Analysis of 132/33 KVA Grid Sub-Transmission Line along Gombe to Yola Power System of Nigeria

Abstract

In Nigeria, effective electric power transmission is a top priority. Power generating and the network of power distribution are connected via electric power transmission. A research project was conducted to determine the status of the networks in order to improve performance, which resulted in the performance evaluation of the 132KV Sub-transmission lines. Data from the Transmission Company of Nigeria (TCN) substations under investigation were utilized in the research work. The Gombe-Yola Sub-region\'s 132KV networks are divided into two 132KV active networks and 11 33KV active networks, with a total of 443.617MVA in active loads connected to the 33KV buses. The network was modeled and simulated using the Electrical Transient Analyzer Program (ETAP 12.6), and the bus voltages and network power losses were investigated using MATLAB and Simulink. It was discovered during simulation that the bulk of the network\'s equipment, including transformers, buses, and transmission lines, experience numerous disturbances that result in forced outages and a corresponding loss of load and productivity. All transformers were critically loaded based on the results of the base-case simulation, with several exceeding 100% loading. As bus voltage magnitudes went outside the +/- 5% nominal rated values, the percentage operational bus voltages were below threshold. Additionally, the systems had undesirable power factor levels. Threatening discoveries prompted an effort to strengthen the networks. In this study, three system enhancement algorithms—capacitor placement, transformer upgrade, and transformer load tap modifications—were applied. To get the best outcome, these algorithms were successively stacked. As a result of significant system improvements, both networks\' performance in the final simulation result was within allowable bounds. System-wide apparent losses decreased to a 50% reduction enhancing the networks\' efficiency in the process.

Introduction

I. INTRODUCTION

The power sector in Nigeria has been facing several challenges, including inadequate power supply, poor infrastructure, and lack of maintenance of existing facilities. Despite the numerous efforts made by the government to improve the situation, there is still a significant gap between the demand for electricity and the supply available. One of the major issues in the power sector is the transmission of electricity from the power generation stations to the distribution networks.

The transmission lines are an essential part of the power system, and any malfunction or failure can lead to power outages, loss of revenue, and damage to electrical equipment. This article, analyze the 132/33 kVA grid sub-transmission line along the Gombe to Yola power system of Nigeria. This power system plays a crucial role in delivering electricity to the region, contributing to the economic and social development of the area.

II. OVERVIEW OF THE GOMBE TO YOLA POWER SYSTEM

The Gombe to Yola power system is an essential part of Nigeria's electricity infrastructure. It encompasses a network of power generation, transmission, and distribution facilities that work together to ensure a reliable supply of electricity to consumers in the region. The 132/33 kV grid sub-transmission line is a critical component of this system, responsible for transmitting power from the generation stations to distribution centers.

The Gombe to Yola Power System is an electricity transmission network in Nigeria that connects the cities of Gombe and Yola. It plays a crucial role in supplying power to the northeastern region of the country, facilitating economic development, and meeting the energy needs of the population.

The power system consists of high-voltage transmission lines and associated infrastructure, including substations and transformers. These components work together to transmit electricity generated from various sources, such as power plants and renewable energy installations, to the consumers in Gombe and Yola.

The transmission lines are designed to carry electricity at high voltages, typically in the range of 132 kilovolts (kV) to 330 kV, to minimize power losses during transmission. These lines are supported by towers or poles and are strategically routed to ensure efficient and reliable power delivery.

Along the Gombe to Yola power system route, there may be intermediate substations that serve as connection points for transferring power between different transmission lines or adjusting voltage levels. These substations play a vital role in regulating and controlling the flow of electricity, ensuring its safe and reliable transmission.

The Gombe to Yola Power System contributes to the overall stability and reliability of the regional power grid. It enables the transfer of surplus power from areas with excess generation capacity to areas with high electricity demand. This helps in balancing the power supply and demand, reducing the likelihood of blackouts or voltage fluctuations.

The power system also supports the integration of renewable energy sources, such as solar and wind, into the grid. As Nigeria strives to diversify its energy mix and reduce dependence on fossil fuels, the Gombe to Yola Power System can accommodate the transmission of renewable energy-generated electricity, promoting sustainable and environmentally friendly power generation.

Efforts are continually made to improve the capacity, efficiency, and reliability of the Gombe to Yola Power System. Upgrades to the transmission infrastructure, such as the installation of advanced monitoring and control systems, are implemented to enhance grid performance, reduce downtime, and enable quicker response to faults or disruptions.

Overall, the Gombe to Yola Power System plays a vital role in ensuring the availability of electricity in the northeastern region of Nigeria. It serves as a backbone for power transmission, supporting economic growth, and improving the quality of life for the residents of Gombe and Yola.

III. IMPORTANCE OF THE 132/33 KV GRID SUB-TRANSMISSION LINE

The 132/33 kV grid sub-transmission line serves as a crucial link in the electricity supply chain. It facilitates the transfer of power from the generation stations, which produce electricity, to the distribution centers, which then deliver it to end consumers. This transmission line plays a vital role in ensuring efficient and reliable power transmission throughout the Gombe to Yola power system.

The 132/33 kV grid sub-transmission line holds significant importance in the power distribution network. It acts as a crucial link between the high-voltage transmission system and the distribution system, facilitating the efficient and reliable supply of electricity to consumers.

Voltage Transformation: The sub-transmission line plays a vital role in transforming the high-voltage electricity received from the transmission system (usually at 132 kV) into a lower voltage level suitable for distribution (commonly at 33 kV). This voltage transformation helps in reducing power losses during transmission and ensures that electricity is delivered to the distribution network at an optimal voltage level.

Power Distribution: The 132/33 kV sub-transmission line distributes electrical power from bulk supply points, such as power plants or primary substations, to various distribution substations. These distribution substations, in turn, further distribute electricity to residential, commercial, and industrial consumers. By efficiently transferring power from the transmission system to the distribution network, the sub-transmission line enables the widespread availability of electricity.

Load Balancing: The sub-transmission line allows for load balancing within the distribution system. It enables the transfer of power between different distribution substations to ensure an equitable distribution of electricity based on the varying demand from different areas. Load balancing helps in preventing overloading of specific substations, reducing the risk of equipment failures, and enhancing the overall stability of the distribution network.

System Reliability: The 132/33 kV sub-transmission line enhances the reliability of the power supply by providing alternative routes for electricity flow. In the event of a fault or maintenance work on a specific section of the line, the power can be rerouted through alternate paths, minimizing disruptions to consumers. This redundancy in the sub-transmission system helps in maintaining a reliable supply of electricity and reducing downtime.

Network Expansion: The sub-transmission line supports the expansion and growth of the distribution network. As new areas are developed or existing areas experience increased electricity demand, the sub-transmission line can be extended to connect new substations or feeders, enabling the provision of power to expanding communities and industries. This flexibility in network expansion ensures that electricity infrastructure keeps pace with the evolving needs of consumers.

In summary, the 132/33 kV grid sub-transmission line serves as a vital link between the high-voltage transmission system and the distribution system. It enables voltage transformation, efficient power distribution, load balancing, system reliability, and network expansion.

These factors collectively contribute to the overall effectiveness and reliability of the electricity supply, ensuring that consumers receive a consistent and uninterrupted power supply.

IV. DESIGN AND CONFIGURATION OF THE 132/33 KV GRID SUB-TRANSMISSION LINE

A. Load Analysis

Determine the load requirements for the sub-transmission line, including the expected power demand, peak loads, and load growth projections. This analysis helps determine the capacity and configuration of the sub-transmission line. To perform a load analysis of a 132/33 kV grid sub-transmission line, you would typically follow these steps:

1. Gather data: Collect information about the electrical load connected to the sub-transmission line. This includes data such as the types of loads (residential, commercial, industrial), their power ratings, operating schedules, and any anticipated future load growth.
2. Load estimation: Determine the total load demand connected to the sub-transmission line. This can be done by summing up the individual load demands or using statistical methods based on historical data.
3. Load diversity: Consider the diversity factor to account for the fact that not all loads are operating simultaneously at their peak. The diversity factor helps to reduce the total load demand estimation. Different types of loads have different diversity factors, and these can be obtained from electrical engineering handbooks or standards.

Diversity factor is defined as the ratio of the sum of the maximum demands of the various part of a system to the coincident maximum demand of the whole system. The maximum demands of the individual consumers of a group do not occur simultaneously. Thus, there is diversity in the occurrence of the load. Due to this diverse nature of the load, full load power supply to all the consumers at the same time is not required.

V. FACTORS AFFECTING THE PERFORMANCE OF THE 132/33 KV GRID SUB-TRANSMISSION LINE

Several factors can affect the performance of a 132/33 kV grid sub-transmission line. Here are some key factors to consider:

1)  Line Length: The length of the sub-transmission line plays a crucial role in its performance. Longer lines tend to have higher resistance, resulting in greater power losses and voltage drops. It is important to minimize line length where possible or use appropriate conductors to mitigate these losses. The distance between Gombe and Yola is about 240Kilometers, Though appropriate conductors were used, but they old enough to be replaced.

2)  Line Configuration: The configuration of the sub-transmission line, such as the choice of conductors and the arrangement of phases, can impact its performance. Proper selection of conductors based on their electrical and thermal characteristics is crucial to minimize losses and ensure efficient power transfer.

Conclusion

The 132 kV lines covers a total distance of 240km with only one 132 / 33 kV with a substations at Savannah, Numan which makes it in sufficient as the line is radial and long. Another one will be require at Kaltungo to alleviate the demand of Federal Polytechnic Kaltungo and its environs. The system may suffer a lot of disturbances leading to forced outages and concomitant loss of load and productivity. Upgrading the system will help in monitoring the system promptly. The Transmission line may require a smart grid to make the system adequate to meet the demand and improve the economic wellbeing of the region.

References

[1] J. A. Jordaan, M. W. Siti and A. A. Jimoh, \"Distribution Feeder Load Balancing Using Support Vector Machines\", Proceedings of 9th International Conference, pp. 65-71, November 2–5. 2018. [2] A.M. Ghadban and M.W. Abdulwahhab (2015); “Short Circuit Analysis for Power System Networks”. Second Engineering Scientific Conference-College of Engineering –University of Diyala 16-17 December. 2015. Diyala Journal of Engineering Sciences, Vol. 8, No. 4, Special Issue 344. Pp 343-354 [3] A.Z. Latt (2019); “Short Circuit Analysis of 33/11/0.4 kV Distribution System Using ETAP”. International Journal of Latest Technology in Engineering, Management & Applied Science (IJLTEMAS) Volume 8, No. 5. ISSN 2278-2540, pp 79-85. [4] M. Li, P. He and L. Zhao, \"Dynamic Load Balancing Applying Water-Filling Approach in Smart Grid Systems\", IEEE Internet of Things Journal, vol. 4, no. 1, pp. 247-257, Feb. 2017. [5] M. R. Vuluvala, L. M. Saini “Load balancing of electrical power distribution system: An overview” International Conference on Power, Instrumentation, Control and Computing (PICC), January 2018. [6] F.O. Agbontaen and N.S. Idiagi (2021); “Coordination of Overcurrent Relay of 132/33 kV Injection Substation”. Umudike Journal of Engineering and Technology (UJET), Michael Okpara University of Agriculture, Umudike, Abia State, Nigeria; Vol. 7, No. 1, pp. 22 – 31; Print ISSN: 2536-7404, Electronic ISSN:2545-5257; http://ujetmouau.net; doi: https://doi.org/10.33922/j.ujet_v7i1_4. Accessed March 15, 2023 [7] H. Khairul, I. Tukiman, M. Putra and L. Subekti (2019); “Short Circuit Analysis on Electrical Power Supply Building # 71 BATAN for Case Reliability Study of Nuclear Power Plant Electrical Protection System”. AIP Conference Proceedings 2180, 020036 (2019); https://doi.org/10.1063/1.5135545 Published Online: 10 December 2019.Accessed March 15, 2023. [8] D.C. Idoniboyeobu, D.C. Briade &E.E.Ayala (2020), “Low Flow Analysis of Ordinance Area, TransAmadi, Port Harcourt, Using Gauss Seidel Technique for Improvement,” Global Scientific Journals, pp.637- 640 [9] A.O. Ibe, T.K. Bala & C.I. Amesi (2017),” Impact of Network Reconfiguration: A Case Study of PortHarcourt Town 132/33kv Sub-Transmission Substation and it’s 33/11kv Injection Substation Distribution Networks,” European Journal of Electrical and Computer Engineering, pp. 3-6 [10] K. Natkar (2015); “Design Analysis of 220/132 kV Substation using ETAP”. International Research Journal of Engineering and Technology (IRJET), vol 2. [11] C.E. Okachi & D.C. Idoniboyeobu (2020), “Electrical Load Evaluation in Igwuruta, Port Harcourt for Improved Distribution,” Global Scientific Journal, pp.718-725 [12] A.M. Eltamaly (2016); “Load Flow Analysis by Gauss-Seidel Method: A Survey”. International Journal of Mechatronics, Electrical and Computer Technology, PISSN: 2411-6173, EISSN: 2305-0543, Egypt. [13] F. O. Agbontaen, N. S. Idiagi. (2022) “Short Circuit Analysis of a Nigerian 132/33 kV Injection Substation.” Journal of Advances in Engineering Design Technology Vol. 4(1) pp. 1-10 ISSN-2682-5848. [14] K. Mansouri, M. Ben Hamed, L. Sbita and M. Dhaoui , (2015) \"Three-phase balancing in a LV distribution smart-grids using electrical load flow variation: “L.F.B.M\", 2015 16th International Conference on Sciences and Techniques of Automatic Control and Computer Engineering (STA), pp. 427-431.

Copyright

Copyright © 2023 Kabiru Abubakar Yahya, Bubakari Joda, Usman Ibrahim Siad. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.