Voltage Fluctuation Suppression Strategy For DC Distribution Network

With the development trend of electric power in urban power supply corridors becoming increasingly saturated and the demand for power supply capacity and power quality increasing,the advantages of DC distribution networks are becoming more apparent.The DC power distribution network phase has high power utilization efficiency,large line transmission capacity at a certain insulation level,and does not need to consider reactive power components and frequency issues.It has been a hot topic in the field of power distribution network research in recent years.This article first analyzes the challenges encountered by traditional AC distribution networks and the opportunities faced by DC distribution networks in the new power development situation,introduces the development overview,key operating technologies,and key equipment technologies of DC distribution networks.Calculate and compare the cost of the traditional AC distribution network and the DC distribution network under the existing technology,and analyze the economics of different forms of distribution network.Secondly,the working principle of each part of the DC distribution network and the DC system power flow calculation are explained.For power grid nodes connected with distributed power,an approximate processing method in power flow calculation is given.This paper introduces the voltage control theory in DC systems,and focuses on the parameter quantization design of converter droop control in different situations.The impact and impact of the distributed power on the grid-connected nodes are analyzed and calculated,which provides a certain theoretical basis for the control and dispatching of the DC distribution network combined with the energy storage system.Focusing on the voltage fluctuation problem of DC distribution network,this paper conducts research from two aspects.On the one hand,controllable load is used to suppress the voltage fluctuation of load nodes,and on the other hand,a new voltage balancer is used to suppress bus voltage fluctuation.In terms of controllable loads,a control strategy for suppressing voltage fluctuations at load nodes is proposed.The DC distribution network including distributed power sources and various controllable loads is the research object.Controllable loads are added as the degree of freedom for voltage regulation.Classify and model different types of controllable loads,use the response characteristics of different controllable loads,coordinately adjust the voltage,and do simulation analysis.In terms of voltage balancer,a new voltage balancer topology is proposed,which can To avoid the danger of direct voltage switch of the traditional voltage balancer,it is suitable for DC systems with high reliability requirements such as aerospace power supplies and data centers.It can make the positive and negative load current continuous and facilitate filtering.A new voltage balancer is proposed.Control strategy,establish a small signal state model for the new voltage balancer,and finally use simulation software to verify the control strategy of voltage balancer.