Chul-Hwan Kim

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A photovoltaic (PV) system's output power fluctuates according to the weather conditions. Fluctuating PV power causes frequency deviations in the power utilities when the penetration is large. Usually, an energy storage system (ESS) is used to smooth the PV output power fluctuations and then the smoothed power is supplied to the utility. In this paper, a(More)
In recent years, focus has been on environmental pollution issue resulting from consumption of fossil fuels, e.g., coal and oil. Thus, introduction of an alternative energy source such as solar energy is expected. However, insolation is not constant and output of photovoltaic (PV) system is influenced by meteorological conditions. In order to predict the(More)
In recent years, introduction of an alternative energy source such as solar energy is expected. However, insolation is not constant and output of photovoltaic (PV) system is influenced by meteorological conditions. In order to predict the power output for PV system as accurate as possible, it requires method of insolation estimation. In this paper, the(More)
From the perspective of global warming mitigation and depletion of energy resources, renewable energy such as wind generation (WG) and photovoltaic generation (PV) are getting attention in distribution systems. Additionally, all electric apartment houses or residence such as dc smart houses are increasing. However, due to the fluctuating power from(More)
In recent years, introduction of an alternative energy source such as solar energy is expected. However, insolation is not constant and the output of a photovoltaic (PV) system is influenced by meteorological conditions. In order to predict the power output for PV systems as accurately as possible, an insolation estimation method is required. This paper(More)
Recently, renewable energy technologies such as wind turbine generators and photovoltaic systems have been introduced as distributed generation. The connection of a large amounts of distributed generation causes voltage deviation beyond the statutory range in distribution system. In this paper, we propose a methodology for voltage control using tap changing(More)
Nowadays, wind turbine generator (WTG) is increasingly required to provide control capabilities regarding output power. Under this scenario, this paper proposes an output power control of wind farm (WF) using pitch angle control connected to small power systems. In this control approach, WF output power control is achieved by two control levels: central and(More)
Many isolated small power systems are powered by diesel generators, which results in greater operating costs than interconnected large grids. It is therefore desirable to integrate renewable energy sources such as wind power into these small grids. However, due to the fluctuating power generation from renewable energy sources, frequency deviations of power(More)
A Photovoltaic (PV) systempsilas power output is not constant and fluctuates depending on weather conditions. Fluctuating power causes frequency deviations in the power utilities when PV power penetration is large. Using a battery is the common practice to smooth PV output power fluctuations. In this paper, we propose a new and simple fuzzy based control(More)
In recent years, distributed generation (DG) and renewable energy source (RES) are attracting special attention to distribution systems. RES such as photovoltaic (PV) system are used as a source of green energy. However, the large amount of distributed generation causes voltage deviation beyond a statutory range in distribution systems. This paper proposes(More)