Design, analysis and simulation of a new current controller for wind power generation system using proportional plus resonance control.

Abstract

This thesis presents design, analysis and simulation of a new current control scheme for wind power generation system (WPGS). Proportional plus resonance (PR) controller is proposed to improve the accuracy of the control loop. Adding a current sensor at the capacitor filter instead of the damping resistor, the proposed two-current loop controller overcomes the instability of the system caused by the LCL filter and minimizes the power loss on the damping resistor (usually 0.8% of rated power). When the impedance of the grid is changing, the proposed current controller still keeps system stable with phase margins more than 45 degree. Moreover, using the proposed current controller, voltage transient characteristics of WPGS are analyzed and a control scheme is introduced to meet the low-voltage ride-through standard. All analysis and evaluation have been conducted for a 250kW WPGS with 208V grid voltage.