Application Of Distributed PV And Energy Storage System In Micro Grid

Photovoltaic power generation systems play an increasingly important role in energy demands of human society and people’s lives because solar energy is non-polluting and renewable. But solar energy itself shows randomness and volatility. If it is not been limited, it is likely to pose a threat to the safety and stability of power system. In order to make photovoltaic power generations better serve the community, this paper carries out a research to study the influences of power grid operation after photovoltaic power generations access the power system and explores the measurements to improve the stability of power system.This paper chooses modeling-simulation research method and the grid structure of Hangzhou Bay New Area. Firstly, simplify the battery characteristics of photovoltaic power generation systems, establish a suitable photovoltaic power supply model to access the power system in steady operation. Then select Benchmark typical medium voltage distribution network system and low voltage power grid as an example to research the influences of power grid operation after photovoltaic power generations access the power system. On the other hand, establish a general model of energy storage systems to analyze the influences of large-scale energy storage device on the dynamic and transient power system.This paper studies the output changes of photovoltaic power generation systems in the typical weather conditions. Outputs in different weather patterns of PVs lead to the different dynamic changes of node voltage of micro-grid. Access capacity is larger, the nearer the photovoltaic access points, the influences are more obvious. This paper mainly studies how to select the capacity of the energy storage device. This paper proposes a probabilistic method for determining the optimal capacity, get the maximum charge and discharge power of the micro-grid energy storage system and the optimal energy storage capacity in order to achieve the optimal economic efficiency and largest renewable energy utilization rate.The results in this paper can be applied to arrange reasonable plan in power grid scheduling and design the capacity of the energy storage device in power grid construction. But the result is based on a specific system. In order to get a universal and normative conclusion, the simulation experiment of several systems is still needed.