Stand-alone systems using renewable energy sources, such as wind energy and photovoltaic (PV) energy with storage battery banks are commonly used to supply remote houses. Stand-alone hybrid wind-PV system with battery storage is considered in this paper. It is proposed to employ squirrel-cage induction generator (SCIG) in wind subsystem. Pulse-width modulation (PWM) rectifier is used to control the SCIG. The proposed control scheme employs the direct torque control (DTC) strategy to modulate the ON / OFF durations of the switching devices of the PWM rectifier to ensure maximum power extraction through the SCIG operation. Furthermore, the control scheme rids the proposed system from the need of dedicated external capacitors for exciting the SCIG. Instead, the required reactive power of the SCIG is provided by the switching of the PWM rectifier. Simulation results are provided in the paper to demonstrate the capabilities of the system. |
