AN INVESTIGATION INTO THE CONSEQUENCES OF OVER LOADING A TRANSFORMER

CHAPTER ONE

INTRODUCTION

Background of the study

Transformers play a crucial role in the electrical power distribution system, facilitating the efficient transfer of energy by increasing and decreasing voltages. The normal service life of a transformer is the standard duration of continuous operation under typical environmental conditions and nominal operating parameters. Exceeding the specified rating of a device and/or using it in hotter conditions has a potential danger and leads to faster deterioration of the insulation. According to Ismial & Jafaru (2023) exceeding the rated values for both the loading and temperature of a transformer may lead to a heightened risk of premature failure. This failure can happen either immediately or after a set period of time, as a consequence of the degradation of the transformer components. 

Significantly, the standard provides guidance for transformer loading in relation to the increase in operating temperature and the degradation of insulation due to thermal ageing; the rate of insulation degradation is evaluated by measuring the hot spot temperature. As argued by Isioma (2021) subjecting transformers to excessive loads may result in significant repercussions, affecting both the machinery itself and the wider electrical network. Exceeding the load capacity of a transformer may result in various technical complications, mostly caused by excessive thermal energy. When a transformer exceeds its rated capacity, it produces excessive heat that it cannot effectively disperse, resulting in the deterioration of its insulation. The degradation of the transformer diminishes its longevity and may eventually result in malfunction (Zhu  2023). In addition, overloading may lead to thermal expansion, which puts strain on the mechanical components of the transformer and can cause bodily harm (Smith & Johnson, 2022). From an economic standpoint, the act of overloading transformers might result in significant expenses. Utilities incur higher operating expenditures due to the need of regular maintenance and the possibility of premature replacement. Furthermore, the occurrence of transformer failures caused by excessive load may result in power blackouts, causing disruptions to both consumers and companies and leading to substantial financial losses. 

Recent data indicate a rise in transformer-related fires in areas with high power demand, emphasizing the urgent need to tackle this problem (Green Energy Journal, 2023). Nevertheless, recent improvements in monitoring and diagnostic technology have enhanced the capacity to identify and avert transformer overloading. An example of this is the incorporation of Internet of Things (IoT) devices and sophisticated sensors, which enables the continuous monitoring of the state and load of transformers in real-time (Chen et al., 2023). These technologies have the capability to detect signs of possible overloading in advance, allowing for proactive steps to be implemented before significant harm occurs. Multiple case studies exemplify the consequences of transformer overloading. An incident of significance occurred when a metropolitan region had a significant power outage. The cause of this outage was determined to be the breakdown of a transformer that was overloaded due to insufficient monitoring (Urban Power Report, 2023). This occurrence highlights the need of having strong monitoring systems and following load management measures diligently. Therefore, the researcher sought to investigate the consequences of over loading a transformer.

Statement of the problem

Transformers are essential components in the electrical power distribution network, playing a vital role in regulating voltage to optimize power transmission efficiency. Nevertheless, the increased need for power, fuelled by the fast growth of cities and industries, has resulted in transformers being often overloaded above their specified limits. In a study by Nneji & Frank (2022), exceeding the capacity of transformers may lead to significant technical, economic, and safety repercussions. Although there have been improvements in monitoring and diagnostic technology, incidences of transformer overloading and consequent failures continue to be widespread. 

Undoubtedly, recent investigations  have shown that overloading has caused a substantial increase in fires connected to transformers, which poses serious dangers to infrastructure and public safety (Green Energy Journal, 2023). Inadequate management of transformer loads may result in extensive power outages, as shown by a recent significant blackout in a metropolitan region caused by an overloaded transformer (Urban Power Report, 2023). A research conducted by Bakare (2022) showed that transformer malfunctions contribute significantly to the economic consequences of power outages, underscoring the need of adhering to the operating constraints of transformers. Ensuring safety is of utmost importance while dealing with the issue of overloading transformers. Excessive heat production may result in the occurrence of fires, which can pose threats to both humans and infrastructure. Excessive load on transformers may also result in electrical malfunctions, which can pose risks such as electric shocks and explosions. Notwithstanding these crucial concerns, there exists a deficiency of efficacious remedies to avert excessive burden and regulate the well-being of transformers.  Hence, the study investigates the consequences of over loading a transformer.

1.3 Objective of the study

The broad objective of the study is to investigate the consequences of over loading a transformer. The specific objectives is as follows

To examine the prevalence of transformer overloading in Nigeria power sector

To evaluate the factors contributing to transformer overloading.

To assess the economic costs associated with transformer overloading

To evaluate the technical impacts of overloading on transformer components

1.4 Research questions

The following questions have been prepared to guide the study

What is  the prevalence of transformer overloading in Nigeria power sector?

What are the factors contributing to transformer overloading?

What are the economic costs associated with transformer overloading?

What are the technical impacts of overloading on transformer components?

1.5 Significance of the study

The study will be significant to policymakers and power regulatory bodies as it will inform them about the critical need for robust regulatory frameworks governing transformer load management. The study will provide recommendations for policy enhancements that ensure the reliable and safe operation of transformers. This will be particularly important in regions experiencing rapid urbanization and increasing power demands. The study will also be significant to the academic community as it will contribute to the existing literature.

1.6 Scope of the study

The study focus on the consequences of over loading a transformer. Empirically the study will evaluate the factors contributing to transformer overloading, assess the economic costs associated with transformer overloading, evaluate the technical impacts of overloading on transformer components and assess the effectiveness of existing monitoring and diagnostic technologies in preventing transformer overloading.

Geographically, the study is delimited to PHCN station Dawaki, Abuja.

1.7 Limitation of the study

Like in every human endeavour, the researchers encountered slight constraints while carrying out the study. The significant constraints are: 

Time: The researcher encountered time constraint as the researcher had to carry out this research alongside other academic activities such as attending lectures and other educational activities required of her.

Finance: The researcher incurred more financial expenses in carrying out this study such as typesetting, printing, sourcing for relevant materials, literature, or information and in the data collection process.

Availability of Materials: The researcher encountered challenges in sourcing for literature in this study. The scarcity of literature on the subject due to the nature of the discourse was a limitation to this study.

1.8 Definition of terms

Transformer: An electrical device that transfers electrical energy between two or more circuits through electromagnetic induction, primarily used to step up or step down voltage levels in power distribution systems.

 Overloading: Operating a transformer beyond its rated capacity, resulting in excessive electrical currents that generate more heat than the transformer can safely dissipate.

 Insulation Degradation: The deterioration of the insulating material within a transformer due to thermal stress, which reduces its effectiveness and can lead to electrical failures.

 Mechanical Stress: Physical strain on the transformer’s components caused by thermal expansion and contraction, which can lead to structural damage over time.

 Power Outage: A temporary loss of electrical power supply, which can be caused by the failure of overloaded transformers among other factors.

 Load Management: Strategies and practices employed to distribute electrical load efficiently across the power grid to prevent overloading of transformers and other electrical components.