CHAPTER ONE
INTRODUCTION 1.1     Background to the Study
Electric power interruptions are quite common in every place, especially after a heavy down pour or a severe storm. To counter this power outage, a search has been to find a reliable and economical alternative source of electricity. Although this kind of project has been dealt with for quite a number of time but the fact still remains that an improvement needs to be done. This in essence makes the project topic “Investigation of the performance index of 3.5KVA/48V inverter” purposeful and resourceful.
        An inverter is a device or an electronic that converts or inverts a direct current into a conventional alternating current. A power inverter is a great tool used to run household / office appliances, where there is no electricity. The input voltage and frequency of the inverter may be fixed or it may vary depending on its application. Inverters finds several applications of which are the valuable speed, alternating current motors, uninterrupted power supply etc. They can be used as the front stage of dc to dc converter. Standby inverters are mostly used to provide emergency supply to the main frequency (50Hz). In the event of main failure, the inverter immediately operates with no loss of waveform. This unique ability makes it related to an automatic change over switch but it differs in a way in that it has a battery, which stores energy when the mains is on and gives out energy when the mains is off while the automatic change over switch operates on contactor (open and close).
         There are many types of inverter as described in chapter 2, but they all have the same principle of operations and it all depends on the component used, whether with a thyristor or a bipolar junction transistor for switching the current ON/OFF. The need for man to prevent his activities from being interrupted in order not to render it incomplete which may subsequently become an unfinished job (loss of files in the computer when there is a sudden power outage) has motivated engineers across the globe to design a device which will be more economical, durable and efficient.
It is pertinent to note that in a well organized company in a developing country like Nigeria, where a lot of transactions are made, if there is an epileptic power supply, the flow of transaction will greatly be hindered and there will be no open ground for the infant companies to spring up and wax great. Power should not be an obstruction between companies and their maximum profits, this in essence makes the use of a power inverter relevant and recommended to all and sundry. Hence, the need for the investigation of the performance index of various inverters comes to play. And this helps to determine which inverter is more efficient, portable, durable, and cost effective.