A comparative study on variable-speed operations of a wind generation system using vector control

Abstract

This paper presents a comparison study among three control methods based on vector control for maximising the output power and improving the performance of a small-scale wind generation system (WGS). The three control methods are a hysteresis-band current controller (HBCC), a PI current controller (PICC) and an improved PI current controller (IPICC) which is based on particle swarm optimisation (PSO). The WGS investigated in this research consists of a permanent magnet synchronous generator (PMSG) directly driven by a vertical-axis wind turbine (VAWT), a current controlled PWM rectifier, and a stand-alone DC load. The principle of maximum power point tracking (MPPT) is to adjust the rotational speed of a wind turbine at optimal speeds that ensures optimal tip-speed ratios (TSR) and maximum power coefficients over a wide range of wind speeds. Simulations are based on actual parameters which are obtained experimentally from a real wind turbine generator system. The simulation results show the effectiveness of the IPICC method compared with the HBCC and PICC methods due to its satisfactory dynamic responses with fast MPPT under wind speed variations.