用单片机控制异步电动机串级调速系统提高功率因素的研究

Study of Improving Power Factor for Induction Motor Cascade Drives Contrelled by Single-Ship Computer

绕线式异步电动机可控硅串级调速普遍采用一台升压变压器,起动采用频敏电阻,但仍未解决系统功率因数低的问题。本文研究了采用单片机8031控制晶闸管串级调速系统,以改善系统的功率因数的可能性,并在一台改制的YZR-160M2型7.5kW绕线式电机上进行了试验。试验结果证实,所提出的方案是经济实用和可靠的,调速范围可达3.5:1以上,功率因数得到改善,从而为中、小型绕线式电机调速驱动提供了一条新途径。

At present, a step-up transformer is widely used in the wound-rotor induction motor thyristor cascade drives, and a starting resistor is often used in the rotor circuit, But the lower power factor in the system ha not been solved yet. A feasibility study due to raise the rotor voltage of medium and small size induction motors has been made and a high performance 8-bite single-chip computer 8031 has been adopted to control 8-thyristor cascade drives. The testing results on a YZR-160M2 7.5kW wound rotor induction motor show that this system is reliable, in addition to its lower cost and the range of speed-control is more than 3.5:1. Moreover the power factor is improved. So that, a new way has been provided for the speed-control of medium and small size induction motors drives.