Dr. Hamish Laird

Hamish Laird is CTO at ELMG

ELMG Digital Power

Why did you start ELMG Digital Power?

“I started ELMG Digital Power to provide high quality digitally controlled power electronics. The emphasis at ELMG Digital Power is on both the control of power electronics converters and the design of the power converters.”

How did you learn power electronics?

“I started at university (college) where we had power electronics course for the last two years of the four-year undergraduate course. In these courses, we had to design and build converters for ourselves. These were simple buck and boost. There were also lots of power graduate students around who did lots of one on one educating of us, the undergraduates. Most of my converters blew up but I learned lots. Then straight away more university with a Masters degree when I built resonant link converters that were grid-interactive. My first job was with a guy who was such a good teacher and mentor from the “let him blow it up – it’ll be good for him” school of teaching. Thanks to Mark for his patience.”

Where did you first work on large converters – at a large company?

“Yes, a large company – I moved to Alstom Grid (it was called GEC Alsthom Transmission and Distribution Power Electronics Systems at the time) working on grid-connected high voltage power converters up to 500MW. Here there was lots of learning by doing with a large company of engineers who had done massive power electronics for 50 years and had made some massive missteps in their time. And I had a very demanding boss.”

“Then I worked in the design of mass manufacturing motor drives company with lots of learning by doing from even more demanding bosses. One very big learning incident was vaporizing copper bars and living to tell the tale. I can still hear the bang.”

“A very theoretical and very practical PhD in non-linear systems followed during which I built a DSP/ FPGA controlled grid connected converter.  I founded ELMG and then worked on HV/MV ( 15kV) converters again while learning about managing and motivating teams.”

“It seems to me so many people come to power electronics by accident. I have always been passionate about it and I have never done anything else for work. I am still learning and every day I realize there is more to learn.”

“I hope to pass on both my enthusiasm and my attention to detail.”

Future challenges

At the moment there are great challenges for power electronics.  The arrival of renewable energy sources such as wind, tidal and wave present great challenges and opportunities to reduce carbon-based fuel use.  The rise of hybrid electric vehicles and electric vehicles presents a great opportunity for efficiency increase and environmental impact reduction.  The addition of storage to the grid may well improve efficiency and grid flexibility. We are looking forward to a great future helping make this happen with our digital power technology.

Other things worth knowing

Masters degree University of Canterbury

After high school and undergraduate engineering, Hamish completed his

masters in 1991 with Dr. Richard Duke as his supervisor.  The Master’s was in resonant switching for shunt active filters.

Aucom

Here Hamish worked on induction motor controls including soft starters and variable frequency drives.  These were digitally controlled using microprocessors.

Hamish says “This was my first exposure to digital control of power electronics.  And it was my first job.  The best thing I learned was that controlling SCR and IGBT gates directly with signals from microprocessors was not only possible but a real advantage. This sent me down the path of digital control of power electronics.”

GEC Alsthom Transmission and Distribution Power Electronic Systems– Now Alstom Grid

GEC Alsthom (now Alstom Grid) supply  HVDC Links and SVCs.  These power converters at multi-megawatt power levels are designed to influence power flow and voltage levels in the grid itself.  GEC Alsthom had a dedicated 220kV feed from the UK grid.  GEC people had been first to use the phase-locked oscillator for HVDC firing control to prevent converter/grid instability through the firing angle.

“At GEC I worked on converters that were large – like really large with the smallest being about 15MVA.  The effect of the converters on the grid was important.  I guess that was what the converters were actually for – to change the grid voltage and grid power flow.  Working at GEC was such a great time for me.  The system for engineering was really well established, the level of care was very high and the attention to detail as, if not higher.  Even though I did not stay at GEC I learned so much about converter grid interaction simply because it was the main control objective. GE, now Alstom Grid, has a great history and future in innovating with large power converter control. “

Eurotherm Drives – Now Parker Drives

Eurotherm Drives, now part of the Parker group , develops and manufactures induction motor and DC motor drives.  The manufacture of the drives was all on-site.  At the time that Hamish was there, the EMC and Low Voltage Directives were being introduced into the European Community.

“I have to say that working in the true mass manufacture of power converters is a real education.  Being able to control quality and keep to a build cost target with then UK labour cost is a real art that comes straight back to the design engineer.  One of the products did not get touched by a human until it was put into its packaging.   Seeing the Eurotherm team people manage this and all the associated logistics such as point of use replenishment (POURs) and supply to the line was amazing.  And being able to help with this was a great experience.

“And being a New Zealander was a real advantage as I had enough common history but was just sufficiently different.  A real added bonus was the EMC directive and LV directive rolling into law while I was there.  I got to learn how the technical requirements for these two could be met.  I also saw how well the team at Eurotherm charged with getting the people part sorted did – what worked and what didn’t.  Looking back it was not an easy organisational change process.  Surprisingly it changed some parts of the development process that I would not have considered. “

“There was analog control and digital control for the drives.  Both were useful with analog providing low cost and simple features.  The digital control allowed all kinds of functions to be added to the drives by simply adding more software.”

“Throughout my time in the UK, I was really privileged to work with some really talented and passionate people.  And I realised that lots of them had PhDs.  So I decided that I should get one. It was a big decision and I shopped around for schools and supervisors. Eventually, I decided on my Alma Mater University of Canterbury with my friend from my time doing my masters, Dr. Simon Round.”

The Early Years

Hamish Laird was born in Wanganui, New Zealand.  He grew up on a dairy farm in Brunswick.  Here he split his spare time between working with electrical circuits and electronics, building crystal sets,  amplifiers,  playing rugby (badly), and cricket (only slightly better). He also built huts, drove go-carts, and sometimes helped around the farm.

Ph.D., Canterbury University, Christchurch New Zealand

Hamish says “My Ph.D. was in the accurate modeling of non-linearities in power converters.  This uses a linear-time-periodic (LTP) approach to give phase accurate frequency coupling models for converters.  These models are really useful for analysing the interaction of converters with different switching frequencies.  The work looked at the interaction of shunt active filters with uncontrolled rectifier loads.

“In order to verify that the analysis and simulation work was accurate and reliable a DSP FPGA Hybrid control platform was constructed that could measure the system response to small-signal injection.  It worked well and the results were great. We use this and some advances on this for analysis of converters connected in parallel.”

Visiting Academic, University of Canterbury

Hamish is a visiting academic at the University of Canterbury where he works helping with research into power electronics. He says “It is a useful connection to academic research.  This aids and informs the work at ELMG Digital Power. Recently I helped with supervising research into the use of fractional step delay filters to manage fixed sample rate operation of grid-connected inverters when the grid frequency changes. Learning how to make this work is a great help in grid-connected converters for solar and energy storage. this type of fundamental research guided know-how continues ELMG Digital Power high quality digitally controlled power electronics”.

High quality digitally controlled power electronics

“I really am inspired and passionate about high quality digitally controlled power electronics”