CN-114944786-B - Synchronous motor control method and system

CN114944786BCN 114944786 BCN114944786 BCN 114944786BCN-114944786-B

Abstract

The invention discloses a control method and a control system of a synchronous motor. The control method of the synchronous motor is applied to a control system of the synchronous motor and comprises the steps of obtaining real-time feedback rotating speed of the motor, obtaining a speed setting instruction input by a user, determining the speed control instruction based on the speed setting instruction and the real-time feedback rotating speed to enable the driving piece to drive the motor to rotate based on the speed control instruction, obtaining current running current of the motor, and adjusting the speed control instruction based on the current running current to enable the driving piece to drive the motor to rotate based on the adjusted speed control instruction until a difference value of the current feedback rotating speeds of a plurality of motors is smaller than a first preset difference value. By adopting the scheme, the balance of the running current of each working motor is ensured, the service life of the motor is prolonged, the motor can be flexibly applied to different motor coupling control fields, and the number of the coupling motors is not limited.

Inventors

WANG WEI
DUAN WENHAO
CHEN XINWEI

Assignees

厦门钨业股份有限公司
西安合升动力科技有限公司

Dates

Publication Date: 20260508
Application Date: 20220602

Claims (8)

1. The control method of the synchronous motor is characterized by being applied to a control system of the synchronous motor, wherein the control system of the synchronous motor comprises a coupling controller, a driving piece and a motor, the driving piece and the motor are in a plurality of numbers and are in one-to-one correspondence connection, the coupling controller is electrically connected with the driving piece, and the control method of the synchronous motor comprises the following steps: acquiring a real-time feedback rotating speed of the motor; Acquiring a speed setting instruction input by a user; Determining a speed control command based on the speed setting command and the real-time feedback rotating speed, so that the driving piece drives the motor to rotate based on the speed control command; Acquiring the current running current of the motor; adjusting the speed control instruction based on the current running current so that the driving piece drives the motor to rotate based on the adjusted speed control instruction until the difference value of the current feedback rotating speeds of a plurality of motors is smaller than a first preset difference value; the speed control command is increased based on the difference value between the current feedback rotating speed of the motor and the speed setting command, so that the driving piece drives the motor to rotate based on the increased speed control command until the difference value between the speed setting command and the real-time feedback rotating speed is smaller than a second preset difference value; the adjusting the speed control command based on the present operating current includes: adjusting the speed control instruction in a negative feedback mode based on the current running current so as to realize current balance of a plurality of motors; Wherein said adjusting said speed control command in a negative feedback based on said present operating current comprises: reducing the speed control command by a preset magnitude based on the current operating current by the formula: F=I*K; Wherein I is the current running current, K is the decreasing proportion, and F is the decreasing preset amplitude.
2. The method according to claim 1, characterized in that the determining a speed control command based on the speed setting command and the real-time feedback rotational speed includes: determining a speed difference between the speed setting instruction and the real-time feedback rotating speed; and determining a speed control instruction through a PID control algorithm based on the speed difference value.
3. The control method of a synchronous motor according to claim 2, wherein the expression of the PID control algorithm is: ; where Kp is a proportionality constant, ti is an integration time constant, td is a differentiation time constant, u (t) is an output signal of the PID control algorithm, and e (t) is a speed difference.
4. The control method of a synchronous motor according to claim 1, wherein the driving member includes a frequency converter; the obtaining the real-time feedback rotating speed of the motor comprises the following steps: and acquiring the real-time feedback rotating speed of the motor estimated by the frequency converter.
5. The method according to claim 4, wherein the determining a speed control command based on the speed setting command and the real-time feedback rotational speed to cause the driving member to drive the motor to rotate based on the speed control command includes: Determining a speed control command based on the speed setting command and the real-time feedback rotating speed, so that the frequency converter outputs a driving frequency to drive the motor to rotate based on the speed control command; correspondingly, the adjusting the speed control command based on the current running current, so that the driving piece drives the motor to rotate based on the adjusted speed control command, comprises the following steps: and adjusting the speed control instruction based on the current running current so that the frequency converter outputs a driving frequency to drive the motor to rotate based on the adjusted speed control instruction.
6. A control system of a synchronous motor, characterized in that the control system of the synchronous motor comprises a coupling controller (1), a driving piece (2) and a motor (3); The number of the driving parts (2) and the number of the motors (3) are multiple, the driving parts (2) are connected in a one-to-one correspondence manner, and the motors (3) are driven to rotate; The coupling controller (1) is electrically connected with the driving piece (2); The coupling controller (1) is adapted to perform the method of controlling a synchronous machine according to any one of claims 1-5.
7. A control system of a synchronous machine according to claim 6, characterized in that the drive (2) comprises a frequency converter (21); The frequency converter (21) is used for outputting driving frequency to drive the motor (3) to rotate, and/or the frequency converter (21) is used for estimating real-time feedback rotating speed of the motor (3).
8. A control system of a synchronous machine according to claim 6 or 7, characterized in that the coupling controller (1) comprises a PLC.

Description

Synchronous motor control method and system Technical Field The embodiment of the invention relates to the technical field of motor control, in particular to a control method and a control system of a synchronous motor. Background The motor coupling control is widely applied to the field of asynchronous motors, a plurality of asynchronous motors drag loads to run simultaneously, and due to slip of the asynchronous motors, the established control function can be realized easily. In the field of synchronous motors, synchronous control of a plurality of motors all needs position feedback by a position sensor to realize corresponding control functions because no slip is caused. Because the encoder is expensive and the signals are easy to interfere, the coupling control of the synchronous motor can only be used for synchronous control application of the low-power synchronous motor in high-precision occasions. In the related art, when a plurality of motors control loads, the output current of each motor is unbalanced, so that each motor generates heat differently, and the motor with larger heat is shortened in service life and is easy to damage compared with the motor with smaller heat. Disclosure of Invention The invention provides a control method and a control system of a synchronous motor, which are used for realizing the effect of prolonging the service life of the motor. According to one aspect of the invention, a control method of a synchronous motor is provided, the control method of the synchronous motor is applied to a control system of the synchronous motor, the control system of the synchronous motor comprises a coupling controller, a driving piece and a motor, the number of the driving piece and the number of the motor are all multiple and are in one-to-one correspondence connection, the coupling controller is electrically connected with the driving piece, and the control method of the synchronous motor comprises the following steps: acquiring a real-time feedback rotating speed of the motor; Acquiring a speed setting instruction input by a user; Determining a speed control command based on the speed setting command and the real-time feedback rotating speed, so that the driving piece drives the motor to rotate based on the speed control command; Acquiring the current running current of the motor; adjusting the speed control instruction based on the current running current so that the driving piece drives the motor to rotate based on the adjusted speed control instruction until the difference value of the current feedback rotating speeds of a plurality of motors is smaller than a first preset difference value; And increasing the speed control command based on the difference between the current feedback rotating speed of the motor and the speed control command, so that the driving piece drives the motor to rotate based on the increased speed control command until the difference between the speed setting command and the real-time feedback rotating speed is smaller than a second preset difference. In an alternative embodiment of the present invention, said adjusting said speed control command based on said present operating current comprises: and adjusting the speed control command in a negative feedback mode based on the current running current. In an alternative embodiment of the present invention, said adjusting said speed control command in a negative feedback form based on said present operating current comprises: reducing the speed control command by a preset magnitude based on the current operating current by the formula: F=I*K; Wherein I is the current running current, K is the decreasing proportion, and F is the decreasing preset amplitude. In an alternative embodiment of the present invention, said determining a speed control command based on said speed setting command and said real-time feedback rotational speed comprises: determining a speed difference between the speed setting instruction and the real-time feedback rotating speed; and determining a speed control instruction through a PID control algorithm based on the speed difference value. In an alternative embodiment of the present invention, the expression of the PID control algorithm is: where Kp is a proportionality constant, ti is an integration time constant, td is a differentiation time constant, u (t) is an output signal of the PID control algorithm, and e (t) is a speed difference. In an alternative embodiment of the invention, the driving member comprises a frequency converter; the obtaining the real-time feedback rotating speed of the motor comprises the following steps: and acquiring the real-time feedback rotating speed of the motor estimated by the frequency converter. In an alternative embodiment of the present invention, the determining a speed control command based on the speed setting command and the real-time feedback rotational speed, so that the driving member drives the motor to rotate based on the speed control comma