Jian Ai

Dr. Jian Ai


Research Focus & Metrics

Academic Career Length

2Years (2025-Present)

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

Representative Publications

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30 September 2025 in Energies
Verified
Journal Article
Open access
PDF file
YWYaoqiang Wang
Yaoqiang Wang
ZSZhaolong Sun
Zhaolong Sun
PLPeiyuan Li
Peiyuan Li
Jian AiJian Ai
Jian Ai
CWChan Wu
Chan Wu
FDFujin Deng
Fujin Deng
The operational stability and performance of dual active bridge (DAB) converters are dictated by an intricate coupling of electrical, magnetic, and thermal dynamics. Conventional modeling paradigms fail to capture these interactions, creating a critical gap between design predictions and real performance. A unified Port-Hamiltonian model (PHM) is developed, embedding nonlinear, temperature-dependent material physics within a single, energy-conserving structure. Derived from first principles and experimentally validated, the model reproduces high-frequency dynamics, including saturation-driven current spikes, with superior fidelity. The energy-based structure systematically exposes the converter’s stability boundaries, revealing not only thermal runaway limits but also previously obscured electro-thermal oscillatory modes. The resulting framework provides a rigorous foundation for the predictive co-design of magnetics, thermal management, and control, enabling guaranteed stability and optimized performance across the full operational envelope.

26 September 2025 in Electronics
Verified
Journal Article
Open access
PDF file
YWYaoqiang Wang
Yaoqiang Wang
ZSZhaolong Sun
Zhaolong Sun
PLPeiyuan Li
Peiyuan Li
Jian AiJian Ai
Jian Ai
CWChan Wu
Chan Wu
FDFujin Deng
Fujin Deng
Current ringing in dual-active bridge (DAB) converters significantly degrades efficiency and reliability, particularly due to resonant interactions in the magnetic tank impedance network. We propose a novel impedance resonant channel shaping technique to suppress the ringing by systematically modifying the converter’s equivalent impedance model. The method begins with establishing a high-fidelity network representation of the magnetic tank, incorporating transformer parasitics, external inductors, and distributed capacitances, where secondary-side components are referred to the primary via the turns ratio squared. Critical damping is achieved through a rank-one modification of the coupling denominator, which is analytically normalized to a second-order form with explicit expressions for resonant frequency and damping ratio. The optimal series–RC damping network parameters are derived as functions of leakage inductance and winding capacitance, enabling precise control over the effective damping factor while accounting for core loss effects. Furthermore, the integrated network with the damping network dynamically shapes the impedance response, thereby attenuating ringing currents without compromising converter dynamics. Experimental validation confirms that the proposed approach reduces peak ringing amplitude by over 60% compared to the conventional snubber-based methods, while maintaining full soft-switching capability.