Monitoring and Control of 3-tier Power Supply
CHAPTER ONE
OBJECTIVES OF THESTUDY
The objectives of this project include:
- To monitor and control a three tier power supply system.
- To automate the power changeover process to ensure a smooth transfer of load for the purpose of safety and convenience.
- To implement a system of power change over with minimal time wastage.
- To optimize power use in a system of 3 power sources by setting the most economical power source as default in the system.
CHAPTER TWO
LITERATURE REVIEW
Electricity in Nigeria
Electricity generation in Nigeria started in 1896 although it was not until 1929 that the first utility company, the Nigerian Electricity Supply Company was established [4].
In the 1950s and 1960s the Nigerian government created the Electricity Corporation of Nigeria to control all existing diesel/coal fired isolated power plants across the country and the Niger Dams Authority to develop hydroelectric power in Nigeria. These two entities were amalgamated into the National Electric Power Authority (NEPA) in 1972, and in 2004, the need to reform the Electricity industry necessitated the transformation of NEPA into Power Holding Company of Nigeria (PHCN).
Electricity generation, transmission and distribution in Nigeria account for less than one per cent of the Gross Domestic Products (GDP) [5]. Until the recent unbundling and handover of PHCN to successor companies, PHCN dominated Nigeria’s electricity sector, supplying most of the electricity consumed in Nigeria, supplemented with power generated from privately-owned plants. There is still a high incidence of privately-owned plants usually referred to as ‘captive power plants’. This in most cases is in response to irregular public power generation and transmission.
Nigeria’s Electricity Sector in Retrospect
Electric Power development in Nigeria started toward the end of 19th century when the first generating plant of 30KW was installed in the city of Lagos in 1898 [6]. From this date onwards and until 1950, the pattern of electricity development was in form of individual electricity undertaking set up in various towns somewhere by Native or Municipal authorities.
In 1946, the Nigerian Government Electricity undertaking was established within the then Public Works Department (PWD) to take over the responsibility for electricity in Lagos State.
In 1950 the Government passed the Electricity Corporation of Nigeria Ordinance No.1 of 1950 to integrate power development and make it effective. This ordinance brought all the electricity undertakings and the electricity sections of PWD under control. The Electricity Corporation of Nigeria (ECN) then became the statutory body responsible for Generation, Transmission, Distribution and Sales of Electricity to all consumers in Nigeria.
In 1962, the Niger Dams Authority was established by an Act of the Parliament. The Authority was responsible for the construction and maintenance of Dams and other works on the river Niger and elsewhere, generating electricity by means of water, improving navigation and promoting fisheries and irrigation.
The Electricity Corporation of Nigeria (ECN) and the Niger Dams Authority (NDA) were merged to become National Electric Power Authority (NEPA) by decree No.24 of 1972. The Authority was to develop, maintain and co-ordinate an efficient economic system of electricity supply for all parts of the Federation. The Authority generates electricity through two major sources: Hydro and Thermal. The Hydro Power stations are Kainji Hydro Power station with capacity of 760MW, Jebba Hydro Power station with 578.4MW capacity, Shiroro Hydro Power Station 600MW. The Thermal Power stations are: Afam Thermal Power station with 696MW, Lagos thermal power station, Delta IV thermal Power station with 600MW and Sapele Thermal Power station 1020MW. The existing power stations in Nigeria are shown in appendix A.
CHAPTER THREE
METHODOLOGY
Introduction
The system design is such that three interconnected power sources: PHCN, solar and generator are constantly monitored with the aim to engage and utilize the preferred power source following preset conditions in the microcontroller. In addition to the microcontroller, the project employs the use of contactors, relays, comparators and overloads devices which are all readily available in the market. The design employs a priority based Automated Switching system using the microcontroller to give preference in the desired order. Shown below is the Priority Table for automatic input selection.
CHAPTER FOUR
SYSTEM DESIGN AND IMPLEMENTATION
Selection Of Components
The system is intended to handle a load of 20KVA.
CHAPTER FIVE
CONCLUSION AND RECOMMENDATION
Conclusion
This project provides a means of cushioning the consequences of unreliable power supply that pervade developing societies like Nigeria by offering a cost effective way of using multitier power supplies. Owing to the fact that modern industrial systems depend on regular supply of electricity, and quality of life as well as standard of living today depend much on electricity, this project is very relevant in our society today.
Recommendation
This device is recommended for use in homes, industries and facilities where power supply from the grid is unreliable, and uninterrupted 3 phase power supply is essential. Further, based on the experience gathered in the course of the design, the following recommendations are suggested:
- The machine should be made more robust, efficient and exportable by using PCB (Printed Circuit Board) technology to develop the electronics control board.
- As an improvement the system can include a computer interface that will link it to a Wide Area Network to facilitate advanced features like data logging and remote sensing.
References:
- Bing Tian et al. “400 V/1000 kVA Hybrid Automatic Transfer Switch”, IEEE Transactions Ind. Electronics Vol. 60 , No. 12, pp. 5422-5435. 2013.
- Oparaku, O.U. “Photovoltaic systems for distributed power supplies in Nigeria”, Renewable Energy, pp 31-40. 2002.
- Energy Sector Management Assistance Program. Nigeria: Expanding Access to Rural Infrastructure Issues and Options for Rural Electrification, Water Supply and Telecommunications. The International Bank for Reconstruction and Development, The World Bank, 2005.
- Nigerian Electricity Market, retrieved fromnipptransactions.com/background/electricity-market, March 2014.
- Electricity supply and demand – National Bureau of Statistics, retrieved from www.nigerianstat.gov.ng, March 2014.
- About Enugu Electricity Distribution Company retrieved from
- http://www.enugudisco.com, February 2014
- Samson A. Aladejare “Energy, Growth and Economic Development: A
- Case Study of the Nigerian Electricity Sector”, American Journal of Business, Economics and Management, vol. 2, No. 2, pp 41-54. 2014.
