LoopForge
discrete current-loop design studio
engine verified against scipy to 1e-9

Discrete-time PMSM current-loop design and delay robustness

Enter the PMSM parameters, sampling frequency and effective delay. The discrete-time gains, z-plane poles, speed sweeps and robustness verdict update live. Curious how the two controllers differ inside? See Inside the designs, or follow the modular learning path.

Choose how the studio teaches you

Guided mode

Plain-language explanations, safe experiments and only the controls you need first.

Explore the loop
1 · machine 2 · experiment 3 · speed 4 · export
Experiment coach

Begin with one controlled change

Choose a motor, freeze the controller, and change the real delay. This isolates the plant effect so the pole movement has a clear meaning.

Computing…

Initial calculation…
Textbook IMC PI  ·  delay ignored at design
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Delay-aware discrete design  ·  LoopForge
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Interpret this result

The calculation is ready

LoopForge will explain the strongest conclusion here after the first valid calculation.

One-click experiments · learn by contrast

Each experiment changes one meaningful assumption and keeps the comparison visible. Restore your setup at any time.

no experiment active

Stability across the speed range

textbook IMC PI delay-aware design above the red line = unstable
Live sensitivity curve

Pole radius versus physical delay at the inspected speed

controller held fixed for this curve
textbook IMC PI delay-aware design vertical line = current Td/Ts
Live pole movement microscope

Magnified dominant-pole motion from the captured baseline

This view automatically zooms around the dominant poles. The full z-plane below keeps the unit-circle context; this microscope makes small but real movements visible while you drag the delay.

auto zoom
× delay-aware ○ textbook hollow marker = captured baseline arrow = movement caused by the current physical delay
delay-aware dominant-pole movementbaseline
textbook dominant-pole movementbaseline
zoom windowautomatic
what to watchDrag Td; the arrows and coordinates update immediately.
Animated operating-point view

Closed-loop poles · z-plane

live
× delay-aware ○ textbook faint marks = previous positions
delay-aware dominant pole…
textbook dominant pole…
Δ max radius from captured baseline…
delay mismatch angle…

\(i_q^{\star}\) reference step at this speed

textbook delay-aware
inspect speed …

Advanced numerical diagnostics

Delay-aware radius…
Textbook radius…
Discrete margin…
\(T_d/T_s\)…
Electrical speed…
Result delta…

Delay-aware gains at this scheduling point


        

          
          
          
        

      

    

  


  
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