鼠笼感应电动机离散变频软起动研究

Research on Soft-starter Based on Discrete Frequency Technology

针对鼠笼感应电动机全压起动时电流大、转矩小的缺点,在不改变电子式软起动器硬件基础上,研究一种离散变频技术,优化电机起动性能。对传统离散变频策略进行优化,采用恒压/频比和等效正弦相结合的控制策略,基于MATLAB/Simulink搭建仿真模型,分别对直接起动、基于固定触发角起动、基于等效正弦变换起动和利用四分频半波替换等效正弦变换起动进行仿真研究,利用四分频半波替换等效正弦变换起动明显降低了电压谐波含量,仿真结果证实改进的离散变频策略优化了起动性能。

When induction motor starts at full pressure,the electric current is large and the torque is small.Aim to solve these disadvantages,the discrete frequency conversion technology was researched to optimize starting performance of motor but not change the hardware of the electronic soft starter.The traditional discrete-frequency control strategy was optimized.A control strategy combining constant voltage/frequency ratio and equivalent sinusoidal transformation was adopted.Simulation model was built by MATLAB/Simulink.The direct starting,the starting based on fixed firing angle,the starting based on equivalent sinusoidal transformation and the starting using a four-way half-wave replacement equivalent sinusoidal transformation were researched by simulation.Harmonic content decreases obviously.The results confirm that the proposed discrete frequency strategy optimizes the starting performance.