Authors: Aziba Dennis Ayemhenre, and J. C. Onuegbu

CITATION: Aziba Dennis Ayemhenre and J. C. Onuegbu (2025).An Ac power system using 33kv transmission line as a case study. Frontline Professionals Journal 2(5), 47-57

ABSTRACT

Background: This research aims to analyse, mitigate, and model harmonics in a power system using MATLAB Simulink to build a 33kV transmission line model. The paper presents the control of harmonics in a 33kV transmission line using SAPF in mitigating harmonic current in the power system.

Methods: Hourly readings of kW, kVar, kV and I of each feeder were obtained from the Transmission Company of Nigeria (TCN), and these results serve as source data for this research. Readings of an average of 3hours interval for 6 days was used as a test case.

Results: The simulation was conducted for the system under two different scenarios: one where the power system was connected to SHAF and another where it was not. By utilizing bus data readings from August 1, 2018, the total harmonic distortion (THD) without the SHAF connection was found to be 80.44%. However, when SHAF was connected, the THD dropped to 3.67%. Additionally, using bus data from August 2, 2018, the THD for the system without SHAF was 84.34%, while with SHAF connected, it was reduced to 3.23%. Using the load data from the 3rd and 4th of August 2018 to run the simulation, the THD values were 92.73% and 101.12%, respectively, when the SHAF was disconnected, while the THD readings dropped to 3.70% and 4.63% when the SHAF was connected to the system.

Conclusion: This paper has presented an analysis of harmonics in a power system and also presented method to mitigating it using a SHAF. A 33kV transmission line was used as a case study, a model of the transmission line was developed and used to evaluate the presence of harmonics on the line, which are due to the presence of non-linear load connected to the network.