A second type of AC source is the micro-turbine generator (MTG). Micro-turbines were developed by the industry through improvements in auxiliary power units. The majority of commercial devices presently available use natural gas as the primary fuel, but they are free to use other fuels: gasoline, diesel, kerosene, naphtha,alcohol, propane, methane or digester gas. A MTG unit is usually a high-speed rotating machine (up to 120 krpm). MTGs have the rated power from 30 to a few hundreds of kilowatts, generating electricity in AC with output frequency from 400 Hz and up to sev-eral kHz. The most common power converter topology that is used for connecting micro-turbines to the grid is the frequency converter with DC-link. Preliminary results of the application of MTGs using MC (Fig. 10a) demonstrated the ability of the MC to deliver a higher quality voltage to the load in comparison to conventional frequency converters