The Official One
Dr. Min Zhang is an EMC consultant based in Oxford, UK. He received his PhD within Newcastle University’s Electrical & Electronics Engineering department in 2013. His research was in novel power switching schemes to reduce EMI emissions, and his research papers have received many citations.
Since then, he has worked as an EMC specialist on milestone projects with Dyson Technology, UK.
With a proven track record designing state-of-the art electronics and electric machines with minimal EMC issues, Min then established the EMC capability for the Dyson Electric Vehicle project.
Following the closure of that project, Min joined Cherry Clough Consultants Ltd to provide independent expertise in good, cost-effective EMC design, worldwide.
Min’s in-depth knowledge in power electronics, digital electronics, electronic machines and product design is sure to benefit your product’s design, helping you win the race against time and cost.
The Personal One
The journey started in the year of 2008.
I landed at Newcastle airport, England, with a dream of learning the state-of-the-art electronics design. I got enrolled with a research project in the school of Electrical, Electronics and Computer Engineering in Newcastle University.
The school at the time had two world class professors in the field of electric machine and drive design, Professor Alan Jack and Professor Barrie Mecrow, who later became the head of school. I had the luxury of attending both’s lectures. Both professors came from a strong industrial background, therefore the school has always enjoyed a strong link with the industries. This also expanded my horizons as I was fascinated by the engineering stories often told in lectures.
The subject of electromagnetic was well taught and I grew interests in electric machine design, drive application and power electronics. I also spotted an interesting area – electromagnetic interference. I was accepted as a PhD research candidate in 2009.
One of my colleagues, Richard Gibson, who is now a product manager at Control Technique, studied the switching events of a power electronics device and its associated EMI for his PhD, and through knowledge sharing, it was the first time I realised that the high switching speed of a power electronics devices creates problems.
Another colleague, Andrew Wechsler, who is now with General Electronics Hydro Power and also a very good friend of mine had encountered many noise issues for his research project. His topic is to measure ripples on capacitors hence to diagnose fault conditions, its application is aerospace. In both theory and simulation, the result was good. But when it came into the actual instrumentation, the noise imposed on the measurement equipment is 10 times or 100 times higher than the measurement signals. Without actual test result, his PhD was in a position of not passing. The professors in the school are good machine design and electronics people, but they don’t understand EMC and I was really surprised by this fact.
Andrew’s PhD eventually ended well (with a little bit delay) thanks to a visit from his father, Frédérich Wechsler, who was a chief system engineer working for European Space Agency (ESA) at the time. He has a wide knowledge base in mechanical, electrical, telecommunication and system engineering. He is also very good at solving the mysteries apparently. With a weekend’s work in the lab, Andrew’s rig worked well and the results he obtained was perfect. This was the first time I saw an EMI fix in action.
Andrew’s father also recommended me a book “Grounding and Shielding Techniques” by the late Ralph Morrison. But I only bought the book many years later, which was a mistake, one of the moments I realised “I wish I read the book 5 years earlier!”.
All these events occurred in parallel with my own research, my topic was to develop a novel switching scheme for a three-phase power system to reduce the common mode noise, so the EMI could be reduced without a transformer. I had my own battle to fight with. I got my PhD in 2013, with a journal publication published with IEEE Transactions on Power Electronics. Many years later, I saw my paper received quite a few citations, it even showed up in some of my clients’ application notes reference list, which always made me happy.
But my understanding of EMI was still limited, because I was limited with the tool I have – A circuit view.
After my PhD, I thought I would like to do something different. I always enjoyed the industry engineering stories told in class and I wanted to join the industry. I started as a motor drive engineer with Dyson Technology in the UK. At the time Dyson was a rather small company, but recruited the best of engineers of all kind. I had the pleasure of working with the best engineers in mechanical, design, electronics, thermal and acoustics.
The products I was heavily involved in design are vacuum cleaners, hair dryers and robotics, all of which had a hard time passing the EMC standards in research and development stage. This, however, was not a reflection of Dyson’s engineering capability. It was mainly because, we make a product which sells millions a year, so we had to be careful with the size, the weight and the cost of a product, which all go against the EMC design.
The most challenging issue, again, was the fact that EMC as a subject was not well understood, even by the best electronics engineers. We had an EMC test house within the company together with a full EMC testing team, but the EMC engineers were busy with testing, and they could not advise the design engineers on the product design. The design engineers could not communicate well with the EMC test engineers. As a result, they kept coming in and out of the EMC chamber, hoping one design will pass the limit.
The only person who speaks the EMC language is Steve Berry, a principal electronics engineer who’s had more than 30 years of experience in industry, also a very good friend of mine. I earned a great deal of EMC design knowledge from him. We still keep in touch today.
I became very efficient in product design for EMC and became the go-to person when the product engineers have questions regarding to EMC. I also started reading more on the subjects. Tim Williams and Ralph Morssion’s books helped me a lot in understanding the subject and applying the techniques.
My highlight in Dyson was a patent on electric motor control and later established its EMC functionality for the electric vehicle programme. The EV programme was a very ambitious programme and sadly it didn’t take off. With that project closing down, I had a choice of going back to the home appliance department or leaving the company. I chose the latter because I met my mentor Keith Armstrong.
Keith was recommended to me by Tim Williams, both are EMC experts in the UK. I consulted Keith on the EV project and I knew his capability. I should have mentioned that we had a very strict selection scheme within Dyson. For EMC consultants, I interviewed about 7 companies, I found many of whom were not good in design or trouble-shooting. Most of the test houses are only good at testing. One of the people I liked a lot is Wolfram Klimars, who is with AVL. But because he is based in Germany, we didn’t choose him as our consultant.
Keith had been in the business for more than 30 years and his reputation was well established. He published many EMC books and training materials. He is also well connected, many EMC experts in the field know him. I often read one consultant’s book and he would recommend Keith’s books/website.
So I spoke to Keith and he was very kind, encouraging me to become an independent EMC consultant like him. The journey was not easy at the beginning, because soon Covid hit the world, with business shut down, activities stopped.
But as soon as the lockdown was eased, we received many inquires and it kept me very busy. I started getting clients from everywhere in the world as now remote working becomes a possibility. Among many of my clients, there are big US companies and small companies in Europe. My reputation was established fairly quickly and I got invitation to present on many platforms, such as InCompliance Magazine, Interference Technology, etc.
This is really the beginning of a long and dedicated journey, so far I have been enjoying it a lot and I found it very rewarding. Having the opportunity of working with many different people/companies really opened my eyes. I have never found engineering could be more exciting.
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