A Review on Wind Energy Conversion Systems (Wecs) Generators

Wake effects cause the wind turbine generators (WTG) in a wind power plant (WPP) to produce different levels of active power and subsequent reactive power. In addition, the impedance between a wind turbine and the point of interconnection (POI) -which depends on the distance between them- affects the reactive power injection capacity from the WPP to the POI. This work proposes a voltage control scheme for a WPP based on the reactive power available from doubly-fed induction generators (DFIG) and its effects on the POI to improve the reactive power injection of the WPP. This article proposes a design strategy for changing the DFIG controller gain and examines the comprehensive properties of these control gains. In the proposed scheme, the WPP controller, operating in the voltage regulation mode, sends the control signal to the DFIGs according to the voltage difference at the POI. DFIG controllers, operating in voltage regulation mode, use a proportional controller with a limiter. The proportional controller gain is adjusted according to the available reactive current of the DFIG and the series impedance between the DFIG and the POI. The performance of the proposed scheme is validated for various faults, such as reactive load connection and network faults, using an EMTP-RV simulator. The simulation results show that the proposed scheme quickly restores the POI voltage by injecting more reactive power after a fault than the conventional scheme.