Trivedi Tapankumar, Jadeja Rajendrasinh, Bhatt Praghnesh, Long Chao, Sanjeevikumar P, Ved Amit
Department of Electrical Engineering, Marwadi University, Rajkot-Morbi Highway, Rajkot, 360003, Gujarat, India.
School of Technology, Pandit Deendayal Energy University, Knowledge Corridor, Raisan Village, Raisan, Gandhinagar, 382007, Gujarat, India.
Heliyon. 2024 Oct 21;10(20):e39597. doi: 10.1016/j.heliyon.2024.e39597. eCollection 2024 Oct 30.
The Unified Power Quality Conditioner (UPQC) is a promising solution for mitigating multiple Power Quality(PQ) issues in distribution systems, including harmonics, poor power factor, voltage sag/swell and voltage imbalance. The conventional Sliding Mode Controller (SMC) in UPQCs suffers from wide switching frequency variations, chattering problems, and inherent active and reactive power coupling. This study proposes a nonlinear control method, Sliding Mode-based Direct Power Control (SMC-DPC), for the simultaneous regulation of the shunt and series compensators in a UPQC. By optimizing voltage vector selection based on real-time power errors, the proposed method effectively mitigates chattering, and reduces switching frequency variations, and ensures precise tracking of instantaneous active and reactive powers even in the presence of coupling effects. The proposed approach simplifies the system design and improves steady state and dynamic power tracking. The simulation results in MATLAB Simulink® on a 20 kVA system demonstrate that the proposed method achieves a source current THD of 1.52%, compared to 2.31% for conventional SMC and 5.11% for linear controller. Furthermore, the method is robust to grid parameter variations and demonstrates satisfactory performance in both strong and weak grids. In weak grids, the proposed method reduces the line losses by 13.71% and 14.54% compared to SMC and linear controller respectively. The reported results comply with international standards such as IEEE-519 and IEC 61000-3-12, confirming effectiveness of SMC-DPC for enhancing PQ in distribution system.
统一电能质量调节器（UPQC）是缓解配电系统中多种电能质量（PQ）问题的一种很有前景的解决方案，这些问题包括谐波、功率因数低、电压暂降/骤升以及电压不平衡。UPQC中传统的滑模控制器（SMC）存在开关频率变化范围大、抖振问题以及固有的有功和无功功率耦合。本研究提出一种非线性控制方法，即基于滑模的直接功率控制（SMC-DPC），用于同时调节UPQC中的并联和串联补偿器。通过基于实时功率误差优化电压矢量选择，该方法有效减轻了抖振，降低了开关频率变化，并即使在存在耦合效应的情况下也能确保对瞬时有功和无功功率的精确跟踪。所提出的方法简化了系统设计，提高了稳态和动态功率跟踪性能。在20 kVA系统上利用MATLAB Simulink®进行的仿真结果表明，与传统SMC的2.31%和线性控制器的5.11%相比，所提出的方法实现的源电流总谐波失真（THD）为1.52%。此外，该方法对电网参数变化具有鲁棒性，并且在强电网和弱电网中均表现出令人满意的性能。在弱电网中，与SMC和线性控制器相比，所提出的方法分别将线路损耗降低了13.71%和14.54%。报告的结果符合IEEE-519和IEC 61000-3-12等国际标准，证实了SMC-DPC在增强配电系统电能质量方面的有效性。
