Yunwei Ryan Li

Yunwei Ryan Li

University of Alberta

H-index: 70

North America-Canada

About Yunwei Ryan Li

Yunwei Ryan Li, With an exceptional h-index of 70 and a recent h-index of 56 (since 2020), a distinguished researcher at University of Alberta, specializes in the field of Power Electronics, Renewable Energy, Microgrids, Electric Drives, Motor Drives.

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

Efficiency-Oriented Optimized Design and Control of Hybrid FSBB-CLLC Converters with Partial Power Processing Capability

Power Flow Control-Based Regenerative Braking Energy Utilization in AC Electrified Railways: Review and Future Trends

An Alternative-Fed Dual-Active-Bridge DC/DC Converter with Wide Voltage Gains and Low Current Ripples

Small‐signal modelling and analysis of microgrids with synchronous and virtual synchronous generators

A Capacitor Fault-Tolerant Scheme for Dual-Active-Bridge DC/DC Converter

An Intuitive and Noniterative Design Methodology for CLLC Chargers Employing Simplified Operation Modes Model

Graph Isomorphism Network: A Learning-based Workflow for Converter Inverse Design Problem

A PWM Current Source Converter-Based Wind Energy Conversion System

Yunwei Ryan Li Information

University

University of Alberta

Position

Professor at

Citations(all)

24043

Citations(since 2020)

12473

Cited By

16469

hIndex(all)

70

hIndex(since 2020)

56

i10Index(all)

233

i10Index(since 2020)

211

Email

University Profile Page

University of Alberta

Yunwei Ryan Li Skills & Research Interests

Power Electronics

Renewable Energy

Microgrids

Electric Drives

Motor Drives

Top articles of Yunwei Ryan Li

Efficiency-Oriented Optimized Design and Control of Hybrid FSBB-CLLC Converters with Partial Power Processing Capability

Authors

Ruizhi Wei,Li Ding,Yunwei Li

Journal

IEEE Transactions on Power Electronics

Published Date

2024/2/8

Combining the highly efficient CLLC topology with the exceedingly flexible Four-Switch Buck-Boost (FSBB) topology, this paper introduces a novel hybrid FSBB-CLLC converter incorporating partial power processing (PPP) capability. This hybrid structure utilizes FSBBs to regulate its output voltage by adjusting its duty cycle, handling a small portion of the total power, and providing a fast dynamic response. Meanwhile, the CLLC in the structure operates in a complete resonant state to ensure high system efficiency. By sharing a bridge arm between the FSBB and the CLLC, where one arm from each system serves a similar function, the number of switches utilized is significantly reduced, resulting in higher system efficiency. In addition to the structural improvements, to achieve a higher average system efficiency under different loads, this paper presents an efficiencybased parameter design methodology. Furthermore …

Power Flow Control-Based Regenerative Braking Energy Utilization in AC Electrified Railways: Review and Future Trends

Authors

Junyu Chen,Haitao Hu,Minghao Wang,Yinbo Ge,Ke Wang,Yi Huang,Kai Yang,Zhengyou He,Zhao Xu,Yunwei Ryan Li

Published Date

2024/1/18

Regenerative braking energy (RBE) utilization plays a vital role in improving the energy efficiency of electrified railways. To date, various power flow control-based solutions have been developed to recycle the RBE for utilization within railway power systems (RPSs). In this paper, an overview of the state-of-the-art power flow control-based solutions for RBE utilization in AC electrified railways is presented. It provides a technical analysis of four primary power flow control-based solutions for RBE utilization, including power sharing-based, energy feedback-based, energy storage-based, and composite solutions. The critical architectures of power flow conditioners for each solution are analyzed in depth. Meanwhile, the power flow control strategies for these solutions are reviewed from the perspectives of power flow management and converter control. From the industrial point of view, the critical challenges associated …

An Alternative-Fed Dual-Active-Bridge DC/DC Converter with Wide Voltage Gains and Low Current Ripples

Authors

Yue Zhang,Nie Hou,Yunwei Li

Journal

IEEE Transactions on Power Electronics

Published Date

2024/4/2

Owing to their distinct principles, voltage-fed dual-active-bridge (VF-DAB) and current-fed dual-active-bridge (CF-DAB) converters each exhibit unique strengths and weaknesses, making them appropriate for varying applications. To increase the application flexibility, an alternative-fed dual-active-bridge (AF-DAB) DC/DC converter, with the merits of wide voltage gains and low current ripples, is proposed in this letter. Through the alternative-fed method, the AF-DAB converter can integrate both DABs’ merits while eschewing unsuitable areas. Ultimately, the operation schemes and control structure are elaborated, and the experimental results are presented to verify the superior performance of the proposed topology.

Small‐signal modelling and analysis of microgrids with synchronous and virtual synchronous generators

Authors

Rui Liu,Li Ding,Cheng Xue,Yunwei Li

Journal

IET Energy Systems Integration

Published Date

2023

In autonomous alternating current microgrids, the grid‐forming virtual synchronous generators can cooperate with the conventional synchronous generators to improve system inertia and frequency regulation capability. However, undesired active power oscillations between the synchronous generators and grid‐forming virtual synchronous generators may trigger their overcurrent protection and even result in a blackout. To explicitly reveal the oscillatory modes over all frequency bands, a high‐fidelity full‐order state‐space model is first developed. A potentially destabilising sub‐synchronous oscillation mode resulting from the interaction between grid‐forming virtual synchronous generators voltage controller and synchronous generators q‐axis damper winding is identified. Other modes reflecting the low‐frequency oscillation and frequency restoration dynamics are also assessed. Subsequently, to make a …

A Capacitor Fault-Tolerant Scheme for Dual-Active-Bridge DC/DC Converter

Authors

Yue Zhang,Nie Hou,Yunwei Li

Journal

IEEE Transactions on Power Electronics

Published Date

2024/2/27

Recently, the dual-active-bridge (DAB) DC/DC converters are widely utilized in renewable energy systems. Lots of research on the optimization of DAB converters has been conducted, including novel topologies, modulation schemes, control schemes, and fault-tolerant schemes for active switches or riding-through, etc. However, there is a limited fault-tolerant scheme developed for capacitor failure in DAB converters so far, due to the low-device redundancy. To address this important issue, a capacitor fault-tolerant scheme is proposed in this paper. With the proposed scheme, the DAB converter can maintain power transfer sustainability even if the port capacitors break down. Besides, potential voltage spikes can also be suppressed by the proposed scheme when the snubber function of port capacitors is lost. Subsequently, the modulation scheme, topology characters, and control scheme are elaborated in this …

An Intuitive and Noniterative Design Methodology for CLLC Chargers Employing Simplified Operation Modes Model

Authors

Ruizhi Wei,Li Ding,Rui Liu,Yunwei Li

Journal

IEEE Transactions on Power Electronics

Published Date

2023/3/2

This article mainly focuses on the simplified operation modes (SOM) model and resonant parameter design for the CLLC charger. Based on the mathematical and detailed operation waveform assumptions, the voltage gain model expressions and the operation mode boundaries are calculated directly, providing the high efficiency and high reliability of the CLLC converter. The proposed SOM model is more accurate in depicting the voltage gain compared with the conventional fundamental harmonic approximation model. Moreover, the SOM model is more intuitive and has less computational complexity than the complicated and unsolvable time-domain model. As for the parameter design process, the inductance ratio and characteristic impedance are selected instead of specific inductances and capacitances. Relying on the SOM model, a step-by-step parameter design methodology is studied, which avoids …

Graph Isomorphism Network: A Learning-based Workflow for Converter Inverse Design Problem

Authors

Cheng Xue,Yuzhuo Li,Faraz Zargari,Yunwei Li

Published Date

2023/10/29

To surpass the limitation of conventional artificial intelligence-enabled automatic design methodology, this work proposes a novel workflow to implement the emerging graph-learning-based method called Graph Isomorphism Networks (GIN) for power converter automated design. A radio-frequency filter design demo is provided to show the merits of bringing GIN into converter design, where similar tasks could take days if not weeks to achieve optimally by hand.

A PWM Current Source Converter-Based Wind Energy Conversion System

Authors

Ling Xing,Qiang Wei,Yunwei Li

Journal

IEEE Transactions on Power Electronics

Published Date

2023/11/16

Current-source converters (CSCs) are a good candidate for the series-connected wind energy conversion system (WECS). However, the existing CSCs either exhibit poor generator stator current harmonics, require bulky low-frequency transformers, are limited in their application to synchronous generator-based wind systems, or necessitate complicated modulation and commutation. In this work, a new CSC is proposed and investigated. It features a unique hybrid structure consisting of a modular medium-frequency transformer-based voltage-source converter on the generator side and a conventional CSC on the grid side. The proposed converter offers superior generator stator current harmonics performance, a smaller size, simplified modulation and commutation schemes, and suitability for both synchronous and induction generator-based wind systems compared with the existing converters. In addition, all the …

Voltage and Current Limited Maximum Torque Algorithm of SPMSM in Traction Applications

Authors

Gabriel M Pauka,Li Ding,Rui Liu,Yunwei Ryan Li

Published Date

2023/5/22

permanent magnet synchronous machines (PMSMs) are widely used in traction applications on account of higher efficiencies, higher torque and power densities. Due to the reluctance torque component, internal PMSMs are commonly found; however, with the evolution of axial-flux PMSMs, machines with surface-mounted magnets are gaining relevancy. This paper developed a wide-speed operation algorithm for surface PMSMs that obtains the maximum mechanical torque possible while respecting the voltage and current constraints of the machine for any speed, named voltage and current limited maximum torque (VCLMT) algorithm, with an adjustable reference that produces a torque that ranges from zero to the maximum possible in all four torque-speed quadrants. The proposed VCLMT is verified and compared through both simulation and experiment.

A High-Robust Control Scheme for the DAB-based PPP Energy Storage System

Authors

Nie Hou,Rui Liu,Ruizhi Wei,Yue Zhang,Yun Wei Li

Published Date

2023/3/19

The energy storage system become more and more important for dealing with the difference between the renewable energy system and the load requirements in islanded dc microgrid. Traditionally, the energy storage system is connected to the dc bus through the dc-dc converter, and usually, multiple energy storage sources such as batteries are required to provide sufficient power capacity, which will increase the cost of the converter system. Thus, based on the partial power processing (PPP) concept, a simple dual-active-bridge (DAB)-based PPP energy storage system is presented for reducing the use of switches, and this converter system can inherit the high-efficiency characteristic of the PPP structure. Moreover, a high-robust control scheme is proposed for this DAB-based PPP converter system for dealing with the change of the load condition, which can provide a stable dc-link voltage for the load consumer …

Power Management System (PMS) in Smart Hybrid AC/DC Microgrids

Authors

Yunwei Ryan Li,Farzam Nejabatkhah,Hao Tian

Published Date

2023

In hybrid AC/DC microgrids, the power management strategies control instantaneous operational conditions toward specific desired parameters such as voltage, current, power, and frequency. The power management strategies can be separated into different types of hybrid microgrids, AC‐coupled, DC‐coupled, and AC/DC‐coupled microgrids, in which the power management objectives are mainly realized through the control of power electronics interfaces. The power management strategies are important for steady‐state operation of the microgrids as well as the transition between grid‐connected and islanding operation modes. Also, it helps to black start or to restore microgrid operation after a blackout. In this chapter, first, power management strategies of AC‐coupled, DC‐coupled, and AC/DC‐coupled hybrid microgrids are discussed. Then, power management schemes during the transition between grid …

Peak Current of Interfacing Power Converters Under Unbalanced Voltage

Authors

Yunwei Ryan Li,Farzam Nejabatkhah,Hao Tian

Published Date

2023

Peak Current of Interfacing Power Converters Under Unbalanced Voltage | part of Smart Hybrid AC/DC Microgrids: Power Management, Energy Management, and Power Quality Control | Wiley-IEEE Press books | IEEE Xplore Peak Current of Interfacing Power Converters Under Unbalanced Voltage Article #: ISBN Information: Electronic ISBN: 9781119598398 Online ISBN: 9781119598411 Print ISBN: 9781119598374 Electronic ISBN: 9781119598404 INSPEC Accession Number: Persistent Link: https://xplorestaging.ieee.org/servlet/opac?punumber=9868196 More » Publisher: Wiley-IEEE Press IEEE Account Change Username/Password Update Address Purchase Details Payment Options Order History View Purchased Documents Profile Information Communications Preferences Profession and Education Technical Interests Need Help? US & Canada: +1 800 678 4333 Worldwide: +1 732 981 0060 Contact & …

Real-Time Thermal Evaluation of Power Converters in Microgrids by Device Current Reconstruction

Authors

Yubo Song,Subham Sahoo,Yongheng Yang,Frede Blaabjerg,Yun Wei Ryan Li

Published Date

2023/6/14

Real-time simulation is increasingly employed in the validation of power electronics and systems, showing great potential in terms of flexibility and efficiency. With it, electrical behaviors of power converters can be simulated with high accuracy. However, when evaluating the reliability of converters, the switching behaviors of power semiconductors should be simulated, which normally requires a rather high sampling rate and powerful computational capability of the hardware platforms, and such simulations usually take much time Therefore, an efficient approach is introduced in this article to evaluate the thermal performances of power devices. Compared to the prior-art methods, the required sampling rate is much lower, and the proposed approach is also simpler, as only the three-phase current is sampled. The junction temperatures can be simulated with high accuracy. Preliminary results have also validated the …

Prescriptive Grid-Tied Inverter Control

Authors

Jorge Lopez-Sarabia,Jonathan C Mayo-Maldonado,Gerardo Escobar,David A Stone,Dunstano Del Puerto-Flores,Yunwei Li

Journal

IEEE Journal of Emerging and Selected Topics in Power Electronics

Published Date

2023/6/27

This article introduces a prescriptive control approach that improves the performance of grid-tied inverters. The current mainstream of contributions is predominantly based on combinations of canonical feedback actions, i.e., proportional ( ), integral ( ), derivative ( ), and resonant ( ). However, this classical view cannot synthesize suitable “intermediate” controller structures—which are not necessarily PIDR interconnections. In contrast, the proposed approach prescribes desired dynamics as initial step, and then synthesizes the exact feedback that enforces such prescription. It is also shown that prescriptive control is downward compatible with the popular PR control. The latter reaches only a narrow set of dynamical responses, since it is neglects crucial signal components, native to the proposed setting—which can improve the inverter performance in terms of achieving short settling times, small overshoots …

An Improved Three-Level Neutral Point Clamped Converter System with Full Voltage Balancing Capability for Bipolar Low Voltage DC Grid

Authors

Bowei Li,Hao Tian,Li Ding,Xuesong Wu,Gregory Kish,Yunwei Li

Journal

IEEE Transactions on Power Electronics

Published Date

2023/9/22

Bipolar low-voltage dc grids are an emerging and promising solution for power distribution. As a natural candidate for the distribution converter, the three-level neutral-point-clamped (3L-NPC) converter has inherent but limited capability in balancing the dc voltages during asymmetrical operation. This article begins by investigating the voltage balancing limits of the conventional 3L-NPC in detail. To overcome the identified limitations, an improved 3L-NPC converter system with a zigzag transformer and a neutral line is proposed. With the designed control strategy, the proposed converter system can provide full bipolar voltage balancing capability without extra devices or penalties on component ratings. The effectiveness and advantages of the proposed scheme are verified by simulation and experimental results.

A review of single-stage multiport inverters for multisource applications

Authors

Zhengqin Huang,Dehong Zhou,Longguang Wang,Zewei Shen,Yunwei Li

Published Date

2023/1/5

Conventional power electronic interfaces for multisource applications always need multiple conversion stages as intermediate dc–dc power conversion stages are inevitably installed for matching the different dc voltage levels and regulating the power distribution among dc sources. Dually, single-stage multiport inverter for multisource applications enables direct connection from the dc source to ac side without an extra conversion stage and has witnessed an upward trend in recent years. The salient advantages of single-stage multiport inverters comprise fewer power losses, fewer passive filters, and higher system efficiency. To capture the advancement in the field, the article reviews various single-stage multiport inverters for multisource applications, offers a comprehensive understanding of the current development of this configuration, and provides an insightful forward look at potential research issues of single …

Common-mode Voltage Reduction Method for Three-level Vienna Rectifiers

Authors

Peng Zhang,Xuezhi Wu,Bowei Li,Li Ding,Yue Zhang,Yunwei Ryan Li

Published Date

2023/10/29

In this paper, a carrier-based implementation method with low calculation burdens is proposed for three-level Vienna rectifiers to improve the common-mode voltage (CMV) characteristic. First, in order to eliminate the six small vectors with high CMV magnitudes in the generated vector sequences, the limitation ranges of the injected zero-sequence component are studied under Alternative Phase Opposition (APOD) PWM. Then the solved zero-sequence component is injected to adjust the relative dwell times of the chosen small vector and medium vector in each sector for NP voltage regulation. Finally, experiments are carried out to verify the performance of the proposed method.

Improved Model Predictive Control With Reduced DC-Link Capacitor RMS Current for Back-to-Back Converter-fed PMSM Drives

Authors

Cheng Xue,Li Ding,Yunwei Li

Journal

IEEE Transactions on Industrial Electronics

Published Date

2023/2/13

A low root mean square (RMS) current flowing through the intermediate dc-link capacitor is always desired in the back-to-back (BTB) voltage source converters (VSCs)-fed motor drive, such that the designed capacitor lifespan can be extended or a lower dc-link size could be the alternative with improved power density. The conventional modulator-based control involves the inherent carrier-based switching operation, and hence the dominant harmonics at carrier frequency multiplier and carrier sideband are introduced into the capacitor current. Therefore, the finite-control-set model predictive control (FCS-MPC) is proposed to optimize the capacitor RMS current. The switching pulse is generated directly without using the carrier, which can give a distinctive capacitor current spectrum and more possible current pulse cancelation between the BTB VSCs can be conveniently achieved through the cost function. Besides …

A Comprehensive Optimized Control Scheme for the Dual-Active-Bridge Dc-Dc Converter

Authors

Nie Hou,Yue Zhang,Yunwei Li

Published Date

2023/11/10

The dual-active-bridge (DAB) converter has been regarded as a promising candidate for the dc-dc power system. Lots of existing articles have presented abundant advanced methods to enhance the performance of the DAB converters, such as the soft-start operation, the high-efficiency method, the fast-dynamic scheme, and the dc-offset elimination method. However, there is not an existing article covering all the optimizations. Therefore, a comprehensive optimized control scheme is proposed for realizing these optimizations simultaneously. Firstly, to realize the high efficiency, a minimum-current-stress modulation is utilized in the DAB converter. Besides, a simple and practical dc-offset elimination approach is presented to deal with the potential dc bias. Then, a soft start-up method is proposed especially for dealing with non-load start, which can avoid the start-up inrush current. Moreover, combining the direct …

Common-Mode Current Reduction of Paralleled Dual Converters for Bipolar DC Distribution

Authors

Bowei Li,Li Ding,Xuesong Wu,Gregory Kish,Yunwei Li

Published Date

2023/3/19

Asymmetrical operation is a main challenge for the application of bipolar dc distribution systems. As a promising solution, paralleled dual converters balance the dc pole voltages without the penalties of increased power ratings by integrating a center-tapped transformer. The interleaving operation of dual converters could realize the harmonics cancellation of neutral line current, which is elaborated by harmonics distribution analysis presented in this paper. Moreover, phase shifting strategy is used to offer an additional degree-of-freedom (DoF), the resultant 2DoF modulation strategy is able to significantly suppress the common-mode (CM) current, which could reduce the size of CM choke and improve power density of converter. The validity and benefit of 2DoF strategy for dual converters are verified by both simulation and experimental results.

See List of Professors in Yunwei Ryan Li University(University of Alberta)

Yunwei Ryan Li FAQs

What is Yunwei Ryan Li's h-index at University of Alberta?

The h-index of Yunwei Ryan Li has been 56 since 2020 and 70 in total.

What are Yunwei Ryan Li's top articles?

The articles with the titles of

Efficiency-Oriented Optimized Design and Control of Hybrid FSBB-CLLC Converters with Partial Power Processing Capability

Power Flow Control-Based Regenerative Braking Energy Utilization in AC Electrified Railways: Review and Future Trends

An Alternative-Fed Dual-Active-Bridge DC/DC Converter with Wide Voltage Gains and Low Current Ripples

Small‐signal modelling and analysis of microgrids with synchronous and virtual synchronous generators

A Capacitor Fault-Tolerant Scheme for Dual-Active-Bridge DC/DC Converter

An Intuitive and Noniterative Design Methodology for CLLC Chargers Employing Simplified Operation Modes Model

Graph Isomorphism Network: A Learning-based Workflow for Converter Inverse Design Problem

A PWM Current Source Converter-Based Wind Energy Conversion System

...

are the top articles of Yunwei Ryan Li at University of Alberta.

What are Yunwei Ryan Li's research interests?

The research interests of Yunwei Ryan Li are: Power Electronics, Renewable Energy, Microgrids, Electric Drives, Motor Drives

What is Yunwei Ryan Li's total number of citations?

Yunwei Ryan Li has 24,043 citations in total.

What are the co-authors of Yunwei Ryan Li?

The co-authors of Yunwei Ryan Li are Frede Blaabjerg, Josep M. Guerrero, Fang Z. Peng, Marco Liserre, Wilsun Xu, Xiongfei Wang.

    Co-Authors

    H-index: 197
    Frede Blaabjerg

    Frede Blaabjerg

    Aalborg Universitet

    H-index: 147
    Josep M. Guerrero

    Josep M. Guerrero

    Aalborg Universitet

    H-index: 106
    Fang Z. Peng

    Fang Z. Peng

    Florida State University

    H-index: 89
    Marco Liserre

    Marco Liserre

    Christian-Albrechts-Universität zu Kiel

    H-index: 78
    Wilsun Xu

    Wilsun Xu

    University of Alberta

    H-index: 70
    Xiongfei Wang

    Xiongfei Wang

    Aalborg Universitet

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