Automotive voltage inverter is an important area in power system engineering. It is the process of using a 12v DC from the battery to achieve a 220/230V AC through the help of oscillator, drivers, power transistors and transformer. The stages are battery to oscillators, oscillators to drivers, drivers to power transistors then from power transistors to transformer which is capable of giving out 220/230V (1000w) as an output. A 1.25KVA (1000w) voltage inverter was constructed, tested and certified okay. Since the inverter as constructed to step-up voltage, the power transformer is used as step-down for charging and as step up transformer for inverting. This project helps in the improvement of the epileptic power supply we are having in Nigeria and it also reduce the high level of power dependence in Nigeria by serving as IPP’s (Independent Power Plants). The project as run in school helps in equipping the students in the practical aspect of the course.
TABLE OF CONTENTS
Title page i
Certification page ii
Table of content vi
Analysis (review of existing system) 2
Aims and objective 3
Scope/Limit of the project 3
Literature review 5
Brief review of used components 5
Operational amplifier 27
A.C. Voltage meter 29
Design and analysis 33
D.C. Supply (input voltage) 35
Voltage regulator 35
Control logical circuit 35
Frequency generator 36
Phase splitter 37
Step-up transformer 38
A.C. supply (output voltage) 38
Methodology II 39
The unregulated supply (input voltage) 39
Isolating relay 39
Step-up transformer/rectifier circuit 40
Changing control/logic comparator circuit 41
Theory and calculation 43
Circuit diagram casing design 44
Constructions test and result 46
Problem encountered 47
Conclusion and recommendations 48
Electrical power being one of the basic criteria for the measurement of development in a country is basic necessity. It is the responsibility of any responsible government to provide stable, cheap and uninterruptible power supply to its citizens through the provision of adequate electrical infrastructures.
Since the advent of the first electricity, generator, and many other forms of generators have been development for the conversion of various forms of energy into electricity. These includes, hydro power generator in hydro power stations, gasoline and diesel fired generators, gas turbine generators, solar generators, steam turbine generators, wind turbine generators and fuel all electric power generators. All the above forms of generators have proved potent but due to disadvantage or drawback or one lead to he invention of another.
All these generators mentioned above are:
- Difficult to step up (gas plant)
- Expensive (fuel)
- Time consuming
- Noisy during operation (generators)
When all these were put into consideration he invention of inverters became necessary due to its following features as listed below:
Small in size
Easy to set up
An inverter is a DC – To-AC converter device that is one efficient in operation. Hence in advanced countries the use of solar panel is being employed to convert radiant energy, the butteries for effective operation of the inverter.
As the saying goes “necessity is the mother of invention” therefore, the need for inverter has become necessary in a country like Nigeria to help boost power supply so as to enhance economic growth of the people and the entire nation at large
ANALYSIS/REVIEW OF EXISTING SYSTEM
The un-automated inverter is not really an inverter is just made up of circuit compilation via transistors and transformer to produce A.C voltage.
Most foreign inverters are low power inverters that cannot withstand a load up to 12.5KVA due to the use of some fragile components. E.G. BJT transistor.
Some local technicians can construct an inverter with no control, i.e. some additional features to enhance the performance of the inverter during operation.
AIMS AND OBJECTIVES
This project is designed to improve on the existing system by not only having in place those thing is some of existing one like automatic trip off when battery voltage drops fully charge, cut off when the battery has reached its peak voltage. The use of MASFET, as rectifier is to charge the battery (in built charger).
SCOPE/LIMIT OF THE PROJECT
The design of this project is limited to input voltage of about 12v capable of delivering circuit ranging from 45A to 400 A D.C.
Although it can be extended further but for high capacity the input voltage should be increased as to minimize the current. The effect of this is that, the higher he current the larger the cross sectional area of conductors that will be used.
This project can withstand load range from – – 800w, 50Hz at 20 – 220v input.
A load of 1000w cannot be attained due to some losses from various part of the design such as transformer losses. 1000w is the power at no load.
His project can be used to supply A.C. of 200 – 220V from input voltage of 12V, provided the input current dos not rise above 15A, when a load of 700w is applied.