Abstract
Photovoltaic energy generation has become a popular renewable alternative to conventional energy generation that utilise fossil fuels. However, given the diversity and complexity of these PV plants, it is imperative that such plant equipment be protected against the greatest contributor to equipment failure; surges. Software simulation using EMTP-RV version 3.3, this paper implements a proposed methodology for the insulation coordination study of a PV plant. The overvoltages associated with the opening of vacuum circuit breakers, at various test points along the network are considered in order to recommend possible selection criteria of surge arresters as well as location thereof. The study finds that for a reduction of surge magnitudes from 8 p.u to within 1.2 p.u would require surge arrester energy capabilities to be greater than 2.8 kJ/kV for the medium voltage (MV) arresters , and capabilities exceeding 259kJ/kV for the low voltage (LV) arrester. For the high voltage (HV) section of the plant, no surge propagation was identified thus exempting it from the insulation coordination. The above mentioned, along with surge current and overvoltage levels comprise the findings of the study providing parameter guidelines for arrester selection.