A Comparison of Electric Power Smoothing Control Methods for the Distributed Generation System

Abstract

Renewable energy such as solar energy has collected the attention as alternative sources of fossil fuel. The output power in photovoltaic generation systems changes steeply. The change of the output power has influence on the electric power quality of the power system. For that reason, the system which can smooth the fluctuation of the output power is required. In this paper, the methods of moving average, modified moving average, single exponential smoothing and double exponential smoothing are applied to electric power smoothing control schemes for the distributed generation system with photovoltaic generation. The reduction rate of the power fluctuation and the maximum stored energy of electric double layer capacitors are adopted as evaluation methods of the system. To confirm the effectiveness of the power smoothing control methods, the distributed generation power system with photovoltaic generation systems is simulated by the power electronics circuit simulation software PSIM. Then, the methods are compared by evaluating the reduction in the capacity of electric double layer capacitors without loss in the power smoothing effect.