Research On Optimal Control Of Hybrid Energy Storage System In New Energy Power Generation System

With the rapid development of the economy,people pay more and more attention to the problem of the energy.The shortage of the non-renewable energy and the environment pollution make the renewable energy become the focus of attention which represent by wind and solar power.Due to the big influence of the environment,the volatility and uncertainty of the wind and solar power has always been the major problem of the stage of development.The vigorously development and research of the energy storage device has become one of the most important means to solve the new energy grid-connected.The single energy storage element cannot satisfy the growing installed base of new energy power generation system.The hybrid energy storage system combined with high energy density and high power density is considered to be an effective way to solve this problem,which the domestic and foreign scholars have launched a lot of research and experimentation on.The main content of the paper is the control strategy and the capacity of optimizing configuration of hybrid energy storage system in new energy power generation system.This article first contrasts and analyses the performance of the energy storage element in details by introducingthe topology of several hybrid energy storage devices,to identify the hybrid energy storage system structure that is connected to the AC bus through the bidirectional DC/AC converterby the super capacitor and battery.Then,the writer studies a hybrid energy storage system based on two-way DC/AC converter dynamic control strategy to solve the power fluctuating problem of wind and photovoltaic grid power generation system.It establishes the double closed-loop control structure in the hybrid energy storage system of super capacitor and battery,to control the internal voltage and current,to distribute the fluctuation current to the super capacity and let the battery response to the slow part of the current component.Secondly,controlling the state of charge of the battery by the way of extended kalman filtering to make its SOC value within the scope of the security in order to extend the service life of the battery.It validates the effectiveness of the hybrid energy storage control method through the Matlab simulation experiment.In addition,thewriter studies a hybrid energy storage system for Wind-PVhybrid system capacity optimization configuration by making full use of the super capacitor and battery,analyzes the calculation process of the system's load power shortage rate in details.At the same time,basing on the whole life cycle cost theory as the foundation,the writer establishes a capacity optimized target function of the hybrid energy storage,takes the loss of lower supply probability of new energy power generation system as the constraints of the optimization and optimizes by applying the standard and the improved particle swarm algorithm.In the end,it shows that the hybrid energy storage capacity of the optimal allocation not only satisfy the reliability of power supply but also reduce the cost of hybrid energy storage system in the Matlab simulation software.