Loss-based investigation and hybrid compensation of parameter variation effects on control of permanent magnet synchronous motors

In this paper, saturation and temperature variation effects on control of permanent magnet synchronous motors are investigated in terms of motor loss on different control methods including unity power factor, maximum torque per ampere, and loss minimization. Afterwards, a hybrid compensation method is proposed to improve the response time to reach maximum efficiency point. In the proposed method, to improve the response time to reach maximum efficiency point, initial value of optimum operating point is determined via model-based method. Then, based on perturb and observe method, d-axis reference current is changed step by step. Next value of d-axis reference current is determined via measuring direction of dc-link power variation. Also, the proposed hybrid method is compared with a conventional search-based method under different parameter variation and step load and reference speed implementation. The proposed hybrid compensation algorithm has been experimentally implemented and proved to be a practically useful method to improve the response time to reach maximum efficiency point under parameter variation and also under load and speed variation.