A Solar-Wind Energy Source Interface with the Public Grid: Design and Implementation
The challenges of interfacing the renewable energy sources with the public grid, are the higher injected power, inverter switches overheating, the misalignment switching instants of the inverter and synchronizing the inverter output with the public grid. This paper presents a complete design for a current link PWM for a renewable energy sources connected to the grid. A battery bank in parallel with a full wave rectifier are used for driving the inverter. An appropriate value of the DC link inductor has been calculated and implemented. A power MOSFTs CSI is designed and implemented. The proposed circuits provide an efficient electrical isolation between both digital and the power sides. The CSI has driven by a space vector PWM. Constraint of the CSI current continuity is hardware fulfilled using the inverter drive circuits. A temperature compensator has been designed for reducing the ON times of the PWM when the MOSFET temperature rises. Interface circuits for adapting both the DC link and the mains line voltages as well as the DC link current to the logic level have been designed and implemented.