Jiayi Geng

Ms. Jiayi Geng


Research Focus & Metrics

Academic Career Length

3Years (2024-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 January 2024 in IEEE Transactions on Industrial Electronics
Verified
Journal Article
Closed access
Tianlu MaTianlu Ma
Tianlu Ma
Chaoqiang JiangChaoqiang Jiang
Chaoqiang Jiang
CCChen Chen
Chen Chen
YWYibo Wang
Yibo Wang
JGJiayi Geng
Jiayi Geng
CTChi K. Tse
Chi K. Tse
Dynamic wireless charging (DWC) technology can help alleviate the problem of short driving range for battery-powered vehicles. In this article, a model predictive control (MPC) is applied to the buck converter on the secondary side of a DWC system to address fast output fluctuations. This approach features a fast-dynamic response, and no communication link is required. To solve the key issue of MPC, which is the computational burden, a polynomial fitting method based on the parsing solution of the sampled-data model is proposed. The complex matrix exponential calculation is replaced by simple polynomial operations, and the optimal duty cycle can be calculated directly by solving a quadratic function. This significantly reduces the computational burden. A DWC experimental setup is constructed, and results show that the proposed MPC has a better dynamic performance compared to proportional-integral control. The adjustment time is only 140 μs (around seven switching cycles) when the reference voltage is stepping. Moreover, the computational burden for matrix calculation in two-step prediction can be reduced by 50.6% and 79.7% compared to the lookup table and Taylor series approximation, respectively. Meanwhile, MPC with current limitation is analyzed and demonstrates a neat spectrum, small ripple but large response time.

22 January 2025 in IEEE Transactions on Power Electronics
Verified
Journal Article
Closed access
JGJiayi Geng
Jiayi Geng
Riccardo MandrioliRiccardo Mandrioli
Riccardo Mandrioli
Chaoqiang JiangChaoqiang Jiang
Chaoqiang Jiang
Mattia RiccoMattia Ricco
Mattia Ricco
Increasing power consumption in data centers is pushing the dc distribution networks system for high efficiency and power density, redundancy, and low-cost design. To comply with this trend, this article presents a dual-bus 48 V to 12/4 V back-to-back converter for high-current power delivery in data centers, designed with a vertical assembling structure. This converter is realized with a modular approach consisting of a four-phase interleaved buck converter cascaded with a switched capacitor voltage selector. The four buck converters are connected in parallel and use an interleaved control modulation to distribute the current, providing a stable voltage to the switched capacitor converter in the second stage. Four mosfets are paralleled in each leg of the switched capacitor converter to withstand the high output current. The architecture has high modularity and scalability ensuring low voltage drop and redundant operations. A vertically stacked prototype with a 200 A maximum output current is tested and discussed in this article. A small equivalent output resistance of 0.34 m$\Omega$, reduced cost of 0.82 €/A, and DOE Level VI efficiency compliance has been achieved.

18 July 2025 in Electronics
Verified
Journal Article
Open access
PDF file
JGJiayi Geng
Jiayi Geng
Rudolf Francesco PaternostRudolf Francesco Paternost
Rudolf Francesco Paternost
SBSara Baldisserri
Sara Baldisserri
Mattia RiccoMattia Ricco
Mattia Ricco
Vitor MonteiroVitor Monteiro
Vitor Monteiro
Riccardo MandrioliRiccardo Mandrioli
Riccardo Mandrioli
The energy transition toward greater electrification leads to incentives in public transportation fed by catenary-powered networks. In this context, emerging technological devices such as in-motion-charging vehicles and electric vehicle charging points are expected to be operated while connected to trolleybus networks as part of new electrification projects, resulting in a significant demand for power. To enable a significant increase in electric transportation without compromising technical compliance for voltage and current at grid systems, the implementation of stationary battery energy storage systems (BESSs) can be essential for new electrification projects. A key challenge for BESSs is the selection of the optimal converter topology for charging their batteries. Ideally, the chosen converter should offer the highest efficiency while minimizing size, weight, and cost. In this context, a modular dual-active-bridge converter, considering its operation as a full-power converter (FPC) and a partial-power converter (PPC) with module-shedding control, is analyzed in terms of operation efficiencies and thermal behavior. The goal is to clarify the advantages, disadvantages, challenges, and trade-offs of both power-processing techniques following future trends in the electric transportation sector. The results indicate that the PPC achieves an efficiency of 98.58% at the full load of 100 kW, which is 1.19% higher than that of FPC. Additionally, higher power density and cost effectiveness are confirmed for the PPC.

20 January 2026 in IEEE Open Journal of Power Electronics
Verified
Journal Article
Open access
Lohith Kumar PittalaLohith Kumar Pittala
Lohith Kumar Pittala
FGFrancesca Grazian
Francesca Grazian
JGJiayi Geng
Jiayi Geng
GGabriele Rizzoli
Gabriele Rizzoli
GPGeorge Papafotiou
George Papafotiou
Riccardo MandrioliRiccardo Mandrioli
Riccardo Mandrioli
This work presents an efficiency-oriented modulation and morphing strategy for a three-phase three-level dual active bridge converter operating across both 800 V and 400 V electric vehicle battery systems. By reconfiguring the converter into a single-phase dual active bridge or a hybrid half-bridge/full-bridge structure at light-load, the proposed approach reduces current-invariant losses. A unified dual phase-shift framework is formulated to analytically model power flow and peak-current minimization across all three-level modulation variants, inner phase shift, duty-cycle control, and T-type zero-level modulation, demonstrating that all combinations produce equivalent voltage and current waveforms. Simulation efficiency maps are generated for all valid primary/secondary modulation pairs and indicate that inner and duty-cycle modulation achieve the highest efficiency across the full operating window. Hardware-in-the-loop experiments confirm stable three-phase-to-single-phase morphing and accurate power tracking between reference and measured power profiles for both voltage levels. The results validate that the proposed morphing strategy enables wide-range, auxiliary-free light-load operation suitable for next-generation EV charging architectures.