Control of a direct-driven permanent magnet synchronous generator-based wind turbine to achieve maximum wind-power extraction

摘要

Wind energy has recently become the most cost-effective and environmentally friendly amongst other renewable energy resources. However, since wind resource is intermittent in nature, the wind power output is inconsistent. Therefore, a control system needs to be implemented to ensure that maximum power is extracted from the wind resource at a wide range of wind speeds to optimize the performance of the wind turbine. This paper deals with the control of the rotor speed of a 2MW direct-driven permanent magnet synchronous generator to perform maximum power point tracking (MPPT). Vector-oriented control technique is used to control the machine-side converter and the types of controllers used are the phase-lead, phase-lag and lead-lag compensators. The proposed wind energy conversion system was implemented in PSIM software and the control system modelling has been carried out in MATLAB using bode plots and step-response curves. The overall system's performance analysis and validation were carried out by simulation. The results obtained show that the MPPT controller enabled the power generated by the WT to closely track pre-determined optimal power curves. This shows that MPPT was ensured when the wind speed was less than the wind turbine's rated wind speed.