A power smoothing control method for a photovoltaic generation system using a water electrolyzer and its filtering characteristics

• Published in: Electrical engineering in Japan Vol. 206; no. 2; pp. 25 - 32
• Main Authors: Takahashi, Akiko, Goto, Akihisa, Machida, Yuuki, Funabiki, Shigeyuki
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc 01.01.2019
• Subjects: Electric vehicles; Filtration; Frequency control; Fuel cells; Hydrogen; hydrogen storage; load frequency control; Photovoltaic cells; photovoltaic generation; power smoothing control; Smoothing; Solar cells; Step voltage; Variations; water electrolyzer; Water purification
• ISSN: 0424-7760; 1520-6416
• DOI: 10.1002/eej.23191

This paper proposes a novel power smoothing control method for a photovoltaic generation (PV) system using a water electrolyzer (ELY). This method realizes that the long‐period components of the PV power fluctuation are supplied to the power grid and the short‐period components of the PV power fluctuation are supplied to the ELY. The power supplied to the ELY is converted to hydrogen for fuel cell vehicles. The results of the power smoothing control method are evaluated in terms of the power in the load frequency control (LFC) band and the ability of generating hydrogen. Furthermore, filtering characteristics of the proposed method are clarified. As the result, the proposed method has reduced the power in LFC band by 83.7% compared to the PV power without the power smoothing control. The filter characteristics of the proposed method have shown that fluctuating components with periods less than 1000 seconds, in which the step voltage regulator does not perform, can be sufficiently eliminated from the PV power fluctuation components. When applying the proposed method for a PV system rated at 800 kW, the ability of generating hydrogen was about 2.30% of the hydrogen required for one hydrogen station.