LAUSR

This paper proposes an efficient power smoothing and fault ride-through control strategy for variable-speed grid-connected permanent magnet synchronous generator (PMSG)-based wind turbine generator (WTG) with supercapacitor energy storage system (SCESS). As WTG installations are increasing, these systems need to have a fault ride-through capability to stay alive during grid faults. As the wind speed is varying, power smoothing is needed as well. The controller proposed has twofold advantage for WTG equipped with SCESS. That is the SCESS is exploited to minimize the short-term fluctuation to have a smooth power profile during normal operation. In addition during grid side fault, the proposed controller stores the generated power from the WTG into the SCESS to ride-through the fault. Two back-to-back-connected three-level neutral-point-clamped (NPC) converters are used for the power conversion. The system model and the control strategy have been developed for the NPCs, the buck-boost converter and the variable-speed WTG system. The real time digital simulator (RTDS)-based results conducted on 2 MW/4 kV PMSG verify the effectiveness and superiority of the proposed controller.