| Title |
PID Gain Auto-Tuning of Heating Operation of Variable Air Volume System and Robustness Analysis against Disturbances |
| Authors |
Jong Hyeok Ryu ; Je Hyeon Lee ; Seok Kwon Jeong ; Ho Won Byun ; IHl wan Choi ; Dong Kwon Kim |
| DOI |
https://doi.org/10.6110/KJACR.2024.36.9.442 |
| Keywords |
공기조화기; 자동 튜닝; 전기식 히트펌프; PID 제어기; 변풍량; VAV Air handling unit; Auto-tuning; Electric heat pump; PID controller; Variable air volume |
| Abstract |
This study dealt with the auto-tuning of a PID controller designed to precisely control the indoor temperature to a setpoint during heating operations in an electric-heat pump (EHP)-based VAV air conditioning system. The proposed method tunes PID gains online through an on/off operation near the setpoint and automatically switches to PID control once tuning is complete. The performance of the PID gain auto-tuning and feedback control with the tuned controller was evaluated under various conditions using a calorimeter. The experiments demonstrated that the PID controller gains were properly tuned under different thermal load conditions and provided a detailed analysis of the tuned controller’s control performance. The auto-tuned controller was shown to precisely control the indoor temperature to the setpoint, even under varying thermal load conditions that differed from the ones used for tuning. Notably, the tuned PID controller maintained the indoor temperature within a 0.2℃ error of the set point (22℃) despite disturbances such as the introduction of low-temperature outdoor air and defrost operations, which are inevitable during heating operations. Finally, the stability and reproducibility of the auto-tuned PID controller were confirmed through the dominant pole analysis of the closed-loop system in the complex plane. |