A comparative study of DC/AC pure sine wave inverters

Abstract

A power inverter or inverter is an electrical power converter that changes direct current (DC) to alternating current (AC). The converted AC can be at any required voltage and frequency with appropriate transformer, switching and control system. In under developed countries, the ever increasing reliance on electrical and electronic devices which utilize AC power highlights the problem associated with the unexpected or sudden loss of power due to electrical load shedding. Therefore, there is a need of inexpensive and reliable pure sine wave inverter to backup sophisticated electronic devices like medical devices and as well as for household appliances like fan, television, tube-lights etc. It has been noted that today’s pure sine wave inverter produces total harmonic distortion (THD) of about 3% [1]. It is due to this THD, the lifetime of other electrical devices like fan, tube-light etc. decreases significantly [2]. This thesis aims to compare and analyze the total harmonic distortion, efficiency and cost effectiveness of different inverters from different renowned companies and finally to propose a design of a pure sine wave inverter with less total harmonic distortion and with greater efficiency than usual. Thus, it will have less effect on the lifetime of any electrical devices such as fan, tube lights etc.