Electric Power Conversion Device Ripple Suppression

The patent changes the filtering approach from a first-order lag low-pass filter to a moving average filter that calculates the average over a predetermined period corresponding to the switching cycle. This parameter change in the filtering method allows effective ripple suppression while minimizing detection delay, as the moving average can be computed with minimal computational overhead and provides timely voltage information for control purposes.

The patent changes the filtering methodology from time-constant-based low-pass filtering to a moving average calculation over a switching cycle period. This allows the system to achieve effective ripple filtering without introducing significant detection delay, as the moving average can be computed rapidly using simple arithmetic operations on recently sampled voltage values.

The patent replaces the first-order lag low-pass filter with a moving average filter calculated over a predetermined period corresponding to the switching cycle. This parameter change in the filtering approach achieves effective ripple suppression while maintaining minimal detection delay, because the moving average can be computed using simple arithmetic operations on a limited set of recent samples rather than requiring integration over a long time constant period.

The patent changes the filtering period to correspond to the switching cycle period, which is a relatively short and fixed duration. This allows the moving average to suppress ripples effectively while maintaining the ability to respond to rapid voltage variations, as the filtering window is tied to the fundamental operating cycle rather than an extended time period that would smooth out important transient information.