High Frequency Resonance of a Structure for PV panel

Inhalt:
A high frequency resonance of a structure for a photovoltaic (PV) panel is investigated in this paper. The resonance causes an overvoltage between a power line and a power conditioner (PC) when the structure is struck by a lightning. An effect of the structure impedance on the lightning overvoltage is clarified. The overvoltage increases when the frequency of the lightning current component is close to the resonant frequency of the structure impedance. Although the resonant frequency is an important parameter, there is no generalized formula for its estimation. The structure impedance is calculated by means of a numerical electromagnetic field analysis method, which can take into account the complex configuration of the structure for the PV panel. The transient response to lightning current of the voltage and current are transformed into the frequency domain. The ratio gives the impedance of the structure as a function of frequency. The resonant frequency is obtained from the impedance.