In three-phase three-wire power systems, unified power quality conditioners (UPQCs) compensate for current/voltage fluctuations while enhancing load-side power quality. However, current solutions face three key limitations: (1) limited responsiveness to rapid disturbances, (2) sensitivity to grid variations, and (3) inadequate phase-locked loop (PLL) performance, all of which undermine compensation effectiveness. Traditional proportional-integral (PI) controllers further exacerbate these issues through overshooting during control quantity disturbances. This paper proposes an enhanced finite control set model predictive control (FCS-MPC) system integrated with linear active disturbance rejection control (LADRC) to improve UPQC's anti-disturbance capabilities. The architecture combines a series active power filter (APF)-side voltage compensation module based on FCS-MPC, a shunt APF-side current compensation module based on FCS-MPC, and a LADRC-optimized mixed second/third-order generalized integrator-based PLL (MSTOGI-PLL). Through rigorous MATLAB/Simulink simulations, the proposed UPQC demonstrates superior robustness compared to conventional controllers, achieving 85% voltage sag compensation within 12.5 ms response time. Simulation result validation confirms that the LADRC-enhanced FCS-MPC system significantly improves disturbance rejection, yielding effectively reduced voltage total harmonic distortion (THD) and enhanced post-compensation power quality across various grid anomalies.
Citation: Yuting Yu, Muhammad Murtadha Othman, Yanting Chu, Ismail Musirin. Promotion of anti-disturbance capability in UPQC systems under FCS-MPC control with LADRC-optimized phase-locked loop[J]. AIMS Electronics and Electrical Engineering, 2026, 10(3): 446-472. doi: 10.3934/electreng.2026018
In three-phase three-wire power systems, unified power quality conditioners (UPQCs) compensate for current/voltage fluctuations while enhancing load-side power quality. However, current solutions face three key limitations: (1) limited responsiveness to rapid disturbances, (2) sensitivity to grid variations, and (3) inadequate phase-locked loop (PLL) performance, all of which undermine compensation effectiveness. Traditional proportional-integral (PI) controllers further exacerbate these issues through overshooting during control quantity disturbances. This paper proposes an enhanced finite control set model predictive control (FCS-MPC) system integrated with linear active disturbance rejection control (LADRC) to improve UPQC's anti-disturbance capabilities. The architecture combines a series active power filter (APF)-side voltage compensation module based on FCS-MPC, a shunt APF-side current compensation module based on FCS-MPC, and a LADRC-optimized mixed second/third-order generalized integrator-based PLL (MSTOGI-PLL). Through rigorous MATLAB/Simulink simulations, the proposed UPQC demonstrates superior robustness compared to conventional controllers, achieving 85% voltage sag compensation within 12.5 ms response time. Simulation result validation confirms that the LADRC-enhanced FCS-MPC system significantly improves disturbance rejection, yielding effectively reduced voltage total harmonic distortion (THD) and enhanced post-compensation power quality across various grid anomalies.
| [1] |
Qasim AY, Tahir FR, Alsammak ANB (2024) Improving Power Quality in Distribution Systems Using UPQC: An Overview. Journal Européen des Systèmes Automatisés 57. https://doi.org/10.18280/jesa.570201 doi: 10.18280/jesa.570201
|
| [2] |
Jin T, Chen Y, Guo J, Wang M, Mohamed MA (2020) An effective compensation control strategy for power quality enhancement of unified power quality conditioner. Energy Reports 6: 2167‒2179. https://doi.org/10.1016/j.egyr.2020.07.027 doi: 10.1016/j.egyr.2020.07.027
|
| [3] |
Farooq A, Bhat AH (2024) Simplified control strategy-based three-phase reduced switch UPQC for mitigation of power quality problems. International Journal of Power Electronics 20: 266‒300. https://doi.org/10.1504/IJPELEC.2024.142280 doi: 10.1504/IJPELEC.2024.142280
|
| [4] |
Palanisamy T, Thangamuthu GS (2024) Optimal power quality improvement in distribution system with UPQC using an improved strategy. Optimal Control Applications and Methods 45: 1433‒1455. https://doi.org/10.1002/oca.3105 doi: 10.1002/oca.3105
|
| [5] |
Feng D, Chen T, Zhang L, Meng W, He J (2024) A control method for the single-phase three-leg unified power quality conditioner without a phase-locked loop. Front Energy Res 12: 1343520. https://doi.org/10.3389/fenrg.2024.1343520 doi: 10.3389/fenrg.2024.1343520
|
| [6] | Han J, Li X, Jiang Y, Gong S (2021) Three-Phase UPQC Topology Based on Quadruple-Active-Bridge. IEEE Access 9: 4049‒4058. |
| [7] |
Yadav SK, Yadav KB, Priyadarshi A (2024) Performance analysis of three-phase solar PV, BESS, and Wind integrated UPQC for power quality improvement. Computers and Electrical Engineering 116: 109230. https://doi.org/10.1016/j.compeleceng.2024.109230 doi: 10.1016/j.compeleceng.2024.109230
|
| [8] |
Kanchana K, Babu V, Gaddam S, Naidu Pudi V (2025) Advancing microgrid power quality: integration of GRU-based control in PV-UPQC systems. Electr Eng 107: 223‒248. https://doi.org/10.1007/s00202-024-02517-2 doi: 10.1007/s00202-024-02517-2
|
| [9] |
Nicola M, Nicola CI, Sacerdoțianu D, Vintilă A (2023) Comparative performance of UPQC control system based on PI-GWO, fractional order controllers, and reinforcement learning agent. Electronics 12: 494. https://doi.org/10.3390/electronics12030494 doi: 10.3390/electronics12030494
|
| [10] |
Fuyin NI, Jian H (2023) Research on UPQC harmonic control strategy based on optimized QPIR controller of beetle antennae search algorithm in microgrid. Electr Eng 106: 2357‒2369. https://doi.org/10.1007/s00202-023-02066-0 doi: 10.1007/s00202-023-02066-0
|
| [11] | Yadav SK, Yadav KB (2023) FOPI Controller with Chicken Swarm Optimization for Power Quality Improvement of HES System Integrated UPQC. Computational Vision and Bio-Inspired Computing: Proceedings of ICCVBIC 2022, 367-378. Singapore: Springer Nature Singapore. https://doi.org/10.1007/978-981-19-9819-5_28 |
| [12] |
Kumar GS, Kumar BK, Mishra MK (2011) Mitigation of Voltage Sags With Phase Jumps by UPQC With PSO-Based ANFIS. IEEE T Power Deliver 26: 2761‒2773. https://doi.org/10.1109/TPWRD.2011.2165301 doi: 10.1109/TPWRD.2011.2165301
|
| [13] |
Zanib N, Batool M, Riaz S, Nawaz F (2022) Performance Analysis of Renewable Energy Based Distributed Generation System Using ANN Tuned UPQC. IEEE Access 10: 110034‒110049. https://doi.org/10.1109/ACCESS.2022.3213948 doi: 10.1109/ACCESS.2022.3213948
|
| [14] |
Kumar A, Kumar P (2024) JAYA based optimization strategy for UPQC PI tuning based on novel SRF-DSOGI PLL control. Int J Syst Assur Eng Manag 15: 3193‒3209. https://doi.org/10.1007/s13198-024-02325-8 doi: 10.1007/s13198-024-02325-8
|
| [15] |
Bueno-Contreras H, Ramos GA, Costa-Castelló R (2021) Power quality improvement through a upqc and a resonant observer-based mimo control strategy. Energies 14: 6938. https://doi.org/10.3390/en14216938 doi: 10.3390/en14216938
|
| [16] |
Xu J, Qian H, Qian Q, Xie S (2023) Modeling, Stability, and Design of the Single-Phase SOGI-Based Phase-Locked Loop Considering the Frequency Feedback Loop Effect. IEEE T Power Electr 38: 987‒1002. https://doi.org/10.1109/TPEL.2022.3201252 doi: 10.1109/TPEL.2022.3201252
|
| [17] |
Hui N, Feng Y, Han X (2020) Design of a High Performance Phase-Locked Loop With DC Offset Rejection Capability Under Adverse Grid Condition. IEEE Access 8: 6827‒6838. https://doi.org/10.1109/ACCESS.2020.2963993 doi: 10.1109/ACCESS.2020.2963993
|
| [18] |
Li G, Chen Y, Luo A, Wang Y (2021) An Inertia Phase Locked Loop for Suppressing Sub-Synchronous Resonance of Renewable Energy Generation System Under Weak Grid. IEEE T Power Syst 36: 4621‒4631. https://doi.org/10.1109/TPWRS.2021.3066481 doi: 10.1109/TPWRS.2021.3066481
|
| [19] |
Alam SJ, Arya SR (2020) Control of UPQC based on steady state linear Kalman filter for compensation of power quality problems. Chinese Journal of Electrical Engineering 6: 52‒65. https://doi.org/10.23919/CJEE.2020.000011 doi: 10.23919/CJEE.2020.000011
|