Influence Of Distributed Energy Storage On Power Quality Of Distribution Network

With the rapid development of the economy,the load of the power grid is increasing rapidly,and the peak-valley difference is becoming larger and larger.At the same time,the penetration rate of new energy power generation in the distribution network is also getting higher and higher.Increased load demand.Under this background,energy storage,due to its bidirectional charge and discharge and rapid response characteristics,has become an effective means to solve the peak-valley difference and suppress the fluctuation of new energy power.Compared with centralized energy storage,distributed energy storage has great advantages due to its small capacity and flexible installation location.When energy storage is peak-shaving and valley-filling,its capacity often has redundancy and cannot be fully utilized.Therefore,the redundant capacity of distributed energy storage can be used to solve other power quality problems of the distribution network,such as voltage deviation,Voltage sag,etc.In this paper,first of all,in MATLB/SIMULINK,the energy-based energy storage-electrochemical energy storage and power-based energy storage-flywheel energy storage is modeled and controlled,and the charge and discharge characteristics of electrochemical energy storage and flywheel energy storage are analyzed.Lay the foundation for follow-up research.Aiming at the application scenarios of distributed energy storage in improving the voltage deviation in the distribution network,a multi-objective optimization strategy model of energy storage including line loss,voltage fluctuation and voltage deviation indicators is established,and the multi-objective optimization problem is solved by AHP Convert to a single objective optimization problem.Taking the IEEE3 3 node system as an example,the quantitative analysis of the different effects of different distributed energy storage configurations on the voltage deviation of the distribution network,and verification of the proposed distributed energy storage optimal scheduling problem considering the voltage deviation indicators.Aiming at the problem of voltage sag in distribution network,a scheme for compensating voltage sag of flywheel energy storage installed in substation is proposed.Dynamic voltage compensator(DVR)is an effective device to solve the voltage sag,but because of its high price and low utilization rate,it is not widely used in China.While the frequency regulation and peak load regulation of the flywheel energy storage of the substation,its redundant capacity can be used to improve the voltage sag problem of the distribution network.The fees paid.Aiming at the application scenarios of energy storage batteries to suppress the fluctuations of new energy power,taking photovoltaic power generation as an example,analyze the influence of photovoltaic on the voltage fluctuation of the distribution network.Build distribution network model and optical storage grid connection model in MATLAB/SIMULINK,simulate and analyze the suppression effect of energy storage device on the fluctuation of photovoltaic power output power,and the improvement effect on the voltage fluctuation problem of each node of the distribution network.In summary,the energy storage device has changed the characteristics of the traditional electric energy that can be generated and used immediately.It can effectively carry out frequency and peak shaving,cooperate with new energy power generation,and can solve the power quality problem of the distribution network.