the motor simulation speed waveform curve of the traditional PI control.

图1中，1.逆变器，2.PMSM模块，3.信号检测电路，4.Clark变换，5.Park变换，6.测速编码器，7.二自由度高阶滑模非奇异终端控制外环控制器，8.反Park变换，9.SVPWM模块。In Figure 1, 1. Inverter, 2. PMSM module, 3. Signal detection circuit, 4. Clark transform, 5. Park transform, 6. Velocity encoder, 7. Two-degree-of-freedom high-order sliding mode non-singular terminal control Outer loop controller, 8. Inverse Park transformation, 9. SVPWM module.

具体实施方式Detailed ways

一种永磁同步电机控制方法，采用矢量控制系统，矢量控制系统包括速度外环和电流内环两部分，主要有主电路、电流信号检测电路3和控制电路；参见图1，主电路包括逆变器1和PMSM模块2，电流信号检测电路3通过霍尔传感器检测电机在三相静止坐标系下的三相电流，取其中的两相输出电流i_A,i_B，经过Clarke变换4，转换为静止两相坐标系下的电流值i_α,i_β，在速度环，给定转速w^*与编码器6测得的反馈速度w相比较，经过二自由度高阶滑模非奇异终端控制外环控制器7调节后，输出转子旋转坐标系下的q轴电流i_q ^*，，静止两相坐标系下的电流值i_α，i_β以及电机转子角θ经过Park变换5，转换为转子旋转坐标系下的两相反馈计算励磁电流电流i_d和转矩电流i_q，给定励磁电流i_d ^*与反馈计算励磁电流i_d相比较，经过电流PI调节之后，得到两相旋转坐标的d轴输出电压u_d；转矩电流i_q ^*与反馈计算转矩电流i_q相比较之后，经过电流PI调节后，得到两相旋转坐标的q轴输出电压u_q；此刻，旋转坐标系下的两相电压u_q与u_d经过Park逆变换8之后转换为静止两相坐标系下的两相电压u_α、u_β，经过SVPWM模块9的调节，产生PWM波，经过三相逆变器之后，驱动电机工作。A control method for a permanent magnet synchronous motor, using a vector control system, the vector control system includes two parts, a speed outer loop and a current inner loop, mainly including a main circuit, a current signal detection circuit 3 and a control circuit; see Fig. 1, the main circuit includes an inverter Inverter 1 and PMSM module 2, the current signal detection circuit 3 detects the three-phase current of the motor in the three-phase stationary coordinate system through the Hall sensor, and takes the two-phase output current i _A , i _B , and converts it through Clarke transformation 4 is the current value i _α , i _β in the stationary two-phase coordinate system. In the speed loop, the given speed w ^* is compared with the feedback speed w measured by the encoder 6, and is controlled by a two-degree-of-freedom high-order sliding mode non-singular terminal After the outer loop controller 7 is adjusted, the q-axis current i _q ^* in the rotor rotating coordinate system is output, the current values i _α , i _β in the stationary two-phase coordinate system and the motor rotor angle θ are transformed into rotor The two-phase feedback calculation excitation current i _d and torque current i _q in the rotating coordinate system, the given excitation current i _d ^* is compared with the feedback calculation excitation current i _d , after the current PI adjustment, the two-phase rotation coordinates are obtained The d-axis output voltage u _d ; the torque current i _q ^* is compared with the feedback calculated torque current i _q , and after the adjustment of the current PI, the q-axis output voltage u _q of the two-phase rotating coordinate is obtained; at this moment, under the rotating coordinate system The two-phase voltages u _q and u _d are transformed into two-phase voltages u _α and u _β in the static two-phase coordinate system after Park inverse transformation 8, and are adjusted by the SVPWM module 9 to generate PWM waves, which are passed through the three-phase inverter After that, the drive motor works.

本发明的主要特点在于，将原有矢量控制系统转速环的PI控制器采用二自由度高阶非奇异终端滑模控制器取代。二自由度高阶非奇异终端滑模控制器的输入为电机的给定转速w^*与电机的实际反馈转速w之差，然后判断给定转速与反馈转速的误差大小。当转速误差较小时，输出的励磁电流i_q ^*是通过单纯的高阶滑模非奇异终端控制器计算实现的；当转速误差较大时二自由度高阶非奇异终端滑模控制的输出为高阶非奇异终端滑模控制的输出i_q ^*为高阶非奇异终端滑模的输出与补偿增益之和。其中这里的补偿增益是将转速误差的乘以一个系数得到的，这样当转速误差实时改变的时候输出的转矩电流也能实时的改变，如此可以更加有效的调节系统，使得电机转速更加平稳，从而减小了转速的波动，达到较好的控制效果。The main feature of the invention is that the PI controller of the speed loop of the original vector control system is replaced by a two-degree-of-freedom high-order non-singular terminal sliding mode controller. The input of the two-degree-of-freedom high-order non-singular terminal sliding mode controller is the difference between the given speed w ^* of the motor and the actual feedback speed w of the motor, and then the error between the given speed and the feedback speed is judged. When the speed error is small, the output excitation current i _q ^* is calculated by a simple high-order sliding mode non-singular terminal controller; when the speed error is large, the output of the two-degree-of-freedom high-order non-singular terminal sliding mode control is The output i _q ^* of the high-order non-singular terminal sliding mode control is the sum of the output of the high-order non-singular terminal sliding mode and the compensation gain. The compensation gain here is obtained by multiplying the speed error by a coefficient, so that when the speed error changes in real time, the output torque current can also change in real time, so that the system can be adjusted more effectively to make the motor speed more stable. Thereby reducing the fluctuation of the speed and achieving a better control effect.

图2中转速偏差是判断转速的的误差大小，若转速偏差较大时，补偿增益与高阶非奇异终端滑模控制的输出之和为i_q ^*；若转速误差较小时，则补偿增益为零，即转矩电流i_q ^*为单纯的高阶非奇异终端滑模控制的输出。其中高阶非奇异终端滑模控制器的设计如下：In Fig. 2, the speed deviation is the error in judging the speed. If the speed deviation is large, the sum of the compensation gain and the output of the high-order non-singular terminal sliding mode control is i _q ^* ; if the speed error is small, the compensation gain is Zero, that is, the torque current i _q ^* is the output of pure high-order non-singular terminal sliding mode control. The high-order non-singular terminal sliding mode controller is designed as follows:

转速环控制器的控制目标是电机实际转速能精确跟踪速度给定，对外界负载扰动以及摩擦阻力等参数摄动具有完全鲁棒性，输出平滑的交轴电流给定信号i_q ^*。令；给定信号为ω^*，假设ω^*足够平滑，几乎处处具有2阶连续导数，定义误差状态：The control goal of the speed loop controller is that the actual speed of the motor can accurately track the given speed, be completely robust to external load disturbances and frictional resistance and other parameter perturbations, and output a smooth quadrature axis current given signal i _q ^* . Let; the given signal is ω ^* , assuming that ω ^* is smooth enough to have 2nd-order continuous derivatives almost everywhere, define the error state:

e_ω=ω^*-ωe _ω =ω ^* -ω

（1）(1)

根据永磁同步电动机状态方程，可得转速误差系统状态方程为：According to the state equation of the permanent magnet synchronous motor, the state equation of the speed error system can be obtained as:

${\overset{\cdot &Center Dot;}{e e}}_{ω ω} = = {\overset{\cdot &Center Dot;}{ω ω}}^{* *} - - \overset{\cdot &Center Dot;}{ω ω} = = {\overset{\cdot &Center Dot;}{ω ω}}^{* *} - - \frac{{pψ pψ}_{f f}}{J J} {i i}_{q q}^{* *} + + \frac{B B}{J J} ω ω + + \frac{{T T}_{L L}}{J J} - - - - - - ((22))$

误差系统状态方程（2）对误差状态（1）的相对阶为1，因此可以通过2阶或2阶以上滑模控制实现系统无抖振，即平滑无高频抖振。这里转速环采用2阶滑模控制，使误差状态e_ω具有二阶滑模运动状态：

为实现误差状态e_ω的2阶滑模运动，设计如下非奇异终端滑模面：The relative order of the error system state equation (2) to the error state (1) is 1, so the second-order or above-order sliding mode control can be used to realize the system without chattering, that is, smooth and free of high-frequency chattering. Here the speed loop adopts second-order sliding mode control, so that the error state e _ω has a second-order sliding mode motion state:

In order to realize the second-order sliding mode motion of the error state e _ω , the following non-singular terminal sliding mode surface is designed:

${l l}_{ω ω} = = {e e}_{ω ω} + + r r {\overset{\cdot &Center Dot;}{e e}}_{ω ω}^{p p / / q q} - - - - - - ((33))$

式中，γ>0，p，q为奇数，且1＜p/q＜2。根据非奇异终端滑模收敛特性，设计恰当的滑模控制律使得非奇异终端滑模面（3）在有限时间内收敛为零，即l_ω=0。系统误差状态e_ω进入终端滑模运动状态，将在有限时间内到达2阶滑模运动。In the formula, γ>0, p, q are odd numbers, and 1<p/q<2. According to the convergence characteristics of the non-singular terminal sliding mode, an appropriate sliding mode control law is designed to make the non-singular terminal sliding mode surface (3) converge to zero within a finite time, ie _lω =0. The system error state e _ω enters the terminal sliding mode motion state, and will reach the second-order sliding mode motion within a finite time.

选择非奇异终端滑模面（3）并设计控制律如下：Choose a non-singular terminal sliding surface (3) and design the control law as follows:

$\{\begin{matrix} {u u}_{q q} = = {u u}_{qeq qeq} + + {u u}_{qn qn} \\ {u u}_{qeq qeq} = = {\overset{\cdot &Center Dot;}{Li Li}}_{q q}^{* *} + + {Lpωi Lpωi}_{d d} + + {R R}_{s the s} {i i}_{q q} + + {pψ pψ}_{f f} ω ω \\ {u u}_{qn qn} = = L L {&Integral; &Integral;}_{00}^{t t} [[\frac{11}{γ γ} \frac{q q}{p p} {\overset{\cdot &Center Dot;}{e e}}_{q q}^{22 - - p p / / q q} + + {k k}_{11} sgn sgn (({s the s}_{q q})) + + {k k}_{22} {s the s}_{q q}]] dt dt \end{matrix} - - - - - - ((44))$

其中，k₁，k₂为参数。Among them, k ₁ and k ₂ are parameters.

若选择李亚普诺夫函数为：v_ω(t)=0.5l_ω ²(t)If the Lyapunov function is chosen as: v _ω (t)=0.5l _ω ² (t)

对v_w(t)时间求导得：Deriving v _w (t) time:

${\overset{\cdot &Center Dot;}{v v}}_{ω ω} ((t t)) = = {l l}_{ω ω} ((t t)) {l l}_{ω ω} ((t t))$

$= = \frac{{l l}_{ω ω} {γ γ}_{11} {p p}_{11}}{{q q}_{11}} {\overset{\cdot \cdot}{e e}}_{ω ω}^{{p p}_{11} / / {q q}_{11} - - 11} [[{\overset{\cdot \cdot \cdot \cdot}{e e}}_{ω ω} + + \frac{{q q}_{11}}{{γ γ}_{11} {p p}_{11}} {\overset{\cdot &Center Dot;}{e e}}_{ω ω}^{22 - - {p p}_{11} / / {q q}_{11}}]]$

$= = \frac{{l l}_{ω ω} {γ γ}_{11} {p p}_{11}}{{q q}_{11}} {\overset{\cdot &Center Dot;}{e e}}_{ω ω}^{{p p}_{11} / / {q q}_{11} - - 11} [[- - (({k k}_{11} + + {η η}_{11})) sgn sgn {l l}_{ω ω} + + \frac{{T T}_{L L}}{J J} - - {η η}_{22} {l l}_{ω ω}]]$

$\leq \leq {- - γ γ}_{11} (({p p}_{11} / / {q q}_{11})) {\overset{\cdot \cdot}{e e}}_{ω ω}^{{p p}_{11} / / {q q}_{11} - - 11} (({η η}_{11} | | {l l}_{ω ω} | | + + {η η}_{22} {l l}_{ω ω}^{22}))$

由上式可以看出，当l_ω≠0时，由于

则

当且仅当

时，

而当e_ω≠0可以证明并不是一个稳定状态，即

不可能一直保持。所以系统在有限时间到达并保持非奇异终端滑模l_ω＝0，则e_ω将在有限时间内收敛。通过调节参数p₂，q₂，k₁，k₂可以调节转速的误差e_ω的收敛速度。由此可证明若选择式（3）为系的非奇异终端滑模面系统是可以收敛的。It can be seen from the above formula that when l _ω ≠ 0, due to

but

if and only if

hour,

And when It can be proved that e _ω ≠ 0 is not a stable state, namely

Impossible to keep. So the system reaches and maintains the non-singular terminal sliding mode l _ω =0 in finite time, then e _ω will converge in finite time. By adjusting the parameters p ₂ , q ₂ , k ₁ , k ₂ the convergence speed of the error e _ω of the speed can be adjusted. From this, it can be proved that the non-singular terminal sliding mode surface system can be converged if formula (3) is selected as the system.

针对高阶滑模非奇异终端在控制过程中还有一定的高频抖动，采用二自由度控制原理，在上述高阶滑模非奇异终端中加入了二自由度控制算法以达到对系统更好的控制。具体控制方法框图如图2所示，将速度给定和速度反馈作差得到转速偏差，如果转速偏差在可以接受的范围内则可直接经过高阶滑模非奇异终端控制得到i_q ^*再同i_q作差之后作为电流环PI控制器的输入；若当转速偏差较大时，则i_q ^*为高阶滑模非奇异终端控制的输出与二自由度反馈的补偿增益之和。这样就可以实时的调整i_q ^*的大小得到较好的转速控制目的。In view of the high-order sliding mode non-singular terminal still has a certain high-frequency jitter in the control process, the two-degree-of-freedom control principle is adopted, and the two-degree-of-freedom control algorithm is added to the above-mentioned high-order sliding mode non-singular terminal to achieve better performance for the system. control. The block diagram of the specific control method is shown in Figure 2. The speed deviation is obtained by making a difference between the speed reference and the speed feedback. If the speed deviation is within an acceptable range, the i _q ^* can be directly obtained through the high-order sliding mode non-singular terminal control and then the same After i _q makes a difference, it is used as the input of the current loop PI controller; if the speed deviation is large, then i _q ^* is the sum of the output of the high-order sliding mode non-singular terminal control and the compensation gain of the two-degree-of-freedom feedback. In this way, the size of i _q ^* can be adjusted in real time to obtain a better speed control purpose.

图2中的系统误差大小控制是采用分段函数，对转速误差较大的时候进行二自由度调节，当转速误差较小的时候不进行处理。若误差状态为

则令：The system error size control in Fig. 2 adopts a piecewise function, and adjusts the two degrees of freedom when the speed error is large, and does not process it when the speed error is small. If the error state is

Then order:

$ξ ξ = = \{\begin{matrix} {ξ ξ}_{11} - - {e e}_{ω ω},, & {e e}_{ω ω} &GreaterEqual; &Greater Equal; {ξ ξ}_{11} \\ 00,, & {ξ ξ}_{22} \leq \leq {e e}_{ω ω} \leq \leq {ξ ξ}_{11} \\ {ξ ξ}_{22} - - {e e}_{ω ω},, & {e e}_{ω ω} \leq \leq {ξ ξ}_{22} \end{matrix} - - - - - - ((55))$

其中，ξ₁和ξ₂为反馈切换点，且ξ₁>0、ξ₂<0，ξ₁、ξ₂为常数。通过选择适当的ξ₁、ξ₂大小即可调整系统性能。当e_ω≥ξ₁时，系统为正反馈；当e_ω≤ξ₂时，系统为负反馈；当ξ₁≤e_ω≤ξ₂时认为是可接受的误差范围不进行处理即该系统仍为一自由度控制系统。由此可以实时动态的控制二自由度反馈环，从而达到更好的系统控制性能。Among them, ξ ₁ and ξ ₂ are feedback switching points, and ξ ₁ >0, ξ ₂ <0, and ξ ₁ and ξ ₂ are constants. The system performance can be adjusted by choosing the appropriate size of ξ ₁ and ξ ₂ . When e _ω ≥ ξ ₁ , the system is positive feedback; when e _ω ≤ ξ ₂ , the system is negative feedback; when ξ ₁ ≤ e _ω ≤ ξ ₂ , it is considered that the acceptable error range is not processed, that is, the system is still is a one-degree-of-freedom control system. Therefore, the two-degree-of-freedom feedback loop can be dynamically controlled in real time, so as to achieve better system control performance.

本发明控制方法同时具有高阶滑模非奇异终端控制和二自由度控制方法的优点。The control method of the invention has the advantages of the high-order sliding mode non-singular terminal control and the two-degree-of-freedom control method at the same time.

本发明是基于二自由度高阶滑模非奇异终端控制系统控制，具有结构简单，易于实现，鲁棒性好，具有速度响应快和跟踪误差小的优点，提高了系统的稳定性，有效地改善了系统的动、静态运行性能。The present invention is based on a two-degree-of-freedom high-order sliding mode non-singular terminal control system control, which has the advantages of simple structure, easy implementation, good robustness, fast speed response and small tracking error, improves the stability of the system, and effectively The dynamic and static performance of the system is improved.

为了验证二自由度高阶滑模控制方法的可行性，本文在MATLAB平台上进行了仿真，选择的永磁同步电机参数为：R=4.96Ω,L_d=0.0085mH，L_q=0.0085mH，B＝0,极对数p=2，ψ=0.375Wb，J＝.26×10^-5kg.m²，仿真结果如下：In order to verify the feasibility of the two-degree-of-freedom high-order sliding mode control method, this paper simulates on the MATLAB platform. The parameters of the permanent magnet synchronous motor selected are: R=4.96Ω, L _d =0.0085mH, L _q =0.0085mH, B=0, number of pole pairs p=2, ψ=0.375Wb, J=.26×10 ^-5 kg.m ² , the simulation results are as follows:

图3、图4分别为给定转速为1500r/min时二自由度高阶滑模控制和传统PI控制的电机仿真转速波形曲线。电机在0.2s时突加5N·m的负载，由图3可以看出在启动阶段转速超调不到10r/min且调节时间仅为0.035s左右与PI控制相比二自由度高阶滑模控制有较快得动态性能，在0.2s时系统突加负载时，二自由度高阶滑模控制能在0.202s左右到达稳态，且加载后电机的转速降落仅为5r/min左右，与传统PI相比能够更快的回到稳定状态，且波动较小。说明该控制方法对负载有较好的鲁棒性，以及快速性能。Fig. 3 and Fig. 4 are respectively the motor simulation speed waveform curves of the two-degree-of-freedom high-order sliding mode control and the traditional PI control when the given speed is 1500r/min. The motor suddenly adds a load of 5N·m at 0.2s. It can be seen from Figure 3 that the speed overshoot is less than 10r/min during the start-up phase and the adjustment time is only about 0.035s. Compared with the PI control, the two-degree-of-freedom high-order sliding mode The control has a fast dynamic performance. When the system is suddenly loaded at 0.2s, the two-degree-of-freedom high-order sliding mode control can reach a steady state in about 0.202s, and the speed of the motor after loading is only about 5r/min. Compared with traditional PI, it can return to a stable state faster and with less fluctuation. It shows that the control method has good robustness to load and fast performance.

Claims

1. method for controlling permanent magnet synchronous motor is characterized in that: adopt vector control system, vector control system comprises speed outer shroud and current inner loop two parts, and the PI controller of der Geschwindigkeitkreis adopts the nonsingular terminal sliding mode controller of two degrees of freedom high-order to replace; The given rotating speed w that is input as motor of the nonsingular terminal sliding mode controller of two degrees of freedom high-order ^*Poor with the actual feedback rotating speed w of motor judged the error size of given rotating speed and feedback rotating speed, when speed error during less than ξ, and the exciting current i of output _q ^*To calculate by the nonsingular terminal control unit of simple High-Order Sliding Mode to realize; When speed error during greater than ξ the nonsingular terminal sliding mode control of two degrees of freedom high-order be output as the output i of the nonsingular terminal sliding mode control of high-order _q ^*Output and compensating gain sum for the nonsingular terminal sliding mode of high-order; Wherein the large I of ξ is according to actual conditions and requirements set.