TY - JOUR
T1 - An Offset-Free Composite Model Predictive Control Strategy for DC/DC Buck Converter Feeding Constant Power Loads
AU - Xu, Qianwen
AU - Yan, Yunda
AU - Zhang, Chuanlin
AU - Dragicevic, Tomislav
AU - Blaabjerg, Frede
PY - 2020/5
Y1 - 2020/5
N2 - The high penetration of power electronic converters into dc microgrids may cause the constant power load stability issues, which could lead to large voltage oscillations or even system collapse. On the other hand, dynamic performance should be satisfied in the control of power electronic converter systems with small overshoot, less oscillations, and smooth transient performance. This article proposes an offset-free model predictive controller for a dc/dc buck converter feeding constant power loads with guaranteed dynamic performance and stability. First, a receding horizon optimization problem is formulated for optimal voltage tracking. To deal with the unknown load variation and system uncertainties, a higher order sliding mode observer is designed and integrated into the optimization problem. Then an explicit closed-loop solution is obtained by solving the receding horizon optimization problem offline. A rigorous stability analysis is performed to ensure the system large signal stability. The proposed controller achieves optimized transient dynamics and accurate tracking with simple implementation. The effectiveness of the proposed controller is validated by simulation and experimental results.
AB - The high penetration of power electronic converters into dc microgrids may cause the constant power load stability issues, which could lead to large voltage oscillations or even system collapse. On the other hand, dynamic performance should be satisfied in the control of power electronic converter systems with small overshoot, less oscillations, and smooth transient performance. This article proposes an offset-free model predictive controller for a dc/dc buck converter feeding constant power loads with guaranteed dynamic performance and stability. First, a receding horizon optimization problem is formulated for optimal voltage tracking. To deal with the unknown load variation and system uncertainties, a higher order sliding mode observer is designed and integrated into the optimization problem. Then an explicit closed-loop solution is obtained by solving the receding horizon optimization problem offline. A rigorous stability analysis is performed to ensure the system large signal stability. The proposed controller achieves optimized transient dynamics and accurate tracking with simple implementation. The effectiveness of the proposed controller is validated by simulation and experimental results.
KW - Constant power load (CPL)
KW - large signal stability
KW - Model Predictive Control (MPC)
KW - nonlinear disturbance observer
KW - offset-free tracking
UR - http://www.scopus.com/inward/record.url?scp=85081589862&partnerID=8YFLogxK
U2 - 10.1109/TPEL.2019.2941714
DO - 10.1109/TPEL.2019.2941714
M3 - Journal article
SN - 0885-8993
VL - 35
SP - 5331
EP - 5342
JO - I E E E Transactions on Power Electronics
JF - I E E E Transactions on Power Electronics
IS - 5
M1 - 8839850
ER -