大容量同步电动机的软起动控制

为了减小大容量同步电动机起动电流并缩短起动时间，提出用恒剩余角控制方法代替恒超前角控制方法，分析了恒剩余角数字控制系统中的一些主要问题： 稳定性、转子位置信号生成、逆变器控制及励磁控制，并给出了解决方法。用在线辨识方法获得的电机参数计算换流超前角，提高了计算的准确性。设计制作了一台７．８ Ｍ Ｗ 同步电动机软起动的数字控制系统。分析和现场运行表明，采用恒换流剩余角控制是减小起动电流并缩短起动时间的有效方法

Soft start control of large-capacity synchronous motor

Soft start with thyristor ac dc ac converter is a dominant starting method of large capacity synchronous motors at present. Constant lead angle control is replaced by constant margin angle control to reduce start current and start time. Some key problems in constant margin angle digital control system were analyzed such as stability, rotor position signal forming and control of inverter and excitation, also their solutions were presented. Motor parameters obtained with on line identification were used to calculate the lead angle, thus its accuracy was raised. A digital control system of a 7.8MW synchronous motor soft start was set up. Both analysis and operation show that the constant margin anlge control is an effective way to lower start current and shorten start time.