MultiPhase Permanent Magnet Synchronous Generators for Offshore Wind Enegy System: Control of six phase PMSG- six leg converter system

Abstract

The three phase permanent magnet synchronous generator with full scale converter arrangement has gained significant market share in win energy turbine topology. This is because of the advancement in production of superior magnetic properties and steady decline in price of the magnets. Permanent magnet synchronous generators are of compact in size and light in weight. They become attractive for offshore wind application. But offshore wind energy system has to be not only light weight and compact in size but also reliable operation. The majority of failures of wind turbines are the electrical systems. To increase the reliability of the ordinary three phase wind energy system, a six phase wind energy system is proposed: a six phase permanent magnet synchronous connected to six leg converter. To harness the maximum energy from the wind, the viable option is using variable speed wind turbine. Variable speed operation of drive is achieved by suitable control of generator-converter system.This project deals with the design, simulation and implementation vector control of six phase permanent magnet synchronous generator-converter system. Step by step approach is used to tackle the problem. First the dynamic modeling of six phase permanent magnet in different references frames is studied. Then the time average and switching model of a six leg converter is presented. The different modulation technique of six leg converter is studied. Last the design or tuning of control parameters for the speed and current controllers are done. Dc link voltage control design is also done.After having the theoretical base, the majority of the work is done in preparation of laboratory setup, understanding of FPGA platforms and fighting with sporadic practical problem.Finally, it is of great personal success to be able to model, and control in the laboratory a low speed Non Standard Six Phase PMSG having 33.27 degree separations between the phase groups.