Review of methods for Voltage Control in AC Inverters

Abstract

DC-AC inverters are electronic devices used to produce mains voltage AC power from low voltage DC
energy (from a battery or solar panel). This makes them very suitable for when you need to use AC power tools or
appliances but the usual AC mains power is not available. Examples include operating appliances in caravans and
mobile homes, and also running audio, video and computing equipment in remote areas. Most inverters do their job by
performing two main functions: first they convert the incoming DC into AC, and then they step up the resulting AC to
mains voltage level using a transformer. And the goal of the designer is to have the inverter perform these functions as
efficiently as possible. So that as much as possible of the energy drawn from the battery or solar panel is converted into
mains voltage AC, and as little as possible is wasted as heat. One of the key factors pertaining to AC inverters is output
regulation. We take for granted the fact that our mains power is very well regulated. So you can plug almost any
appliance into a standard point outlet, and it will operate correctly. That’s because the electricity supplier has enormous
generating plants, with automatic regulation systems to keep the mains voltage and frequency very close to constant,
despite load variations of many megawatts. Inevitably you can’t get this kind of performance from a much smaller
electronic inverter, connected to a modest battery or solar panel as the energy source. However most modern inverters
can provide reasonably good regulation for loads of up to their rated capacity (given in watts) assuming of course that
they are running from a well-charged battery.
In this paper a brief review of most widely used methods for voltage regulation in AC inverters is explain and a
mutual comparison is also drawn.