SPRUHJ1I January 2013 – October 2021 TMS320F2802-Q1 , TMS320F28026-Q1 , TMS320F28026F , TMS320F28027-Q1 , TMS320F28027F , TMS320F28027F-Q1 , TMS320F28052-Q1 , TMS320F28052F , TMS320F28052F-Q1 , TMS320F28052M , TMS320F28052M-Q1 , TMS320F28054-Q1 , TMS320F28054F , TMS320F28054F-Q1 , TMS320F28054M , TMS320F28054M-Q1 , TMS320F2806-Q1 , TMS320F28062-Q1 , TMS320F28062F , TMS320F28062F-Q1 , TMS320F28068F , TMS320F28068M , TMS320F28069-Q1 , TMS320F28069F , TMS320F28069F-Q1 , TMS320F28069M , TMS320F28069M-Q1
Integrator windup is an issue where the integrator component of a standard PI controller has built up a large reserve of error. This happens when the controller goes into saturation and there is a steady state error in the speed. This steady state error will continue to build up the value in the integrator and when the condition causing the saturation is removed, this error will cause the speed to drastically overshoot the speed reference. The SpinTAC Velocity Control does not have this issue. The ADRC technology is estimating the system error in real-time and does not rely on an integrator that can cause integrator windup issues.
Figure 13-14 shows a case where a traditional PI controller experiences integrator windup. In this case the motor could not overcome the torque disturbance and it was forced to run at the speed slower than the setpoint. This placed the controller into saturation where the PI controller's integrator term built up over time. Once this torque disturbance was removed, the integrator term of the PI caused it to have a very large overshoot and take a much longer time to settle back to the speed setpoint. The SpinTAC controller did not see any of these ill effects since it does not contain an integrator term that can build up and cause integrator windup issues. It is also interesting to compare Figure 13-14 with Figure 13-12. You should notice that SpinTAC's response to removing the torque disturbance is very similar for the 50% rated torque disturbance and the 80% rated torque disturbance.