摘要
该电流型可控硅交流电机调速电源,采用150°导通角,具有低百分比的高次谐波,优于120°导通角的调速电源。主电路采用可控硅整流和辅助可控硅关断的三相桥式逆变器。逆变主触发信号由单板机控制,并与同步脉冲列相“与”而成,较好地解决了脉冲变压器的饱和问题。实验所得的电流波形经谐波分析证明了预期的效果。本电源用于交流电机的调速,可以降低电机的损耗。
As a new SCR source for the speed control of AC motor, the current-typeinverter developed with a conducting angle of 150°and low percentage of hig-her-order harmonics has been proved superior to those with a conducting ang-le of 120°. The main circuit consists of several thyristors and a 3--phase bridgeSCR inverter with a set of auxiliary SCR for turn-off purpose. A sigle--boardmicrocomputer is used to control the main triggering signals come from inve-rter, and these signals are in combination with a synchronous pulse train thro-ugh the AND function. In this way the saturation problem of pulse transfor-mer can be well solved. The current waveform, as the result of experiments,is proved in expectation through harmonic analysis. Using this new sourceto the speed control of an AC motor will reduce its losses with high efficiencyavailable.
