Safety Analysis of Grounding Resistance with Depth of Water for Floating PVs
Jae Woo Ko,
Hae Lim Cha,
David Kwang-Soon Kim,
Jong Rok Lim,
Gyu Gwang Kim,
Byeong Gwan Bhang,
Chang Sub Won,
Han Sang Jung,
Dong Hyung Kang,
Hyung Keun Ahn
Affiliations
Jae Woo Ko
Department of Electrical Engineering, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Korea
Hae Lim Cha
Department of Electrical Engineering, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Korea
David Kwang-Soon Kim
Department of Electrical Engineering, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Korea
Jong Rok Lim
Department of Electrical Engineering, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Korea
Gyu Gwang Kim
Department of Electrical Engineering, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Korea
Byeong Gwan Bhang
Department of Electrical Engineering, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Korea
Chang Sub Won
Power Conversion R&D Center, LS IS Co., Ltd., LS-ro 116 beon-gil 40, Dongan-gu, Anyang-si 14118, Gyeonggi-do, Korea
Han Sang Jung
Water Facility Research Center, K-Water Institute (KWI), 125, 1689 beon-gil, Yuseong-daero, Yuseong-gu, Daejeon 34045, Korea
Dong Hyung Kang
Operation & Management Team, K-Water Institute (KWI), K-Water Hapcheon Dam Office, 705, Hapcheonhosu-ro, Yongju-myeon, Hapcheon-gun 50215, Gyeongsangnam-do, Korea
Hyung Keun Ahn
Department of Electrical Engineering, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Korea
Underwater grounding methods could be applied in deep water for grounding a floating PV (photovoltaic) system. However, the depth at which the electrodes should be located is a controversial subject. In this study, grounding resistance was measured for the first time by analyzing the water temperature at different water depths in an area where a floating PV system is installed. The theoretical calculation of the grounding resistance has a maximum error range of 8% compared to the experimentally measured data. In order to meet the electrical safety standards of a floating PV system, a number of electrodes were connected in parallel. In addition, the distance between electrodes and number of electrodes were considered in the test to obtain a formula for the grounding resistance. In addition, the coefficient of corrosion was obtained from an electrode installed underwater a year ago, and it was added to the formula. Through this analysis, it is possible to predict the grounding resistance prior to installing the floating PV system. Furthermore, the electrical safety of the floating PV system could be achieved by considering the seasonal changes in water temperature.
