Development and Implementation of an Adaptive Overcurrent Protection Algorithm for a Modern Power Distribution Network

There has been a prediction for the future power system that penetration of distributed generators (DG) to be high. One of the challenges for the modern power system is a protection issue when DGs are connected. The level of fault current is dependent on the sources of the main power grid. However, when the DGs are connected to the distribution system, there is a change in the fault current. Therefore, the setting of protection coordination varies which leads to maloperation of the distribution network. It is not effective to use the traditional overcurrent protection as it is fixed to one value. Therefore, the proposed solution for this problem is to employ adaptive overcurrent protection. The advantage of this protection is that it adapts to realtime changes automatically and isolation of the fault is faster. In this paper, an algorithm is proposed based on which adaptive overcurrent protection relay works. This algorithm is verified by using a circuit system with three different types of test systems. All the simulation studies are carried out via Electrical Transient and Analysis Program (ETAP) software environment.