新型软起动最小转矩脉动的控制策略研究

研究了基于自关断器件的新型软起动。分析了新型软起动的摹本原理和工作特性，给出了软起动系统的数学模型，重点研究了电机起动过程中的转矩脉动问题。在仿真分析电机连接三相系统时定了电压的第一个系统周期内开关时刻与转矩脉动关系的基础上，给出了转矩脉动的控制策略。利用开关时刻计算函数，得到施加电压的最佳开关时刻。按照此开关时刻施加电压，可以减小甚至消除电机起动时的脉动转矩。实验结果证明该方法对于新型软起动是切实可行的。

CONTROL STRATEGY OF MINIMUM TORQUE PULSATION FOR A NOVEL SOFT STARTER OF INDUCTION MOTORS

The novel soft starter based on self-commutated devices was studied. The principle and the performance of the soft starter were analyzed and the mathematical model of was given. The problem of torque pulsation was emphatically discussed. According to the relationship between torque pulsation and the switching point in the first cycle of the stator voltage, the control strategy for eliminating torque pulsation is given when the motor is connected with the three-phase system. Using the switching point function, the optimal switching point is acquired. When applying the voltage to the motor at this point, the torque pulsation is diminished and even eliminated during starting induction motors. The experimental results prove that this method of eliminating torque pulsation is practicable for the novel soft starter.