一种改进的模型参考自适应多相感应电机转速估计方法

Improved Speed Estimation Method Based on Model Reference Adaptive System for Multi-phase Induction Motor

转速估计是无速度传感器矢量控制系统的关键,其精度将直接影响矢量控制系统的控制性能。将基于电机反电动势的模型参考自适应系统MRAS(model reference adaptive system)方法用于多相感应电机转速估计,对该方法进行了理论推导和稳定性分析。针对输入信号的噪声导致的估算精度降低问题,引入低通滤波器滤除噪声信号,并从理论上分析了其对稳定性的影响。在此基础上设计了变PI参数、变滤波截止频率的MRAS转速估计方法,仿真和实验结果表明优化的转速估计方法具有较好的估计精度和静、动态性能。

Speed estimation is the key to the vector control system ( VCS ) with no speed sensor, and its accuracy has a direct influence on the control performance of VCS. In this paper, the model reference adaptive system ( MRAS ) method based on back electromotive force is applied to the speed estimation of a multi-phase induction motor, and the theoretical derivation and stability analysis of this method are conducted. Moreover, a low-pass filter is introduced to remove the noises of input signals that affect the estimation accuracy, and the effect of the filter on the system stability is analyzed theoretically. On this basis, the speed estimation method based on MRAS is further optimized by changing the PI parameters and cut-off frequency. Simulation and experimental results show that the optimized method is accurate in speed estimation and has satisfying static and dynamic performances.