Large Photovoltaic Power Station Power Quality Analysis And Management Scheme Research

With the rapid development of large photovoltaic power station, power quality problems caused by photovoltaic power station grid are becoming more and more serious. This paper discusses the large photovoltaic power station power quality modeling and power quality characteristics of photovoltaic power station access grid. The external characteristics of large-scale photovoltaic power station access grid and power quality problems caused by access grid,such as voltage, frequency, fluctuation and the harmonic are discussed and analyzed.The research for power quality of large photovoltaic power station access grid mainly concentrated on a single power quality. With the power quality status measured data in Golmud photovoltaic power station, this paper built the large photovoltaic power station simulation model, which was based on Golmud photovoltaic power station measured data and used for comprehensive analysis of a variety of power quality problems.Secondly, based on the large photovoltaic power station simulation model, the main contents are as follows:analysis of power quality characteristics when the output of photovoltaic power station is constant, fluctuation and mutation; power quality characteristics when system load of photovoltaic power station changes; power quality characteristics when common short circuit fault occurs. With the above analysis, find out the main factors influence power quality of photovoltaic power station, and the power quality problems which were the most likely to occur when external conditions of grid system changed.In this paper, with the simulations, power quality problems of photovoltaic power station about fluctuations of voltage and the power factor and output harmonic current exceed the standard when the light temperature or grid load changes too frequently were discussed; how to solve the problem of providing voltage support to the photovoltaic power station system when faults occur in access power grid was studied. Finally, in this paper, the stability of photovoltaic power station and network voltage, power factor, the electric power system fault time to provide solutions for voltage support to reduce harmonic current and power output of photovoltaic power station were provided. By modeling and simulation analysis, validity of the solution was proved, and provide a theoretical basis to promote the large-scale photovoltaic power generation system access grid and large-scale application process.