A novel configuration and control of CSI wind energy system with diode rectifier and buck converter

This thesis is dedicated to the research of a new converter configuration and control scheme development for direct drive permanent magnet synchronous generator (PMSG) based high power wind energy conversion system (WECS). The proposed converter consists of a diode rectifier, a buck converter and a pulse-width modulated (PWM) current source inverter (CSI). Detailed feasibility study of the proposed configuration is conducted based on the theoretical analysis. A suitable control scheme is designed to optimize the system performance. The maximum power point tracking (MPPT) is achieved through duty cycle adjustment of the buck converter, while the reactive power delivery and the DC current regulation are realized by the CSI controller through manipulating modulation index and delay angle. More importantly, the DC current is evaluated and controlled to the minimum value at various operating conditions. Simulation of a 2 MW WECS is carried out in Matlab/Simulink to verity the control objectives of MPPT, power factor adjustment and DC current minimization. The simulation results prove the feasibility of the proposed system that serves as an attracting alternative for high power WECS.