一种新型搜索电机转子频率的方法

摘要

针对高压变频调速系统,提出了一种新型的“飞车起动”控制算法.该算法无需配置电压互感器及转速传感器,仅由定子电流幅值的大小即可快速搜索出旋转电机的转速.为了实现该功能,推导了维持定子电流恒定时,定子电压与输出频率、电机转速之间的稳态数学表达式,证明了定子电流与电机估计转速之间具有单调递增的函数关系,并获得了该函数关系成立的限制条件.在此基础上,在搜频过程中,算法根据设定的规律动态改变变频器的输出频率,提高了电机转子频率搜索的快速性和准确性.仿真结果验证了理论分析的正确性和所提方法的有效性.%A new method of searching rotor speed without voltage or speed sensor was proposed.The method searched the rotor speed according to the magnitude of the stator current.The steady-state mathematical expression between the stator voltage,the output frequency and the rotor speed was deduced which kept the stator current constant.Then the monotonicity between the current magnitude and the estimated speed under the certain conditions could be found.A searching strategy of changing the output frequency according to the given laws was proposed,which improved the rapidity and the accuracy of the searching process.The simulations verified that the theoretical analysis and the proposed method were correct and effective.