I am opening a serious discussion for the validity of implementing the SHE modulation for a specific three phase converters controlled by Vector Control and regulating the DC-Link. Implementing SHE as open loop control (fixed modulation index and arbitrary phase shift) is visible and easy. Also, single phase implementation is easy and really visible for open loop (99% of research using open loop).

Here is the issue for 3-phase converter: to eliminate the harmonics, the pulse pattern must be produced for a complete period (20 ms for 50 Hz) for each phase. this means the sampling time for the control loop should be 20 ms ( too slow). in other words, let us check only for Phase A. the pattern need to be ready each period (20 ms) and the SHE will not update the its reference angles during executing the full pattern with takes 20 ms. This concept is also applied for phase B and C. Otherwise, if we contentiously update the modulation index and the converter vector phase shift (relative to grid vector), the SHE becomes some sort of random PWM pattern.

The Question is: Is SHE valid for controlling three phase converters using vector control method in a closed loop control strategy?