In order to allow the voltage recovery at different points
after voltage sags, tests were performed with rectangular
voltage sags by a 4.5 kVA fully programmable three-phase
source with an integrated arbitrary waveform generator. The
programmable ac power source enables a flexible, variable
amplitude and frequency voltage output. The output voltage
waveforms can be complied from an equation expression.
This is useful for specifying exact harmonic components in
sine waves as well as specifying exact amplitudes and phase
angles for transient and steady state conditions [8].