Electronic Load Controller explained
What is an Electronic Load controller or governor?
In order to make the power of your generator useable, you need to make sure the voltage (Volts) and the frequeny (Hz) stay stable.
The AVR Automatic Voltage regulator takes care of the voltage.
The ELC/ELG takes care of the frequency.
The higher the user load, the lower the frequency will get. So if you switch on the kettle, the frequency will drop. The ELC does nothing more than switching off an equal amount of power (wattage), so the frequency stays stable even after you've switched on the kettle.
So in effect, the total amount of power consumed always stays the same.
To ensure this switching works as smooth as possible, the ELC uses a Proportional-Integral feedback loop, PI-Controller