Master-slave control method of high-voltage frequency converter

Abstract

The invention discloses a master-slave control method of a high-voltage frequency converter, and the method is suitable for a control system of the high-voltage frequency converter. The method comprises the following steps: S1, providing a host frequency converter and a slave frequency converter; S2, enabling the host frequency converter to receive a speed instruction sent by a control system andto carry out preliminary processing, and synchronously sending the preliminarily processed speed instruction to the slave frequency converter to synchronously control the speed of the slave frequencyconverter; S3, enabling the slave frequency converter to obtain a slave speed detection value through a slave speed regulator, and feeding back the slave speed detection value to the host frequency converter; S4, enabling the host frequency converter to receive the slave speed detection value and calculate the slave speed detection value according to the host speed detection value and the torque compensation instruction so as to output a compensation result; S5, enabling the host frequency converter to send the calculation result to the slave frequency converter so as to compensate for the torque instruction of the slave frequency converter. The method has the beneficial effect that high-precision synchronous control is realized through speed sensorless vector control.

Description

technical field [0001] The invention relates to the technical field of high-voltage frequency converters, in particular to a master-slave control method for high-voltage frequency converters. Background technique [0002] The high-voltage inverter is a power control device that converts the industrial frequency power supply to another frequency by effectively controlling the on-off of the power semiconductor device. Because the rotation frequency of the driven motor is adjustable, the load can effectively save electricity and achieve the highest work efficiency. [0003] At present, there are many control methods such as constant V / f control, vector control, direct torque control, and speed sensorless vector control of high-voltage inverters. When facing constant torque loads such as belt conveyors and tube belt conveyors, multiple motors are required To jointly drive the same load often requires the master-slave control of multiple frequency converters, so as to realize th...

AI Technical Summary

Problems solved by technology

Due to the lag of the torque response, the speed synchronization accuracy is not high. When starting with heavy load and heavy load, it is easy to cause the belt to stretch or accumulate, and in severe cases, the belt will break, so it cannot meet the requirements of some high-precision synchronous control occasions.

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