2013-04-03 - ABB’s coordinated islanding and load shedding system supplies power to Reliance Energy’s customers during western grid blackouts.
The Reliance Energy (erstwhile Bombay Suburban Electric Supply, or BSES) power distribution network with two 250 megawatt (MW) generating stations in the coastal city of Dahanu is spread across western Mumbai, stretching from Ghodbunder in the east to Borivali in the west. This system is connected to two different utility grids: Maharashtra State Electricity Transmission Company Limited (MSETCL) and TATA Power, for importing the extra power required in their distribution network.
The generation, load data and network status available from the substation automation system (ABB’s SCS-200 system) installed earlier at each substation and locally used for control and monitoring, provided very slow-speed communication networks, using power line carrier communication (PLCC) links. Providing rapid indication of islanding for change of mode in operations, within the critical clearing time of the system, was a challenge for generating units at Dahanu. It was also imperative to prevent tripping during isolation and for stable operation of the entire 220 kV electrical network during grid disturbances.
Providing reliable power to consumers
In 2006, the local substation automation systems for 220 and 33 kilovolt (kV) substations were upgraded with ABB’s 800xA technology with AC800M controllers, S800 IO modules, and a communication network using Fox series equipment and new SCADA system for Reliance Energy’s entire distribution network with ABB’s Network Manager Technology. The generation and load data from individual substations were made available to the centralized islanding and load shedding system using fast communication network supported with 61850 technologies. Aarey, one of the main central transmission and distribution stations, was identified for the centralized control and monitoring of the entire transmission and distribution network.
Our installed solution now provides fast detection of the system islanded and tie line connections for change of mode of operation for the units at Dahanu, and subsequent fast load shedding of non-critical feeders across the distribution network, as required while islanding. The load shedding systems delivered by us, support priority setting options for tripping 33 kV load feeders, as desired by the operator.
Besides, ABB is also upgrading the Network Management system to include updated technologies and many of the new 220 kV, 33 kV substation automation systems for the substations at Saki, Gorai and Goregaon in the existing system. The load shedding system is also extended to these new substations to provide reliable power to consumers during grid disturbances.