Wei Han (韩伟)

Wei Han (韩伟)

University of Toronto

H-index: 23

North America-Canada

About Wei Han (韩伟)

Wei Han (韩伟), With an exceptional h-index of 23 and a recent h-index of 23 (since 2020), a distinguished researcher at University of Toronto, specializes in the field of Power electronics, Wireless power transfer, Machines and Drives, Electric Vehicle Technologies.

His recent articles reflect a diverse array of research interests and contributions to the field:

Analysis and Elimination of Power Oscillation in Inductive Power Transfer Systems with Active Rectifier

Synchronous Rotation Coordinates-Based Low Voltage Ride Through Control Technology for Distributed VSG

A Novel Wireless-Power-Transfer-Based Snubber Circuit for Suppressing High-Frequency Oscillation of SiC Power MOSFETs

Common-Ground-Type Inverter with Dynamic Boosting and Reactive Compensation for Grid

Simultaneous Identification of Multiple Parameters in Wireless Power Transfer Systems Using Primary Variable Capacitors

Common-Ground Type Switching Step-up/Step-down VSI for Grid-Connected PV System

Simple-Structure Active Lossless Decoupling Rectifier With Automatic PFC

Analysis of Self-Oscillation Frequency in an Inductive Power Transfer System

Wei Han (韩伟) Information

University

University of Toronto

Position

Postdoc

Citations(all)

1409

Citations(since 2020)

1319

Cited By

483

hIndex(all)

23

hIndex(since 2020)

23

i10Index(all)

32

i10Index(since 2020)

32

Email

University Profile Page

University of Toronto

Wei Han (韩伟) Skills & Research Interests

Power electronics

Wireless power transfer

Machines and Drives

Electric Vehicle Technologies

Top articles of Wei Han (韩伟)

Analysis and Elimination of Power Oscillation in Inductive Power Transfer Systems with Active Rectifier

Authors

B. Zhang,W. Han,W. Hu,Y. Hu

Journal

IEEE Transactions on Transportation Electrification

Published Date

2024/4/22

Normally, an inductive power transfer (IPT) system with an active rectifier adopts two controllers, one each for the primary and secondary sides to separately control two converters. However, the frequency out-of-synchronization of two independent controllers will cause periodic power oscillations, which eventually lead to the system breakdown. To achieve frequency synchronization and eliminate power oscillation without any bilateral communications, this paper proposes an approach that autonomously drives bridges of the active rectifier with zero-crossing signal captured from the secondary resonant current. Specifically, this paper provides in-depth analyses of dual-side phase-shift control modes, the transient and steady-state processes of bus voltage establishment in the synchronous rectification, and the power oscillation mechanism caused by random frequency differences of two controllers. Besides, by …

Synchronous Rotation Coordinates-Based Low Voltage Ride Through Control Technology for Distributed VSG

Authors

C. Yang,W. Han,Y. Hu

Published Date

2024/4/15

Traditional virtual synchronous control strategies lack the ability to perform Low Voltage Ride Through (LVRT) in the event of a fault in the distribution network. When the original power command value is high, the steady-state output current may exceed acceptable levels, and the reactive power response time may be sluggish, thereby failing to meet L VRT requirements. This paper suggests an improved L VRT control technology for VSGs using synchronous rotation coordinates. The approach suppresses instantaneous current through virtual impedance and controls output current in sequence. An improved current and power control loop is introduced, allowing the VSG to inject reactive power within a specified time and calculate active and reactive power command values for L VRT requirements. The strategy avoids the impact generated during control mode switching and meets the power grid's LVRT …

A Novel Wireless-Power-Transfer-Based Snubber Circuit for Suppressing High-Frequency Oscillation of SiC Power MOSFETs

Authors

B. Cao,B. Zhang,Y. Hu,W. Han

Published Date

2024/3/9

The high dv/dt and di/dt during the high-speed switching transient of SiC MOSFET cause serious switching oscillations, producing severe EMI and affecting device reliability. This paper proposes a novel wireless power transfer (WPT) based snubber circuit to suppress switching oscillations. It can achieve galvanic isolation and does not require high-voltage components. This paper not only analyzes the detailed switching process and oscillation mechanism but also estimates the parasitic parameters by experiment. Moreover, the optimal oscillation suppression point is determined by adjusting the damping of the WPT system. Finally, based on the double-pulse test platform, the experimental results show that the proposed method can significantly shorten the damping time of voltage oscillation by 60% when the SiC MOSFETs frequency is at 20 kHz.

Common-Ground-Type Inverter with Dynamic Boosting and Reactive Compensation for Grid

Authors

H. Tian,W. Han,M. Chan,G. Liang,Z. Tang

Journal

IEEE Transactions on Power Electronics

Published Date

2024/2/22

Given the lack of transformer isolation in operational non-isolated photovoltaic inverters, common mode leakage currents are known to exist within the stray capacitance of the photovoltaic array, leading to electromagnetic interference and safety concerns for the entire system. This article introduces a novel solution: the common ground non-isolated multilevel PV inverter. This innovative design is built upon the Boost circuit and incorporates a switched capacitor network to connect the negative terminal of the dc side to the neutral point of the ac side. The primary objective of this configuration is to theoretically eliminate common mode leakage currents originating from the stray capacitor, effectively grounding them. Furthermore, this inverter eliminates the necessity of a cascade boost unit, thereby significantly reducing its dependency on the voltage level on the dc side. Additionally, it adopts a feed-forward space vector …

Simultaneous Identification of Multiple Parameters in Wireless Power Transfer Systems Using Primary Variable Capacitors

Authors

C. Liu,W. Han,Y. Hu,B. Zhang

Journal

Applied Sciences

Published Date

2024/1/17

Featured Application The methodology proposed in this article can be employed to improve the capability of the transmitting end of a WPT system to identify and adapt to parameter variations. Abstract This paper proposes a novel approach to simultaneously identifying multiple critical parameters in a wireless power transfer (WPT) system, such as the resonant frequency, mutual inductance, and load resistance, solely from the primary side. The key is to adopt a primary-side-switch-controlled capacitor (SCC) to ensure that the imaginary part of the input impedance is only caused by the secondary-side reflected impedance at three predesigned frequencies. The DSP controller then samples and processes the primary voltage and current using a gradient descent algorithm to derive the above parameters. After the identification, the SCC adjusts its equivalent capacitance based on the secondary-side practical resonant frequency to ensure a zero-phase angle (ZPA), thereby significantly improving the compatibility of the WPT system with unknown receivers. Compared to the previous frequency-sweeping method, the proposed approach is simpler and more suitable for deployment on the controller. Finally, experimental results demonstrate that the identification error of mutual inductance and resonant frequency are within 7.5% and 2.68%, respectively.

Common-Ground Type Switching Step-up/Step-down VSI for Grid-Connected PV System

Authors

H. Tian,W. Han,M. Chen,G. Liang,Z. Tang

Journal

IEEE Transactions on Power Electronics

Published Date

2024/4/23

Microinverter without transformer structure is widely used in photovoltaic grid-connected systems because of its low cost and high efficiency, but the challenge is to solve the common-mode leakage current caused by common-mode voltage. This paper studies a novel transformerless dual-mode voltage source inverter (VSI) in which the common ground structure short-circuits the parasitic capacitance and theoretically completely eliminates leakage currents. The inverter consists of a switching-buck-boost (SBB) module integrated with an LC filter network and has a good symmetry of the output waveform. The proposed topology features a wide input voltage range to meet the grid voltage gain, a compact structure, and a simple modulation strategy. Meanwhile, the SBB module allows for soft charging and current stress control within the permissible range. The structural characteristics and operating principle are …

Simple-Structure Active Lossless Decoupling Rectifier With Automatic PFC

Authors

Hanlei Tian,Guozhuang Liang,He Liu,Zixin Tang,Qiao Li,Wei Han

Journal

IEEE Journal of Emerging and Selected Topics in Power Electronics

Published Date

2023/6

One of the main challenges is how to prolong the lifetime of converters, and as in most single-phase converters, the need for electrolytic capacitors. A simple structure rectifier is proposed with lossless buffer and power factor correction (PFC) abilities. It has the advantages of low cost, fewer auxiliary components, and high conversion efficiency. The active buffer circuit as an auxiliary unit consists of just one capacitor and one switch. It not only makes it possible for the rectifier to operate without electrolytic capacitors but also provides zero voltage switching (ZVS) for the buffer tank. Additionally, a simple control scheme is presented, in which a near-perfect power factor is obtained. Finally, the operating principles, control methods, and design guidelines are presented in detail, and the feasibility of the proposed converter is verified through a 58-W (48-V/1.2-A) hardware prototype. All the superior performances of the …

Analysis of Self-Oscillation Frequency in an Inductive Power Transfer System

Authors

W. Hu,B. Zhang,Y. Hu,W. Han

Published Date

2023/11/16

Inductive power transfer (IPT) systems conventionally operate at the natural resonant frequency for efficient power transmission, but their output power is sensitive to mutual inductance changes. Recent studies have shown that parity-time-symmetric IPT systems have two splitting frequencies in the strongly coupled range, enabling robust wireless power transfer with constant output power and high efficiency. Self-excited oscillation circuits can automatically track these optimal frequencies without measuring circuit parameters. However, practical self-oscillating systems contain voltage harmonics and feedback delays, which are often ignored in the analysis of steady-state performance. In this paper, the effects of high-order harmonics and time delay on steady-state frequencies are systematically analyzed. First, the formula of ideal bifurcation frequency is derived based on the zero-phase-angle condition. Then, steady …

Frequency Tracking Synchronization Technique for a Bidirectional Inductive Power Transfer System

Authors

Bowang Zhang,Wei Han,Youhao Hu,Weikang Hu

Published Date

2023/3/23

Bidirectional Inductive Power Transfer (BD-IPT) is a promising technology that plays a significant role in specific scenarios such as vehicle-to-grid/home/vehicle systems. However, the BD-IPT system requires frequency synchronization between primary and secondary sides. Some researchers utilize a dedicated wireless communication interface to get the synchronization tracking information. But this solution will increase the cost and complexity while decrease the robustness and universality of the system. Therefore, this paper proposes a synthesizer PLL based frequency tracking technique for the BD-IPT system without adopting any communications. Specifically, the proposed controller includes two closed-loops, which decide and calculate the details of the active power, respectively. A proposed synthesizer PLL, which includes the phase detector, low-pass filter and voltage-controlled oscillator, is designed to …

Robust Speed Control for Wireless Motor Systems with Maximum Efficiency Point Tracking

Authors

Y. Hu,B. Zhang,W. Hu,W. Han

Published Date

2023/11/16

In this paper, a robust closed-loop speed control for wireless motor systems is proposed with the consideration of maximum efficiency point tracking (MEPT). Firstly, the optimal load condition for maximum efficiency point tracking of wireless motor systems is derived, a buck converter with an optimal duty cycle is adopted to achieve impedance match of the wireless power transfer system such that maximum efficiency can be guaranteed. Then, an integral fixed-time sliding mode (FTSM) control strategy is designed to achieve robust speed tracking control for wireless motors in the presence of parameter variation and external disturbance. The simulation results illustrated superior tracking performance with 15.90% speed tracking overshoot reduction, 26.90% speed tracking error RMS reduction compared with the conventional PID control. And the efficiency of the WPT systems is well maintained at 85.55% simultaneously.

Power Decoupling Rectifier With Common-Ground Concept for Lighting Applications

Authors

Hanlei Tian,Yuan Cao,Wei Han,Guozhuang Liang

Journal

IEEE Transactions on Power Electronics

Published Date

2023/3

The lightweight and the electrolytic capacitor-less are the development trends of microconverters for transportation lighting applications. Some solutions available to address the power fluctuations are caused by electrolytic capacitor-less. However, the leakage currents caused by nonisolated converters have been little studied. Given this, an improved transformerless single-phase rectifier based on the virtual dc-bus concept is proposed in this letter. This solution connects the negative of the LED array directly to the grid neutral, thus shorting the stray capacitance to the ground, suppressing leakage currents, and improving system reliability. In addition, the active pulsating power buffering solution is introduced with only one additional power switch due to the sharing of cells. Finally, the experimental results verify the correctness and superior performance of the proposed solution.

Sequential Mutual-Inductance Identificationmethod for Wireless Power Transfer Systems of Electric Vehicles

Authors

S. Nie,W. Han,Z. Luo,C. Perera,P. W. Lehn

Journal

IEEE Transactions on Transportation Electrification

Published Date

2023/10/2

In a multi-transmitter static wireless power transfer (WPT) system for electric vehicles (EV), the transmitter-to-receiver mutual-inductance value is required to assign current to each transmitter. This article proposes a sequential mutual-inductance identification method (SMIM) that identifies the transmitter-receiver mutual inductance transmitter by transmitter in sequence. The proposed method simplifies the multi-transmitter system into a single-transmitter system through the current blocking principle. The identification only requires measuring the magnitude of DC bus voltage and transmitter rms currents where no receiver-side sensor is needed. The mutual-inductance can be obtained through simple calculations with low computation requirements. It is demonstrated that SMIM robustness against transmitter self-inductance deviation is greatly enhanced by introducing a two-point identification technique. High SMIM …

ELM-Based Adaptive Practical Fixed-Time Voltage Regulation in Wireless Power Transfer System

Authors

Y. Hu,B. Zhang,W. Hu,W. Han

Journal

Energies

Published Date

2023/1/17

This paper proposes an extreme learning machine (ELM)-based adaptive sliding mode control strategy for the receiver-side buck converter system in the wireless power transfer system subjecting to the lumped uncertainty. The proposed control strategy utilizes a singularity-free fixed-time sliding mode (FTSM) feedback control, which ensures a fixed-time convergence for both the sliding variable and voltage tracking error. An ELM-based uncertainty bound estimator is further designed to learn the uncertainty bound information in real-time, which opportunely loosens the constraint of bound information requirement for sliding mode control design. The global stability of the closed-loop system is rigidly analyzed, and the good performance of the proposed control strategy is validated by comparison experiments which exhibit ideal overshoot elimination, 45.70–51.72% reduction of settling time, and 13.65–36.96% reduction of the root mean square value for voltage tracking error with respect to different load types.

Automotive Revolution and Carbon Neutrality

Authors

C. C. Chan,W. Han,H. Tian,Y. Liu,T. Ma,C. Q. Jiang

Journal

Frontiers in Energy

Published Date

2023/7/26

The automotive industry is in the midst of a groundbreaking revolution, driven by the imperative to achieve intelligent driving and carbon neutrality. A crucial aspect of this transformation is the transition to electric vehicles (EVs), which necessitates widespread changes throughout the entire automotive ecosystem. This paper examines the challenges and opportunities of this transition, including automotive electrification, intelligence-connected transportation system, and the potential for new technologies such as hydrogen fuel cells. Meanwhile, it discusses the key technologies and progress of the hydrogen energy industry chain in the upstream hydrogen production, midstream hydrogen storage and transportation, downstream hydrogen station construction and hydrogen fuel cells in turn. Finally, it proposes the directions for future layout, providing guidance for future development.

An all-the-time synchronization technique for 2.2 kW bidirectional inductive power transfer system

Authors

B. Zhang,W. Hu,Y. Hu,W. Han

Published Date

2023/7/25

This paper proposes an all-the-time synchronization technique without the dual-side frequency difference and power oscillation. Compared to the traditional method such as average frequency tracking with non-all-the-time synchronization, no accuracy requirements of controller for PLL, phase calibration and complex auxiliary circuits are needed. Without additional phase calibration, only the zero cross detections (ZCDs) and external trigger by the DSP controller is required to synchronize the phase and frequency. Meanwhile, it is more effective and simple to control the value and direction of active power and reactive power by adjusting the delay of output from ZCDs to achieve phase shift control. Finally, experimental results based on a 2.2 kW platform are presented to verify the effectiveness and practicality of this technique.

Analysis and design for constant current/constant voltage multi‐coil wireless power transfer system with high EMF reduction

Authors

Zhichao Luo,Mehanathan Pathmanathan,Wei Han,Shuang Nie,Peter W Lehn

Journal

IET Power Electronics

Published Date

2022/9

The investigation on the constant current (CC)/constant voltage (CV) charging for the electric vehicle wireless power transfer (WPT) system has been widely conducted. However, the CC/CV performance under misalignment cases has been scarcely studied especially for the multi‐coil WPT system. The resonant tank compensation methodology for the exciter‐quadrature‐repeaters (EQR) transmitter‐based multi‐coil WPT system is studied to achieve high power factor CC/CV charging with low leakage flux over ±150 mm lateral misalignment range. The EQR transmitter consists of one small exciter coil powered by a single full bridge inverter and two larger decoupled quadrature repeater coils which are magnetically coupled to the exciter coil. A variable switched capacitor is applied on the exciter side to maintain a high power factor in the CV mode. A 3‐kW experimental setup with a 200 mm nominal vertical distance …

Design and Analysis of Demand-Customized Selective Wireless Power Transfer System

Authors

X. Tian,K.T. Chau,Z. Hua,W. HAN

Journal

IEEE Transactions on Industrial Electronics

Published Date

2022/1/24

A demand-customized selective wireless power transfer system is proposed in this article. Multiple receivers can be recognized based on their positions and the magnetic field in the powering area can be controlled and regulated accordingly. For authorized receivers, the system can simultaneously deliver power to meet different output requirements for different electrical appliances, while for unauthorized ones, they can be shut down independently for energy security, even when they are also in the powering area. Compared to the traditional calculation models for multi-input multi-output systems, the proposed current control algorithm uses a piecewise optimization procedure to simplify the iteration and improve control flexibility. Hybrid-frequency pacing is adopted as the control strategy to further reduce the output fluctuation and raise the system efficiency. An experimental prototype with a 3 × 3 transmitter matrix is …

Wireless Power and Drive Transfer Using Orthogonal Bipolar Couplers and Separately Excited Modulation

Authors

W. Han,K. T. Chau,W. Liu,H. Wang,Z. Hua

Journal

IEEE Transactions on Industrial Electronics

Published Date

2021/4/7

This article proposes and implements a novel wireless power and drive transfer system using orthogonal bipolar couplers and separately excited modulation (SEM). Specifically, two bipolar coils are orthogonally integrated and naturally decoupled to form a compact magnetic coupler which will be utilized in the transmitter and receiver, respectively. The key is to employ the SEM to alternatively energize bipolar coils in the transmitter while self-driven circuits in the receiver can directly extract the drive information to control receiver-side switches. Consequently, the concurrent wireless power transfer and wireless drive transfer can be skillfully realized via the shared transfer channel at the single resonant frequency. Moreover, the proposed system can effortlessly achieve the wireless dc motor drive with the capability of bidirectional motion, or the wireless ac motor drive with the variable-voltage variable-frequency …

3-D Analytical Model of Bipolar Coils with Multiple Finite Magnetic Shields for Wireless Electric Vehicle Charging Systems

Authors

Zhichao Luo,Shuang Nie,Mehanathan Pathmanathan,Wei Han,Peter W Lehn

Journal

IEEE Transactions on Industrial Electronics

Published Date

2021/9/14

The bipolar pad is one of the most promising topologies in inductive power transfer (IPT) systems for electric vehicles. However, there is scant literature on the analytical model of the bipolar pad. In this article, a three-dimensional (3-D) analytical model of the IPT system including a bipolar transmitter and a square receiver is developed based on the superposition of two 2-D subdomain analytical models. Ferrite and the aluminum shields with finite dimension are taken into account on the transmitter and receiver sides. An analytical calculation of the mutual inductance is then carried out with respect to the main parameters of the IPT system, namely the dimension of the coils, the conductivity, and the permeability of the shield. Three study cases are demonstrated to highlight how the proposed method can accelerate speed up the pad design process. Calculation results of the proposed model are compared with both a …

A Dual-Resonant Topology-Reconfigurable Inverter for All-Metal Induction Heating

Authors

W. Han,K. T. Chau,W. Liu,X. Tian,H. Wang

Journal

IEEE Journal of Emerging and Selected Topics in Power Electronics

Published Date

2021/4/4

Traditionally, domestic induction heating (IH) is designed to heat the ferromagnetic (FM) pan. However, it is incompetent to heat the non-FM (NFM) pan since the small equivalent resistance of the pan will easily result in overcurrent on the inverter. Inspired by the compensation network in the wireless power transfer (WPT), the series–parallel resonance (SPR) network with a relay switch is newly integrated into the IH technology to develop a dual-resonant topology-reconfigurable inverter for all-metal IH. The proposed system can be purposely configured to a half-bridge series resonant inverter with the pulse width modulation (PWM) to heat the FM pan, or a full-bridge SPR-based inverter with the phase shift control (PSC) to heat the NFM pan, respectively. Moreover, the output–input current gain of the SPR network equals the heating-coil quality factor, thereby readily eliminating the overcurrent issue of the inverter …

See List of Professors in Wei Han (韩伟) University(University of Toronto)

Wei Han (韩伟) FAQs

What is Wei Han (韩伟)'s h-index at University of Toronto?

The h-index of Wei Han (韩伟) has been 23 since 2020 and 23 in total.

What are Wei Han (韩伟)'s top articles?

The articles with the titles of

Analysis and Elimination of Power Oscillation in Inductive Power Transfer Systems with Active Rectifier

Synchronous Rotation Coordinates-Based Low Voltage Ride Through Control Technology for Distributed VSG

A Novel Wireless-Power-Transfer-Based Snubber Circuit for Suppressing High-Frequency Oscillation of SiC Power MOSFETs

Common-Ground-Type Inverter with Dynamic Boosting and Reactive Compensation for Grid

Simultaneous Identification of Multiple Parameters in Wireless Power Transfer Systems Using Primary Variable Capacitors

Common-Ground Type Switching Step-up/Step-down VSI for Grid-Connected PV System

Simple-Structure Active Lossless Decoupling Rectifier With Automatic PFC

Analysis of Self-Oscillation Frequency in an Inductive Power Transfer System

...

are the top articles of Wei Han (韩伟) at University of Toronto.

What are Wei Han (韩伟)'s research interests?

The research interests of Wei Han (韩伟) are: Power electronics, Wireless power transfer, Machines and Drives, Electric Vehicle Technologies

What is Wei Han (韩伟)'s total number of citations?

Wei Han (韩伟) has 1,409 citations in total.

What are the co-authors of Wei Han (韩伟)?

The co-authors of Wei Han (韩伟) are Peter Lehn, Philip W. T. Pong, C.Q. Jiang, Mehanathan Pathmanathan, Zhichao Luo.

    Co-Authors

    H-index: 44
    Peter Lehn

    Peter Lehn

    University of Toronto

    H-index: 35
    Philip W. T. Pong

    Philip W. T. Pong

    New Jersey Institute of Technology

    H-index: 25
    C.Q. Jiang

    C.Q. Jiang

    University of Cambridge

    H-index: 12
    Mehanathan Pathmanathan

    Mehanathan Pathmanathan

    University of Toronto

    H-index: 9
    Zhichao Luo

    Zhichao Luo

    University of Toronto

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