Real-time estimation of areal output power of photovoltaics under Japanese smart grid system

As the amount of photovoltaic systems in distribution system increases, the need to grasp areal photovoltaic output power increases. Assuming Japanese smart grid system, this paper proposes a method to estimate areal photovoltaic output power of distribution system in real-time using smart meters, a pyranometer, and IT switches. By using 30 minute integrated areal photovoltaic output energy obtained by smart meters, the proposed method can perform estimation accurately throughout the year. Also, to track fast fluctuations of photovoltaic output power, the proposed method estimates low and high frequency components separately. To apply frequency classification in real-time, the proposed method uses a frequency classification method using a sliding window and linear fit. Simulations were performed using real measured data, and the proposed method was able to improve a previously proposed method and estimate areal photovoltaic output power with root mean square error less than 4% of the system capacity.