间接矢量控制中的转子电阻辨识方法研究

Study on Rotor Resistance Estimation in Indirect Vector Controlled Induction Motor

针对感应电机的间接磁场定向控制系统中转子电阻在低速时大范围变化造成定子电流和电磁转矩脉动严重的问题,依据模型参考自适应理论和瞬时无功功率理论,提出一种基于无功功率参考模型的转子电阻在线辨识方法。辨识模型不依赖于感应电机的定子电阻,对定转子电感和转速的变化鲁棒性好,准确观测转子磁链角,使得定子电流和电磁转矩的脉动减小。将该辨识算法应用于电动轮自卸车调速系统实验平台的感应电机转子电阻辨识,仿真结果表明,较未辨识转子电阻时系统性能得到了较明显改善,转子电阻辨识能够快速收敛于实际值,响应速度快,且对定转子电感的动态变化不敏感,能有效降低转子磁链观测误差,抑制定子电流和转矩脉动,在低速时控制性能提升显著,验证了辨识算法的正确性及其工程实用价值。

To solve problems such as serious stator current pulsation and torque ripple in induction motor control system based on indi- rect field oriented control （IFOC）, which caused by the wide range rotor resistance changing at low speed. A kind of rotor resistance estimation method based on reactive-power reference model （RPRM） is proposed. The mentioned algorithm is constructed by theories of MRAS and instantaneous reactive power. It is independent of the stator resistance, and show high robustness with variable of stator in- duction, rotor induction and rotor speed, therefore, high precision rotor flux estimation, reducing rotor current and electromagnetic torque are achieved. Applying this scheme on the electric wheel dump truck experimental platform and estimates its rotor resistance. Simulations are carried out to verify the proposed strategy based on simulink, and compared to the strategy without rotor resistance esti- mation. Simulation results show that the estimation method improve control performance remarkable. It can achieve high precision and fast track of the rotor resistance dynamic process, and observe the rotor flux with high precision. Thus it can greatly reduce current pul- sation and torque ripple, which verify its practical value.