Implementation of distributed photovoltaic power supply systems

Photovoltaic power systems are based on photovoltaic or solar modules which are very reliable and do not require any fuel or servicing. The object of this paper is to investigate power converter topologies and control techniques for a photovoltaic power supply system with parallel operation. All the modules have the same control configuration and each module includes inner current loop and outer voltage loop control in the proposed system. The system controller is based on a DSP and achieves the double loop control by using deadbeat control theory. Only two proportional controllers are required to implement the proposed control for the system with excellent output characteristics. The control is simple and effective with the easy program development. Instantaneous current sharing control is used to achieve the equal current distribution by a current sharing bus and ensure a fast dynamic response, equal load sharing capability and eliminates the circulation current. Simulation and experimental results verify the system performance.