Research of the power frequency magnetic fields distribution around dry-type air-core reactor

The strong magnetic fields generated by reactors, which not only interfere other electric equipmentspsila regularly running, but also are potentially harmful to substation employeespsila health, are the main electromagnetic contamination in substations. In this paper, a mixed finite-element (FE) model for dry-type air-core reactor, which considers the effect of eddy current, is proposed for calculation of magnetic fields. According to the analysis of this model, 7 times of the air-core reactor group region is suitable for calculation region. Based on this model, the magnetic fields distribution of equilateral triangle arranged 35 kV reactor group in 500 kV substation is calculated. The comparison between calculation results and measured values shows that the mixed FE model may accurately assess the magnetic field distribution around air-core reactors and provide theoretical basis for installation of air-core reactors for power department. Besides, based on the magnetic field distribution around air-core reactors, an early-warning mechanism can be established, which can provide safeguard for other electronic equipments running and the substation employees working.