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.