With the goal of promoting the technology of power electronics, CPSS TPEA is expected to be a favorable platform to strengthen information exchange in this area through publishing and disseminating research findings worldwide. Authors are cordially invited to submit your papers through the website.

The objective of this journal is to finish the 1st round review within 6 weeks from submission.

CPSS TPEA Vol.11 No.1 (March 30, 2026)

Invited Paper

Power Conversion Solutions for Future Server Boards Operating Directly From High-Voltage DC

M. J. Kasper, G. Bernacchia, K. Tomas Manez, A. Pevere, N. Nain, and G. Deboy

Abstract The rapid scaling of accelerated computing is pushing rack power well beyond 1 MW, making conventional 48 V distribution increasingly inefficient due to busbar and connector currents. High-voltage DC (HVDC) distribution (e.g., 800 V) enables lower distribution losses and motivates server boards that interface directly to an HVDC bus. This paper addresses two enabling building blocks on the server board: (i) safe hot-swap and eFuse functionality with controlled pre-charging and telemetry, and (ii) high-power-density conversion from 800 V to intermediate-bus voltages. For hot-swap, a 1200 V-rated SiC JFET cascode is evaluated in linear mode and demonstrated to pre-charge 300 μF from 0 V to 800 V in approximately 1.5 s while staying within the device SOA limits. For power conversion, an unregulated LLC-DCX approach is investigated. An 800 V-to-50 V input-series-output-parallel (ISOP) half-bridge converter using GaN switches on the primary and secondary side and a matrix transformer reaches 98.1% efficiency at full load and a peak efficiency above 98.4%. A direct 800 V-to-12 V converter prototype achieves 97% at 6 kW and 98.2% peak efficiency.

Regular Papers

Frequency Response of Power System Load-Side Asynchronous Motors Considering ROCOF

Y. Li, Z. Liu, G. Song, and J. Huang

Abstract Load-side asynchronous motors (AMs) inherently lower rotor speeds during frequency dips, reducing active power absorption and delivering vital inertial support. However, existing frequency regulation strategies overlook the dual objectives, neglecting frequency response adaptability and induction motor operational stability. This paper proposes a segmented rate of change of frequency (ROCOF) control strategy for AM-based primary frequency regulation. First, ROCOF is divided into distinct intervals. In low ROCOF regions, AMs leverage natural electromechanical transients to stabilize frequency. In medium-high ROCOF regions, coordinated control AMs, which incorporate with variable-frequency asynchronous motors (VFAMs) using adaptive droop coefficients are deployed. This coordination maximizes frequency support while maintaining VFAMs’ stability. An adaptive model predictive control (MPC) framework is then designed to optimize dynamic frequency tracking for VFAMs. Simulations and hardware-in-the-loop (HIL) validate the strategy under uncertain system disturbances. Compared to conventional methods, the proposed approach elevates frequency nadirs, confirming enhanced transient performance, while maintaining normal operating conditions.

A Graph-Based Layout Automation Approach for Three-Level SiC Power Modules Considering Complex Mutual-Inductance

L. Zhang, Y. Zhao, G. Zhu, L. Li, and Y. Mei

Abstract This paper addresses the challenges of automatically designing low-inductance, compact three-level SiC power modules. The graph-based layout design automation method has the merit of seeking all possible solutions but may result in a significant calculation burden when considering complex mutual-inductance influences. To overcome this limitation, an efficient analytical method is developed to calculate parasitic inductance with mutual-inductance effects considered. Comparisons with numerical and experimental results prove the efficacy and accuracy of the proposed analytical method. A graph-based layout automation approach is developed, enabling multi-objective optimization of parasitic inductance and module footprint by incorporating mutual inductance. The method is applied to a three-level SiC module featuring six chips (four MOSFETs and two diodes). Pareto front solutions are analyzed to identify optimal trade-offs between inductance and compactness, demonstrating the effectiveness of the proposed methodology in enhancing design efficiency and performance for high-efficiency power electronics applications.

A New Single-Phase Switched Capacitor Based Five-Level Inverter With Double Gain for Grid-tied PV Applications

P. Ravali and A. Kirubakaran

Abstract This paper presents a new single-phase, switched-capacitor-based five-level inverter with double voltage gain, designed for renewable energy applications. The topology utilizes switched capacitors (SCs) alongside a simple T-type converter and a half-bridge circuit with self-voltage balancing capability, eliminating the need for additional sensors to balance the capacitors. Furthermore, a midpoint clamping neutral is incorporated to reduce leakage current and common-mode voltage, making it particularly suitable for photovoltaic applications. A simple proportional-resonant (PR) controller is employed for grid current control, while a straightforward level-shifted pulse-width modulation (LS-PWM) technique generates the five-level output voltage waveform using two carrier signals, simplifying control complexity. An experimental setup is developed to validate the effectiveness of the proposed topology with R and RL loads under both steady-state and dynamic conditions, as well as grid-tied operation. Capacitor voltage balancing and the effect of the modulation index are also presented. Moreover, a hardware-in-the-loop (HIL) cosimulation is performed for grid control using Xilinx System Generator blocks in the MATLAB/Simulink environment, with the results provided. Additionally, a comprehensive comparison highlights the advantages of the proposed topology compared to recent solutions reported in the literature.

Optimized Design of AC-Side Inductance for Grid-Forming Inverters

L. Gao, J. Lyu, J. Dai, H. Wang, and X. Cai

Abstract With the large-scale integration of renewable energy into modern power systems, grid-forming (GFM)-based inverters will play an increasingly important role. Currently, the design approach for the AC-side inductance of filter in GFM inverters still follows that of grid-following (GFL)-based inverters, potentially hindering optimal performance. To tackle this issue, an optimized design method for the AC-side inductance of GFM inverters is proposed in this paper by taking into account the specific requirements of various applications. Furthermore, a customized parameter design method for the AC-side inductance is introduced, aiming to achieve a balance between dynamic performance needs and control challenges. Finally, the validation of the proposed optimized design method is demonstrated through simulations and experimental results obtained from the Modeling Tech StarSim controller hardware-in-the-loop platform.

Analysis of the Operating Mechanism of Photovoltaic Power Generation Systems Constrained by Arc Faults and Its Identification Methods

K. Chen, J. Teng, P. Li, J. Guo, L. Qi, and X. Sun

Abstract Series/parallel are faults are typical problems existing between photovoltaic (PV) and boost converter. Current research lacks a unified system model to describe the operation mechanism and power characteristics under are faults. This paper proposes an equivalent model of PV-boost power generation system based on series/parallel are constraints. Firstly, by coupling the are equivalent model in the PV model, the output characteristics of the PV system in normal and fault states are ob tained. Then, by adding the are link in the power conversion and control model of the PV-boost system, the operation mechanism and power transfer characteristics of the system under two types of are faults are revealed. Finally, based on the multi-modal PV output voltage-current characteristics under are faults and the voltage-current characteristics at the input end of the boost under maximum power point tracking control, a specific fault identifica tion and classification method for series/parallel ares is designed, which is easy to implement in engineering and based on the degree of hazard. The feasibility of this scheme is verified.

A Software-Based Bandwidth Compensation Method for Small-Resistance Coaxial Current Shunt

Z. Chen, Y. He, Y. Zhang, and Y. Wei

Abstract Due to the increasing switching speed of the wide band gap (WBG) devices, there is an urgent demand for the high-bandwidth current sensor. However, the low bandwidth of the low-resistance coaxial current shunt (CCS) becomes the hindrance to the WBG device characterizations. This paper proposes a low-cost bandwidth compensation method for the low-resistance CCS. Since the structure of the CCS is complicated, it is regarded as a two-port network, and a high-resistance high-bandwidth CCS is used to generate the compensation transfer function. The proposed method is verified by the double pulse test (DPT) of a Gallium Nitride (GaN) device. The maximum errors for the turn-on switching loss and total switching loss after compensation are 1.1% and 1.2%, respectively. While these values before compensations are 35.3% and 31.7%, respectively. In addition, the proposed method is not sensitive to the preselected testing condition, which indicates its high practical engineering value. 

Single-Phase Independent Model Predictive Control for Open-End Winding Motor Fed by Dual Three-Level Inverters

C. Luo, G. Wang, Q. Du, J. Ji, W. Shi, and K. Li

Abstract For open-end winding induction motor (OEWIM) fed by dual three-level inverters, traditional model predictive current control (MPCC) suffers from issues such as excessive vector enumeration, complex control algorithm design, and slow dynamic response. This paper proposes a low voltage jump single-phase independent model predictive current control (LVJ-SPI-MPCC) method. Firstly, by establishing a single-phase independent predictive current model, the independent prediction and optimization of the switching states for each phase leg are achieved, reducing the number of optimal switching state selections per control cycle from 729 to 27. Secondly, to suppress phase voltage jumps, a switching state selection rule based on a voltage jump constraint is proposed, constructing a collaborative optimization strategy for low voltage jump and single-phase independent control. This limits the phase voltage jump within the range of ±Udc/2 and further reduces the predictive computations per cycle to 15. Finally, the effectiveness of the proposed method is verified based on MATLAB/Simulink simulations and the Typhoon HIL 402 experimental platform. Experimental results show that the proposed method significantly reduces the computational burden and improves the system’s dynamic response speed while ensuring control accuracy.

Analysis and Optimized Design of Conducted Common-Mode EMI Characteristics of CLLC Circuits

K. Lin, S. Lin, C. Huang, and W. Chen

Abstract The CLLC converter offers advantages such as high efficiency, high power density, bidirectional Buck-Boost capability, and soft-switching operation, and has been widely applied in automotive onboard chargers and renewable energy systems. Electromagnetic compatibility (EMC) is one of the critical performance indicators for CLLC circuits. To investigate the conducted common-mode (CM) EMI characteristics of the CLLC converter, a CM EMI equivalent circuit model was established based on the noise transmission mechanism, and an equivalent model of the CLLC converter was derived, clarifying the noise source characteristics and the key CM noise transmission path impedances. The noise source characteristics under different operating conditions were analyzed to reveal the CM noise behavior in each condition. Based on this analysis, a symmetry-based design method for optimizing the CM EMI performance of the CLLC converter was proposed, and the impacts of resonant inductor and capacitor symmetry were examined. The correctness of the CM characteristic analysis for the CLLC converter is verified through simulations and experimental tests. By constructing a symmetric resonant cavity structure, the CM noise is attenuated by 20–30 dB, which further validates the feasibility of the symmetric structure-based optimization design method.

An Improved FCS-MPC Algorithm for Three-Phase Three-Level T-Type Off-Grid Inverters Based on Current Tracking 

J. Lv, Y. Dou, and Y. Zhang

Abstract This paper presents a finite control set model predictive control (FCS-MPC) strategy for three-phase three-level T-type off-grid inverters, with the aim of optimizing current tracking performance. First, the voltage vector function range and the subsector regions are redefined with the integration of the voltage vector synthesis concept, which helps reduce current ripples and thus total harmonic distortions. Then, to promote neutral point potential balance, a time compensation mechanism is introduced, complementing the passive balance through voltage vector synthesis. To address the issue of high computational complexity, a two-step sector determination strategy is proposed. The proposed FCS-MPC is both tested through simulation and experiment. Compared with the conventional approach, the proposed strategy shows superior results in terms of algorithm execution time, neutral potential balance, steady-state performance, and dynamic response.

High Voltage Gain Bidirectional DC-DC Converters for Supercapacitor Assisted Electric Vehicles: A Review

Ankit Kumar Singh; Anjanee Kumar Mishra; Krishna Kumar Gupta; Yam P. Siwakoti

LLC and CLLC resonant converters based DC transformers (DCXs): Characteristics, issues, and solutions

Yuqi Wei; Quanming Luo; Homer Alan Mantooth

A Review of Magnetic Core Materials, Core Loss Modeling and Measurements in High-Power High-Frequency Transformers

Zenong Li;Weijian Han;Zhen Xin;Qing Liu;Jianliang Chen;Poh Chiang Loh

A review of SiC power module packaging: Layout, material system and integration

Cai Chen;Fang Luo;Yong Kang

Critical Review of Vehicle-to-Everything (V2X) Topologies: Communication, Power Flow Characteristics, Challenges, and Opportunities

Gaurav Kumar; Suresh Mikkili

Overview of Voltage Regulator Modules in 48 V Bus-Based Data Center Power Systems

Jiawei Liang; Liang Wang; Minfan Fu; Junrui Liang; Haoyu Wang

A novel model predictive current control with reduced computational burden based on discrete space vector modulation for PMSM drives

Jun Sun;Yong Yang;Jiefeng Hu;Xinan Zhang;Xinghe Li;Jose Rodriguez

A SiC-Based Liquid-Cooled Electric Vehicle Traction Inverter Operating at High Ambient Temperature

Chi Zhang;Srdjan Srdic;Srdjan Lukic;Keyao Sun;Jun Wang;Rolando Burgos

Review of GaN totem-pole bridgeless PFC

Qingyun Huang;Alex Q. Huang

A new high gain DC-DC converter with model-predictive-control based MPPT technique for photovoltaic systems