Adaptive Proportional-Resonant Controller based Reactive Power Control for Wind Energy Conversion Systems

Wind energy conversion systems (WECSs), which are based on permanent magnet synchronous generators (PMSG), typically have a wide range of operating speed. The variations in the generator speed lead to significant deviations in the frequency of the electrical output power. Typically, in this type of WECSs, the power converter needs to control the phase of the current with respect to the phase of the back EMF. Thus, the control system should perform reactive power control over a wide range of frequencies. In order to operate over a wide range of frequencies, advanced synchronizing algorithms are required to generate precise references for reactive power control. In this paper, a three phase reactive power control scheme based on adaptive proportional-resonant (APR) controller is presented. The APR controller adaptively adjusts the coefficients of the digital controller based on the terminal voltages of the machine. This algorithm not only provides wide bandwidth operation of the PR-controller but also helps compensate the harmonic currents injected into the machine. The theoretical analysis of the proposed closed-loop control scheme, which is given in this paper, is supported by simulation and experimental results.