Calculation And Analysis Of HGIS Power Frequency Electric Field Based On Particle Swarm Optimization And Charge Simulation Method

In recent years,composite gas insulated switchgear(HGIS)has been used more and more in the construction of UHV substations in China due to its advantages of moderate cost,small area and safe and reliable operation.At the same time,the vigorous construction of substations also brings a series of electromagnetic environment problems,which has been highly concerned by people.The research and analysis of HGIS power frequency electric field distribution law has important guidance and practical significance for the design and construction of intelligent substation,electromagnetic environment assessment and eliminating people’s unnecessary worries about electromagnetic radiation in power transmission and transformation projects.Because the traditional simulated charge method(CSM)is too cumbersome to deal with the problem of complex computing scenarios,this paper proposes to combine particle swarm optimization(PSO)and traditional simulated charge method to form an optimized simulated charge method(PSO-CSM),and apply it to the calculation and analysis of power frequency electric field in 500 kV HGIS distribution device area.The main contents of this paper are as follows:(1)Based on particle swarm optimization(PSO)and simulated charge method,an optimized simulated charge method is proposed.The basic idea of the optimized simulated charge method is explained,the reasonable fitness function and termination strategy are selected,and the application steps of the optimized simulated charge method are summarized.Based on the optimized simulated charge method,only the feasible region of simulated charge position and charge parameters is given,and the algorithm can automatically find the optimal location and charge value.(2)The factors affecting the calculation accuracy and iteration efficiency of the optimized simulated charge method are analyzed.In order to make the algorithm have a good global optimization ability in the early stage and focus more on local refinement search in the later stage,a reasonable inertia weight factor selection strategy is selected through experiments.The learning factor is used to describe the ability of particles to learn from themselves and society in the algorithm,which needs to be weighed according to specific problems.(3)To verify the validity and feasibility of the optimized charge simulation method,simplified models of ball-plate,ball-end bar-ground,single-phase transmission line and three-phase transmission line are established respectively,and the optimizationproblems are established.The optimized charge simulation method is used to calculate them respectively.For the problem that particle swarm optimization can not actively optimize complex numbers,a parallel scheme is proposed,which divides complex variables into real and imaginary parameters,continuous variables optimization and combination optimization.In addition,in order to further improve the iteration speed of the optimization algorithm,the initialization of the simulated charge magnitude parameters was improved.(4)In order to establish a simplified calculation model of power frequency electric field,the main and minor effects in the field are analyzed,and the corresponding simplification principles are put forward.On this basis,the monitoring models of HGIS equipment,suspended pipe busbar,A-type structure and equipment entry and exit lines are established.The influence of main equipments on power frequency electric field and the distribution of power frequency electric field in the whole power distribution area are calculated and analyzed by using the optimized simulated charge method.The relevant suggestions and improvement measures of electric field optimization are put forward.