PWM Drive Current Regulator Phase Lag Compensation

The patent applies preliminary action by calculating and applying phase lag compensation in advance. The current regulator computes the phase lag between commanded and actual voltage references, then pre-adjusts the rotor position signal by this calculated amount before it is used in control calculations. This anticipatory compensation ensures that the control system accounts for the inherent delay introduced by PWM switching and digital sampling, maintaining stability even when operating at higher PWM frequencies where the delay becomes more significant.

The patent applies parameter changes by dynamically adjusting the rotor position signal based on the calculated phase lag. When the carrier frequency approaches the fundamental frequency, the phase lag increases, but the system compensates by modifying the position parameter accordingly. This allows the motor drive to operate efficiently at lower PWM frequencies while maintaining control stability through real-time parameter adjustment rather than being constrained to operate at high frequencies.

The patent applies feedback by continuously monitoring the phase lag between commanded and actual voltage references, then using this feedback information to adjust the rotor position signal. The system samples the actual output voltage, compares it with the commanded reference, calculates the phase lag, and feeds this information back to compensate the position signal. This closed-loop approach maintains measurement precision despite digital sampling delays while keeping the implementation relatively simple.