Power Frequency Electromagnetic Field Analysis Of Indoor GIS Substation Based On Parallel Genetic Algorithm

With the development of urbanization in China,urban land is increasingly scarce,and the space between urban buildings is small.Therefore,in order to reduce the area of urban land,reduce the impact of electromagnetic radiation and noise in the surrounding environment of urban substation on the surrounding residents,the indoor layout of power equipment is often used,resulting in the urban indoor substation.Although the indoor substation reduces the power frequency electromagnetic field intensity of its external environment,due to its compact internal structure and dense equipment,the distance between the electric field source and the magnetic field source,and between the working area and the field source of the operators is small,which makes the operators easily exposed to the electromagnetic field with high field strength.Therefore,the calculation and research of the power frequency electromagnetic field distribution in the indoor substation It is of great significance to evaluate the working environment of operators and design and construction of substations.At present,the simulation research of power frequency electromagnetic field distribution in substation is mainly focused on air insulated substation,but there is little research on power frequency electromagnetic field distribution in indoor GIS Substation.Due to the variety of indoor substation equipment,compact distribution and complex structure,the traditional simulation method will reduce the accuracy of calculation.Therefore,this paper uses the numerical calculation method combined with the optimization algorithm to calculate the power frequency electromagnetic field distribution in and around the 220 k V indoor substation.The specific work arrangements are as follows:(1)Study the basic theory of the simulation charge method and the optimization algorithm,combine the calculation steps and basic principles of the two methods,select appropriate parameters and iterative formula,design the optimization simulation charge method,and elaborate its principle,idea and specific application steps.In order to improve the efficiency of the algorithm,the master-slave parallel algorithm is applied to optimize the simulated charge method.(2)In this paper,the optimized simulated charge method is applied to the calculation of the electric field of the live wire in the actual indoor substation.The length of the line charge on the wire is optimized,and the advantages and disadvantages of the three algorithms,i.e.tianniuxu algorithm,genetic algorithm and particle swarm optimization algorithm,are compared with the combination algorithm of the simulated charge method.Genetic algorithm is selected as the optimization tool of this paper because of its good optimization ability.The three-phase transmission line model verifies the results of genetic algorithm,which shows the accuracy of the optimization algorithm.In addition,the verification results of the parallel algorithm show that the optimized parallel simulation charge method in this paper has better parallelism.(3)The actual models of transformer room,current limiting reactor room and other main power equipment in indoor substation are established,and the transmission line model obtained by genetic algorithm is applied in the actual model.On this basis,the power frequency electric field in each electrical equipment room is calculated and analyzed,and the results show that the electric field strength at 1.5m of the ground in indoor substation is lower,but close to bare conductor If the electric field on the top of the transformer exceeds the limit value specified in the standard.(4)According to the actual situation of indoor GIS Substation,the calculation model of power frequency magnetic field is established,and the power frequency magnetic field in and outside the GIS Substation is calculated by biotsavart law.The overall strength of power frequency magnetic field in indoor substation is similar to that in outdoor substation,but because of the dense distribution of equipment and conductor,the high field strength area is concentrated around current carrying conductor and reactor,and the attenuation is faster with the increase of distance.