Power control strategy for grid connected permanent magnet synchronous generator for wave energy harnessing

Abstract

This paper describes the operation and control of a variable speed Well's turbine driven permanent magnet synchronous generator connected 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. In such systems primary aim is to achieve a low distortion, high power quality power export from the converter with the objective to regulate the power flow or power factor optimization. Control schemes are implemented for regulating the dc link voltage for varying input conditions and for regulating the grid current entering the distribution network and hence the power flow into the grid. Response of the system under steady state at balanced/unbalanced, sinusoidal/distorted grid voltage, constant/varying grid frequency and transients such as voltage sag balanced /unbalanced, step variation in input power and under different fault conditions are investigated. In each case the grid current distortion and the dynamic performance of the converter control schemes are evaluated.