单位功率因数的内馈斩波串调系统研究

Research on Unity Power Factor Inner-feed Chopper Cascaded Speed-adjusting System

提出一种基于PWM整流技术的内馈斩波串级调速系统。它采用IGBT代替晶闸管,并利用PWM整流技术,使网侧电流接近于正弦波,甚至可向网侧提供容性无功,以补偿串级调速系统产生的感性无功,因此可大大提高系统的功率因数,减少网侧谐波含量。文中介绍了PWM整流技术的工作原理和控制策略。通过仿真和实验进行了验证。

The conventional cascaded speed-adjusting system has some disadvantages of low power factor and much harmonic,so it is limited in some industrial field.A new cascaded speed-adjusting system scheme based on PWM technique is proposed in this paper.SCR is substituted with IGBT and PWM technique can be used in this new scheme. Sine wave current can be gotten.At the same time,harmonic can be reduced,too.h can also provide capactive reactive power to compensate inductive reactive power which the conventional cascaded speed-adjusting system produces.So it can improve power factor and reduce harmonic of system.The control strategy is introduced in this paper,some experiment results and simulation prove the scheme is completely realizable.