Success deployment of 6 digital substations in Vietnam 2020-21 - return of experience

IEC 61850 standard has been widely accepted and used in the transmission and distribution substation. Many utilities had built the IEC61850 digital substation and demonstrated many benefits including massive reduction of copper wirings, installation time, labour and footprint. Vietnam Electricity Northern Power Corporation (EVNNPC) have been using IEC 61850 at station bus for years and started to look into the first IEC 61850 process bus digital substation 110kV Que Vo 2, Bac Ninh Province 110kV pilot project in 2019. Application of IEC 61850-9-2LE process bus introduces merging units, fibre optic network replacing copper wiring, network traffic bandwidth, Ethernet switches and process bus protection relays. EVNNPC considered them as a protection and control (PAC) scheme and the reliability and redundancy of PAC in digital substation must be equivalent or better as compared to a conventional substation. EVN's first digital substation, Que Vo 2 110kV digital substation project was constructed, commissioned and energized in 2020 successfully. The success of Que Vo 2 110kV digital substation project marked a significant milestone, proving the concept and benefits of digitalization. By mirroring the success of 110kV Que Vo 2 digital substation, EVNNPC subsequently deployed another 2 greenfield and 2 brownfield 110kV digital substations. Beside EVNNPC utility, the independent power producer (IPP) followed to deploy a 220kV green field digital substation project connecting to the windfarm. The standardization of digital substation optimised the manpower and cost of operation, maintenance service as well as reducing execution time of these projects. All 5 subsequent projects were successfully constructed, commissioned, and energized by 2021.This paper describes the design principles, architecture adopted, reliability analysis of protection and control (PAC) scheme in digital substation, benefit of digital substation standardization, proven benefit of IEC 61850 process bus, lessons learned and the return of experience of deploying these six digital substations.