Abstract:

With the large-scale integration of new energy sources represented by electric vehicle charging piles and distributed photovoltaics into the Shanghai distribution network,traditional sulfur hexafluoride (SF₆) gas-insulated ring main units (RMUs) equipped with load switches are increasingly unable to meet the requirements of new energy connection.To meet the core demands of reliability and intelligence for environmentally friendly gas-insulated RMUs,research on structural optimization and key digital technologies is carried out.In terms of structural design,type tests at 0 bar gauge pressure are passed through the optimization of electric field fillets,shield rings,and the spatial arrangement of copper bars,thus improving the insulation reliability of environmentally friendly gases.For the development of the digital and intelligent system,a collaborative architecture of “cable fault indicator—TTU—IoT master station” is adopted,which enables active emergency repair responses within 1 minute after the occurrence of ring network faults.The results of 18 months of operation of the developed prototype in Shanghai show that the power supply reliability rate is increased by 0.08%,and the annual average operation and maintenance working hours are reduced by 32%.The research results provide an engineering practice paradigm for the selection of environmentally friendly switchgear in urban distribution networks under the “dual carbon” goals.

Key words: new energy, environmentally friendly ring main unit, fault emergency repair, distribution network