| With the continuous development of distributed power technology,the power distribution network has gradually developed from passive to active.Power generation system of photovoltaic-storage is an important distributive generation form of active power distribution network.However,node voltage weakness problems of power distribution network can be influenced when photovoltaic-storage system access into power grid.Aiming to study the problems that node voltage variety can be easily caused when photovoltaic-storage system access in power distribution network,the influence that the photovoltaic-storage system accession have on node voltage weakness of power distribution network is analyzed in this thesis.Photovoltaic-storage system configuration and active reactive power control strategy for the weak nodes of the distribution network are studied.A simulation model of a power distribution network in Qinghai province containing photovoltaic-storage system is set up.The specific research contents are as follows:(1)Research on node voltage weakness influence of power distribution network when photovoltaic-storage system access into power grid.Based on stability principle of node voltage,node voltage weakness index of distribution network is proposed.Quantitative analysis method of distributed photovoltaic-storage system on distribution network voltage is studied.A distribution system model of Buhahe substation in Qinghai province is built in the PSCAD simulation platform and had example analysis.The influence of distributed photovoltaic connected grid on distribution network voltage and the impact of distributed photovoltaic-storage system connected grid on the node weakness are analyzed.(2)Research on optimal configuration of photovoltaic-storage system access distribution network and reactive power prediction.In view of the node voltage weakness of distribution network,configuration method of distributed photovoltaic-storage system access distribution network is studied,and on the basis of this research,capacity optimization model of photovoltaic-storage unit based on genetic algorithms is studied.In this thesis,the influence factors of reactive power of photovoltaic array are studied.Reactive power output of energy storage systems based on energy storage charge state is predicted.The prediction model of reactive power output of photovoltaic-storage system is established.(3)Research on active reactive power control strategy for photovoltaic-storage system of Power distribution network.Based on the primal-dual interior point method,reactive power optimization control strategy for photovoltaic-storage system connected to the distribution network is studied.A global voltage control strategy model of photovoltaic-storage system is established.Simulation model of active reactive power control is built according to a 35 kV substation in Buhahe of Qinghai province.Active reactive power control method for photovoltaic-storage system and global reactive power control strategy for distribution network are verified by simulation. |
PDF Full Text Request