Design And Construction Of Automatic Changeover For 3-Phase Power Supply.

ABSTRACT

This project work is on the design and construction of automatic changeover for 3-phase power supply. It provides a means of switching from one phase of AC mains to another in the case of failure in the existing phase but when there is no power in any of the three phases the system when then switchover to generator. This device brings solution to overcome power fluctuation/phase interruption by selecting next most healthy available phase to feed the equipment without any notice of power outage.

In this system, When the power failure occurs this system will send one SMS to the particular person. “POWER is OFF”. If loads get the power from main means the SMS is send as “MAIN POWER is ON”. We can control the generator ON/OFF by using the GSM. If we have more than one generator means we can select any one for the particular time, based upon the DEMAND by fixing this kit for every Generator.

CHAPTER ONE

1.0                                                        INTRODUCTION

In Nigeria today the problems of power outage across phases is so rampant thus leading to some sensitive equipment and appliances being redundant, this could sometimes be the cause of one phase going out with respect to the other.

It may surprise one to note that in an attempt to solve this problems, so many unskilled electricity consumers has in recent past resorted to some crude means of swapping between phases to obtain power. So many souls have been lost in this act. This is an undesirable condition to consumers and the need now arises to design a device that can automatically select among the phases and make power supply available at the consumers terminal. It provides a means of switching from one phase of AC mains to another in the case of failure in the existing phase but when there is no power in any of the three phases the system will then switchover to generator.

PIC Microcontroller is the heart of the device which handles all the sub devices connected across it. We have used as microcontroller. It has flash type reprogrammable memory. It has some peripheral devices to play this project perform. It also provides sufficient power to inbuilt peripheral devices. We need not give individually to all devices. The peripheral devices also activates as low power operation mode. These are the advantages are appear here.

In this system, When the power failure occurs this system will send one SMS to the particular person. “POWER is OFF”. If loads get the power from main means the SMS is send as “MAIN POWER is ON”. We can control the generator ON/OFF by using the GSM. If we have more than one generator means we can select any one for the particular time, based upon the DEMAND by fixing this kit for every Generator.

                                                            1.1 BACKGROUND OF THE PROJECT

If some of these big firm do not make provisions for stand-by power source, frustration could set in which may lead to the closure of business and thus throwing workers into unemployment. Also in the case of hospital, undergoing a surgical operation and power supply suddenly go off, the patient might loose his or her life due to the power outage.

An Engineering Author, “Tony Rudkin” said in his book titled “Upgraded Signal Source with Improved Performance and Reliability” that the cost and depredation associated with breakdown vary from one application to the other, and in some cases, the user has little choice but to ensure that a stand-by unit is available to take over on event of failure of primary system.

Furthermore, if the president of the country is making nationwide broadcast and all of a sudden power went off in the transmitting station, it would be viewed as an attempt to sabotage the government ruling and some people must pay for it.

Sequel to the rate at which more sophisticated electrical/electronics gadgets are being procured and installed in our homes, hospitals and business premises, there is a justifiable need for a faster and more reliable change over system in an event of power outage.

In view of these considerations, this project is aimed at designing and constructing a workable automatic change over switch with a GSM module which switches on the head from power Holding Company (PHC) to a generator when power fails and from generator to PHC when power comes back and at the same time alerts the user via sms the power that is in use.

1.2                                                  PROBLEM STATEMENT

Power failure or outage in a country, state or city is highly detrimental to development in public and private industries. The insecurity associated with constant or frequent power failure or outage brings about limitation to power consistent investments, thus hampering the development of industries and multinational ventures. Processes like carrying out surgical operations in hospitals, laboratories which require constant power supply for research, money transactions between banks and more require constant use of uninterrupted power. In other to solve this problem, an automatic changeover switch was invented. It has the capacity to automatically switch power from  national grid to generator and vice versa, once there is power failure in the mains and at the same time has the capacity of shutting down a generator set once the mains grid is been restored via SMS.

                                                                  1.3 OBJECTIVE OF THE PROJECT

The objective of this work is to design a device that will overcome power interruption by automatic changing over from mains supply to generator with a GSM module, which switches on the head from power Holding Company (PHC) to a generator when power fails and from generator to PHC when power comes back and at the same time alerts the user via sms the power that is in use.

                                                            1.4 SIGNIFICANCE OF THE PROJECT

Industries require three phases power to run their machinery. Some of them require continuous \ uninterrupted power to maintain their data.

Auto changeover introduces an automatic solution to overcome power fluctuation \ phase interruption by selecting next most healthy available phase to feed the equipment.

                                              1.5 SCOPE AND LIMITATION OF THE STUDY

This work covers only a device that changes supply from mains to generator when power failure occur and as well send one SMS to the particular person. “POWER is OFF”. If loads get the power from main means the SMS is send as “MAIN POWER is ON”. We can control the generator ON/OFF by using the GSM. If we have more than one generator means we can select any one for the particular time, based upon the DEMAND by fixing this kit for every Generator.

                                                    1.7 APPLICATION OF THE PROJECT

Some common examples of entities that implement automatic switches out of necessity are: hospitals, data centers, jails and prisons, fire departments, defense organizations, and police departments.

                                                       1.8 DEFINITION OF TERMS

CHANGEOVER: Generally, a changeover switch is a system which could be operated manually or automatically , that changes one source of power supply to another source in case of power failure from either of the two sources.

RELAY: relay is one of the major components used in this work which is an electrical device, typically incorporating an electromagnet, which is activated by a current or signal in one circuit to open or close another circuit.

POWER FLUCTUATIONS: is a periodic dip or spikes in the electrical current of any given circuit.

POWER FAILURE: is a short- or long-term loss of the electric power to an area.

                                          1.9 PROJECT WORK ORGANISATION

The various stages involved in the development of this project have been properly put into five chapters to enhance comprehensive and concise reading. In this project thesis, the project is organized sequentially as follows:

Chapter one of this works is on the introduction to changeover switch. In this chapter, the background, significance, objective limitation and problem of changeover switch were discussed.

Chapter two is on literature review of changeover switch. In this chapter, all the literature pertaining to this work was reviewed.

Chapter three is on design methodology. In this chapter all the method involved during the design and construction were discussed.

Chapter four is on testing analysis. All testing that result accurate functionality was analyzed.

Chapter five is on conclusion, recommendation and references.