Research And Design Of Soft Starter Based On Single Chip

Induction motors have been used widely in all kinds of industrial fields because of their low cost, high reliability and little maintenance. But high starting current often happens when the motor starts. It will accelerate the motor's aging process and lose lots of energy. The very high current will also affect the power network and make the power voltage fluctuant. Therefore, how to improve the starting performance of asynchronous motors has very important economic value.In the paper the theory of soft starting AC motors is deduced based on the analysis of the motor starting process. Five starting methods and four workings about soft starter are compared and analyzed.In this paper a three-phase voltage regulating circuit and harmonics produced by the circuit are analyzed. A model of soft starter system based on voltage regulating is established and simulated with SIMULINK and POWER SYSTEM in MATLAB. Especially the simulation model of asynchronous motor with two-phase stationary reference frame is emphasized. The simulation results are excellent with the simulation system.In the paper the hardware and software design based on 80C196KC single chip is presented. Concrete designs of synchronous circuit, drive circuit, and phase sequence detection circuit are given. It also gives detail program flow diagram of interrupt routines and soft starting method subprogram.In the last part of the paper, debugging for the design system is described. Test waveforms and data are shown and analyzed, which demonstrates the correctness of the system design above.