Vector oriented control of voltage source PWM inverter as a dynamic VAR compensator for wind energy conversion system connected to utility grid

Abstract

This paper presents analysis, design, and simulation for vector oriented control of three-phase voltage source pulse-width modulation (PWM) inverter which aims to optimize the utilization of wind power injected into the grid. To realize this goal, a digitally controlled converter-inverter system is proposed which provides economic utilization of the wind generator by insuring unity power factor operation under different possible conditions, and full control of active and reactive power injected into the grid using a digitally controlled voltage source inverter. The wind energy conversion system (WECS) is represented by three -phase self-excited induction generator (SEIG) driven by a variable-speed prime mover (VSPM) such as a wind turbine for the clean alternative renewable energy in rural areas. Mathematical models for both the converter and inverter are presented and simulated. A vector oriented control scheme is presented in order to control the energy to be injected into the grid. Closed-loop control of the converter/inverter utilizes a conventional proportional integral (PI) controller. In order to examine the dynamic performance of the system, its model is simulated and results are analyzed. Simulation results for different disturbance conditions show good performance of this proposed control algorithm. The simulation results are given using MATLAB7/SIMULINK program. Experimental results using DSpace-1104 confirm that the good performance of the proposed control system and agree with the simulation results to a great extend.