阅读说明：本技术 一种新型的多永磁同步电机同步控制方法 (Novel multi-permanent magnet synchronous motor synchronous control method ) 是由 李文娟 颜世博 于 2020-06-01 设计创作，主要内容包括：一种新型的多永磁同步电机同步控制方法属于多电机高精度转速同步控制领域,由主从控制方法和交叉耦合控制方法结合而成：传统的主从控制系统因为转速由前一台电机所提供,所以同步时存在着时间差,特别是在启动、停止阶段同步效果最差。传统的交叉耦合控制系统由于其结构的特殊性,只适用两台电机的场合。本发明在主从控制方法和交叉耦合控制方法的基础上进行改进,结合了主从控制和交叉耦合控制的优点,使其可以应用于三台及以上电机转速同步的场合,同时结构稳定,控制精度高,能有效减小控制系统的跟踪误差和同步误差。(A novel synchronous control method for multiple permanent magnet synchronous motors belongs to the field of multi-motor high-precision rotating speed synchronous control, and is formed by combining a master-slave control method and a cross coupling control method: the traditional master-slave control system has time difference during synchronization because the rotating speed is provided by the previous motor, and particularly has the worst synchronization effect in the starting and stopping stages. The traditional cross coupling control system is only suitable for the occasions of two motors due to the structural particularity of the traditional cross coupling control system. The invention improves on the basis of a master-slave control method and a cross-coupling control method, combines the advantages of the master-slave control and the cross-coupling control, can be applied to the occasions of synchronizing the rotating speeds of three or more motors, has stable structure and high control precision, and can effectively reduce the tracking error and the synchronization error of a control system.)

1. the novel control method of the multi-permanent magnet synchronous motor is characterized by comprising a direct current power supply module (1), an inverter module (2), a driving circuit module (6), a permanent magnet synchronous motor (3), a main control module (5) and a sensor module (4), wherein the sensor module comprises a voltage detection module, a current detection module and a main control module, and the main control module comprises PARK coordinate transformation, C L ARK coordinate transformation, PARK coordinate inverse transformation, a speed controller, a current controller and space voltage vector pulse width modulation.

2. A novel control method for a multi-permanent magnet synchronous motor is characterized by comprising the following steps:

(1) the collection of many PMSM's rotational speed signal includes:

a. acquiring the rotating speeds of a plurality of permanent magnet synchronous motors, and subtracting the rotating speed of each motor from a reference rotating speed to obtain a tracking error;

b. making difference between the rotating speeds of different motors to obtain a synchronous error;

c. designing a feedback loop according to the tracking error and the synchronous error, and compensating the rotating speed of each motor;

d. collecting three-phase stator current of each motor, and converting the three-phase stator current and voltage into stator current components on a two-phase static α - β coordinate system;

e. and (3) acquiring the rotor magnetic field angle of each motor, and converting the stator current component of each motor on a two-phase stationary α - β coordinate system into the stator current component on a two-phase rotating d-q coordinate system.

(2) The control method combining master-slave control and cross coupling control comprises the following steps:

a. a feedback signal. For the motor 1, the input is the reference rotation speed ω_refActual rotational speed ω of the motor 1₁And subtracting the actual rotating speed of other motors to obtain a synchronous error, summing the synchronous error and dividing the sum by the number of the motors to obtain a feedback signal of the motor 1. Wherein, the difference of the rotating speed of the motor 1 and other motors is the feedback signal of other motors;

b. and (4) cross coupling control. Subtracting the actual rotating speed of the motors from the selected main motor to obtain the synchronous error delta omega_sAnd subtracting the main motor and each slave motor to obtain a synchronous error, and multiplying each synchronous error by a feedback coefficient K to compensate the rotating speed of each slave motor. And averaging all the synchronous errors, and multiplying the average value by a feedback coefficient of the main motor to compensate the rotating speed of the main motor. Obtaining reference stator voltage on a d-q coordinate system of two-phase rotation of the motors 1 and 2 through PI regulation and an inner loop current controller;

c. and a space vector pulse width modulation method is adopted to generate control signals of each set of inverter switching tubes and respectively control the rotating speeds of a plurality of motors.

3. The novel multi-PMSM control method of claim 1, wherein the feedback coefficient calculation method comprises:

(1) listing a parameter table of the permanent magnet synchronous motor;

(2) constructing a state space model according to the motor parameters;

(3) calculating a transfer function of the synchronous control method according to the state space model;

(4) and (4) listing a Laus criterion table according to the transfer function, and calculating the value range of the feedback coefficient.

4. The new multiple-pm synchronous motor control method as claimed in claim 1, wherein in one example specifically:

many permanent-magnet machine system electric volume collection and calculation include:

a. sampling the real-time rotating speed of the motor, collecting the actual rotating speed of the motor by adopting an encoder, transmitting the collected real-time rotating speed signal to a DSP, and subtracting the reference rotating speed from the actual rotating speed of each motor to obtain a rotating speed tracking error required by controlling the motor;

b. in the DSP, subtracting the rotating speed of each motor from the rotating speed of the main motor to obtain the rotating speed synchronization error required by the control motor;

c. collecting three-phase stator current of each motor by using a Hall current sensor, transmitting the collected real-time rotating speed signal to a DSP (digital signal processor), and converting the three-phase stator current into stator current components on a two-phase static coordinate system in the DSP;

d. acquiring a rotor magnetic field angle of the motor by using an encoder, and using the rotor magnetic field angle in d-q conversion;

e. and a Hall voltage sensor is used for acquiring a voltage value at the direct current side and inputting the voltage value into the DSP.

Technical Field

The invention relates to a multi-motor synchronous control method. In particular to a control method combining master-slave control and cross coupling control applied to a speed synchronous control system of a multi-permanent magnet synchronous motor.

Background

More and more mechanical devices require two or more electric motors to drive them together, such as numerically controlled machines, paper machines, textile machines, printing machines, and even in high speed railway traction systems. In the applications, the requirement on the synchronization of the rotating speed between each motor is higher and higher, and the quality of the synchronization is directly related to the stability and the safety of the operation of the equipment and the quality of products. In many occasions, the single motor control is difficult to meet the use requirement, and the requirement of industrial production on multi-motor synchronous driving makes the synchronous control technology become a research hotspot. The cross-coupled control structure can achieve better synchronization performance than the non-coupled structure, and thus becomes one of the control structures mainly applied to the multi-motor control at present.

Master-slave control is the most basic motor synchronous control method, where each controller obtains a speed reference separately. The master-slave technique feeds back a reference speed to the master PMSM and then provides the output speed to the next PMSM as its reference. In the traditional cross coupling control structure of two motors, the feedback coefficient affects both the tracking performance and the synchronization performance, in the actual engineering, the two performances are difficult to be considered, and the traditional cross coupling structure is only suitable for the rotation speed synchronization control of the two motors and cannot be applied to the conditions of more than three motors. Aiming at the problem, the invention provides a control method combining master-slave control and cross-coupling control of a plurality of permanent magnet motors, the method combines the advantages of master-slave control and cross-coupling control, not only has the advantages of small tracking error and synchronization error of cross-coupling control, but also is suitable for the situation of more than three motors. Meanwhile, a detailed feedback coefficient calculation method is provided, and the method is convenient to apply to actual engineering.

Disclosure of Invention

The present invention aims to propose a speed synchronization control method for a multi-motor (three or more motors) system that emphasizes minimizing synchronization errors between motors.

The invention adopts the technical scheme that a control method combining master-slave control and cross coupling control comprises the following steps:

(1) the collection of many PMSM's rotational speed signal includes:

a. acquiring the rotating speeds of a plurality of permanent magnet synchronous motors, and subtracting the rotating speed of each motor from a reference rotating speed to obtain a tracking error;

b. making difference between the rotating speeds of different motors to obtain a synchronous error;

c. designing a feedback loop according to the tracking error and the synchronous error, and compensating the rotating speed of each motor;

d. feedback signal: for the motor 1, the input is the reference rotation speed ω_refActual rotational speed ω of the motor 1₁And subtracting the actual rotating speed of other motors to obtain a synchronous error, summing the synchronous error and dividing the sum by the number of the motors to obtain a feedback signal of the motor 1. Wherein, the rotation speed difference between the motor 1 and other motors is the feedback signals of other motors.

(2) The calculation method of the feedback coefficient comprises the following steps:

a. listing a parameter table of the permanent magnet synchronous motor;

b. constructing a state space model according to the motor parameters;

c. calculating a transfer function of the synchronous control method according to the state space model;

d. and (4) listing a Laus criterion table according to the transfer function, and calculating the value range of the feedback coefficient.

Compared with the prior art, the invention has the following beneficial effects:

the present invention combines cross-coupling technology with master-slave technology to apply it to speed synchronization of multiple PMSM systems. By this combination, close coupling like cross coupling technology can be achieved, but it can also be applied to multiple permanent magnet synchronous motors like master-slave technology.

The invention provides a speed synchronization control method for a multi-motor (three motors or more) system, which emphasizes the minimization of synchronization errors among motors. The method is a novel speed synchronization control technology, and combines a cross coupling control technology with a master-slave control technology, so that the method can be used for a plurality of permanent magnet synchronous motor control systems with high-speed synchronization. And (3) solving a closed loop transfer function of the system according to the motor parameters, solving a feedback gain by using a Laus criterion, and controlling the motors to keep synchronous by using the speed difference between the motors.

Description of the drawings:

FIG. 1 is a view showing the structure of the present invention

FIG. 2 is a control schematic of the present invention

FIG. 3 is a speed compensation diagram of the present invention (taking the three motor case as an example)

FIG. 4 is an electrical topology of the present invention

Detailed Description

The invention replaces a rotation speed setting and compensating module in the traditional structure, collects a rotation speed signal of the motor through an encoder, and the compensating mechanism is to make a difference between the rotation speed of a main motor and the rotation speed of a slave motor, compensate the slave motor through a difference value, and compensate the main motor through averaging all the difference values, thereby solving the problem that the load is disturbed when a system stably operates, so that the synchronization error is overlarge. The motor part adopts a closed-loop current loop, and PI adjustment is carried out on the rotating speed compensated by the tracking error and the synchronous error to obtain a current reference value under a rotating coordinate system, and the current reference value is sent to the current loop. Collecting stator current by Hall current sensor, and converting by d-q to obtain i_dAnd (5) obtaining a current value through coordinate transformation, and controlling the inverter through SVPWM to further control the rotating speed of the motor.

The following describes embodiments of the present invention with reference to the drawings.

As shown in fig. 1, a novel synchronous control method for multiple permanent magnet synchronous motors comprises a direct current power supply module (1), an inverter module (2), a driving circuit module (6), a permanent magnet synchronous motor (3), a main control module (5) and a sensor module (4), wherein the sensor module comprises a voltage detection module, a current detection module and a main control module, and the main control module comprises PARK coordinate transformation, C L ARK coordinate transformation, PARK coordinate inverse transformation, a speed controller, a current controller and space voltage vector pulse width modulation.

The sensor module comprises a voltage detection module, a dual-wave module CHV-25P Hall voltage sensor is adopted, an AHBC-L TA series Hall current sensor is adopted as the current sensor, an incremental encoder E40S6-5000 is adopted as the speed sensor, IGBT switching tubes used by the inverter are all selected from IGBTs with models of CM200DY-34A, a chip used by the driving circuit module is an IR driving chip produced by American IR company, a chip used by the main control circuit is a DSP, and the model is TMS320F28335 produced by TI company.

Principle of operation

As shown in the attached figure 2, after the actual rotating speed and the synchronous error of the motor are compared with the given rotating speed, the difference value is processed by a speed controller to obtain a current reference value, the reference voltage value is obtained by a current controller to control the output voltage of an inverter to control the motor, a Hall sensor detects the three-phase current of the permanent magnet synchronous motor, the detected current is converted by C L ARK to obtain the current under a α - β coordinate system, and then the current is converted by d-q to form closed-loop control in a current inner loop.

The three-phase permanent magnet synchronous motor is provided with three stator windings and a permanent magnet rotor. Assuming that no external voltage acts on the rotor and the constant flux linkage, the mathematical model of the voltage of the permanent magnet synchronous motor is as follows:

the Clark conversion and Park conversion are utilized to convert a mathematical model of the non-salient pole permanent magnet synchronous motor from a three-phase static coordinate system to a two-phase rotating coordinate system, so that a stator voltage equation under the two-phase rotating coordinate system of the permanent magnet synchronous motor is as follows:

wherein u is_d、u_qD-q axis components of the stator voltage L_sIs a stator inductance; r_sIs a stator resistor; i.e. i_d、i_qRespectively d-q axis component of the stator current

The stator flux linkage equation is

ψ_d＝L_si_q+ψ_f

ψ_q＝L_si_q

Wherein psi_d、ψ_qIs the d-q axis component of the stator flux linkage.

The torque formula of the permanent magnet synchronous motor under a rotating coordinate system is as follows:

further, the mechanical angular velocity and the electrical angular velocity of the permanent magnet synchronous motor have the following relationship:

ω_e＝pω_mech

wherein ω is_mech，ω_eMechanical and electrical angular velocities, T_emAnd T_LJ is the moment of inertia, p is the pole pair number, and B is the damping coefficient.

After a mathematical model of the permanent magnet synchronous motor is calculated, the mathematical model is converted into a d-axis zero-current state space model (control characteristic i)_d0), state space model of the control systemComprises the following steps:

constructing an open-loop transfer function of the system according to the d-axis zero-current state space model:

the feedback loop of the main motor is as follows:

the closed loop transfer function of the main motor control system is obtained according to the open loop transfer function as follows:

through a closed-loop transfer function, a feedback coefficient K can be obtained according to the Laus criterion, and the feedback coefficients of other motors can be obtained respectively in the same way.

The feedback loop of the slave motor is as follows:

H_i(S)＝K_i(ω₁-ω_i)

solving a closed loop transfer function from the motor control system according to the open loop transfer function as:

the main motor rotation speed compensation is as follows:

the compensation of the rest slave motors is as follows:

ω_i'＝K_i(ω₁-ω_i)