Zhigang Liu

Zhigang Liu

New York University

H-index: 40

North America-United States

About Zhigang Liu

Zhigang Liu, With an exceptional h-index of 40 and a recent h-index of 29 (since 2020), a distinguished researcher at New York University,

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

2-DOF Internal Model Direct Power Control Scheme Based on H∞ Theory for Dual Traction Rectifiers with Parameter Perturbations

P991 Serum anti-TNF levels correlate with tissue levels in perianal fistulising Crohn’s Disease

Adaptive Subband Forward Blind Source Separation Algorithms based on Kalman Mechanism

Evolution analysis of wheel polygon wear considering the effect of interharmonics in electrical traction drive system

Optimization of Railway Pantograph-Catenary Systems for Over 350 km/h Based on an Experimentally Validated Model

Low-Frequency Stability Analysis of Train-Grid System: A Perspective from DAB Converter

An Optimized dq-Frame Admittance Modeling Method for Single-Phase Railway Vehicle-grid System Considering the Impact of Asymmetric αβ Control

Influence of Surface Roughness of Sliding Friction Pairs on Pantograph-Catenary Contact Resistance

Zhigang Liu Information

University

New York University

Position

___

Citations(all)

5641

Citations(since 2020)

3021

Cited By

1357

hIndex(all)

40

hIndex(since 2020)

29

i10Index(all)

129

i10Index(since 2020)

102

Email

University Profile Page

New York University

Top articles of Zhigang Liu

2-DOF Internal Model Direct Power Control Scheme Based on H∞ Theory for Dual Traction Rectifiers with Parameter Perturbations

Authors

Xinju Wang,Xiaomin Wang,Zhigang Liu

Journal

IEEE Transactions on Transportation Electrification

Published Date

2024/2/26

For dual traction rectifiers (DTR) of high-speed trains, system uncertainties, such as parametric uncertainties, load variations, and external disturbances, may result in significant DC-link voltage fluctuations, degrade the quality of grid currents, and even lead to system instability. While robust control can maintain the robust performance of DTR in a comparatively wide range of parameter perturbations, it ignores the transient performance requirements. Additionally, due to the limitations of the one-degree-of-freedom (1DOF) control structure, it is difficult to consider the tracking and anti-interference performance simultaneously. To this end, a H ∞ based internal model direct power control ( H ∞ IM-DPC) approach is developed. First, a modified dynamic model is established in a stationary frame, and a 2DOF IM-DPC structure is presented. A desired closed-loop transfer function is also added to ameliorate the dynamic …

P991 Serum anti-TNF levels correlate with tissue levels in perianal fistulising Crohn’s Disease

Authors

S Anandabaskaran,Z Liu,L Hanna,A Hart,P Tozer

Journal

Journal of Crohn's and Colitis

Published Date

2024/1/1

Background Perianal fistulising Crohn’s Disease (PFCD) affects up to 25% of patients and remains difficult to treat despite medical and surgical advancements.1 Perianal fistulas have unique immunopathogenic features associated with an aggressive phenotype of CD with studies showing the need for higher drug levels for fistula healing in pCD.2-4 Unfortunately, no medical therapy has been shown to be more than 40% effective in maintaining sustained remission suggesting a therapeutic ceiling in PFCD management.5 This calls for a better understanding of the role tissue drug penetrance plays in PFCD patients on biologic therapy. Previously, Adegbola et al.4 failed to identify tissue levels in PFCD patients using a Liquid chromatography-mass spectrometry (LC-MS) assay. Enzyme-linked immunosorbent assay (ELISA) is well validated and used in standard clinical practice for anti-TNF drug level …

Adaptive Subband Forward Blind Source Separation Algorithms based on Kalman Mechanism

Authors

Jianhong Ye,Yi Yu,Yuriy Zakharov,Zhigang Liu,Hongsen He

Journal

IEEE Transactions on Instrumentation and Measurement

Published Date

2024/4/30

In forward blind source separation (FBSS) scenarios, subband adaptive filtering ( SAF) algorithms provide fast convergence due to the SAF decorrelation ability. However, existing SAF algorithms suffer from a signal delay stemmed from the utilization of the synthesis filters. To solve this problem, we propose a delayless multi-sampled FBSS (DMSFBSS) algorithm by inserting a delayless multi-sampled multiband SAF structure. For a fixed SAF step-size, there is also a trade-off between the convergence speed and steady-state error. We break this relationship by further developing an optimal DMSFBSS (ODMSFBSS) algorithm that minimizes the mean squared deviation of DMSFBSS with respect to the subband gain vectors, to provide simultaneously fast convergence and low steady-state behavior. Intrinsically, the ODMSFBSS algorithm is an extension of the Kalman filtering theory over the subband-based FBSS …

Evolution analysis of wheel polygon wear considering the effect of interharmonics in electrical traction drive system

Authors

Bing Lu,Yang Song,Zhigang Liu,Gongquan Tao,Xufan Wang,Qiao Zhang,Zhixiang Li

Journal

Mechanism and Machine Theory

Published Date

2024/1/1

The formation and development of wheel polygon wear (WPW) present significant challenges to the safety of railway vehicle operations. It is widely accepted that WPW occurs due to the mechanical vibration within the wheel-rail system. The output torque produced by the traction motor acts as the primary power source for the vehicle's movement. The pulsating torque, resulting from interharmonics can directly impact the wheelset's dynamic behavior, contributing to the occurrence of WPW. However, the precise mechanism by which interharmonics affect WPW remains incompletely understood. Therefore, this paper aims to establish the link between interharmonics originating from the electric traction drive system and the wheelset vibration. A comprehensive WPW evolution model that incorporates an electromechanical coupling model and a wheel wear calculation model is developed. This model allows to elucidate …

Optimization of Railway Pantograph-Catenary Systems for Over 350 km/h Based on an Experimentally Validated Model

Authors

Yang Song,Xiaobing Lu,Yanhong Yin,Yuhui Liu,Zhigang Liu

Journal

IEEE Transactions on Industrial Informatics

Published Date

2024/2/21

The pantograph-catenary system is widely used in most electrified rail networks around the world to transmit continuous electric current to the train. Most studies about the pantograph-catenary interaction are performed at a speed of lower than 350 km/h. In this article, the experimental test and the numerical simulation of the pantograph-catenary interaction were conducted at different speed levels, including the 380 km/h speed close to the catenary's wave speed. The pantograph-catenary contact force collected via an inspection vehicle was used to validate the numerical accuracy. The contact force statistics obtained by both the simulation and experimental test exhibit excellent agreement at different speeds. Then a neural network optimization algorithm is implemented to optimize the contact quality at four operating speeds. The best optimization performance is observed at the speed of 380 km/h in terms of the over …

Low-Frequency Stability Analysis of Train-Grid System: A Perspective from DAB Converter

Authors

Chunxu Lin,Xinglai Ge,Huimin Wang,Xiangyu Meng,Junwen Mu,Zhigang Liu

Journal

IEEE Transactions on Power Electronics

Published Date

2024/4/8

Despite the great potential of power electronic traction transformer (PETT) in high-speed train, the issue of lowfrequency oscillation (LFO) is a concern. Unfortunately, current studies assessing the low-frequency stability of the PETT often oversimplify the dual active bridge (DAB) converter as a passive circuit, which may lead to an unreliable analysis result. To clarify this issue, this letter examines the mechanism of LFO in the PETT-based train-grid system from the perspective of a DAB converter. Specifically, a complete impedance model of the PETT is first established by using the harmonic linearization method. Then, the stability differences between simplified PETT and complete PETT are investigated, and the impact mechanism of DAB converter on the LFO is thoroughly revealed. Experimental test results verify the correctness of modeling and analysis.

An Optimized dq-Frame Admittance Modeling Method for Single-Phase Railway Vehicle-grid System Considering the Impact of Asymmetric αβ Control

Authors

Siqi Wu,Siqi Bu,Zhigang Liu

Journal

IEEE Transactions on Power Electronics

Published Date

2024/2/5

To tackle the small-signal instability in the single-phase railway vehicle-grid system, the dq admittance modeling method has received great attention. However, the orthogonal β components created by the asymmetric quadrature signal generators (QSGs) for dq control inevitably suffer from amplitude or phase errors at non-fundamental frequencies, which are not fully considered in the traditional dq modeling method. As revealed in this letter, due to the inherent signal dimensionality reduction process from the actual control output [two-dimension (2-D) scalar] to the single-phase power stage input (1-D scalar), the non-ideal β components can introduce non-negligible errors to the traditional dq model. Thus, as a solution, an optimized dq admittance modeling method for the single-phase converter in vehicles is proposed, which involves the impact of the asymmetric QSGs by capturing the signal dimensionality …

Influence of Surface Roughness of Sliding Friction Pairs on Pantograph-Catenary Contact Resistance

Authors

Xiaokang Wang,Fengyi Guo,Fuhua Li,Zhigang Liu,Jiabao Kou

Journal

IEEE Transactions on Transportation Electrification

Published Date

2024/4/1

Pantograph-catenary systems are the key equipment for current conduction from power grids to electric locomotives, and within such a system, the property of the slide, especially the contact resistance ( Rj ), directly affects its current collection performance. Compared to previous studies, this paper focuses on the microscopic roughness parameters which affects Rj greatly. The changing rule of Rj under different roughness conditions is studied on 128 groups of data collected from experiments. More importantly, the second-order partial correlation coefficient is introduced to quantify the impact strength of different roughness parameters on Rj . Based on this, a multi-parameter influence model of Rj is established and verified by non-linear fitting. The results show that the impact strength of the relevant roughness parameters is ranked as Rpc > Rp > Rsm . The conclusion provides a theoretical basis for minimizing …

Suppression of Railway Catenary Galloping Based on Structural Parameters’ Optimization

Authors

Yuhui Liu,Yang Song,Fuchuan Duan,Zhigang Liu

Journal

Sensors

Published Date

2024/2/2

Railway catenary galloping, induced by aerodynamic instability, poses a significant threat by disrupting the electric current connection through sliding contact with the contact wire. This disruption leads to prolonged rail service interruptions and damage to the catenary’s suspension components. This paper delves into the exploration of optimizing the catenary system’s structure to alleviate galloping responses, addressing crucial parameters such as span length, stagger dropper distribution, and tension levels. Employing a finite element model, the study conducts simulations to analyze the dynamic response of catenary galloping, manipulating structural parameters within specified ranges. To ensure accurate and comprehensive exploration, the Sobol sequence is utilized to generate low-discrepancy, quasi-random, and super-uniform distribution sequences for the high-dimensional parameter inputs. Subsequent to the simulation phase, a genetic algorithm based on neural networks is employed to identify optimal parameter settings for suppressing catenary galloping, taking into account various constraints. The results gleaned from this investigation affirm that adjusting structural parameters can effectively diminish the galloping amplitude of the railway catenary. The most impactful strategy involves augmenting tension and reducing span length. Moreover, even when tension and span length are fixed, adjusting other parameters demonstrates efficacy in reducing galloping amplitudes. The adjustment of messenger-wire tension, dropper distribution, and stagger can achieve a 22.69% reduction in the maximum vertical galloping amplitude. Notably …

Antibody responses to Influenza vaccination are diminished in patients with inflammatory bowel disease on infliximab or tofacitinib

Authors

Zhigang Liu,James L Alexander,Kai Yee Eng,Hajir Ibraheim,Sulak Anandabaskaran,Aamir Saifuddin,Laura Constable,Rocio Castro Seoane,Claire Bewshea,Rachel Nice,Andrea D’Mello,Gareth R Jones,Sharmili Balarajah,Francesca Fiorentino,Shaji Sebastian,Peter M Irving,Lucy C Hicks,Horace RT Williams,Alexandra J Kent,Rachel Linger,Miles Parkes,Klaartje Kok,Kamal V Patel,Julian P Teare,Daniel M Altmann,Rosemary J Boyton,Ailsa L Hart,Charlie W Lees,James R Goodhand,Nicholas A Kennedy,Katrina M Pollock,Tariq Ahmad,Nick Powell

Journal

Journal of Crohn's and Colitis

Published Date

2023/11/6

Background and Aims We sought to determine whether six commonly used immunosuppressive regimens were associated with lower antibody responses after seasonal influenza vaccination in patients with inflammatory bowel disease [IBD]. Methods We conducted a prospective study including 213 IBD patients and 53 healthy controls: 165 who had received seasonal influenza vaccine and 101 who had not. IBD medications included infliximab, thiopurines, infliximab and thiopurine combination therapy, ustekinumab, vedolizumab, or tofacitinib. The primary outcome was antibody responses against influenza/A H3N2 and A/H1N1, compared to controls, adjusting for age, prior vaccination, and interval between vaccination and sampling. Results Lower antibody responses against influenza A/H3N2 were observed in patients on infliximab (geometric mean …

Proceedings of the 6th International Conference on Electrical Engineering and Information Technologies for Rail Transportation (EITRT) 2023: Safety Assurance and Operation …

Authors

Matteo Maffei,Mark Ryan

Published Date

2017/4/22

Proceedings of the 6th International Conference on Principles of Security and Trust - Volume 10204 | Guide Proceedings ACM Digital Library home ACM home Google, Inc. (search) Advanced Search Browse About Sign in Register Advanced Search Journals Magazines Proceedings Books SIGs Conferences People More Search ACM Digital Library SearchSearch Advanced Search Browse Browse Digital Library Collections More Home Browse by Title Proceedings Proceedings of the 6th International Conference on Principles of Security and Trust - Volume 10204 Proceedings of the 6th International Conference on Principles of Security and Trust - Volume 10204 PreviousNext ACM Digital Library ABSTRACT No abstract available. Recommendations Comments Login options Check if you have access through your login credentials or your institution to get full access on this article. Sign in Full Access Get this …

The gut microbiota and metabolome are associated with diminished COVID-19 vaccine-induced antibody responses in immunosuppressed inflammatory bowel disease patients

Authors

James L Alexander,Benjamin H Mullish,Nathan P Danckert,Zhigang Liu,Marton L Olbei,Aamir Saifuddin,Melissa Torkizadeh,Hajir Ibraheim,Jesús Miguéns Blanco,Lauren A Roberts,Claire M Bewshea,Rachel Nice,Simeng Lin,Hemanth Prabhudev,Caroline Sands,Verena Horneffer-van der Sluis,Matthew Lewis,Shaji Sebastian,Charlie W Lees,Julian P Teare,Ailsa Hart,James R Goodhand,Nicholas A Kennedy,Tamas Korcsmaros,Julian R Marchesi,Tariq Ahmad,Nick Powell

Journal

EBioMedicine

Published Date

2023/2/1

BackgroundPatients with inflammatory bowel disease (IBD) treated with anti-TNF therapy exhibit attenuated humoral immune responses to vaccination against SARS-CoV-2. The gut microbiota and its functional metabolic output, which are perturbed in IBD, play an important role in shaping host immune responses. We explored whether the gut microbiota and metabolome could explain variation in anti-SARS-CoV-2 vaccination responses in immunosuppressed IBD patients.MethodsFaecal and serum samples were prospectively collected from infliximab-treated patients with IBD in the CLARITY-IBD study undergoing vaccination against SARS-CoV-2. Antibody responses were measured following two doses of either ChAdOx1 nCoV-19 or BNT162b2 vaccine. Patients were classified as having responses above or below the geometric mean of the wider CLARITY-IBD cohort. 16S rRNA gene amplicon sequencing …

Enhancing power quality of high‐speed railway traction converters by fully integrated T‐LCL filter

Authors

Maged Al‐Barashi,Xiangyu Meng,Zhigang Liu,Mahmoud SR Saeed,Ibrahim Adamu Tasiu,Siqi Wu

Journal

IET Power Electronics

Published Date

2023/4

Modulating the traction converters produces current harmonics at the switching frequencies and their multiples. These harmonics should be minimized to meet the network specifications. The LC‐trapped filters, tuned to these frequencies, can easily meet this requirement, but the existing applicable trap filters have not been studied with the traditional traction system topologies. Thus, this paper presents a trapped LCL filter with an LC resonator on the converter side, called a fully integrated T‐LCL filter, for the traction power supply system. The model and analysis reported in this research demonstrate that the presented filter has several advantages, which can be summarized by: reducing the size by winding many coils through magnetic integration, attenuating the switching frequency and its multiple harmonics that reduce the current total harmonic distortion, assuring durability against the filter parameters differences …

Influence of Electric Traction Drive System Harmonics and Interharmonics on the Vibration of Key Locomotive Components

Authors

Bing Lu,Zhigang Liu,Xufan Wang,Yang Song,Qiao Zhang,Siqi Wu,Gongquan Tao

Journal

IEEE Transactions on Vehicular Technology

Published Date

2023/5/19

Abnormal vibration can lead to frequent maintenance requirements of electric locomotives. Many factors contribute to the vibration, and the influence mechanism of pulsating torque generated by interharmonics in the traction drive system (TDS) is not clear at present. In this article, an electromechanical coupling model is developed to investigate the influence of harmonics and interharmonics in the electric TDS on the vibration of key locomotive components. Firstly, this article attempts to analyze the generation mechanisms of interharmonics and their resulting pulsating torque in electric TDS and derives the formulas for calculating interharmonics and pulsating torque frequencies. Then, an electromechanical coupling model is established based on the electric TDS and the multibody dynamics, and the influence of pulsating torque caused by interharmonics on the vibration of the locomotive key components is …

P535 COVID-19 vaccine-induced neutralising antibody responses against SARS-CoV-2 Omicron BA. 4/5 are diminished in patients with inflammatory bowel disease on anti-TNF or JAK …

Authors

Z Liu,J Alexander,K Le,X Zhou,H Ibraheim,S Anandabaskaran,A Saifuddin,K Lin,L McFarlane,N Anand,L Constable,R Castro-Seoane,R Nice,C Bewshea,A D'Mello,GR Jones,S Balarajah,F Fiorentino,S Sebastian,P Irving,L Hicks,H Williams,A Kent,R Linger,M Parkes,K Kok,KV Patel,J Teare,D Altmann,A Hart,C Lees,R Boyton,J Goodhand,N Kennedy,K Pollock,T Ahmad,N Powell,VIP investigators

Journal

Journal of Crohn's and Colitis

Published Date

2023/2/1

Background Low bone mineral density (BMD) in inflammatory bowel disease (IBD) is multifactorial and includes nutritional status. The study aimed to look for the association between fat body mass and fat-free mass and BMD of the lumbar spine (L1-L4), femoral neck and total body. Methods The study subjects included 95 patients with Crohn’s disease (CD), 68 with ulcerative colitis (UC) and 40 healthy adults (control group - CG) in age of 18-50 years old, recruited at the Department of Gastroenterology, Dietetics and Internal Medicine, Poznan University of Medical Sciences between 2020-2021. The summary of the methods is presented in Figure 1. DXA- Dual-energy X-ray absorptiometry Results A lowered fat mass percentage occurred in about 8% of CD, 13% of UC and 3% of CG. Additionally, an increased percentage of fat …

Catenary Support Components and Their Characteristics in High-Speed Railways

Authors

Zhigang Liu,Wenqiang Liu,Junping Zhong

Published Date

2023/4/11

The catenary system is an important part of high-speed railways and is responsible for providing stable power transmission for high-speed trains. The catenary system is mainly composed of two parts: the support device and the suspension device. These devices contain many components of different functional types.

Dynamic Characteristics of Electric Shoegear and Conductor Rail System Considering the Track Irregularities

Authors

Xufan Wang,Zhigang Liu,Yang Song,Wei Jin,Zhao Xu,Jiaming Xiong,Sheng Zhou

Journal

IEEE Transactions on Instrumentation and Measurement

Published Date

2023/7/10

The electric shoegear-conductor rail system (the shoe-rail system) is one of the electric energy collection devices for metro vehicles. A good interaction performance between the electric shoegear and the conductor rail is essential to ensure the current collection quality and operational safety. The conductor rail irregularities and vehicle-track excitation (induced by track irregularities) are the major disturbances to the shoe-rail interaction. Only the vertical effect of the vehicle-track excitation has been considered in previous studies, which cannot reproduce the realistic behavior of the shoe-rail system. To address this deficiency, this work attempts to build a spatial vehicle-shoe-rail system coupling model, including the disturbances from both the conductor rail irregularities and vehicle-track excitations. The numerical accuracy is verified by comparison with the measurement data collected from Guangzhou Metro Line 5 …

LLD-MFCOS: A Multi-scale Anchor-Free Detector Based on Label Localization Distillation for Wheelset Tread Defect Detection

Authors

Haonan Yang,Jing He,Zhigang Liu,Changfan Zhang

Journal

IEEE Transactions on Instrumentation and Measurement

Published Date

2023/9/18

Wheelset surface defect detection is an important aspect of train safety maintenance. However, due to the constraints of low industrial computing power, multiscale defects, and complex backgrounds, conventional defect detection methods are difficult to fully exploit their detection performance. To solve the above issues, we proposed a novel multiscale anchor-free detector based on a label localization distillation strategy, called LLD-MFCOS. In the proposed method, we designed a cross-layer refined feature pyramid network (CR-FPN) for the multiscale problem of tread defects. It integrates and allocates the multilevel features in the backbone network to the lateral connection of feature pyramid network (FPN) to improve the ability of multiscale feature extraction. To weaken the influence of complex background, a newly designed hybrid nonlocal (HNL) module, which is obtained by extending the channel pipeline in …

Research on Optimal Power Flow Control Strategy for Urban Rail Flexible Traction Power Supply System

Authors

Junjie Zhang,Shuai Jiang,Zhigang Liu,Jie Chen

Published Date

2023/10/19

In order to solve the problems of uncontrollable DC voltage and low utilization of regenerative braking energy in traditional traction power supply system, a bi-directional converter is used instead of diode rectifier to form a flexible traction power supply system. Firstly, the AC network and DC network of the system, as well as the working mode are introduced. Then a system hierarchical control strategy is proposed to study the modeling, dual closed-loop control of the bidirectional converter, and the optimization objectives, variables, and Gray Wolf optimization algorithm are introduced to achieve flexible control of the system. Finally, a simulation example is given to verify the proposed control strategy. The results show that the control strategy can better improve the regenerative braking energy distribution of the train and realize the energy-saving optimization of the system.

An improved passivity‐based control for suppressing the traction motor torque ripples due to traction network voltage fluctuation in high‐speed railways

Authors

Wenqing Zhao,Bing Lu,Zhigang Liu,Guinan Zhang

Journal

IET Power Electronics

Published Date

2023/11

When the voltage fluctuation of the traction network occurs in high‐speed railways, the interharmonics in the grid‐side voltage will propagate to the traction motor, which results in the motor torque ripple of running trains. The ripple can cause abnormal vibrations of key train components and even influence train operation safety. However, the traditional proportional‐integral controller used in the inverter‐motor system has a weak anti‐interference capability when facing nonlinear disturbances. This paper proposes an improved passivity‐based control (IPBC) to suppress the impact of interharmonics on trains. First, the Euler‐Lagrange mathematical model of the traction inverter‐motor system is established. Then, the PBC for this system is designed by damping injection, ensuring the asymptotic stability of the system. Furthermore, to purposely suppress the impact of the periodic disturbance on the system, a repetitive …

See List of Professors in Zhigang Liu University(New York University)

Zhigang Liu FAQs

What is Zhigang Liu's h-index at New York University?

The h-index of Zhigang Liu has been 29 since 2020 and 40 in total.

What are Zhigang Liu's top articles?

The articles with the titles of

2-DOF Internal Model Direct Power Control Scheme Based on H∞ Theory for Dual Traction Rectifiers with Parameter Perturbations

P991 Serum anti-TNF levels correlate with tissue levels in perianal fistulising Crohn’s Disease

Adaptive Subband Forward Blind Source Separation Algorithms based on Kalman Mechanism

Evolution analysis of wheel polygon wear considering the effect of interharmonics in electrical traction drive system

Optimization of Railway Pantograph-Catenary Systems for Over 350 km/h Based on an Experimentally Validated Model

Low-Frequency Stability Analysis of Train-Grid System: A Perspective from DAB Converter

An Optimized dq-Frame Admittance Modeling Method for Single-Phase Railway Vehicle-grid System Considering the Impact of Asymmetric αβ Control

Influence of Surface Roughness of Sliding Friction Pairs on Pantograph-Catenary Contact Resistance

...

are the top articles of Zhigang Liu at New York University.

What is Zhigang Liu's total number of citations?

Zhigang Liu has 5,641 citations in total.

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