The Research On The Influence Of High Permeability Intermittent Power Supply Access On Distribution Network

Energy is the foundation and lifeline of the world’s national economy.With the increasingly depletion of traditional energy,it’s contradiction with human development,environmental pollution and other aspects is getting tense,so looking for new energy power generation is the focus of national energy strategy projects.The two types of intermittent power:Wind power generation and photovoltaic generation,are valued by the world policy makers because of its resource-rich,renewable,non-polluting,etc.But the intermittent power is effected by the wind speed or sunshine,so the output power is not as stable as the traditional thermal power and the hydroelectric power owing to its intermittence and uncertainty.Therefore,when a large number of intermittent power access to the distribution network,it will impacts voltage distribution,tidal current,power quality and other aspects of the distribution network.At the first,this article introduces the research background and significance of the subject according to the development and utilization of intermittent power supply at present.Based on the research focus of research scholars at home and abroad,this paper points out that the influence of intermittent power supply on distribution network is mainly focused on three aspects:stable operation of power grid,power quality and system protection.Secondly,this paper establishes a mathematical analysis model for three kinds of wind turbines in wind power generation and solar photovoltaic cells in photovoltaic power generation.Besides,This paper also deduces the mathematical expression of the output power of the wind turbine and the output current of the PV array.Then,aiming at the problem of common mode current in photovoltaic power generation system,a carrier modulation strategy for H7 three-phase PV inverter is proposed in this paper.And the validity and accuracy of the proposed strategy are verified by simulation analysis.Finally,an inverse model of intermittent power is established.Through the concrete example of simulation,this paper studies the law of voltage distribution,power quality and system protection of distribution network with high permeability intermittent power supply.