CN102904505A - An integrated inverse control method for six-phase permanent magnet synchronous linear motor - Google Patents

Abstract

The invention discloses an integrated inverse control method for a six-phase permanent magnet synchronous linear motor. When the secondary flux linkage is oriented, the six-phase permanent magnet synchronous linear motor adopts the primary current d-axis component i _d = 0 control method to form a six-phase Permanent magnet synchronous linear motor speed control system. Analyze the reversibility of the mathematical model of the system, construct the right inverse control model of the six-phase permanent magnet synchronous linear motor speed control system; on the premise that the functional relationship between the speed and current and its derivative exists, substitute the functional relationship into the right inverse control In the model, a new type of integrated inverse system is formed. LSSVM is used to approximate the new integrated inverse system model, and its dynamic characteristics are characterized by corresponding integrators and differentiators, and the LSSVM integrated inverse system is obtained. The LSSVM integrated inverse system is connected in series before the original system, and a controller is added to realize the LSSVM integrated inverse control of the six-phase permanent magnet synchronous linear motor. The invention has good control effect, strong anti-interference ability and robustness, and is easy to realize.

Description

An integrated inverse control method for six-phase permanent magnet synchronous linear motor

technical field

The invention relates to an integrated inverse control method of a six-phase permanent magnet synchronous linear motor, which is suitable for the technical field of electric drive control.

Background technique

As a new type of motor, linear motors show great vitality in modern motion control systems. With the rapid development of permanent magnet materials, the application fields of permanent magnet linear motors with advantages such as high efficiency, energy saving and flexible structure are increasingly broadened. Multi-phase permanent magnet synchronous linear motor is a further development of permanent magnet synchronous linear motor, which has many advantages: high power can be realized by low voltage devices, especially suitable for occasions where high voltage cannot be obtained but high output power is required; the harmonic loss of the motor can be significantly reduced, Reduce motor torque ripple, improve system efficiency and stability. Therefore, it is widely used in logistics systems, industrial equipment, information and automation systems, transportation and civil, military and other aspects.

At the same time, the control requirements of multi-phase permanent magnet synchronous linear motors are becoming increasingly stringent. However, the multi-phase permanent magnet synchronous linear motor is a multivariable strongly coupled nonlinear system, and due to the direct drive method, the load disturbance, ripple thrust disturbance, friction force disturbance and other uncertain disturbances will directly act on the motor, Seriously affect the control accuracy of the motor. The traditional PID control strategy can no longer meet its control requirements; the adaptive PID control relies too much on the parameter identification of the object, which has a large amount of calculation and poor real-time performance. In nonlinear control theory, sliding mode control has strong robustness to parameter perturbation and external disturbance due to its fast response speed, but this robustness is based on the high-frequency chattering of the control variable, and switching control The time discontinuity increases the degree of buffeting. The fuzzy neural network method can obtain better speed tracking effect, but this method is a strategy based on error control, which cannot fundamentally weaken the influence of nonlinear factors on system performance. Neural network inverse control, as an intelligent feedback linearization method, combines the clear and easy-to-understand physical concept of the inverse system method with the advantages of highly nonlinear function approximation and strong self-adaptive ability of the neural network. It is more and more used in AC speed control system.

Accurate speed is a prerequisite for reliable operation and high-performance control of multi-phase permanent magnet synchronous linear motors. As far as conventional technologies are concerned, speed sensors are generally installed to measure speed. However, the introduction of the speed sensor not only increases the system cost and complexity, but also reduces the reliability and environmental adaptability of the system operation, which limits the application range of the multi-phase permanent magnet synchronous linear motor. In recent years, scholars at home and abroad have carried out extensive research on the speed sensorless technology, mainly including the identification method based on the back EMF of the motor and the identification method using observation technology.

Contents of the invention

Purpose of the invention: This invention takes six-phase permanent magnet synchronous linear motor as the object, and the purpose is to provide an integrated inverse system control method suitable for multi-phase permanent magnet synchronous linear motor, and realize speed identification and control at the same time.

Technical solution: an integrated inverse control method for a six-phase permanent magnet synchronous linear motor, including:

When oriented according to the secondary flux linkage, the six-phase permanent magnet synchronous linear motor adopts the control method of the primary current d-axis component i _d = 0 to form a six-phase permanent magnet synchronous linear motor speed control system. Analyze the reversibility of the mathematical model of the six-phase permanent magnet synchronous linear motor speed control system, and build a right inverse control model of the six-phase permanent magnet synchronous linear motor speed control system on this basis; at the same time, determine the relationship between speed and current and its derivative On the premise that the functional relationship exists, the functional relationship is substituted into the right inverse control model to form a new integrated inverse system. The least square support vector machine (LSSVM) is used to approximate the model of the new integrated inverse system, and its dynamic characteristics are characterized by the corresponding integrator and differentiator, and the LSSVM integrated inverse system is obtained. The LSSVM integrated inverse system is connected in series before the six-phase permanent magnet synchronous linear motor speed control system, and an additional controller is designed to realize the LSSVM integrated inverse control of the six-phase permanent magnet synchronous linear motor.

Beneficial effects: Compared with the prior art, the integrated inverse control method of the six-phase permanent magnet synchronous linear motor provided by the present invention has the following advantages:

1. The pseudo-linear system obtained after connecting the LSSVM integrated inverse system in series realizes the linearization of the six-phase permanent magnet synchronous linear motor speed control system, making it possible to obtain high-performance control effects by adding a simple controller.

2. The method proposed by the present invention does not rely on the internal mechanism and prior knowledge of the system, has strong anti-interference ability and robustness to uncertain factors such as parameter changes and load disturbances, and realizes the high performance of six-phase permanent magnet synchronous linear motors. performance control.

3. The integrated inverse method of LSSVM realizes the identification and control of the speed in one framework, and has a simple structure and is easy to realize; it provides a feasible new way for the speed sensorless operation of the six-phase permanent magnet synchronous linear motor.

Description of drawings

Fig. 1 is the structural representation of the embodiment of the present invention;

Fig. 2 is a block diagram of an LSSVM integrated inverse controller controlling a six-phase permanent magnet synchronous linear motor speed regulation system according to an embodiment of the present invention.

Detailed ways

Below in conjunction with specific embodiment, further illustrate the present invention, should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention, after having read the present invention, those skilled in the art will understand various equivalent forms of the present invention All modifications fall within the scope defined by the appended claims of the present application.

The integrated inverse control method of the six-phase permanent magnet synchronous linear motor is implemented in the following six steps:

1. When oriented according to the secondary flux linkage, the six-phase permanent magnet synchronous linear motor adopts the control method of the primary current d-axis component i _d = 0, and combines with the load to form a six-phase permanent magnet synchronous linear motor speed control system 1, six-phase The model of permanent magnet synchronous linear motor speed control system 1 is simplified as a nonlinear system with single input and single output. The input is the q-axis component u _q 2 of the primary voltage, and the output is the motor speed ω _r 4 . The primary current q-axis component i _q 3 and the motor speed ω _r 4 are selected as the state variables of the six-phase permanent magnet synchronous linear motor speed control system 1, and the obtained mathematical model is a second-order state equation.

输出变量为初级电压q轴分量u_q2。2. Use the Interactor algorithm to calculate the partial derivative of the output quantity (motor speed ω _r 4) of the six-phase permanent magnet synchronous linear motor speed control system 1 until the apparent input quantity u _q 2, and its relative order is second order. The right inverse system corresponding to the six-phase permanent magnet synchronous linear motor speed control system 1 exists, and it can be determined that the input variable of the right inverse system is the second derivative of the motor speed ω _r 4

The output variable is the primary voltage q-axis component u _q 2 .

之间存在函数关系，即ω_r4可由通过i_q3及其一阶导数

进行观测，得到速度观测值

将该函数关系代入右逆模型中，构成新型的一体化逆系统，其输入变量为初级电流q轴分量i_q4和电机速度ω_r3的二阶导数

输出变量为速度观测值

和初级电压q轴分量u_q2。3. According to the left inverse soft measurement theory, it can be seen from the expression of the primary current q-axis component i _q 3 that the motor speed ω _r 4 is related to the primary current q-axis component i _q 3 and its first derivative

There is a functional relationship between , that is, ω _r 4 can be obtained by i _q 3 and its first derivative

Make observations to get velocity observations

Substitute this functional relationship into the right inverse model to form a new integrated inverse system, whose input variables are the q-axis component i _q 4 of the primary current and the second derivative of the motor speed ω _r 3

The output variable is the velocity observation

and the primary voltage q-axis component u _q 2.

4. The six-phase permanent magnet synchronous linear motor speed control system 1 is operated by the primary current d-axis component i _d = 0 control method, and a random square wave in line with the actual operating range is used as the input quantity u _q 2 . Sampling, smoothing, derivatives, and sampling at equal intervals are carried out on the corresponding data. The Gaussian function K(x, _xi )=exp(-||xx _i || ² /2σ ² ) is selected as the kernel function to train the least squares support vector machine (LSSVM) 6 offline.

5. Add two integrators and a differentiator to LSSVM 6 that has been trained offline to form an LSSVM integrated inverse system 7, as shown in the dashed box in the upper figure of Figure 1. The LSSVM integrated inverse system 7 is connected in series before the six-phase permanent magnet synchronous linear motor speed control system 1, and the six-phase permanent magnet synchronous linear motor speed control system 1 is linearized into a pseudo-linear second-order system 8 of the motor speed, as shown in Figure 1 As shown in the figure below.

6. Based on the linear system design method, design an additional controller for the obtained pseudo-linear second-order system 8, and use the simplest and most mature PID regulator 9 with the most engineering applications. The LSSVM integrated inverse system 7 and the PID regulator 9 are combined to form the LSSVM integrated inverse controller 10 (shown in the dotted line box in FIG. 2 ), to control the six-phase permanent magnet synchronous linear motor speed control system 1, as shown in picture 2. The speed sensor is omitted in the figure, and the speed sensorless operation of the six-phase permanent magnet synchronous linear motor speed control system 1 is realized.

Claims (3)

1. the integrated contrary control method of six-phase permanent-magnet linear synchronous motor is characterized in that, comprising:

During by secondary flux linkage orientation, the six-phase permanent-magnet linear synchronous motor adopts primary current d axle component i _d=0 control method consists of six-phase permanent-magnet linear synchronous motor governing system;

Analyze the invertibity of six-phase permanent-magnet linear synchronous motor governing system Mathematical Modeling, make up on this basis the contrary control in the right side model of six-phase permanent-magnet linear synchronous motor governing system;

Determining under the prerequisite that functional relation exists between speed and electric current and the derivative thereof, in the right contrary control model of this functional relation substitution, be integrally formed novelization inverse system;

Utilize least square method supporting vector machine to approach described novel all-in-one inverse system model, and characterize its dynamic characteristic by associated quad device and differentiator, obtain the integrated inverse system of LSSVM;

The integrated inverse system of LSSVM is connected on before the six-phase permanent-magnet linear synchronous motor governing system, and the design additional controller, realize the integrated contrary control of LSSVM of six-phase permanent-magnet linear synchronous motor.

2. six-phase permanent-magnet linear synchronous motor as claimed in claim 1 is integrated against control method, it is characterized in that: describedly characterize its dynamic characteristic by associated quad device and differentiator, obtain the integrated inverse system of LSSVM, be specially: the LSSVM that off-line training is good adds two integrators, a differentiator consists of the integrated inverse system of LSSVM.

3. six-phase permanent-magnet linear synchronous motor as claimed in claim 1 is integrated against control method, it is characterized in that: the integrated inverse system of LSSVM is connected on before the six-phase permanent-magnet linear synchronous motor governing system, six-phase permanent-magnet linear synchronous motor governing system is linearized to be the pseudo-linear second-order system of motor speed, to the additional PID adjuster of pseudo-linear second-order system that obtains, the integrated inverse system of LSSVM and PID adjuster are formed the integrated inverse controller of LSSVM jointly, to the control that six-phase permanent-magnet linear synchronous motor governing system is carried out, realized the Speedless sensor operation of six-phase permanent-magnet linear synchronous motor governing system.

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