Research On Application Of Photovoltaic And Energy Storage Mode In Heyuan Low-voltage Distribution Network

With the reduction of photovoltaic power generation costs and the support of the national photovoltaic poverty alleviation policy,a large number of household photovoltaics will be connected to the low-voltage distribution network in rural areas,which can alleviate the low voltage problem of the rural network lines to a certain extent.But,with a large number of household pv access,it will also have some impact on the planning and operation of the local distribution network.Energy storage can not only overcome the intermittent shortcomings of distributed photovoltaic power generation,but also can be used to curb the phenomenon of electricity peak and valley fault,and become a new way to solve the negative impact of distributed photovoltaics on the power grid.Therefore,the “photovoltaic + energy storage”model is bound to become the mainstream trend of rural network upgrading and transformation.In this paper,the mode of "photovoltaic + energy storage" is applied in the upgrading and transformation of heyuan rural network In solving the power quality problems of users at the end of the rural network and the reliability of power supply.The main contents of this paper are as follows:(1)Analyzes the current situation and user-side working conditions and demands of rural networks in remote areas,investigates the current situation of rural network construction and operation and maintenance in remote areas,summarizes the existing problems,analyzes the electricity consumption of different types of users of rural networks,including electricity usage habits,electricity quality and electricity reliability,and summarizes the electricity demand of rural network users.(2)According to the characteristics of the rural network users and the operation and maintenance requirements,this paper proposes a photovoltaic and energy storage integrated application mode based on remote rural network users.The design of the photovoltaic and energy storage integrated application mode mainly includes: the design of coupling mode between photovoltaic system and energy storage system,design of multi-mode energy storage charge-discharge controller,photovoltaic and energy storage intelligent operation and maintenance system for rural low-voltage users.(3)Power flow simulation and operation analysis of low-voltage distribution network with photovoltaic and energy storage power generation system.According to the characteristics of low voltage distribution network connection mode in China,we put forward the photovoltaic(pv)and energy storage power generation system of rural low voltage distribution network three-phase power flow calculation method,and came up with the concept of the tolerant permeability ratio of photovoltaic(pv)connected to low-voltage distribution network,As an evaluation index to measure the ability of low-voltage distribution networks to absorb photovoltaic(pv),Through the simulation of power flow,analyzed the operating state of the low-voltage distribution network with photovoltaic(pv),and studied the ultimate capacity of photovoltaic access to low-voltage distribution network,which provides a basis for the planning and design of photovoltaic and energy storage system..