Autonomous Voltage Fluctuations Control of Distribution System by Available Reactive Power of Fuel Cell Cogeneration System

Abstract

Fuel cell cogeneration system has enough potential to control voltage fluctuations during day time. Hence, this paper presents a method for suppressing voltage fluctuations by controlling the reactive power output of fuel cell cogeneration system. The amount of reactive power for voltage control is decided based on the variation of the active power output of photovoltaic generation. However, the effectiveness of suppressing voltage fluctuations depends on conditions of the distribution system. In the method, the automatic gain tuning control is applied to generate appropriate reactive power for voltage control depending on conditions of distribution system. In the paper, the effectiveness of the proposed method to reduce the number of Load Ratio control Transformer operation for controlling voltage fluctuations is demonstrated by the simulation of distribution system model based on feasible cases.