STDA034 May   2026 F29H859TU-Q1

 

  1.   1
  2. 1Executive Summary
  3. 2Why Traction System Efficiency Matters
  4. 3Optimal Pulse Positioning: A New Modulation Strategy
  5. 4Key Challenges to Implement OPP and How TI Has Solved Them
  6. 5Synchronous PWM Pulse Generation
  7. 6SVPWM to OPP Transition
  8. 7Dynamic Response and Robust Closed-Loop Control
  9. 8Conclusion

6 SVPWM to OPP Transition

A transition from Space Vector Pulse-Width Modulation (SVPWM) to OPP is highly complex. This transition is needed in the first place because at low speeds (start-up), the system must be operating in SVPWM mode to maximize efficiency. However, as motor speeds increase, transition to OPP is needed to maintain efficiency. A smooth and seamless transition from one mode (SVPWM) to another (OPP) is enabled by yet another Type 5 ePWM feature on F29: shadow and active registers. Shadow and active registers allow SVPWM and OPP configurations to coexist simultaneously and enable and on-the-fly PWM reconfiguration. The image below highlights TI's implementation of Type 5 ePWM to solve the problem of SVPWM to OPP transition.

Shadow and Active Registers Visualization Figure 6-1 Shadow and Active Registers Visualization