A Proposed Strategy for Power Management of a Standalone Wind Energy Conversion System with Storage Battery
Several strategies have been suggested to optimize power extracted from the Standalone Variable Speed Wind Energy Conversion System (SVSWECS) using a Squirrel Cage Induction Generator (SCIG). Where, many of them use the battery as a storage unit for future use. However, the latter is assumed as an ideal component and that no maximum charging or critical limit. With the considered strategy, the generated wind power can be managed using a fast and reliable fully rugged electrical control. Indeed, the use of reliable Power Management and Control (PMC) algorithm where the battery current is well controlled. However, this solution allows maintaining the system operation in two stable modes.
The considered system consists of an SCIG connected mechanically to the wind turbine through a gearbox, and electrically through a PWM rectifier to the DC bus capacitor, the latter is connected to the load and the battery through a PWM inverter and buck-boost converter respectively. In this paper, to approach the system to reality, a new PMC is proposed using a purely reliable electrical control. The Direct Torque Control (DTC) is used. The latter is combined with the Maximum Power Point Tracking (MPPT) technique and the State Of Charge (SOC) of battery. The important key of the proposed control strategy are the SOC and the sign of the difference between the generated and the demanded powers. The obtained simulations results are assessed and carried out using MATLAB/Simulink package and show the effectiveness and the performance of the proposed algorithm.