Research On Reactive Power Optimization Control Method For Distribution Network With Wind Turbine

In recent years,China's wind power generation technology has developed rapidly.A large number of wind turbines are connected to the distribution network,which has a certain impact on the safe and economical operation of the traditional distribution network and the control of voltage and reactive power.As the main type of wind power in China,DFIG can realize decoupling control of active power and reactive power and continuously regulate reactive power in a planned way.In this paper,reactive power optimization control method of distribution network with DFIG units is studied to achieve optimal coordination between DFIG units and traditional voltage reactive power control equipment.Firstly,the location and capacity of distributed wind power in distribution network are studied.Considering the reactive power regulation capacity of DFIG,DFIG unit was selected as the research object.According to the steady-state model of DFIG unit,the expression of its power limitation relation was deduced.The wind power prediction curve is segmented and the time series of wind farm output is taken into account.A two-stage planning method was adopted to determine the access location of wind power supply to be selected in the first stage by weight coefficient method,and the optimal access node and capacity of wind power supply were determined in the second stage,and the problem of constant capacity planning of wind power supply with ieee-14 nodes was solved by genetic algorithm.Secondly,a dynamic reactive power optimization method for distribution network with wind turbine is proposed.DFIG unit is used as a reactive power source to participate in the dynamic reactive power optimization of the distribution network based on its own reactive power regulation capacity.A comprehensive dynamic reactive power optimization model with minimum network loss,minimum accumulated error sum of node voltage and minimum action times of discrete compensation equipment is established.The global optimization of the control in each stage is realized by using the improved genetic algorithm.Finally,an example of ieeee-14 node system is given to verify the feasibility and effectiveness of the dynamic reactive power optimization algorithm model and its solution algorithm.Finally,a reactive power distribution network optimization method considering DFIG unit reactive cost is proposed.Considering the purchase cost of fan reactive power can promote the optimal utilization of power system resources,reduce the network loss,ensure the voltage quality,and mobilize the enthusiasm of power generation companies for reactive power service.By studying the power limitation relation of DFIG unit and considering the reactive power cost of the fan,the area of its reactive power regulation range was divided,and the reactive power valuation cost of DFIG was analyzed,and the reactive power purchase function of each part was given.Considering the reactive capacity analysis of DFIG under the fluctuation of wind speed,the improved wind speed calculation method within the time period is given.Under the scenario of fan reactive power cost being considered,a reactive power optimization model aiming at system network loss,total control cost and fan reactive power cost optimization was established.