On the Assessment Procedure of Imposed Duty on Interrupting Devices in Distribution System Considering Penetration of Distributed Generations

Determination of the maximum permissible size of distributed generators at any location ofdistribution system is the key step during interconnection procedures. Recently some methods have beendeveloped based on prevention of recloser-fuse miscoordination problems. These methods consider theeffects of fault current contribution of distributed generators on the lost coordination between circuitbreakers, reclosers and lateral fuses. This paper introduces another criterion which should be consideredduring interconnection studies. The criterion is based on possibility of interference between the existinginterrupting device rating and duties imposed on them. Interference may occur as consequence of increasedsymmetrical and dc decaying time constant of short circuit current, after interconnection of distributedgeneration. The procedure introduced in international standards is used to assessment the imposed duty oninterrupting devices and obtain a limit for interconnected distributed generations. The method is applied toa sample distribution system implemented in PSCAD/EMTDC. The obtained results revealed that theproposed method is accurate and capable of reducing some disadvantages of distributed generation such asrating violation and miscoordination problems of protective devices.

کلیدواژه ها:

Distributed Generation ، Interrupting Duty ، Protective Devices ، Coordination ، Short Circuit Current