Skip to main content

Research Repository

Advanced Search

All Outputs (14)

Scanning for dark matter subhaloes in Hubble Space Telescope imaging of 54 strong lenses (2023)
Journal Article
Nightingale, J. W., He, Q., Cao, X., Amvrosiadis, A., Etherington, A., Frenk, C. S., Hayes, R. G., Robertson, A., Cole, S., Lange, S., Li, R., & Massey, R. (2024). Scanning for dark matter subhaloes in Hubble Space Telescope imaging of 54 strong lenses. Monthly Notices of the Royal Astronomical Society, 527(4), 10480-10506. https://doi.org/10.1093/mnras/stad3694

The cold dark matter (DM) model predicts that every galaxy contains thousands of DM subhaloes; almost all other DM models include a physical process that smooths away the subhaloes. The subhaloes are invisible, but could be detected via strong gravit... Read More about Scanning for dark matter subhaloes in Hubble Space Telescope imaging of 54 strong lenses.

Condition Monitoring Power Module Solder Fatigue Using Inverter Harmonic Identification (2012)
Journal Article
Xiang, D., Ran, L., Tavner, P., Yang, S., Bryant, A., & Mawby, P. (2012). Condition Monitoring Power Module Solder Fatigue Using Inverter Harmonic Identification. IEEE Transactions on Power Electronics, 27(1), 235-247. https://doi.org/10.1109/tpel.2011.2160988

Condition monitoring power semiconductor devices can inform converter maintenance and reduce damage. This paper presents a method to monitor solder fatigue in a voltage source inverter insulated gate bipolar transistor power module by detecting the c... Read More about Condition Monitoring Power Module Solder Fatigue Using Inverter Harmonic Identification.

An industry-based survey of reliability in power electronic converters (2011)
Journal Article
Yang, S., Bryant, A., Mawby, P., Xiang, D., Ran, L., & Tavner, P. (2011). An industry-based survey of reliability in power electronic converters. IEEE Transactions on Industry Applications, 47(3), 1441-1451. https://doi.org/10.1109/tia.2011.2124436

A questionnaire survey was carried out to determine the industrial requirements and expectations of reliability in power electronic converters. The survey was subjective and conducted with a number of high-profile semiconductor manufacturers, integra... Read More about An industry-based survey of reliability in power electronic converters.

Condition Monitoring for Device Reliability in Power Electronic Converters: A Review (2010)
Journal Article
Yang, S., Xiang, D., Bryant, A., Mawby, P., Ran, L., & Tavner, P. (2010). Condition Monitoring for Device Reliability in Power Electronic Converters: A Review. IEEE Transactions on Power Electronics, 25(11), 2734-2752. https://doi.org/10.1109/tpel.2010.2049377

Condition monitoring (CM) has already been proven to be a cost effective means of enhancing reliability and improving customer service in power equipment, such as transformers and rotating electrical machinery. CM for power semiconductor devices in p... Read More about Condition Monitoring for Device Reliability in Power Electronic Converters: A Review.

Mechanical to Electrical Energy Conversion in a Hybrid Liquid-Solid Dielectric Electrostatic Generator (2009)
Journal Article
Crossland, A., Wyllie, P., & Ran, L. (2009). Mechanical to Electrical Energy Conversion in a Hybrid Liquid-Solid Dielectric Electrostatic Generator. Journal of Applied Physics, 106(4), Article 044108. https://doi.org/10.1063/1.3207834

The authors are studying the effect of the dielectric choice in electrostatic generators on the energy yield. Despite having high permittivities, solid dielectrics are shown to have a lower performance than is first apparent, due to the effect of the... Read More about Mechanical to Electrical Energy Conversion in a Hybrid Liquid-Solid Dielectric Electrostatic Generator.

A multilevel modular converter for a large, lightweight wind turbine generator (2008)
Journal Article
Ng, C., Parker, M., Ran, L., Tavner, P., Bumby, J., & Spooner, E. (2008). A multilevel modular converter for a large, lightweight wind turbine generator. IEEE Transactions on Power Electronics, 23(3), 1062-1074. https://doi.org/10.1109/tpel.2008.921191

In an onshore horizontal axis wind turbine, generator and converter are usually in the nacelle on the top of the tower, while the grid step-up transformer is placed at the bottom. Electric power is transmitted down through flexible cables of high cur... Read More about A multilevel modular converter for a large, lightweight wind turbine generator.

Development of a prototype solid state fault current limiting and interrupting device for low voltage distribution networks (2006)
Journal Article
Ahmed, M., Putrus, G., Ran, L., & Penlington, R. (2006). Development of a prototype solid state fault current limiting and interrupting device for low voltage distribution networks. IEEE Transactions on Power Delivery, 21(4), 1997-2005. https://doi.org/10.1109/tpwrd.2006.874587

This paper describes the development of a solid-state Fault Current Limiting and Interrupting Device (FCLID) suitable for low voltage distribution networks. The main components of the FCLID are a bidirectional semiconductor switch that can disrupt th... Read More about Development of a prototype solid state fault current limiting and interrupting device for low voltage distribution networks.

Control of a Doubly Fed Induction Generator in a Wind Turbine During Grid Fault Ride-Through (2006)
Journal Article
Xiang, D., Ran, L., Tavner, P., & Yang, S. (2006). Control of a Doubly Fed Induction Generator in a Wind Turbine During Grid Fault Ride-Through. IEEE Transactions on Energy Conversion, 21(3), 652-662. https://doi.org/10.1109/tec.2006.875783

This paper analyzes the ability of a doubly fed induction generator (DFIG) in a wind turbine to ride through a grid fault and the limitations to its performance. The fundamental difficulty for the DFIG in ride-through is the electromotive force (EMF)... Read More about Control of a Doubly Fed Induction Generator in a Wind Turbine During Grid Fault Ride-Through.

Coordinated control of an HVDC link and doubly fed induction generators in a large offshore wind farm (2006)
Journal Article
Xiang, D., Ran, L., Bumby, J., Tavner, P., & Yang, S. (2006). Coordinated control of an HVDC link and doubly fed induction generators in a large offshore wind farm. IEEE Transactions on Power Delivery, 21(1), 463-471. https://doi.org/10.1109/tpwrd.2005.858785

Doubly fed induction generators (DFIGs) are an economic variable-speed solution for large wind turbines while high-voltage dc (HVdc) transmission is being considered for the grid connection of some offshore wind farms. This paper analyzes the need fo... Read More about Coordinated control of an HVDC link and doubly fed induction generators in a large offshore wind farm.

Sampling-induced resonance in an encoderless vector-controlled induction motor drive (2004)
Journal Article
Ran, L., & Liao, Y. (2004). Sampling-induced resonance in an encoderless vector-controlled induction motor drive. IEEE Transactions on Industrial Electronics, 51(3), 551-557. https://doi.org/10.1109/tie.2004.825371

This paper illustrates an effect of sampling in an encoderless vector-controlled induction motor drive with a digital controller. The analysis focuses on the speed observer and the speed control loop which is executed at discrete instants. It is show... Read More about Sampling-induced resonance in an encoderless vector-controlled induction motor drive.

Evaluation of the effects of rotor harmonics in a doubly-fed induction generator with harmonic induced speed ripple (2003)
Journal Article
Liao, Y., Ran, L., Putrus, G., & Smith, K. (2003). Evaluation of the effects of rotor harmonics in a doubly-fed induction generator with harmonic induced speed ripple. IEEE Transactions on Energy Conversion, 18(4), 508-515. https://doi.org/10.1109/tec.2003.816606

This paper is concerned with the low-frequency harmonics which originate from the rotor inverter of a doubly-fed induction generator (DFIG). By including the mechanical speed response, it expands the transformer approach previously taken to analyze t... Read More about Evaluation of the effects of rotor harmonics in a doubly-fed induction generator with harmonic induced speed ripple.

Dynamic selective harmonic elimination of a three-level inverter used for static VAr compensation (2002)
Journal Article
Ran, L., Holdsworth, L., & Putrus, G. (2002). Dynamic selective harmonic elimination of a three-level inverter used for static VAr compensation. IEE proceedings. Generation, transmission and distribution, 149(1), 83-89. https://doi.org/10.1049/ip-gtd%3A20020082

The paper investigates the harmonic interaction between the AC and DC sides of a 3-level inverter used as a static synchronous VAr compensator (STATCOM). It is illustrated that due to the 3rd harmonic voltage across each DC side capacitor. the conven... Read More about Dynamic selective harmonic elimination of a three-level inverter used for static VAr compensation.