Short Circuit Analysis for Effective Relay Coordination in Nigerian Port Authority, Rivers state

This study seeks to address the poor order of operation of relays in Nigerian Ports Authority (NPA) for effective relay coordination. NPA is fed from Marine Base distribution substation of 2 X 15MVA, 33kV. Short circuit analysis is used and Inverse Definite Minimum Time (IDMT) for prompt response of the relay and hence, the circuit breakers. Modelling and simulation of the network is carried out using Electrical Transient Analyzer (ETAP 19.0.1) using data obtained from the Port-Harcourt Electricity Distribution Company and the Transmission Company of Nigeria. The outcome of the analysis shows that in the existing case, the order of tripping of the primary feeder relays with their respective backup is wrong.When a 3-phase fault is initiated on the existing NPA feeder, the order of time of operation in response to fault is 82.9ms, 137ms, 213ms and 110ms, with the sequence from feeder breaker 33kV to line breaker, 33kV control panel breaker and then to 11kV incomer control breaker. The improved case gives an order of 226ms, 343ms, 411ms and 420ms. 420ms.The existing case means that fault occurs in the order of 1,4,3,2. This negates the right sequence, which is 1,2,3,4. Proper and effective relay coordination is necessary because it protects both the equipment connected in the network and the personnel working on such equipment from danger. {"references": ["1.\tNoghabi, A. S., Sadeh, J., & Mashhadi, H. R. (2009). Considering different network topologies in optimal overcurrent relay coordination using a hybrid GA. IEEE Transactions on Power Delivery, 24(4), 1857-1863.", "2.\tSo, C. W., & Li, K. K. (2000). Overcurrent relay coordination by evolutionary programming. Electric power systems research, 53(2), 83-90.", "3.\tAlam, M. N., Das, B., & Pant, V. (2015). A comparative study of metaheuristic optimization approaches for directional overcurrent relays coordination. Electric Power Systems Research, 128, 39-52.", "4.\tHussain, M. H., Musirin, I., Rahim, S. R. A., Abidin, A. F., & Azmi, A. (2013). Optimal overcurrent relay coordination using particle swarm optimization. In 2013 International Conference on Electrical, Control and Computer Engineering,(InECCE 2013) (Vol. 2013, pp. 42-47).", "5.\tRazavi, F., Abyaneh, H. A., Al-Dabbagh, M., Mohammadi, R., & Torkaman, H. (2008). A new comprehensive genetic algorithm method for optimal overcurrent relays coordination. Electric Power Systems Research, 78(4), 713-720.", "6.\tHorsfall, D. J., Idoniboyeobu, D. C., Ahiakwo, C. O., & Braide, S. L. (2021). Relay Coordination Analysis in SPDC Forcados Distribution Network for Operation, Planning and Future Expansion. Journal of Newviews in Engineering and Technology (JNET), 3(4).", "7.\tObire, P., Idoniboyeobu, D. C., & Braide, S. L. Protective Relay Coordination in an Injection Substation Using Short Circuit Analysis. International Journal of Advances in Engineering and Management (IJAEM), 4(8), 753-763."]}