Voltage Regulation Method Of Distribution Network Based On Demand Response

Burning fossil energy causes serious pollution to the earth,prompting the rapid development of clean energy.Although,the integration of renewable energy to distribution network has slightly relieved the pressure of environmental pollution,due to its characteristic of uncontrollable,the distributed generators output is irregular variation.At present,although the forecast accuracy of distributed power sources is progressively improving,it still cannot achieve accurate dispatching of the power system.The share of distributed power integration increase has caused numerous issues such as voltage amplitude fluctuation and poor voltage quality in the distribution network,which brings challenges to the security of the distribution network,so the voltage fluctuation problem needs to be solved urgently.Currently,the distribution network usually uses existing voltage regulating devices to regulate the voltage,such as by changing the on-load regulating transformer taps,throwing capacitors or synchronous regulators.The response of existing regulating methods is not timely,and the frequent operation of regulating devices will reduce the reliability of equipment operation and increase the cost of mechanical maintenance.As the power market becomes more mature,demand response based on flexible and reliable characteristics as a new type of resource optimization mode,coordinates between the various components of the power system It has made contributions to the frequency and load and regulation of the distribution network.In response to the problems of slightly inferior flexibility and poor economy of traditional voltage regulation,this thesis investigates the dynamic voltage regulation methods for active distribution networks based on demand response characteristics as follows:Firstly,this thesis provides an overview of active distribution networks and Monte Carlo sampling methodologies.Active power probability models for wind and photovoltaic power generation are established.The impact of distributed generation on the voltage of distribution system after grid integration is highlighted.Secondly,to guarantee the validity of voltage regulation based on demand response and users’ satisfaction.According to the affiliation function,the active distribution network load is divided into three periods: peak,valley and flat,and the load transfer rate model,interruptible load power configuration model and response power configuration model of dual storage system based on time of use are built.To establish a mixed integer second-order cone planning model of the above model with the objective function of minimizing the sum of voltage excursions at each node of the distribution network in one operating cycle,and to improve the voltage magnitude of the active distribution network by coordinating and optimally controlling the power of controllable loads and dual energy storage systems.Simulation of the optimization strategy using the modified IEEE-33 distribution system is undertaken to confirm the validity and feasibility of the voltage adjustment strategy.Finally,in order to improve the optimization of the distribution network.In this paper,a voltage regulation strategy combining demand response and distribution network reconfiguration is proposed.The distribution network is reconstructed based on the demand response,and the second-order cone-pair model is linearized to take the minimum loss of the distribution network in one operating cycle as the objective function.The improved IEEE-33 node distribution system is used to simulate the single-period and multi-period active distribution network reconstruction.The results show that the voltage amplitude optimization effect and the economy both are better in the distribution network reconstruction with the participation of demand response.