Q.What is the function of Inverter?

An inverter converts DC power into AC power at a desired output voltage and frequency. It is a DC-to-AC converter used in variable-speed AC motor drives, aircraft power supplies and uninterruptible power supplies (UPS) for computers, where a battery's DC must be turned into usable AC.

A common arrangement is the single-phase full-bridge inverter, which uses four switching devices (typically IGBTs), labelled Q1-Q4, with only two diagonally opposite devices ON at a time:

• When Q1 and Q4 conduct, load current flows one way and the load voltage is $+E_{dc}$.
• When Q3 and Q2 conduct, the current reverses and the load voltage becomes $-E_{dc}$. …