Simulation Study On The Short-circuit Current Of Distributed Photovoltaic Power Integrated To The Distribution Network

Currently, the sunlight can provide a source of energy photovoltaic technology has matured and reached the level of large-scale commercial and industrial applications. It is foreseeable that in the next period of time, there will be a large number of countries in grid photovoltaic power grid. Photovoltaic power access, effectively easing the countries on the one hand, especially in the economic development of China as the representative of the rapid energy demand of the country’s huge power shortage situation; on the other hand has inevitably led to the traditional power grid impact. Because the output voltage of the photovoltaic power supply itself is low, small power generation capacity of a single device, it is generally a direct access to the distribution network, which will affect the traditional distribution network in all aspects. The topic from the perspective of the distribution network Fault Analysis of departure, research photovoltaic power grid, the impact on the distribution network failure caused by a short circuit, hoping to provide a reference for the future to develop photovoltaic power grid and operating rules.In this paper, using a variety of simulation experiments to validate the proposed photovoltaic power model and controller design correctness, studied the simulation results are consistent with the traditional power system analysis to the conclusion, based on the verification of the correctness of the model in the future will promote the research and application of the model to other PV Grid project.Secondly, the use of photovoltaic power circuit model simulation software built in a variety of simulation experiments to study photovoltaic power grid, the impact of the traditional distribution network short-circuit current calculation and analysis of the resulting simulation results show that:During the short-circuit fault, PV power supply short-circuit current rapidly reaches a saturation value, during a short circuit fault, all aspects of the photovoltaic power model can correctly respond to external disturbances, by influencing the output current of the photovoltaic power analysis of different factors seen during a short circuit fault, the photovoltaic power model used, and the network structure, the exit of the filter capacitor in parallel whether other factors will not have a photovoltaic power output short circuit current during a visible impact, after photovoltaic power grid have changed the structure of the traditional distribution network, However, its impact on the distribution network and the size of the short-circuit current caused not obvious, and this affects the conclusions are in line with the existing tradition formed fault Analysis:the closer the fault location, the greater the output current during short circuit; penetration the higher rate level, the greater the contribution of the short-circuit current; asymmetric short-circuit fault is also output negative-sequence current.