The Evaluation of Over Current Relay and Ground Fault Relay Settings on Power Transformers

  • Fikri Fatwa Ulhuda Universitas Riau, Pekanbaru, Indonesia
  • Azriyenni Azhari Zakri Universitas Riau, Pekanbaru, Indonesia
  • Umair Ali CECOS University of IT and Emerging Science, Peshawar, Pakistan
Abstract viewed: 78 times
pdf downloaded: 40 times
Keywords: Ground Fault Relay, Overcurrent Relay, Power Transformer, Settings Relay


Power transformer is an important component of the substation and has an important role in the electric power distribution system. During operation the power transformer can’t be isolated from distribution system when abnormal conditions or faults occur. A fault in the power transformer will have huge impact on the power transformer itself. The substation has an installed capacity of 60 MVA of power transformers, and during operation there is a possibility of relay failure, which may interrupt the power distribution process to the load. To avoid this failure, it is necessary to analyse the settings of Over Current Relay (OCR) and Ground Fault Relay (GFR) on the 60 MVA transformers. The analysis was carried out by simulating short circuit faults of the electrical system in the ETAP software application, and then configure the setting of the relay by referring to the magnitude of the short circuit current value for phase to phase and phase to ground. The results of this analysis are used as a reference to determine the OCR and GFR relay values in the power transformer. The results obtained show that the recommended value for OCR setting on 150 kV power transformers is 0.92 second while for GFR is 0.96 second, and for the 20 KVA power transformers the OCR and GFR setting values are 0.40 and 0.20 seconds respectively. Comparison based on the results of the setup data and the analysis data has carried out, there is difference in the working time of the relay, with a difference of 5%, where the value of the analysis results is not much different from the conditions in the field.


BPS, Pertumbuhan Pelanggan Listrik Wilayah Riau. Pekanbaru, Badan Pusat Statistik, 2021.

PLN, Buku Pedoman Pemeliharaan Proteksi dan Kontrol Transformator. Jakarta, Perusahaan Listrik Negara, 2014.

NPFA, “Life Safety Code,” 2018. (accessed October 20, 2023).

Zulkarnain and Sepriadi, “Over Current Relay Coordination Analysis at the Indarung III Cement Mill PT. Semen Padang,” Rang Tek. J., vol. 4, no. 1, pp. 42–51, 2021.

H. Saadat, Power System Analysis. New York: McGraw-Hill, 1999.

R. H. M. Noor, “Analysis of Over Current Relay Coordination for Phase and Ground Disturbances at PT. KPC,” Institut Teknologi Nasional, 2017.

A. S. Sampeallo, N. Nursalim, and P. J. Fischer, “Analysis of Short Circuit Faults in the Own Use Network of PLTU Bolok PT. SMSE (IPP) Unit 3 and Unit 4 Using Etap 12.6.0 Software,” J. Media Elektro, vol. 8, no. 1, pp. 76–85, Apr. 2019.

T. A. Al qoyyimi, O. Penangsang, and N. K. Aryani, “Determining the Location of Short Circuit Faults in the 20 kV Distribution Network Tegalsari Surabaya Feeder Using the GIS Based Impedance Method,” J. Tek. ITS, vol. 6, no. 1, Mar. 2017.

J. H. Harlow, Electrical Power Transformer Engineering, 3rd ed. New York, Taylor & Francis Group, 2012.

Karyana, Sistem Proteksi Transmisi dan Gardu Induk Jawa Bali Edisi Pertama. Jakarta: PT. PLN (Persero), 2013.

M. Madani, T. Suheta, and T. Odinanto, “Analysis of Over Current Relay (OCR) and Ground Fault Relay (GFR) Settings on 60 MVA Transformers in 150 KV GIS,” Semin. Nas. Sains dan Teknol. Terap. VII 2019, pp. 683–690, 2019.

I. K. W. Iswara, G. D. Arjana, and W. A. Wijaya, “Analysis of Safety Relay Settings Due to Reconfiguration at the Blahbatuh Feeder,” J. Spektrum, vol. 2, no. 2, pp. 74–79, 2015.

I. Gunawan, W. Rinas, and I. G. N. Janardana, “Analysis of Resetting Over Current Relay and Ground Fault Relay on 60 MVA 150/20 kV Transformer 20 KV Feeder Padang Sambian Main Substation”, SPEKTRUM, vol. 5, no. 2, pp. 246–252, 2018.

H. Y. Kustanto, M. Suyanto, and S. Hani, “Analysis of Over Current Relays and Ground Fault Relays on 60 MVA Power Transformers at Bantul 150 kV Substation Using the Etap Program,” J. Elektro, vol. 1, no. 1, pp. 58–68, 2014.

I. Abdullah, June Tyastuti, and S. Handoko, “Evaluation of OCR, GFR and Recloser Relay Settings After Distribution Network Reconfiguration at Transformer 2 of Srondol Semarang Substation Using Etap 12.6.0,” TRANSIENT, vol. 5, no. 3, pp. 329–337, 2016.

C. Fang, W. Yan, X. Zhiwei, and Y. Zili, “A Survey of Disconnecting Circuit Breaker’s Application” in 2018 International Conference on Smart Grid and Electrical Automation (ICSGA), June. 2018, pp. 80–84.

J. P. Barret, P. Bornard, and B. Mayer, Power System Simulation. London: Chapman & Hall, 1997.

D. C. Idoniboyeobu, B. A. Wokoma, and V. C. Ibanibo, “Preventive Maintenance for Substation with Aging Equipment Using Weibull Distribution,” Am. J. Eng. Res, vol. 7, no. 4, pp. 106–112, 2018.

How to Cite
F. Fatwa Ulhuda, A. Azhari Zakri, and U. Ali, “The Evaluation of Over Current Relay and Ground Fault Relay Settings on Power Transformers”, IJEEPSE, vol. 7, no. 2, pp. 100-110, Jun. 2024.