Xia Changliang

Fuzzy Logic Based Adaptive PID Control of Switched Reluctance Motor Drive

The severe nonlinearity of switched reluctance motor (SRM) make it hard to get a good control performance with the conventional PID controller. Therefore, in this paper, fuzzy logic based adaptive PID control strategy is developed. According to the error and change-in-error in the transient period, parameters of the adaptive PID controller are tuned on online according to fuzzy logic tuning rules which are summarized from the experts control knowledge and operators experience. Fuzzy logic based adaptive PID controller has the merit of both fuzzy controller and PID controller. It has the advantage of flexibility, adaptive, expert knowledge based, robustness, model free and high control precision. Experimental results demonstrate that a good control performance is achieved. The system responds quickly with little overshoot. There is no error at steady state. The system shows a strong ability to reject disturbance and a strong characteristic of robustness.

Direct power control for three-level PWM rectifier based on hysteresis strategy

This paper presents a mathematical model of three-level voltage PWM rectifier, and derives a power control model from the theory of instantaneous power. In the vector-space, the influences on instantaneous power exercised by all the switching vectors are studied and illustrated separately, then a direct power control (DPC) scheme for three-level PWM rectifier which uses multistage band hysteresis comparator is proposed, and a novel switching table is designed. Meanwhile, the neutral-point voltage unbalance is inhibited by selecting the redundancy switching states of small voltage vectors. Simulation and experimental results show that the proposed strategy can not only stabilize the DC bus voltage but also realize the unity power factor operation and the balance of neutral-point voltage. Moreover, the proposed method can improve the performance of the three-level rectifier.

An Application of Fuzzy Logic Controller for Switched Reluctance Motor Drive

This paper develops a fuzzy logic controller (FLC) for the speed control of switched reluctance motor (SRM) drive. The advantage of this method is that the proposed FLC has the characteristics of robustness, nonlinearity and facility to take advantage of human control knowledge. In this paper, the inputs and output of the FLC are described. Also, the principles of the fuzzy logic control are given. The universe of discourse of error, error in change and output are given. The control rule base in the form of linguistic rule is given. The control rule surface is given. The experimental tests are carried out for the proposed FLC. The experimental results demonstrate that the proposed FLC presents a better performance than the conventional PID controller.