Power Control Strategy for Grid Connected variable speed Permanent Magnet Synchronous Generator

Vol.3 No.1

Year: 2009

Issue: Jul-Sep

Title: Power Control Strategy for Grid Connected variable speed Permanent Magnet Synchronous Generator.   

Author Name: Vinatha U, K P Vittal   

Synopsis:   

This paper describes the operation and control of a variable speed Well’s turbine driven permanent magnet synchronous generator connected to the grid. The generator is interfaced to the grid  by means of fully controlled frequency converter which consist of a PWM rectifier, an intermediate dc circuit and a PWM inverter through a LCL filter. Power flow into the grid can be controlled regulating the grid current. Control is achieved in two stages namely by regulating the dc link voltage and then regulating the grid current entering the distribution network. This  is realized by coordinated control of generator side converter and the grid side converter. Although current and voltage control schemes are possible, current control principle is used for its excellent dynamic characteristics. The  performance of the control schemes are evaluated based on  their steady state and dynamic response characteristics, harmonic distortion of the output currents and the quality of power injected to the grid. Response of the system  under steady state and dynamic conditions are studied. Also the behavior  with varying input conditions and with grid voltage distortions are analyzed. Various fault conditions are also  investigated. In each case the grid current distortion and the dynamic performance of the converter control schemes are evaluated.