Integrated operation of EHVAC & HVDC in Indian power system using synchrophasors

The Indian power system operation consists of integrated operation of AC and DC transmission system. HVDC back to back stations were used to transfer power between regional grids when various regions in Indian grid were not synchronised. EHVAC and HVDC based high power corridors helped regions deficit in power to obtain power availability from surplus regions. The skewed distribution of natural resources like coal, natural gas pushed for better connectivity across the grid. Now Indian Power System also has international power transfer with Bhutan, Bangladesh, Nepal & Myanmar in a step forward towards SAARC grid. The interconnection of the grids is an amalgamation of HVDC links (500 kV & 800 kV) and EHVAC (400 kV & 765 kV) lines for both inter regional/national as well as intra-regional power transfer. Synchrophasors at transmission level were first introduced in India in the year 2012 when a total of 14 PMUs were commissioned in Northern, Western & Southern Region however the usage for real-time visualization led to higher role of synchrophasor technology across control centres. However by the year 2017, the number of PMUs installed went up to 77 and with the better visualization tools, the usage of Synchrophasors for real-time operation by the system operator has increased. The enhanced visibility in grid operation with the use of synchrophasors has helped operator in identifying various aspects of integrated operation and take actions in real time. The paper discusses the utilization of synchrophasors in control room application for both real-time despatch and post-despatch analysis.