IEEE Journal of Emerging and Selected Topics in Power Electronics最新文献

{"title":"A Natural Continuity of States Seamless Switching Control for Grid-Connected Inverters","authors":"Rui Zhao;Xiaofeng Yang;Ange Wei;Menghan Lv;Trillion Q. Zheng","doi":"10.1109/JESTPE.2026.3711760","DOIUrl":"10.1109/JESTPE.2026.3711760","url":null,"abstract":"Seamless switching control between grid-following (GFL) and grid-forming (GFM) modes is a critical solution for addressing the stability challenges of grid-connected inverters (GCIs) under a wide range of grid strength fluctuations. However, the essence of traditional methods is a constrained switching system that artificially forces the discontinuous states to be continuous through additional control, such as synchronization links. As a result, the traditional methods suffer from the issue of real-mode switching lagging behind the switching command, which is referred to as pseudoswitching in this article. If the grid strengths fluctuate into the unstable region, the instability risks of GCIs with pseudoswitching will increase. Another nonnegligible issue is that the control structure and logic of the existing methods are complex, which limits their engineering applicability. To address the above issues, a natural continuity of states seamless switching control (NC-SSC) strategy is proposed. The NC-SSC designs a scheme of phase switching point advancement and integrator sharing, which ensures the continuity of phase at the switching time without relying on extra synchronization mechanisms. Then, a modal transition adaptive PI (MT-API) controller is proposed, which ingeniously embeds the switching logic into the controller by the modal factor <inline-formula> <tex-math>$sigma $ </tex-math></inline-formula>. This approach achieves natural continuity of the reference current while significantly simplifying the operational logic. Moreover, NC-SSC eliminates the need for traditional amplitude synchronization through a dynamic <inline-formula> <tex-math>$d$ </tex-math></inline-formula>-axis grid voltage component assignment technique, further saving control resources. With these enhancements, the proposed NC-SSC breaks through the constraints of the traditional switching system, effectively resolving the issues of pseudoswitching and control complexity. Simulation and experimental results verify the correctness of the theoretical analysis and the superiority of the NC-SSC.","PeriodicalId":13093,"journal":{"name":"IEEE Journal of Emerging and Selected Topics in Power Electronics","volume":"14 5","pages":"6625-6638"},"PeriodicalIF":5.7,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148414904","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"State-Space Modeling and Linearization of Radial DC Microgrids: A Method for Coupling DC--DC Converters State-Space Average Models","authors":"Guilherme Henrique Favaro Fuzato;Thales Augusto Fagundes;Cassius Rossi de Aguiar;Paulo Soares Filho;Tárcio André dos Santos Barros;Ricardo Quadros Machado","doi":"10.1109/JESTPE.2026.3719182","DOIUrl":"10.1109/JESTPE.2026.3719182","url":null,"abstract":"DC microgrids are composed of various nonlinear elements, including power converters (e.g., DC–DC and DC–AC/AC–DC converters for grid-connected operation), power sources (fuel cells, photovoltaics, and batteries), and controllers that may be linear or nonlinear. Accurately capturing the dynamic behavior of such systems requires developing a model that closely reflects the interactions among these nonlinear elements. These interactions influence the transient response, the steady-state operating points, and stability of the microgrid. In this context, this article presents a systematic modeling approach for radial DC microgrids based on the proposed DC-link Coupling Equation. This method enables systematic coupling of nonlinear average models of DC–DC converters with their associated linear or nonlinear controllers into a unified state-space representation. The methodology is applied to two case studies: one employing a droop controller and the other using a cascaded DC-link voltage controller. The nonlinear microgrid model accounts for interactions among all nonlinear elements and is validated through comparison of results from MATLAB ordinary differential equation (ODE) solver applied to the DC microgrid model and experimental data obtained from a hardware-based prototype. Finally, linearization of the nonlinear DC microgrid model is employed to assess the stability of the microgrid under varying load conditions.","PeriodicalId":13093,"journal":{"name":"IEEE Journal of Emerging and Selected Topics in Power Electronics","volume":"14 5","pages":"5720-5731"},"PeriodicalIF":5.7,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11635891","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148633686","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"High-Precision In Situ Inductor Loss Evaluation for DC–DC Converters Based on Gain–Phase Frequency Characteristics Correction in Voltage/Current Measurement Systems","authors":"Takaaki Ibuchi;Tsuyoshi Funaki","doi":"10.1109/JESTPE.2026.3681269","DOIUrl":"10.1109/JESTPE.2026.3681269","url":null,"abstract":"Accurate in situ evaluation of inductor losses in operating DC–DC converters is hindered by frequency-dependent gain and phase errors in practical voltage and current probes, especially when the voltage–current phase approaches 90° in a low-loss inductor. This article presents a frequency-domain gain–phase correction method based on vector network analyzer (VNA) characterization of commercially available probes. The proposed approach is based on the same fundamental principle as the cross-power method and enables high-accuracy loss evaluation using general-purpose oscilloscopes and probe systems during actual converter operation. Gain–phase characteristics are measured for high-voltage differential probes, AC/DC current probes, and optically isolated probes. Applying the derived correction to harmonic components measured in a 100-kHz, 450-W boost converter reduces the discrepancy between different probe combinations from approximately 20 W to below 0.2 W. The results demonstrate that frequency-dependent correction is essential for reliable in situ magnetic loss evaluation using the standard measurement equipment.","PeriodicalId":13093,"journal":{"name":"IEEE Journal of Emerging and Selected Topics in Power Electronics","volume":"14 5","pages":"6459-6470"},"PeriodicalIF":5.7,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149091401","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimal Multitimescale Model Predictive Control-Based Power Allocation of Hybrid Energy Storage Systems via Reference Curve Tracking","authors":"Weihao Zhang;Dongsheng Yu;Zhichao Zhang;Samson Shenglong Yu;Shing Chiang Tan;Chee Peng Lim","doi":"10.1109/JESTPE.2026.3689151","DOIUrl":"10.1109/JESTPE.2026.3689151","url":null,"abstract":"The intermittency of renewable energy has made stable power supply a focal and challenging research topic in today’s power system. However, most existing intelligence-enabled control protocols pose significant computational complexity, hindering their practical applications in multitimescale power control scenarios. This article proposes an optimal power allocation method for hybrid energy storage systems (HESSs) based on complementary power reference curves. The approach leverages batteries’ dynamic characteristics and output properties and algorithmic features to construct complementary power reference curves. Through real-time tracking of these reference curves, the method achieves coordinated and stable power output across multiple timescales. The improved model predictive control (MPC) is integrated into the control strategy to efficiently convert power tracking into current prediction. This approach enhances system dynamic response without needing excessive computational resources. Furthermore, the proposed method is integrated into a dynamic voltage restorer (DVR) for power quality control. Finally, the feasibility and effectiveness of the proposed approach is validated through hardware experiments.","PeriodicalId":13093,"journal":{"name":"IEEE Journal of Emerging and Selected Topics in Power Electronics","volume":"14 5","pages":"6501-6512"},"PeriodicalIF":5.7,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149091404","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Virtual Synchronous Generator Stability Enhancement and Power Oscillation Suppression With Adaptive Virtual Impedance Control","authors":"Xiangqian Su;Xiangyang Xing;Xiangjun Li;Yan Li;Zhiyuan Meng;Jiadong Sun;Frede Blaabjerg","doi":"10.1109/JESTPE.2026.3689505","DOIUrl":"10.1109/JESTPE.2026.3689505","url":null,"abstract":"With the rapid growth of renewable power generation (RPG), grid inertia gradually decreases. Therefore, the virtual synchronous generator (VSG) is proposed to enhance the inertia and damping of the power system. High-penetration RPG, characterized by intermittency, stochasticity, and output volatility, could cause grid impedance variations, thereby leading to short-circuit ratio (SCR) fluctuations that are detrimental to system stability. When the grid reactance is much larger than its resistance, VSG is stable under weak grids while less stable under strong grids, so it is challenging for VSG to meet the stability criteria under a wide range of SCRs. Furthermore, power oscillation may occur during SCR fluctuations. Therefore, this article proposes an adaptive virtual impedance (AVI) control strategy which fully retains the characteristics of the grid-forming (GFM) mode, mitigates power oscillation during SCR fluctuations, and improves the stability of VSG under strong grids. First, a state-space model of the VSG is developed to analyze the control parameters. Then, an open-loop small-signal transfer function of the active power loop (APL) is derived to analyze the proposed strategy. Finally, an appropriate feedback coefficient is determined based on the developed model. Experimental results verify the effectiveness of the proposed strategy.","PeriodicalId":13093,"journal":{"name":"IEEE Journal of Emerging and Selected Topics in Power Electronics","volume":"14 5","pages":"6513-6530"},"PeriodicalIF":5.7,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149091409","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sensorless Control of Dual-Three-Phase PMSM Using a Subspace Decoupling-Based Fuzzy Super-Twisting Sliding Mode Observer","authors":"Luhui Xu;Zhiguo Zhao;Peng Tang","doi":"10.1109/JESTPE.2026.3702105","DOIUrl":"10.1109/JESTPE.2026.3702105","url":null,"abstract":"To address the chattering, parameter sensitivity, and limited operating-condition adaptability of conventional sliding mode observers (SMOs) in sensorless control of dual-three-phase permanent magnet synchronous motors (DTP-PMSMs), this article proposes a subspace-decoupling-based integrated method combining a fuzzy super-twisting SMO (F-STSMO) and gray wolf optimization (GWO). In the proposed method, fuzzy control is integrated with the super-twisting SMO (STSMO) to construct a fuzzy time-varying-gain observer. The stability of the observer under time-varying disturbances is demonstrated, which effectively suppresses chattering and improves the observation performance over a wide dynamic range. By exploiting the multiple degrees of freedom of DTP-PMSMs, a GWO-based parameter estimation algorithm is developed. The sensitivity to initial settings and the convergence conditions are discussed, enabling high-accuracy real-time motor parameter estimation and enhancing the robustness of the STSMO against parameter variations. Furthermore, the Lyapunov stability constraints of the integrated F-STSMO and GWO method are analyzed. Experimental results show that the proposed integrated F-STSMO and GWO sensorless control method achieves a resistance estimation error of 0.9% for the DTP-PMSM, reduces the rotor position error caused by parameter variations by 88.6%, and keeps the rotor position error fluctuation within 2.51° under both steady-state and dynamic operating conditions.","PeriodicalId":13093,"journal":{"name":"IEEE Journal of Emerging and Selected Topics in Power Electronics","volume":"14 5","pages":"6331-6344"},"PeriodicalIF":5.7,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149092326","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Power Balance Modulation for Cascaded H-Bridge Inverters via Carrier Optimization","authors":"Jun Gu;Yu Liu;Xiang Zhu;Qiangqiang Ning;Jiamin Pan;Song Li","doi":"10.1109/JESTPE.2026.3691928","DOIUrl":"https://doi.org/10.1109/JESTPE.2026.3691928","url":null,"abstract":"Cascaded H-bridge (CHB) inverters are widely used in medium-voltage, high-power motor drives, photovoltaic grid-connected systems, and energy storage systems due to their high modularity and ease of scalability. However, traditional modulation strategies face the inherent tradeoff between power balancing and harmonic optimization. Imbalanced output power or poor harmonic characteristics of the output voltage directly compromise the quality of the inverter’s output voltage waveform. To address the aforementioned issues, an improved carrier-layered (ICL) technology is proposed. Through carrier reconstruction, it achieves optimal total harmonic distortion (THD) while utilizing redundant switching states to uniformly distribute power across cascaded units. This strategy, based on universal constraints, can be directly extended to n-unit topologies, maintaining power balance among remaining units even after any unit failure. Finally, the effectiveness of this strategy is validated through theoretical analysis, simulation, and experimental verification.","PeriodicalId":13093,"journal":{"name":"IEEE Journal of Emerging and Selected Topics in Power Electronics","volume":"14 5","pages":"6743-6753"},"PeriodicalIF":5.7,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149097259","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"3-D PLL Model Considering Frequency-Impedance Coupling for Accurate Whole-Process Dynamic Capture and Transient Stability Analysis","authors":"Mingyao Ren;Ziqian Zhang;Chuang Liu;Zhe Zhang;Chao Liu;Robert Schuerhuber;Ikromjon Usmonovich Rakhmonov","doi":"10.1109/JESTPE.2026.3691116","DOIUrl":"https://doi.org/10.1109/JESTPE.2026.3691116","url":null,"abstract":"Transient synchronization stability of the grid-connected converter is critically affected by the phase-locked loop (PLL) dynamics. However, frequency-impedance coupling (FIC) induced by PLL frequency deviation is often neglected in the conventional quasi-steady-state (QSS) PLL model, which may lead to an inaccurate post-fault stability assessment. To address this issue, this article proposes a 3-D frequency-impedance coupling (FIC) PLL model that explicitly incorporates frequency drift during faults, enabling whole-process transient stability analysis from fault occurrence to recovery. Based on that, the existence conditions of stable equilibrium points and the evolution of the domain of attraction (DOA) are investigated comprehensively with respect to grid strengths, PLL parameters, and fault durations. Furthermore, a DOA-oriented parameter design framework is developed to enhance transient stability. Finally, experimental results on a scaled-down GCC platform validate that the FIC-PLL model provides more accurate stability assessments than conventional QSS models, and the optimized PLL parameters effectively improve transient stability under weak-grid conditions.","PeriodicalId":13093,"journal":{"name":"IEEE Journal of Emerging and Selected Topics in Power Electronics","volume":"14 5","pages":"5760-5771"},"PeriodicalIF":5.7,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149097332","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dynamic Clamping Arm Control for Voltage Balancing of Series-Connected Modular Switches in MV/HV VSCs","authors":"Tianji Zhou;Biao Zhao;Xueyin Zhang;Ruihang Bai;Zhongjian Song;Bin Cui;Lu Qu;Zhanqing Yu;Qiang Song;Rong Zeng","doi":"10.1109/JESTPE.2026.3686706","DOIUrl":"10.1109/JESTPE.2026.3686706","url":null,"abstract":"The modular multilevel converter (MMC) is widely deployed in medium-voltage DC (MVDC) and high-voltage DC (HVDC) systems but suffers from high cost and bulky submodule (SM) capacitors. Voltage source converters (VSCs) offer a compact and cost-effective alternative but require voltage-balancing control for series-connected devices in MV/HV high current applications with significant stray inductance. This work advances existing active clamping module (ACM) to self-powered, bypass-capable modular switches (MSs) and proposes a dynamic clamping arm (DCA) control for series-connected MSs, enabling soft-switched recovery of turn-off energy and low-bandwidth sorting-based voltage balancing. The commutation process under DCA control is discussed in detail. Analytical models quantify voltage-balancing modes and derive design constraints for key parameters of a 10 kV/5 MW prototype. Performance comparisons of the proposed scheme with MMC and existing balancing methods are discussed. A phase-unit of the prototype, employing eight series-connected 1.7 kV IGBT-based MSs per arm, is tested in a power-cycling setup. The experimental results demonstrate robust voltage balancing and minimal auxiliary switch stress, confirming the effectiveness of DCA control and its feasibility in MV/HV VSCs.","PeriodicalId":13093,"journal":{"name":"IEEE Journal of Emerging and Selected Topics in Power Electronics","volume":"14 5","pages":"6104-6118"},"PeriodicalIF":5.7,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147735667","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantitative Parameter Design for Transient Synchronization Stability of Parallel VSGs","authors":"Liang Yuan;Yifan Guo;Mingxin Hu;Yaran Li;Zhangjie Liu;Mei Su;Zhao Yang Dong","doi":"10.1109/JESTPE.2026.3667480","DOIUrl":"10.1109/JESTPE.2026.3667480","url":null,"abstract":"Virtual synchronous generator (VSG) systems are an attractive solution for inertia support and for improving grid frequency stability. Nevertheless, the interaction mechanisms among parallel VSG systems are still insufficiently understood. The quantitative design of virtual inertia and damping, which is critical for maintaining transient synchronization stability (TSS), has not yet been systematically addressed. To address these gaps, a mathematical model of parallel VSG systems is developed. This model incorporates the dynamic characteristics of damping dissipation, system interactions, and reactive power control (RPC). Second, the feasible parameter region (FPR) is then determined to satisfy transient stability and rate of change of frequency (RoCoF) requirements under large disturbances. The influence of system parameters on stability margins is systematically evaluated. Finally, experimental results confirm the accuracy of the proposed parameter range. The study provides practical guidance for parameter design and engineering applications of parallel VSGs.","PeriodicalId":13093,"journal":{"name":"IEEE Journal of Emerging and Selected Topics in Power Electronics","volume":"14 5","pages":"6376-6388"},"PeriodicalIF":5.7,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147279873","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}