Professor Ron Hui, Chair Professor of Power Electronics and Philip Wong Wilson Wong Professor in Electrical Engineering, Department of Electrical and Electronic Engineering.
As the world grapples with existential threats posed by climate change, the research team led by Professor Ron Hui, the Chair Professor of Power Electronics and Philip Wong Wilson Wong Professor in Electrical Engineering, is spearheading efforts to accelerate cleaner, more robust power generation.
Having returned to the University of Hong Kong (HKU) last year after a two-and-a-half-year stint building the first Wireless Power Research Laboratory for Singapore at Nanyang Technological University (NTU), Professor Hui has obtained a HK$28 million Theme-based Research grant from the Research Grants Council for his pioneering research on high-power (HP), high-frequency (HF) and high-efficiency (HE) Wireless Power Transfer (WPT) operating regime. Such novel technologies can create new opportunities to reduce the size, and improve the energy efficiency of the Wireless Power Transfer (WPT) systems.
Professor Hui returned to HKU at the invitation of President Zhang Xiang and the Dean of the Faculty of Engineering to continue with his research in the uncharted territory of HP, HF and HE WPT operating regime. With more than 125 patents under his belt, Professor Hui is also drawn by the sizeable RGC funding support.
“We sought the grant because we had achieved some enabling technology to help us break the ground,” said Professor Hui, a world-renowned authority on power electronics, who has also been ranked among the top 20 out of 110,000 scientists in the field of Electrical Engineering (Energy) over the last few years in the Stanford University Top 2% Scientists List and top 10 scientists in Power Electronics by ScholarGPS.
Building on ground-breaking technology
The technology he referred to is that of a printed circuit board resonator that can be manufactured in mass production for future wireless power application, and the electronic gate drive which can operate at megahertz operation. “One megahertz means it can switch one million times per second,” Professor Hui explained. “If you can get into between one to ten megahertz, it means one million switching per cycle to ten million switching per cycle.”
“Very few people can make a resonator at this high quality,” he added. “By using printing technology, we can reproduce the same structure easily in mass production to support for example mobile robots.”
Compared to Singapore, he said, Hong Kong enjoys less restrictions in conducting research.
Professor Hui conducting research on wireless power transfer.
A veteran inventor, Professor Hui won RGC Theme-based Research grants three times between 2011 and 2021, which together were worth more than HK$100 million. In its field of expertise, his team was among the top five in the world, attracting the attention of both budding and accomplished scientists. “We have lots of enquiries from students who wish to work with us from around the world.”
Among his inventions are the wireless charging pads for mobile phones, and the wireless charging platform technology that underpins key dimensions of Qi, the world’s first wireless power standard launched by the Wireless Power Consortium in 2010, with freedom of positioning and localised charging features for wireless charging of consumer electronics. The Consortium comprises over 430 companies worldwide.
In addition, he pioneered the Photo-Electro-Thermal Theory for LED Systems, unifying the nonlinear interactions of heat, light, power and colour under the same mathematical framework. “We worked like a big army before. We managed to file for patents in the first two years of receiving our first RGC Theme-based grant; in the third year we had our product; we completed all the objectives within the first four years and eventually, the RGC panel gave us the freedom to explore new ideas in the fifth year using the remaining funding,” he recalled.
Supporting electric vehicles and more
Now with a smaller team, he and his four young, dedicated scientist teammates remained focused and driven in enlarging the capacity of renewable power generation.
“Power electronics is an enabling technology, and can be used for wide-ranging power applications, from very low power to tens of megawatts, just like a fast charger,” said Professor Hui, who received the Distinguished Research Achievement Award at HKU in 2019. “It has implications for electric vehicles, but its other potential applications are beyond our imagination.”
One important application is to create green energy, such as solar and wind power, which accounts for less than 1 % of the electricity produced by local power companies. Professor Hui’s team is seeking a grant from the Government’s Innovation and Technology Support Programme to take forward the project using his own invention of the electric spring technology – a fast demand-side response for smart grid with intermittent renewable energy sources.
“We hope to create a model that can be tested in power system simulator. Our idea is to develop circuits that can allow the power company to accommodate huge amount of wind and solar power. And the electric spring can absorb the power fluctuation of wind and solar power, on top of the support for the voltage and frequency,” he said. “We have a laboratory prototype that demonstrates that our idea works.”
The alternative sources of energy can help tackle the pressing issue of climate change facing humankind, amid the drives by governments worldwide to curb carbon emissions. Time is not on our side, he warns. The United Nations Secretary-General António Guterres has warned of the world moving from global warming to global boiling.
And with the increased human dependence on high-power electric devices, it is vital to maximise energy efficiency and minimise charging time.
The power level of wireless charging applications increases from 15W for consumer electronics to 2.2kW for robotics and kitchen electrical appliances and also to 11kW for electric vehicles. Professor Hui points to the urgency of shifting the paradigm from “compatibility” to both “compatibility” and “optimal performance”. “We achieved the new paradigm shift by transferring most of the optimal performance control to the primary side while leaving the receiver to handle basic protection functions such as over-voltage, over-current and over-temperature of the battery.”
“We pioneered the primary-side monitoring to construct a battery digital twin on the primary side and apply our patented maximum efficiency point tracking (MEPT) method based on primary-side control. Simultaneously, we utilise the temperature-regulated charging control on the receiver control to minimise the charging time.”
Currently, a US company is negotiating with the Technology Transfer Office of HKU to license Prof. Hui’s 2018 US patent for wireless charging of electric vehicles.
Professor Hui and his research team members.
Starting with advanced science projects
While a school student in Hong Kong, Professor Hui hoped to become a poet. But he decided to study science instead considering that it might be hard to make a living being a poet.
He counts himself fortunate to have worked on a frontier research project during his final year at the University of Birmingham decades ago. It was a continuation of a PhD project done by a senior colleague, who eventually developed the high-speed train in France. It opened the door for him to pursue doctoral study later at Imperial College, London.
His another assignment during his undergraduate years further inspired him to pursue a research career. It was a project on developing software for a railway system, which was later sold to the Mass Transit Railway Corporation in Hong Kong. Besides receiving half a million pounds in return for the university, Professor Hui and his peers were thrilled to hear from their professor that they had become a ‘world authority’ as a result of their work.
Their professor told them that was because when other people dared not study the problem, they took up the challenge and solved it.
“Everybody can be a world authority,” Professor Hui noted. He has since stuck to the path of research when most engineering graduates opted for the security of joining the government or power companies. “I was the only student among the Hong Kong students in my university class who chose to do research,” he recalled.
Interestingly, his son – now an academic at Cambridge University – has inherited his passion, as a medieval literature scholar who also specialises in Old Norse as well as the martial arts novels penned by the literary giant Jin Yong. His son is developing a new research discipline of Comparative Literature of Jin Yong, Tolkien and Shakespeare.
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Professor Hui obtained a PhD degree at Imperial College, London.
Learning and sharing about life
The main reason he moved to Singapore was to help with his son’s translation of Jin Yong’s acclaimed works, while his son was an Assistant Professor of Medieval Literature at NTU. After he moved to Cambridge, Professor Hui decided to settle back in Hong Kong, continuing with his journey of scientific pursuits. The process of venturing into the unknown fills him with both excitement and satisfaction. It is a reward shared by his three teammates, former post-docs at NTU and now Research Assistant Professors at the Faculty, who followed him to Hong Kong from Singapore.
“It is a curiosity-driven career. You have to be willing to take risks if you want to do research,” he said. “I would also tell students today that the most important is to pursue their own interests.”
As echoed by his teammates, the limited moments of scientific discovery are a source of much happiness. It has taught Professor Hui to be humble as well. “The more you know, the more you know how little you know. The more understanding we have, the more knowledge we gain, the more we feel we are ignorant,” he noted.
Posted on his website is an inspiring line written by the great inventor Nikola Tesla: “Discoveries come from the resonance of human minds and the creation. It is important to know the Creator. So do read the Bible.”
Trying to support and enlighten others, for 17 years he has preached to prisoners once a month at Stanley Prison. He also preaches at local churches, sharing his faith with others when he is not needed at the laboratory.
On his latest research, he said: “We will focus on extremely high quality, high impactful work. If we are successful, our technology will be five to ten years ahead of the world.”