Biography

Li Ran received a PhD degree (1989) in Power Systems Engineering from Chongqing University in China for his work on reliability evaluation of the transmission network planned for the Three-Gorge Hydro Power Plant. He then participated in the commissioning of Gezhouba-Shanghai HVDC System (1989-1990).

Between 1992 and 1999, he was a postdoctoral research fellow with the Universities of Aberdeen, Nottingham and Heriot-Watt (Edinburgh), working on marine electrical propulsion, offshore electrical systems and electromagnetic compatibility (EMC) in power electronic motor drives. He became a Lecturer with the University of Northumbria at Newcastle in 1999 and moved to Durham University in 2003 where he was promoted to a Chair in 2010. He joined the University of Warwick as a Professor of Power Electronics - Systems in 2012, and was part-time for part of the period. His work at Northumbria, Durham and Warwick has centred around power conversion and control for renewable generation, and reliability of power semiconductors. He was seconded to Alstom Power Conversion at Kidsgrove, the UK (2001-2003) and took a sabbatical leave at MIT, the USA (2007-2008).

Dr Li Ran was the recipient of a Global Research Award of the Royal Academy of Engineering, Stanley-Gray Award of IMarEST and IEEE Prize Paper Awards.

Dr Li Ran was a professor and is an adjunct professor with Chongqing University. He is a Co-Director of the Warwick-Chongqing Joint Key Laboratory (WaCky Lab) in SiC Power Electronics, and the Student Experience Tutor of the Warwick-Chongqing 2+2 Programme in Electrical Engineering and Electronics.

Li Ran is a slow, but regular, 5 km Parkrun participant (home | parkrun UK).

Research Interests

Application of power electronics for electrical power generation, delivery and utilisation;

Power semiconductors and packaging.

Teaching Interests

Electric Circuit Theory, Analogue Electronics, Instrumentation Systems, Electromagnetic Compatibility, Control Theory, Electric Machines and Drives, Electrical Power Systems, Power Electronic Systems, Renewable Power Generation, and Embedded Generation.

Students are welcome to contact Professor Li Ran to discuss study in these subject areas.

Professor Li Ran is maintaining the ETAP Power Lab, a Digital Twin Platform for Design and Operation of Electrical Power Systems, at the University of Warwick, denoted by ETAP.

Selected Recent Publications

Book

• Tavner P, Ran L and Crabtree C, Condition Monitoring of Rotating Electrical Machines, 3rd Edition, IET Press, 2020

Papers in Journals of Learned Societies

• Wang D, Wei J, Feng H and Ran L, A Thermal Black-box Theory for Scaling Design of Planar Magnetic Coils in Wireless Charging Systems, IEEE Trans. on Power Electronics, 2024 (IEEE early access)
• Yang J, Che Y, Guo X, Ran L and Chen Y, In-situ Monitoring Chip Failure in Multichip IGBT Modules Using Turn-on Delay Time Extracted from Auxiliary Emitter Voltage, IEEE Journal of Emerging and Selected Topics in Power Electronics, 2024 (IEEE early access)
• Jiang P, Feng H and Ran L, ZVS Analysis and a Design Method for Unidirectional Medium-Voltage LLC-DCX with High Step-Up Ratio, IEEE Trans. on Power Electronics, Vol. 39, No. 3, 2023, pp2948-2953
• Wei JX, Feng H and Ran L, Multi-Dimensional Design of DC-Link for Two-Stage Solid-State Transformer Cell Considering Second-order Harmonic Current Distribution, IEEE Trans. on Power Electronics, Vol. 38, No. 8, 2023, pp10244-10255
• Wei JF, Jiang H, Xiao N, Wu Z, Wang L and Ran L, Multiple Phase Change Materials Integrated into Power Module for Normal and High Current Reliability Enhancement, IEEE Trans. on Device and Materials Reliability, Vol. 23, No. 1, 2023, pp127-133
• Tang L, Jiang H, Zhong X, Qiu G, Mao H, Jiang X, Qi X, Du C, Peng Q, Liu L and Ran L, Investigation into the Third Quadrant Characteristics of Silicon Carbide MOSFET, IEEE Trans. on Power Electronics, Vol. 38, No. 1, 2023, pp1155-1164
• Mao H, Hu J, Jiang H, Ran L, Qiu G, Wei J, Chen H, Zhong X, Xiao L, Wang L and Wu Y, An Asymmetrical Power Module Design for Modular Multilevel Converter with Unidirectional Power Flow, IEEE Trans. on Power Electronics, Vol. 38, No. 1, 2023, pp1092-1102
• Wei JX, Feng H and Ran L, Integrated Design for Lifetime Extension and ESR Monitoring of Hybrid DC-Link in Solid-State Transformer from the Perspective of High-Frequency Ripple Current, IEEE Trans. on Power Electronics, Vol. 37, No. 12, 2022, pp15583-15593
• Ren H, Liu L, Djurovic S, Ran L, Liu X, Feng H and Mawby P, In-situ Contact Pressure Monitoring of Press Pack Power Module Using FBG Sensors, IEEE Trans. on Instrumentation and Measurement, Vol. 71, No. 7, 2022, pp1-11 (7006211)
• Qiu G, Ran L, Feng H, Jiang H, Mao H and Wei J, A High-precision Sensor Based on AC Flux Cancellation for DC Bias Detection in Dual Active Bridge Converters, IEEE Trans. on Power Electronics, Vol. 37, No. 11, 2022, pp13513-13524
• Jiang X, Jiang H, Zhong X, Mao H, Wu Z and Ran L, Impact of Gate Resistance on Improving the Dynamic Overcurrent Stress of the Si/SiC Hybrid Switch, IEEE Trans. on Power Electronics, Vol. 37, No. 11, 2022, pp13319-13331
• Shillaber L, Jiang Y, Ran L and Long T, Ultra Fast Current Shunt (UFCS): A Gigahertz Bandwidth Ultra Low Inductance Current Sensor, IEEE Trans. on Power Electronics, Vol. 37, No. 12, 2022, pp15493-15504
• Zhong X, Jiang H, Tang L, Qi X, Jiang P and Ran L, Gate Stress Polarity Dependence of AC Bias Temperature Instability in Silicon Carbide MOSFETS, IEEE Trans. on Electron Devices, Vol. 69, No. 6, 2022, pp3328-3333
• Jiang H, Qi X, Qiu G, Zhong X, Tang L, Mao H, Wu Z, Chen H and Ran L, A Physical Explanation of Threshold Voltage Drift of SiC MOSFET Induced by Gate Switching, IEEE Trans. on Power Electronics, Vol. 37, No. 8, 2022, pp8830-8834
• Hu Z, Hu B, Ran L, Tavner P, Kong H, Mawby P and Wu R, Monitoring Power Module Solder Degradation from Heat Dissipation in Two Opposite Directions, IEEE Trans. on Power Electronics, Vol. 37, No. 8, 2022, pp9754-9766
• Wu Z, Jiang H, Zheng Z, Qi X, Liu L and Ran L, Dynamic dv/dt Control Strategy of SiC MOSFET for Switching Loss Reduction in the Operational Power Range, IEEE Trans. on Power Electronics, Vol. 37, No. 6, 2022, pp6237-6241
• Mao H, Qiu G, Jiang H, Zhong X, Tang L and Ran L, Investigation on the Degradations of Parallel Connected 4H-SiC MOSFETs under Repetitive UIS Stresses, IEEE Trans. on Electron Devices, Vol. 69, No. 2, 2022, pp650-657
• Yang J, Che Y, Ran L, Du M, Jiang H and Hu B, Monitoring Initial Solder Layer Degradation in a Multichip IGBT Module via Combined TSEPs, IEEE Trans. on Device and Materials Reliability, Vol. 22, No. 1, 2022, pp26-35
• Ren H, Ran L, Liu X, Liu L, Djurovic S, Jiang H, Barnes M and Mawby P, Quasi-distributed Temperature Detection of Press Pack IGBT Power Module Using FBG Sensing, IEEE Journal of Emerging and Selected Topics in Power Electronics, Vol. 10, No. 5, 2022, pp4981-4992
• Qiu G, Ran L, Feng H, Jiang H, Long T, Forsyth A, Shao W and Hou X, A Flux Gate-based Current Sensor for DC Bias Elimination in a Dual Active Bridge Converter, IEEE Trans. on Power Electronics, Vol. 37, No. 3, 2022, pp3233-3246
• Zhong X, Jiang H, Qiu G, Tang L, Mao H, Xu C, Jiang X, Hu J, Qi X and Ran L, Bias Temperature Instability of Silicon Carbide Power MOSFET under AC Gate Stresses, IEEE Trans. on Power Electronics, Vol. 37, No. 2, 2022, pp1998-2008
• Hu B, Konaklieva S, Kourra N, Williams M, Ran L and Lai W, Long Term Reliability Evaluation of Power Modules with Low Amplitude Thermomechanical Stresses and Initial Defects, IEEE Journal of Emerging and Selected Topics in Power Electronics, Vol. 9, No. 1, 2021, pp602-615
• Hu B, Hu Z, Ran L, Ng C, Jia C, McKeever P, Tavner P, Zhang C, Jiang H and Mawby P, Heat-Flux Based Condition Monitoring of Multi-chip Power Modules Using a Two-Stage Neural Network, IEEE Trans. on Power Electronics, Vol. 36, No. 7, 2021, pp7489-7500
• Ren H, Shao W, Ran L, Hao G, Zhou L, Mawby P and Jiang H, A Phase Change Material Integrated Press Pack Power Module with Enhanced Overcurrent Capability for Grid Support – a Study on FRD, IEEE Trans. on Industry Applications, Vol. 57, No. 4, 2021, pp3956-3968
• Jiang H, Wei J, Fang X, Ren H, Shao W, and Ran L, A delta_Tj Reduced Power Module with In-built Phase Change Materials for Reliability Enhancement, IEEE Trans. on Electron Devices, Vol. 68, No. 9, 2021, pp4557-4564
• Shao W, Wu R, Ran L, Jiang H, Mawby P, Rogers D, Green T, Coombs T, Yardley K, Kastha D and Bajpai P and Zhou L, A Power Module for Grid Inverter with in-built Short-Circuit Current Capability, IEEE Trans on Power Electronics, Vol. 35, No. 10, 2020, pp10567-10579
• Bashar E, Rogers D, Wu R, Ran L, Jennings M, Green T and Mawby P, A New Protection Scheme for an SSSC in an MV Network by Using a Varistor and Thyristors, IEEE Trans on Power Delivery, Vol. 36, No. 1, 2020, pp102-113
• Mohammed A, Hu B, Hu Z, Djurovic S, Ran L, Barnes M and Mawby P, Distributed Thermal Monitoring of Wind Turbine Power Electronic Modules Using FBG Sensing Technology, IEEE Sensors Journal, Vol. 20, No. 17, 2020, pp9886-9894
• Jiang H, Zhong X, Qiu G, Tang L, Qi X and Ran L, Dynamic Gate Stress Induced Threshold Voltage Drift of Silicon Carbide MOSFET, IEEE Electron Device Letters, Vol. 41, No. 9, 2020, pp1284-1287

Projects and Grants