保护装置外壳孔缝电磁屏蔽特性的研究

With the increasingly extensive application of wireless communications method in power system, the automated level of power system raise continuously. But at the same time, the wide application of wireless communications solutions brings a new radio frequency electromagnetic interference problem to electromagnetic shielding of the protection equipment in power system. Electromagnetic shielding effectiveness of protection equipment directly influences the electromagnetic compatibility (EMC) of it and stability of power system. It is important to forecast the electromagnetic shielding effectiveness of the box with apertures at the range of the frequency of wireless communications for evaluating the EMC of the protection equipment. To solve this problem, the influence of apertures’ shape, number, size and arrangement on electromagnetic shielding effectiveness of the protection equipment was studied at the range of wireless communication frequency by full wave finite element method. To prove the validity of methods described here, the electromagnetic shielding design of the case of protection equipment was carried out and the electromagnetic shielding effectiveness was improved by 15 dB.