Power Optimization of Wind Electric Conversion Systems Integrated into the Utility Grid

Abstract

This paper is concerned with the interconnected operation of WECS with the utility grid.Specifically ,it addresses problems of stability , protection and power flow optimization from the WECS to the power lines. The approach followed contains both a theoritical and a experimental component.A variable-speed constant-frequency wind electric system utilizing a synchronous generator and line-commutated inverter provides experimental verification of computer simulation studies for the dynamic and steady-state performance of the interconnected system. Simulation results indicate that the transient bahavior of the wind electric-power grid system is satisfactory with appropriate devices providing adequate protection to both the wind generator and the utility grid from a variety of fault conditions. A maximum power tracking mechanism has been designed for the continuous matching of the wind-electric generator to the grid impedance characteristics.As a result,maximum electric power is transferred from the wind machine to the power lines.Computer simulation studies of this type of operation indicate the substantial improvement in power transfer that is achieved. The proposed scheme tends to minimize equipment and maintenance costs while maximizing the energy transfer capabilities of the wind-electric conversion system and maintaining a high degree of reliability in overall system performance.