Expanding the Scope of Protective Relays across Traditional Boundaries

The new competitive environment is having visible affects on the traditional vertically integrated utilities of the past and on modern relay and ontrol system design. Changing needs and rules by which utility companies are operated require new approaches in design and management of protection and substation control. In the past, each function of distribution switchgear was separately performed by function-dedicated devices. The installation, testing and operation of each set of devices were even sometimes the responsibility of separate departments. The migration of local control and metering into protective relaying is an attractive option for economic and efficient asset management, although it breaks with traditional practises. Data sharing of all involved functions, and interoperable data communication from the bay level up to system level, fully utilises all viable synergy. Modern intelligent electronic devices (IEDs) now enable the manufacturers to meet a multitude of different customer requirements and previously dedicated stand-alone functions, e.g. system protection, metering and supervisory control. This combined IED is a comprehensive database of all feederdedicated status and event data. It allows economic co-ordination with substation- or distribution automation schemes and one common human machine. The German Association of Electric Utilities, VDEW, has established since 1987 working groups, which define their requirements on modern numerical IEDs and serial communications among IEDs. Target of the efforts is the defined scope of core functions and communications interoperability among IEDs.

کلیدواژه ها:

Power System Protection ، Digital Relays ، IED