Modified One Cycle Controlled Scheme for Single-Phase Grid Connected Pv-Fc Hybrid System

Abstract

AC to DC converters based on one cycle control exhibit instability in current control. In this paper modified one cycle control(MOOC) for bidirectional ac to dc is proposed. The sum of fictitious current and the actual load current is compared with a sawtooth waveform to generate the generating switches. In order to interface the inverter with the grid service of a phase locked loop(PLL) is required. Designing a phase locked loop for interfacing with a weak grid is always a difficult proposition considering the nonidealities like frequency variation and harmonic distortions in the line voltages. Renewable energy is currently widely used one of these resources is solar energy. The pv array normally uses a maximum power point tracking (MPPT) technique to continuously deliver the highest power to the load when there are variations in irradiation and temperature, making it an uncontrollable source. The disadvantage of pv energy is that the pv output power depends on weather conditions and cell temperature further it is not available during night. In order to over these drawbacks alternative source such as proton exchange membrane fuel cell (PEMFC) should be installed in the hybrid system by changing the fuel cell output power the hybrid sources output becomes controllable. Keywods: Maximum power point tracking (MPPT), One cycle control (OCC), Bidirectional ac to dc converter, PV Array, Proton exchange membrane fuel cell(PEMFC).