Application of fuzzy fractional order controller in wind power convertor

The three-phase voltage PWM rectifier of direct-drive permanent synchronous wind generator-side rectifier is a strong nonlinear and time-varying system, so the results of conventional PID controller are not very satisfactory. Therefore, this paper proposes a fuzzy fractional order controller based on fuzzy control and fractional order control. Compared with the conventional integer order PID controller, fractional order PI^λD^μ controller adds two adjustable parameters, namely, the integral order of λ and the differential order of μ. The λ mainly affects the steady-state accuracy and the μ mainly affects the system overshoot. It is due to the two degree of freedom increased, the design of the controller becomes more flexible and the performance of the controller becomes more superior. The fuzzy controller can track the error signal and change dynamically the parameters of PI^λD^μ controller. Consequently, the system robustness is improved. In this paper, fractional order PI^λD^μ of the voltage and current are designed separately, which achieve network-side current sinusoidal and phase control, and the output voltage can quickly reach steady-state value. By comparison with the simulation results of conventional PID controller, it can be proved that the controller designed in this paper is effective and superior.