Research On Regional Reactive Power Allocation Strategy And Coordinated Control Method Of Urban Power Grid

The traditional circuit breaker throwing capacitor bank is widely used in the reactive power voltage regulation of the power grid,but there are generally limitations on the number of throwing times and large gradation differences,which cannot continuously regulate the reactive power and other shortcomings.At present,the reactive power compensation devices with continuous dynamic reactive power regulation function include TCR,SVG and MCR,among which,MCR is more suitable for 110 kV and above high-voltage systems,and the distributed reactive power configuration helps to realize the optimal control of reactive power in regional power grids.For the needs of distributed reactive power configuration,this paper analyzes voltage-reactive power sensitivity and local voltage stability indexes,and proposes a comprehensive degree of voltage stability by combining the two indexes with reasonable weights as the basis for selecting reactive power configuration points;adopts an improved particle swarm algorithm for reactive power optimization,and improves the convergence accuracy of the algorithm by introducing crossover and variation operators and the strategy of dynamic parameter adjustment.The IEEE-14 case is simulated for configuration optimization,and the comparative analysis of active loss,node voltage and reactive power variation shows that the configuration according to the integrated degree of voltage stability is more effective than the single index optimization,and the improved PSO algorithm effectively improves the convergence accuracy.To improve the defects of the traditional reactive power regulation method,a dynamic reactive power regulation strategy based on MCR-type SVC is proposed,and the coordinated control strategy of adding MCR-type SVC is determined by combining the existing voltage and reactive power control strategies in the AVC system.The IEEE-14 algorithm under dynamic load change is simulated by PSCAD and MATLAB,and the changes before and after regulation are compared and analyzed to verify the effectiveness of the dynamic regulation strategy.Finally,the reactive power allocation optimization method and dynamic regulation strategy are combined with PSCAD and MATLAB to conduct simulation experiments under dynamic load changes for a 220 kV level regional power grid,comparing the optimization before and after the addition of MCR-type SVCs.The results show that the distributed reactive power allocation optimization and dynamic regulation strategy described in this paper effectively reduces the active power loss of the system with a maximum loss reduction rate of 17.15%,reduces the number of switching times compared with the original fixed capacitor configuration scheme,and improves the operational reliability of the system.