DSP based overcurrent relay using fuzzy bang–bang controller

Overcurrent relays are very important protection component that require high reliability to maintain high security in power systems. With the new numerical relay technology using digital signal processor (DSP), it is possible to improve the performance of the relay significantly. However, application of DSP in numerical overcurrent relays is limited especially in coordination among the group of relays. The relay must work proficiently to coordinate with the networks in order to avoid mal-operation. Therefore, in this paper, an implementation of overcurrent relay with improved coordination on a DSP, TMS320F2812 is described. The fuzzy bang–bang controller is used as the control strategy for the relay to provide efficient control for overcurrent protection. The performance evaluation of the proposed system is based on steady state analysis, transient state analysis, coordination and lastly the execution time of the DSP. The results obtained using this new proposed controller is very promising.

► A DSP based overcurrent relay using fuzzy bang–bang controller is implemented. ► The system is competent in achieving minimum time to trip and detect transient input. ► Mal-trip event is prevented and at the same time maintain coordination requirement. ► Less execution time enables to obtain decision faster and execute isolation quickly.