Research On Smart And Comprehensive Voltage Regulation Strategies In Active Distribution Network

With the increasing demand for energy,because DG can alleviate the trend of energy shortage and does not pollute the environment,it has become an inevitable trend that a large number of DGs connected to the power grid.With the gradual increase of DG,it will bring more complex daily load change rate and voltage distribution,which poses a new challenge to the traditional distribution network voltage regulation.In view of the above problems,this paper studies the LDC-based voltage regulation strategy,the partition coordination voltage control strategy,and the multi-period voltage optimization strategy according to the different control layers and time scale,which combines theoretical analysis and simulation analysis based on the analysis of voltage characteristics on the active distribution network.The specific work and main research results of the dissertation are as follows:For the active distribution network with DQ this dissertation studies the effects of different locations and permeability of DG on the voltage of the distribution network.Based on the simulation with OpenDSS,this dissertation obtained the distribution law of power flow and voltage on the active distribution network.It provides a reference for the configuration of DG and reactive power compensation in the following simulation examples.For the purpose of controlling the target node voltage,the voltage regulation strategy based on LDC control is studied.Based on the research of its control principle and parameters setting,the influence of DG access on LDC control is analyzed.The IEEE 13 simulation model is built in the OpenDSS.The settings of LDC parameters,the limited precision of voltage regulation by LDC and the failure of LDC control due to DG,which are verified by simulation.The necessity of research on voltage regulation strategy for active distribution network is further emphasized.For the purpose of controlling area voltage and voltage control on the short time scale,this dissertation proposes a coordinated voltage control strategy based on FCM clustering partition and the theory of secondary voltage control,which realizes the rapid regulation of voltage.The strategy divides the distribution network into several autonomous voltage-regulating areas based on voltage-reactive sensitivity and fuzzy C-means clustering.It makes full use of the voltage regulation resources with fast response speed on the distribution network,and realizes the decentralized voltage control through the autonomous regulation with reactive power compensation and the overall regulation of the voltage regulator based on fuzzy control.For the purpose of global voltage control and voltage optimization on the long time scale,the multi-time voltage optimization strategy is studied which combined with third voltage control theory.The goals of the problem are to reduce the network loss,voltage deviation and the action times of equipment.And then a two-stage solving method is proposed.The improved NSGA2 algorithm and multi-attribute fuzzy decision-making are used to solve the problem.Finally,the global voltage optimized output scheme with the best comprehensive effect is obtained.