Additional Protection Device for Grid Inverter of Photovoltaic Station

Abstract

The article describes the large-scale implementation of solar photovoltaic installations and systems in the regions of Uzbekistan, and considers the issues of operation of the component equipment of photovoltaic power plants (PVPP) integrated with the low-voltage electric grid. There is carried out the analysis of the influence of low quality of electric power on the operating modes of the grid inverter in PVPP. There are studied the values of voltage, current and frequency of each phase in the low-voltage electric grid using a two-channel flat-panel oscilloscope FNIRSI -1013D. The voltage deviations of each phase in the low-voltage electric grid are determined; their values are δUm(−)A−7,8 %, δUm(−)B−20% and δUm(−)C−20% underwinter conditions, respectively. The archives of most inverters in PVPP integrated with the low-voltage distribution grid in the regions of Uzbekistan are studied and analyzed. The reasons for frequent disconnection and connection of grid inverters have been identified, which include voltage instability in phases, losses in the electrical network, incorrect grounding of the inverter, etc. Additional protective equipment has been developed and created for inverters of the solar power plant integrated with the low-voltage electrical network, distinguished by reliability, automation and availability of electrical components on the domestic market of Uzbekistan.