Patent ID: 7902788

Claim:
A method for controlling the application of AC operating power from a multi-phase AC power source in one or more phases to an AC induction motor that is coupled to a mechanical load having a load requirement, the method comprising the following steps performed for each phase: receiving AC supply voltage at a fundamental power distribution frequency from the multi-phase AC power source at an input terminal of a low pass filter connected in series between the multi-phase AC power source and an electronic controller; delivering filtered AC supply voltage from the low pass filter to a power input terminal of the electronic controller; adjusting power output at the electronic controller by way of current flow interruption to dynamically match the load requirement during each half cycle of the applied power waveform; providing that the current flow interruption be proportional to a measured phase difference between a voltage waveform and current waveform zero crossings in the proceeding half cycle; and applying the power output to a reactive capacitor element connected in shunt from phase to neutral across one or more output terminals of the electronic controller, the one or more output terminals coupled to windings of the AC induction motor.