The main intention of this project is to implement a system that can be used in power transformer protection. The system checks the operating parameters of the transformer i.e. current and reports the quantity that is flowing through the transformer. The system is designed such that it is able to detect currents above the normal operating level and isolate the power transformer from the distribution line. This isolation process is to ensure that the transformer is safe from any excess current levels that can make it to overheat thus get damaged. It gives a solution to the need to reduce cost of maintenance and ensure that supply of electricity to consumers is not interrupted for long periods taken while repairing or replacing destroyed transformers.
CHAPTER ONE
INTRODUCTION
Background and Justification
Transformers are generally very important in our daily lives. The transformer is an electrical machine that allows the transmission and distribution of electrical energy simply and inexpensively, since its efficiency is from 95% to 99%, i.e., the transformer operates more efficiently than most electrical devices. They are involved in the formation of various electronic devices and power electrical grids. When we talk about power transformers, we refer those step up and step down transformers used in generation, transmission and distribution networks. Power transformers are in the second place in importance after the generator, so it is one of the most equipment that is many protections are provided for them, so it is necessary to make specific, preventive, diagnostics and corrective tests for them from birth (manufacturing stage) through their lifespan, until they reach their end of life.
In the design of electrical power transmission and distribution system, there are various factors that need to be considered in the quest to satisfy the needs of electricity consumers. Electrical power systems experience faults at various times due to various reasons. These faults must be foreseen and safety precautions applied to the power system. The power systems engineer must include in his design, safety measures in order to avert any destructive occurrences that the system may undergo at any given time. Power system protection is very essential and necessary for a dependable electrical power supply. It ensures that the system is protected from itself and that the consumer is also safe as he benefits from the electrical power supply. An electrical power system consists of various components such as generators, switches, transmission cables, transformers, capacitor banks among other components. It cannot therefore operate without an effective protective device to keep these components safe and the system stable. Faults in a power system refer to the undesired conditions that occur in the electrical power system. These conditions may include short circuit, over current, overvoltage, high temperatures among others.
It is clear that over time, there has been an increase in human population, economic growth and technological advancement. This has continuously made the demand for electrical power to go high because as technology, human population and economy grows; there is an increase in demand for power as many more electrical loads are introduced into the supply line. An increase in load leads to a lot of current drawn from the power line. At times the demand goes above what the power distributor can supply. The consequence of this is that electrical power overload cases ᵠᵠbecome common thus posing danger to power system components. This therefore throws in the need for devices that can monitor the rate of power consumption in accordance with the level that a given system is designed to sustain. Such a device must be designed to cut off consumption if the system oversteps its ability thus being dangerous to users and the components. In this project, we look at the protection of power transformer from various faults that may occur and may be destructive to the component if left undetected. The transformer is a very important component in an electrical power system as distribution of electrical power to consumers is more efficiently effected. Every transformer is designed to comfortably supply a given load. Cases of overload or short circuits can lead to transformer being damaged. To combat such occurrence, an elaborate system that monitors these excesses in supply parameters needs to be built. Such a device controls the flow of electrical power to the load so that the transformer is not overworked. Over current relays and overvoltage relays have been used for a long period of time and have been electromechanically controlled. In this system, a microcontroller is used to monitor cases of electrical faults and communicate to a switch to isolate the transformer from the system.
Aim and Objectives of the Study
1.Collect practical data for the tests that have been done
2.Know the equipment used in the particular test, and its quality.
3.Checking the interest of transformers while in service.
4.Trying to designing a simulation for some of those tests, to help the transformer specialists know the expected results of the test
Motivation
Faults occur in substation will eliminate the services from the units for this reason effective protection action is required to minimize damage and repair costs where it senses fault, Ensure safety of personnel
Contribution to Knowledge
Occurrence of fault is hazardous to both electric power user and the electric system itself. To the user, life is of most important concern. The main concern of the system is to ensure a stable supply of electric power to consumer and to ensure that the electrical components do not get destroyed. In summary, power protection is necessary to:
a)User/Personnel- ensure safety i.e. Prevent injury/accident.
b)Electrical equipment – to protect the equipment from cases of over current, overvoltage and frequency drift that can destroy the equipment.
c)General Safety -Prevent secondary accidents that occur as a result of system fault like fire.
d)Power Supply Stability- Ensures a continuous and stable supply of electrical power.
e)Operation Cost -Ensure optimal operating efficiency so as to reduce equipment maintenance/replacement cost
Scope and Limitation of project
The investigation carried out in this project is limited to power transformer protection methods. The extent of the work is to build a device that detects current spikes/overload in the primary and secondary sides of a single phase transformer and isolate it from the power system.
1.7 Structure of the Report
This section will discuss the layout of the report, the chapters are;
Chapter 2 will look at literature on ……
Chapter 3 this involve adopting engineering methodology, then implement the methodology
Chapter 4 this section will discuss test result, all measurement and analysis will be carrying out
Chapter 5 will state the conclusion, project appraisal, and recommendation.
