6 Kv High-voltage Motor Soft Starting System Design And Research

In the industrial field more and more high-voltage AC motor has been applied inhigh-power overload. But High-power AC motor will produce a large number ofserious problems when started directly, there will be a sudden sharp decline in thegrid voltage, which causes that other electrical equipment in the power system can‘toperate normally. An impact on the current cause the motor overheating, endangeringthe life of the motor.Hard-Starting will produce a very large starting torque, whichcauses a great deal of mechanical impact to the device and load, and causes damage tomachinery and equipment itself as well as shafts, gears and other precisionequipment.Hard-Starting will produce a lot current which will causes electromagneticinterference and interrupt to the electrical instrument around.This article study with motor soft-start which is controlled by SCR, the startingand protecting of the motor is controlled by Microcontroller, the Microcontrollercontrols phase angle of SCR to trigger it so as to reduce the voltage of the motor. Andthen according to the change of phase angle to add the voltage, making the currentand the tongue of the High-voltage motor being changed according to the ruled route,until the motor runs as normal speed.The design of software and hardware of high voltage motor is completed, studywith the principle of the SCR soft starter, including the principle of lowing-voltagestarting of asynchronous motor and the principle of how to use phase-shift of SCR toregulation the voltage of the motor. Resolve the electrical isolation of the high-voltagepart and the low-voltage part. Resolve the balance of the voltage among the SCRwhich are serried. In the article, we use fuzzy PID control strategy to achieve aclosed-loop control with the sampled current, and use a variety of electronic circuitsto protect the start-process of the high-voltage motor, achieved to start thehigh-voltage motor started with non-current-impact and little torque oscillation.Finally using Matlab/Simulink tools to simulate the current and torque of themotor when starting, Compared Directed start with Soft-start of High-voltage motor, verified that soft-start can effectively reduce the starting current of motor, increase thetorque of motor, and has achieved the anticipation of the study.