基于DSP的异步电动机离散变频软起动系统

摘要

针对电机的输出电磁转矩跟供电电源频率成反比，在不改变传统软起动系统主电路结构的基础上，通过有选择地控制晶闸管的导通和关断，使得一些工频半波导通或是不导通，对加在电机定子端的电压实现离散变频，使得基波频率发生变化，通过降低电压频率使得输出起动转矩增大。利用DSP高速数据处理能力，设计制作了离散变频软起动控制系统的实验装置，通过仿真试验和实验数据结果，验证了离散变频软起动在重载起动情况下的可行性和实用性。%The output torque of the motor is inversely proportional to the power supply frequency,without changing the traditional soft start system on the main circuit structure,transistors can be selectively controlled to be turned on and off,thus some half-wave frequency is guided or not. The voltage applied to the motor stator is discrete,so that the frequency of the fundamental wave changes and the starting torque is increased by reducing the voltage frequency. Using the DSP high-speed data processing capability,the experimental device of the discrete variable frequency soft start control system is designed. The feasibility and practicability of the discrete variable frequency soft starting in the heavy load starting is verified by the experimental results of the simulation experiment and experimental device.