A5043908499- Microgrid Control and Optimization
- HVDC Systems and Fault Protection
- Islanding Detection in Power Systems
- Power Systems and Renewable Energy
- Electric Motor Design and Analysis
- Magnetic Bearings and Levitation Dynamics
- High-Voltage Power Transmission Systems
- Power Transformer Diagnostics and Insulation
- Sensorless Control of Electric Motors
- Wireless Power Transfer Systems
- Geoscience and Mining Technology
- Power System Optimization and Stability
- Smart Grid and Power Systems
- Advanced Sensor and Control Systems
- Vibration and Dynamic Analysis
- Magnetic Properties and Applications
- Smart Grid Energy Management
- Advanced Computational Techniques and Applications
- Energy Harvesting in Wireless Networks
- Wind Turbine Control Systems
- Traffic Prediction and Management Techniques
- Power Systems Fault Detection
- Geomechanics and Mining Engineering
- Semiconductor materials and devices
- Advanced Battery Technologies Research
University of Hong Kong
2024-2025
Agency for Science, Technology and Research
2024
Institute of Microelectronics
2024
Nanjing University of Aeronautics and Astronautics
2009-2023
Hunan University
2018-2022
IBM (United States)
2019
Zhengzhou University of Light Industry
2019
Electricity North West (United Kingdom)
2012
Beijing Wuzi University
2010-2012
Jilin Medical University
2011
In recent years, the virtual synchronous generator (VSG) concept has been widely studied to integrate renewable energy sources. However, instability occurs due implementation of dc-link voltage controllers under weak grid, and its mechanism remains unclear, which is investigated in this article. At first, wideband <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dq</i> -frame impedance models VSGs with for two cases are established. Then,...
This paper presents a novel dual-stator hybrid excited synchronous wind generator and describes its structural features operation principle. The no-load magnetic fields with different field currents are computed by 3-D finite-element method. Static characteristics, including the flux-linkage EMF waveforms of stator windings, inductance armature windings winding, analyzed. simulation results show that due to structure, air-gap flux can be easily controlled, while output voltage increased...
Small-signal stability problems often occur when the inverter for renewable energy generation is connected to weak grid. A small-signal transfer function integrated model reflecting interaction of grid impedance, phase locked-loop (PLL), and current control loop established in this paper. Based on model, oscillation mechanism grid-connected system revealed: inductance flowing through impedance can produce a voltage disturbance, which will eventually affect PLL loop. Therefore, composed...
Source-side virtual synchronous machines (VSGs) and load-side VSMs (LVSM) are gradually utilized together in the microgrid to provide inertia damping. However, instability occurs islanded system due interaction dynamics between VSG LVSM, which has been investigated this article. At first, <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dq</i> -frame impedance models of LVSM established compared. It is revealed that d-d channel behaves...
In this study, an improved control method of the grid-connected inverter is presented to enhance harmonic suppression. The capacitor-current-feedback-based active damping applied LCL-type inverter, which controlled in virtual synchronous generator mode. A virtual-impedance design based on modulation signal proposed, can not only stability under weak-grid situations, but also improve quality voltage and current. transfer function impedance model system are established analyse performance...
The load-side virtual synchronous machine (LVSM) enables the load to actively participate in grid regulation, but it might still induce oscillations a weak grid. Considering dc-link voltage controller, power loops, ac and current control delay, sampling filters, wideband dq-frame impedance model of LVSM is first established, found that Z <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dd</sub> exhibits negative resistor within 10 Hz. In...
Virtual synchronous machine (VSM) based high voltage dc systems enhance the inertia of power system. However, dynamic interactions between VSM-based rectifier station, inverter and grid could induce system oscillation, which has been investigated in this article. At first, hybrid ac–dc impedance models VSMs considering coupling ac dynamics are established. Then, relationships impedance, <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dq</i>...
Impedance-based approachis generally studied for stability analysis of the power electronic converter-based system. Considering multiple-frequency coupling effects, in this article, we establish harmonic transfer function (HTF) based <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">αβ</i> -frame impedance models droop inverters islanded microgrid with unbalanced loads. Therein, HTF-based -impedance modeling methods loads, as well parallel, are...
In Nanosheet (NS) device architecture, it is much more challenging than FinFET to develop a suitable multiple threshold voltage (multi-Vt) integration with restrictive requirement on the dimensions due critical dimension scaling and complex structure. this abstract, we reported an innovative scheme enable volumeless multi-Vt metal provide solutions in NS technology for high performance computing (HPC) low-power applications. We developed new solve geometry constraint offer margin opportunity...
Multilevel converters have attracted more and attention for their advantages over the two-level in breaking voltage limitation multichannel wireless power transfer (WPT), but switching loss is unbearable due to lack of an effective soft-switching modulation method. To fill this gap, article proposes implements a segmented-vector pulse frequency (SVPFM) half-bridge three-level inverter WPT systems. Moreover, sigma-delta (Σ-Δ) modulator SVPFM-WPT system proposed, range expanded [0, 1]. It can...
Due to the dynamic interaction between inverter and grid, may have power oscillation problems under a weak grid. In this article, considering frequency coupling, more precise broadband sequence admittance model of current-controlled virtual synchronous generator (CVSG) is established, characteristics CVSG traditional grid-connected (TGCI) are compared analyzed. The amplitude generally larger than that TGCI in low-frequency region, entire sweep range, coupling TGCI. has great impact on...
According to the characteristics of line‐commutated converter high‐voltage direct current (LCC‐HVDC) and voltage source (VSC‐HVDC), respective additional emergency DC power support (EDCPS) controllers are designed, a coordinated control strategy based on hybrid multi‐infeed HVDC system for EDCPS is proposed. Considering differences in recovery performance between LCC‐HVDC VSC‐HVDC providing EDCPS, priority issues allocation schemes discussed detail. To maintain stability receiving‐end AC...
In this paper a hybrid excitation brushless claw-pole motor is developed to fulfil the special requirements for industrial application, such as high power density, efficiency, starting torque and wide operation range. The has magnetic fields contributed by both permanent magnet field winding on rotor. no-load of six-pair poles numerically analyzed three-dimensional finite element method. distributions in airgap rotor under different DC currents are visually shown. It also illustrated that...
Because of the advantages high stability, small ripple, linear power supply is suitable to stability requirements fields. The working principle and deficiencies existing DC analyzed. And implementation a new with tunable voltages put forward. In premise no change output voltage circuit feedback dynamic performance, can be adjustable. has characteristics over-current protection for lower error caused by temperature drift, time component parameter tolerance cost, higher resolution, etc.
Alternating current (AC) permanent magnet (PM) contactor is a new type of contactor, which coil does not consume energy during its working course. This paper proposes structure and analyzes field distributions PM arrangements both on stator armature based finite element method. The computed results two are almost the same for making course, but breaking arrangement has much more inertia than that certain supplied voltage. Experiments displacement versus time verify theoretical prediction.
In the series-compensated grid-connected system (SCGCS), there is an impedance interaction between inverter and grid that prone to cause resonance in SCGCS. this paper, firstly, considering effects of phase-locked loop (PLL), current-loop, frequency coupling, broadband model SCGCS established. The stability analyzed by impedance-based Nyquist criterion. It found from analysis leading resonance. An reshaping based suppression method proposed suppress phase characteristics equivalent output...
With power electronic loads penetrating into grid increasingly, the is progressively developing low inertia and less damping network, which seriously leads to instability problems. To address issues, load virtual synchronous machine (LVSM) technology introduced for ability support damping. And control scheme described in details, with not only loops but inner ac voltage current loops. Then taking dc-side account, d-q small-signal output impedance model of LVSM derived, behaves inductive,...
According to the rational function approximation method of Gaussian filter, transfer an 8-order filter is obtained. Based on value quality factor Q pole function, analog cascade circuits are determined. The optimal cascading sequence and principle components given. When selecting cut-off frequency 400 Hz, experiment circuit in domain time done. result shows that achieves desired target.