An improved approach to reduce harmonics in the utility interface of wind, photovoltaic and fuel cell power systems

In this paper, an improved approach to reduce harmonics in the utility interface of wind, photovoltaic and fuel cells power systems is presented. The approach is based on circulating third harmonic current injection to reduce utility line current harmonics in SCR converters. In this paper, a new injected current shape is computed from analysis to achieve sinusoidal utility line currents. A controllable single switch boost converter connected in shunt is employed to circulate the new injected current shape. A method to implement the proposed approach under varying load conditions is shown. Analysis, design, limitations, simulation and experimental result are presented.