Study On Improving The Power Gird’s Adopt Capacity For Distributed PV System

Nowadays, along with the increasing depletion of fossil fuels, solar energy has made a considerable progress as a kind of renewable energy. The photovoltaic system which is connected to distribution grid as a kind of distributed generation is an important way for effective use of solar energy. Distributed PV systems are ushering in a rapid development in our country.The analysis of the comprehensive impact on net load caused by the large numbers of gird connections of distributed PV systems is made from the perspective of PV penetration. From the perspective of PV penetration, analysis of the various factors which limit the photovoltaic adopt capacity of power system is made, assessment of various measures to improve PV penetration limits is made, measures such as load transfer and power energy storage are adopted to improve the photovoltaic adopt capacity.In terms of load transfer mechanism, the load transfer mechanism based on real-time pricing and customer response is proposed. From the perspective of the periodicity characteristic of PV system output, a real-time price mechanism responding to PV output is proposed. From the perspective of demand response, a customer response model is established. A load transfer model is established through a comprehensive analysis of the relationship between real-time pricing and customer response. By the established load transfer mechanism, the periodic response to local photovoltaic energy is generated by users’ tradition load, a quantity of transferable load is shifted to PV output period and the power system’s net load value in PV output period is increased. Calculation example shows that the proposed method can weaken the adverse impact caused by the periodicity of the distributed PV systems and improve power systems adopt capacity for distributed PV systems.In terms of power energy storage mechanism, the power energy storage mechanism based on the orderly charge and discharge of electric vehicles is proposed. A suspended vehicles probability model and a SOC probability model at home arrival moment of electric vehicles are established via analyzing the driving characteristics of large numbers of household vehicles. In order to stabilize the power system’s load curve volatility, the ordered charging and discharging model of electric vehicles is established, striving to apply the available charging and discharging capacity of electric vehicles based on random driving behavior to the process of stabilizing the rapid fluctuations of distributed PV systems’ output as rapid response load. Calculation example shows that the proposed method can effectively improve the stability of the power system’s net load and improve the power systems adopt capacity for distributed PV systems.