Description

TABLE OF CONTENT

 

DEDICATION.. ii

DECLEARATION.. iii

CERTIFICATION.. v

ACKNOWELEDGEMENT. vi

SUMMARY.. vii

TABLE OF CONTENT. viii

LIST OF FIGURE.. x

CHAPTER ONE.. 1

1.0          INTRODUCTION.. 1

1.1          BACKGROUND OF STUDY.. 1

1.2          STATEMENT OF PROBLEM… 4

1.3          SIGNIFICANCE OF THE PROJECT. 4

1.4          AIM AND OBJECTIVES OF THE STUDY.. 4

1.5          SCOPE OF THE PROJECT. 5

1.6          MOTIVATION OF STUDY.. 5

CHAPTER TWO.. 7

2.0          LITERATURE REVIEW… 7

2.1          REVIEW OF PREVIOUSLY DONE WORKS. 7

2.2          IMPROVEMENT ON THE PREVIOUS WORKS. 9

2.3 BLOCK DIAGRAM… 10

2.4          EXPLANATION OF BLOCK DIAGRAM… 10

2.5          DESCRIPTION OF CIRCUIT COMPONENTS. 12

2.6          TRANSFORMER FAULTS. 38

2.7          POWER TRANSFORMER PROTECTION.. 44

2.8          TYPES OF PROTECTION IN TRANSFORMER.. 46

CHAPTER THREE.. 48

3.0          RESEARCH AND DESIGN METHODOLOGY.. 48

3.1          METHODOLOGY.. 48

3.2          DESIGN PROCEDURE/APPROACH FOR PROJECT IMPLEMENTATION.. 49

3.3          CIRCUIT DESIGN.. 51

3.4 CIRCUIT ANALYSIS. 52

3.5 HARDWARE COMPONENTS. 54

3.6 ANALYSIS OF HARDWARE COMPONENTS. 54

3.7 WORKING AND IMPLEMENTATION.. 55

3.8          TRANSFORMER WINDING DESIGN.. 57

3.9 EXPECTED RESULT. 62

REFERENCES. 63

LIST OF FIGURE

Figure 2.1: Block diagram of transformer smart monitoring and control system.. 10

Figure 2.2: A bridge rectifier 13

Figure2.3: A bridge rectifier current flow during a positive half cycle. 13

Figure 2.4: A bridge rectifier current flow during a negative half cycle. 14

Figure 2.5: Input-Output waveforms of the bridge rectifier 14

Figure 2.6:  Non-polarized capacitor pictorial and graphical symbol 16

Figure 2.7: Polarized capacitor and graphical symbol 17

Figure 2.8: Resistor pictorial and graphical symbol 20

Figure 2.9: Core type with concentric and vertically layered winding. 21

Figure 2.11: core type transformer winding placement 22

Figure 2.12: Shell type transformer winding placement 22

Figure 2.13: Schematic, graphical and pictorial symbol of step-down transformer 24

Figure 2.14: Op-amp and comparator op-amp symbol 29

Figure 2.15:  Development board of ESP32 and Architectural block. 31

Figure 2.16: GSM Module. 32

Figure 2.17: LDR pictorial and graphical symbol 32

Figure 2.18: LED pictorial and graphical symbol 33

Figure 2.19: Pictorial and graphical diagram of voltage regulator 34

Figure 2.20: Pictorial and graphical diagram of crystal oscillator 35

Figure 2.21: inter-turns fault 41

Figure 2.22: Transformer phase-phase fault 43

Figure 2.23: Transformer under short-circuit 43

Figure 3.1: Schematic diagram of a smart Transformer fleet monitoring system.. 51

Figure 3.2: Different transformer windows shapes. 58

Figure 3.3: Step down transformer 59

CHAPTER ONE

INTRODUCTION

1.1       Background of the Study

Right from when alternating current was experimented, humans have been looking for ways to make life easier by inventing more technologies which make use of alternating current to operate. As a result, this has led to increase in demand for electric power supply due to the increase in the use of appliances. We have seen the rise of smart initiatives that can monitor the power consumption, power transmission and distribution equipment to increase electric grid’s efficiency by reducing the possibility of downtime. Electricity is mostly generated, transmitted, and distributed in AC form and therefore, transformer becomes an inevitable device for transforming voltage levels at different points in power system. Transformer is a key component of power system whose failure could lead to total power outage. Therefore, being able to monitor the health of transformer will help provide guide for the maintenance team to take proper action before a fault becomes severe and consequently causes total transformer breakdown. Some important parameters have to be monitored to avoid breakdown of any form. These parameters are current, voltage, ambient temperature, oil level, oil contamination, phase angle, overload etc.

The Transformer Monitoring System refers to a circuit or group of components built together in order to sense and monitor various parameters of either a single transformer or fleet of transformers in power system network. This project is targeted at designing and constructing of a system that will monitor and control parameters values aforementioned above.

A transformer is then defined as a static indispensible component of power system network used for supply purposes, stepping up and stepping down voltage levels from generation to transmission, distribution and to consumers. Due to its high cost and significance, maintaining a healthy transformer is a key to ensuring reliable and continuous power supply. Hence transformer health monitoring Systems have become very imperative in power system.

In this project, my focus will be mainly on four parameters: the current, voltage, oil-level, oil ambient temperaturewhile oil contamination will be left for further research. For current reading (which strongly has a major role to play in terms of the temperature variations) current sensor consisting of some biasing components will be used to measure the current from the secondary side of the transformer. Voltage transformer along with other discrete components will be employed to read Line/Phase voltage across the secondary part of the transformer. A level detector sensor will be used to determine the level of oil in the transformer. Temperature module or sensor will be connected to the body of the transformer to read the ambient temperature. The read parameters will be sent continuously through the internet with the help of the embedded device (which is an ESP32 micro-controller with built-in Wi-Fi module) to a cloud server through application programming interface (API) and fetched by a graphical user interface GUI or desktop application and send to Mobile phone for monitoring and receiving messages over time.

Imagine a world where technological breakthroughs have created a systematic, smart grid system where transformers can talk to each other as you or we talk to one another. A world where slightest faults and failures of energy lines are noticed within a matter of second as opposed to hours or even days. This world may seem impractical years from now, but with today’s technology the future is coming sooner than one might expect. Initiatives from the United States Government to create a smart grid system have already been placed into motion.  The U.S. Department of Energy, Office of Electric Transmission and Distribution, In 2003released a document describing the nation’s vision for revolutionizing electric power in North America through the development of a Smart Grid by 2030.

“Imagine the possibilitiesof their vision. Electricity and information flowing together in real time, near-zero economic losses from outages and power quality disturbances, a wider array of customized energy choices, suppliers competing in open markets to provide the world’s best electric services, and all of this supported by a new energy infrastructure built on superconductivity, distributed intelligence and resources, clean power, and the hydrogen economy” (“Grid”).

In order to achieve such idea, the U.S. Government passed the Energy Independence and Security Act of 2007 which created the Federal Smart Grid Task Force. This task force is responsible for the “…coordination and integration…” of any activity “…related to Smart Grid technologies, practices, and services” (“Department”). As the framework behind the Smart Grid begins to mature, the time for individual engineers and engineering companies to construct the devices that will drive this Revolution is now. With my motivation set in stone, I present, a Distribution Transformer IOT based Technology for enhanced Monitoring and control of their parameters.

The device is a real time, mounting device that monitors a single or fleet of transformers. This device paves way for a smarter grid system and allows consumers to enjoy the simple necessities of the new era of technology without fear or stress of prolonged electrical power outage or down time. The power companies expect and heavily rely on the responses of their customers to provide useful input for when a transformer is blown or power is out. This is not an effective way of determining when a transformer needs maintenance or needs to be replaced, for the down time is reliant on the customer’s ability to call the power company.

1.2       Statement of Problem

As one of the major power system equipment, transformer is one of the main targets of faults due to the fact that 80-90% of transformers used in power system network are dangerously exposed to the atmosphere. As a result of this, transformer can experience all sorts of electrical faults such as, oil leakage, lightning strike, over load, winding short circuit, moisture, humidity, overheating etc, which over time when they occur leads to damage of power equipment, loss of life and total system collapse. So when it develops faults due to various reasons named above, transmission, distribution and consumption supplies are disrupted. Building a system for monitoring and controlling transformer operating conditions will ensure power stability, high production and will lead to economy boom.

1.3       Aim and Objectives ofthe Study

The main aim of this work is to Design and Construct aSmart Monitoring and Control System for Distribution Transformers, A Study in Petroleum Training Institute’s 500kVA, 11kV/0.415kV Substation, inWarri’

The Specific Objectives are:

1. To design a system which uses different transformer parameters sensors such as voltage, current, temperature, oil level and oil contaminant sensors (biasing components) to monitor the mentioned parameters of the transformer(s)
2. To develop programmable codes and to implement it in the hardware of the transformer condition monitoring system using embedded ESP32 microcontroller.
3. To ensure that all analogue signals are converted digital signals by the ADC to enable the microcontroller to understand it.
4. The parameters recorded from the sensors will be sent over the internet of things (IOT) through ESP32 to a web server and mobile phone (as SMS or Email) to constantly inform the engineers when a threshold of a set parameter is exceeded.
5. To ensure steady working condition of a transformer thereby improving the rate of power supply at Petroleum Training Institute (PTI)
6. 1.4       Significance of the Project

This project work has a lot of significancewhich includes but not limited to the Following:

1. Monitoring working condition of transformers will help faults to be detected early before they become severe and cause total shut-down or total damage.
2. Using IOT will enable the device to work in a distance independent manner thereby increase flexibility and convenience to personnel.
3. It will aid in building more reliable power system that is very less likely to experience downtime.
4. To servicemen, this study will reduce the periodic visit of to the distribution station since most of the routine check can be carried out using IOT at the comfort of their homes or offices.
5. To the Government/Management, this study will serve as a means of ensuring that a transformer has a steady working condition which will ensure power stability, high production and lead to economy affluent.
6. Finally, to the student involved, this study will make the student become familiar with high tech project equipment like IOT devices such asESP32 Controller, sensors, GSM module, transformer workings and faults associated with transformers.
7. The system will afford opportunity not only to the operators in control roombut also to anyone who cares within where the transformer serves that has the website address. With this, everyone within the transformer location becomes a part of monitoring team.

1.5       Scope of the Project

This project coversjust four basic parameters of interest which are current, voltage, ambient temperature, andoil level of distribution transformers. The system offers control to faulty section when faults are detected. It has an internal Wi-Fi connectivity to enhance the transformer parameters to be monitored on the web serverdeveloped and through GSM configured. The device is limited to areas where Wi-Fi is available, and it references just two transformers asdepicted in the circuit diagram.

1.6       Motivation of Study

Due to erratic state of power supply in our country, higher percent of this irregular power supply is as a result of failure due to lightning surges, earth fault, short circuit, wrong switching operations,  insulation failures, equipment aging or failures, reduction of oil in one or more transformers, either from the transmitting substations or distribution substationsetc.

Taking petroleum training institute as a case study, the institute experiencedtotal blackout for a period of four months, due to the fault that the 33kV/11kV transformer developed due to temperature rise. After series of test conducted, it was gathered that the dielectric strength of the transformer oil broke down, resulting to overheating( temperature rise) of the transformer coils which in turn lead to reduction of transformer efficiency, short circuit due to melting of windings, oil expansion and breakdown and lastly reduction of transformer life or total breakdown of transformer. The transformer coils were severely damaged beyond repair and it had to be replaced. Assuming the institute had an IOT base smart transformer monitoring and control system, the sensor (biasing components) would have sensed the oil contamination and send a signal to the website or mobile phone and the cost of getting a new transformer would have been averted. The cost of maintaining the transformer would have been about 6million naira to get transformer oil but now that the transformer coils are completely damaged, the cost of replacing the 33kv/11kv 7.5M transformer is going to be about 75million to 100million naira depending upon the made of the transformer. The outcome of this story could have been dictated and averted if only there was IOT transformer monitoring and remote control system.

 

CHAPTER FIVE

5.0       CONCLUSION AND RECOMMENDATION

A Smart fleet of Transformer monitoring and control system was mimicked, designed and constructed accordingly as presented in the circuit schematic representation using small transformer with limited current or power capacity. Through Application programmable Interface (API) the device is able to send temperature, current, voltage and oil level and oil contaminant parameters to the cloud through the help of ESP32 Microcontroller with imbedded Wi-Fi to the internet. Using client desktop application or GSM all sent parameters are fetched, seen or monitored remotely.

5.1       PROBLEMS ENCOUNTERED/SOLUTIONS

Designing and constructing a system that will check, dictate the presence of any fault and get it cut or cleared off will on no doubt face many challenges such as components range selection, which was selected base on experience and knowledge of the supply voltage and power, current and voltage requirements of the featured components. Where to get certain uncommon required components like ESP 32 delayed the project, and thereafter it was ordered since it could not be obtained within the locality. Not knowing how to run a program which is part of the project design posed also a challenge, until a programmer was contacted. Delay and disappointment from the person that helped with the construction part nearly pulled us apart because the delay made me not to defend my project on the first and second scheduled dates, which unfortunately led me to pay extra school fees.

5.2 RECOMMENDATION

It is pertinent to monitor and control costly and major power system equipment such as transformers from generation station down to consumer or domestic substations and its premises by availing and installing a smart monitoring and control system incorporating a centerized display unit, in addition with featured mobile phone, as doubled means for others to also view processed result, because safety is everyone’s business.  Another recommendation is to build mobile application in addition to desktop application to allow monitoring on the go.

5.3 CONCLUSION

Design and installation of smart Transformer monitoring and control system in substations is sacrosanct and cannot be overemphasized due to its widely acceptable significance to power system equipment, humans and environment. With this Technology, power equipment are monitored and controlled conveniently against fault of all kinds thereby promote power supply continuity, stability and reliability. The system is suitable as it reduces period of down time, man hour, offers adequate protection to the equipment and eradicate manual routine check of the aforementioned parameter