Keywords: wave energy conversion, permanent magnet synchronous generator, PMSG, fully controlled frequency converter, power control, oscillating water column, OWC, Wells turbine, distributed generation, wave power, modelling
Power control strategy for grid connected permanent magnet synchronous generator of a distributed generation unit
This paper describes the studies on the operation and control of a variable speed wave energy conversion system. The wave energy conversion system considered is oscillating–water–column (OWC) based Wells turbine driven permanent magnet synchronous generator connected to the grid by means of fully controlled frequency converter. 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 optimisation. In this paper wave energy conversion system is modelled and 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 is investigated under steady state, dynamic and transient conditions. In each case the grid current distortion and the dynamic performance of the converter control schemes are evaluated.