Inverter PWM Edge Phase Control Near Zero Cross

The patent applies preliminary action by pre-calculating and storing the relationship between modulation wave zero-cross points and PWM pulse edges in a lookup table before operation. During real-time control, the system simply retrieves the appropriate phase difference correction value from the table based on the current operating region, avoiding complex real-time calculations and ensuring accurate pulse timing even in the near-zero cross region where voltage errors would otherwise occur.

The patent changes the parameter of PWM pulse phase positioning by introducing a region-dependent phase difference between the modulation wave zero-cross point and the PWM pulse edge. Instead of using a fixed phase relationship, the system adjusts this phase difference based on the operating region (overmodulation vs. one-pulse region), thereby optimizing voltage control precision across different operating conditions while maintaining high output voltage capability.

The patent applies parameter changes by introducing a controlled phase difference parameter between the modulation wave zero-cross point and the PWM pulse edge. This parameter is adjusted based on the operating region (overmodulation vs. one-pulse region) to maintain stable output torque and minimize noise/vibration. The phase difference is determined from pre-calculated lookup tables, which keeps the control logic relatively simple while achieving the desired torque stability.

The patent uses preliminary action by pre-calculating the optimal phase difference values for different operating regions and storing them in lookup tables. This approach maintains relatively simple control logic during real-time operation while ensuring stable output torque by retrieving pre-determined phase difference values that have been optimized to minimize torque fluctuation and noise/vibration.