What types of phase converter are there?
The final option is to use a single to three-phase converter. The easiest of these to visualise is a single-phase electric motor driving a three-phase electric generator and such motor generators do indeed exist. However this approach is uneconomic for almost all applications and tends to be restricted to exotic frequency changing problems – for example converting from a 50 Hz three-phase input to 400 Hz three-phase output. Having discarded the conceptually simplest we are now left with three other types of common phase converter: static phase converters, rotary phase converters, and sine wave inverters (there are some uncommon ones but let’s keep it simple). Sine wave inverters are exactly the same as motor drive inverters in that they first rectify to give DC, and then invert it back to AC but on three different phases. The difference is that they add extra circuitry and so are able to give out a cleaner sinusoidal waveform than motor drives, and they maintain a constant frequency. T
