Analysis of the Stability of Speed Adaptive Observer and Its Design for Induction Motor Drive at Low Speeds

作者：Li, Xiaojun; Yang, Shuying^*; Cao, Pengpeng; Ma, Mingyao

来源：Transactions of China Electrotechnical Society, 2018, 33(23): 5391-5401.

DOI：10.19595/j.cnki.1000-6753.tces.171558

• Adaptive observer
• Damping characteristics
• Equivalent Transfer Functions
• Full-order flux observers
• Induction motor drive
• Low speed
• Speed estimation
• Weighting coefficient

Although full order flux observer is widely used in induction motor drive for speed estimation, the problem of stability, especially in low-speed regenerating mode still has not been solved very well, resulting in limited operation performance in low-speed range. Based on the equivalent transfer function built in this paper, the reason for unstable operation is exposed, and the corresponding unstable region is identified quantitatively. To improve the operation performance at low speeds, a novel speed adaption scheme, i. e. error weighting adaption, is proposed. In this scheme the magnetizing component of the stator current is introduced into the adaption process directly, and the performance can be ensured by proper design of the weighting coefficient. Through root locus analysis, the low-speed stability of the proposed error weighting adaption observer scheme is demonstrated, and through the comparison analysis, the better damping characteristics and converging process brought by this error weighting adaption observer are clarified. At last, the validation of the scheme and the correctness of the theory analysis are confirmed through simulation and experiments on 4kW induction motor.

• 出版日期2018
• 单位合肥工业大学