Synchronverter based grid connected voltage source converters for renewable energy systems

Abstract

To control the environmental crisis and fulfill the power requirement, distributed gener ation (DG) is emerging as a viable option. Photovoltaic (PV) generation is a widely used solar energy application for electricity generation. Distributed PV generation uses voltage source converters (VSCs) to supply power to the grid. The VSCs are controlled by either voltage or current control depending on whether the DGs are operating in the islanding or grid-connected mode. Due to the intermittent and uncertain behaviour of renewable energy sources (RESs), many challenges are present in system operation. However, when the pen etration of DGs reaches to a certain level, it may affect the stability of the grid as it reduces the overall inertia of the power grid. Therefore, it is desirable that if DGs behave like a synchronous generator (SG), it will be helpful in power regulation of the grid. Avirtual synchronous generator (VSG) is one of the promising solutions today for inte gration of renewable energy sources to the grid, which provides the virtual inertia function. In this thesis, the synchronverter control scheme is taken as a VSG model.