Driver parallel connection system control method considering current sharing and motor control effect

Abstract

Provided is a driver parallel connection system control method considering current sharing and the motor control effect. The method includes: the differences between the d-axis current and the q-axis current output by each driver and the d-axis current and the q-axis current equalized by a system are observed, and whether current-sharing adjustment is performed is selected according to current deviation values; when the current different exceeds a current difference threshold upper limit, a compensation voltage is generated by a current-sharing difference compensation hysteresis controller and superposed on a voltage instruction, and the differences between the d-axis current and the q-axis current output by the adjusted driver and the average d-axis current and the average q-axis current of the system are enabled to be zero; and when the difference between the current output by the driver and the average current of the system is less than a threshold lower limit, the compensation voltage output by the current-sharing difference compensation hysteresis controller is forcibly set as zero, and a current loop no longer performs current-sharing difference compensation. The method is applicable to a driver parallel connection motor driving system, the parallel-connection output and current sharing of each driver can be adjusted, the derating of driver modules is reduced, and in the condition of low output current of the parallel-connection system, the parallel-connection control method is simplified, and the dynamic performance of the current loop is enhanced.

Description

technical field [0001] The invention belongs to the field of power electronics and motor control, relates to a motor drive system, is widely used in speed regulation of high-power AC motors, and is a current equalization hysteresis loop control method for a driver parallel system. Background technique [0002] In order to meet the increasing requirements of the capacity of the motor drive system, parallel three-phase inverters are used to increase the capacity of the motor speed control system. In practical engineering applications, the common parallel connection method is to directly parallel the output of the AC side of the inverter in series with the current sharing reactor. [0003] In some engineering applications, in order to simplify the system controller and control method, the synchronous PWM control method is used for the parallel drives. The principle of this method is that the current loop control of the parallel system is the same as that of a single drive. The...

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Problems solved by technology

[0006] The problem to be solved by the present invention is: the existing current sharing control method for the driver parallel system has the disadvantages of complex control or poor adaptability, and cannot effectively meet the needs of adjusting the parallel output current sharing of each driver and reducing the derating of the driver module

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