Detecting, locating and identifying the type of faults on the interfacing link between an industrial cogenerator and a utility

The process of simultaneous generation of energy in two or more forms, such as heat and electricity, is known as cogeneration. The electric power produced in this way can be used to partially or totally supply the load within the industrial premises. To improve the reliability, flexibility and economy compared with standalone operation, cogenerators are usually operated in parallel with a utility network. However this mode of operation requires that special attention should be given to the protection requirements of the interfacing circuits between an interconnected industrial cogenerator and a utility. Currently the protection of the interfacing circuit is based on conventional methods using dedicated relays which in many cases makes it uneconomical. A microprocessor based technique for detecting, locating and identifying the type of faults on the interfacing circuit is described. The results obtained from this technique as applied on a simulated system are presented