Design of AC Motor's Soft Start Energy-saving Based on Single Chip Microcomputer

The paper analyzes the working principle of asynchronous motor soft-starter,and realizes software and hardware expansion based on single-chip microcomputer Intel-89C51.A interface between human and soft-starter,where the operation data of the motor could be modified has also been added.The power factor measure circuit and the soft-starter's thruster voltage modulator form a close circuit feedback system,by which the single-chip microcomputer can change the motor's terminal voltage according to the load,and make the motor runs under the set power factor.In this way,the asynchronous motor's constant power factor control system is realized,and the energy saving operation is achieved.