AVC System Control Parameter Setting Method Based On Dynamic Reactive Power Optimization Of Regional Power Grid

With the continuous development and progress of society,it has become a common phenomenon that a large number of impulse loads and distributed new energy directly connected to the regional power grid,which makes the network power flow change more frequently and has a higher requirement for the coordination control of voltage and reactive power.The voltage and reactive power control of regional power grid is mainly realized by the automatic voltage control(AVC)system.However,the actual control effect of the system is easily affected by the parameter setting.If the parameters are not set properly,it will not only affect the economy of network operation,but also lead to voltage safety problems.Therefore,based on the dynamic reactive power optimization,this paper studies and explores the optimal setting method for AVC system control parameters of regional power grid.The main work is as follows:(1)Aiming at the problems that the existing dynamic reactive power optimization model of regional power grid fails to reasonably limit the number of discrete equipment actions,and it`s difficult to solve the model directly and efficiently,a regional grid dynamic reactive power optimization method based on interior point method and decoupled dynamic programming method is proposed in this paper.Firstly,the dynamic reactive power optimization model is built based on the 5-minute load curve after the fusion segment.By using piecewise linear action cost objective function,the dual objective of minimizing the number of actions of discrete equipment and keeping the limit as much as possible is achieved.Then a two-stage solution method is proposed to solve the model.In the first stage,by using the sigmoid function,the piecewise function and the absolute value function in the model become continuous and differentiable,and then the continuous optimal solution is obtained by the interior point method.In the second stage,on the basis of continuous solution,the dynamic reactive power optimization problem of regional power grid is solved by decoupling and coordination among stations,voltage regulation and reactive power compensation equipment,as well as dynamic planning calculation in stations.The effectiveness of the regional grid dynamic reactive power optimization model and algorithm proposed in this paper is verified by the simulation results of G 220 kV control zone in S City.(2)Because of the load curve fusion segmentation,the dynamic reactive power optimization results of the regional power grid are not suitable for all substations.Considering the fact that the hybrid integer linear programming method is faster in the case of less discrete control variables and the programming is simple,a substation dynamic reactive power optimization method based on the interior point method and the linearization strategy is proposed in this paper.In this method,a substation dynamic reactive power optimization model considering the requirements of regional coordination is constructed firstly.Then a two-stage solution method is proposed to solve the model.In the first stage,the interior point method is used to obtain the continuous optimal solution.In the second stage,according to the results of continuous optimization,a linear dynamic reactive power optimization model based on variable substitution is constructed.The optimal discrete solution of the original problem can be obtained by solving this model with branch and bound method or optimization tool kit.The effectiveness of the substation dynamic reactive power optimization model and algorithm proposed in this paper is verified by the simulation results of G 220 kV control zone and X substation in S City.(3)The control parameter setting method in the existing research ignored the mutual influence of the equipment controlled by different voltage and reactive power control(VQC)parameter at the time of action.The influence caused by the uncontrollable actual action sequence may lead the equipment to refuse to act or be in a wrong situation.Aim at this problem,a AVC parameter setting method by considering the mutual interference of equipment actions is proposed in this paper.Based on the dynamic reactive power optimization results and fifteen-zoon diagram control strategy,a AVC system control parameters are set by considering a certain margin value and the possible monitoring result caused by different action sequences of other equipment.This set of parameters can ensure that the AVC system can operate as dynamic reactive power optimization strategy,even in the situation that the control equipment has action interference and the load curve has certain error.The rationality and effectiveness of the substation dynamic reactive power optimization model and algorithm proposed in this paper is verified by the simulation results of G 220 kV control zone and X substation in S City.