EV SiC-based Inverter Project Update

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SPS has just started testing the latest version of the highly challenging PCB it has designed for an automotive SiC-based EV inverter. The PCB not only implements all the required gate drive but integrates many other essential sensing and other auxiliary features to ensure electrical and functional safety. The space available for the PCB is very tight, the DC voltage high (up to 900V) and it has to press-fit to a power module where all the connection locationss are already set. The combined effect of this is that it has really challenged our most experienced PCB layout designer who has 25+ years experience.

The entire development of the PCB has been done in-house including the validation testing and manufacture of prototype PCBs. Given SPS’s senior staff have been working on xEV systems for well over 20 years, it is not surprising that our end customer has also asked us to assist with many other areas of their development. This includes advice on electrical / functional safety, EMC mitigation measures and thermal management. SPS has also carried out critical testing of the inverter system including full double pulse switch testing over the entire range of voltages, current and temperatures. This is an essential aspect of power electronics development that is unfortunately either skipped entirely or not done thoroughly by many other companies. This can result in an unacceptable amount of unknown risk in a product leading to reliability problems in the field. Most certainly not an option for an automtive product!! Please do contact us if our facilities and experience could be of use to your company.

PCIM 2019

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May in Nuremberg – must be time for PCIM again!! This year as well as our Technical Partner Dr. Charlie Elliott, our Production and Quality Manager Alan Yarker also attended. Sadly no sitting outside drinking cold beers this year and thanks to KLM it was a bit of a truncated visit but still well worth while. Very good to see there is more than just marketing hype to the introduction of Wide Band Gap semiconductors. Very notable increase in the number of major players with physical parts now in modules. Availability and cost are still major issues but things are improving on both fronts. It was great to catch up with many of our key suppliers, find a new one or two and even chat with competitors. PCIM is still the go to event as far as we can see. Can’t say we have ever been to APEC but am seriously considering it for next year.

Stephenson Challenge / Driving the Electric Revolution

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Our Technical Partner Dr. Charlie Elliot has been involved in this cross industry initiative for quite some time as it originated in Power Electronics UK. He recently attended a key update meeting in Birmingham. A detailed video giving more details can be found here. Subject to business case and match funding from industry, government has announced that it is prepared to invest up to £78 million in this challenge. This will be managed through Innovate UK and the Industrial Strategy Challenge Fund – wave 3.
The challenge is all about developping a UK supply chain for power electronics machines and drives across 7 industrial sectors. All 7 sectors are cruicial if we are to hit our future emmissions targets whilst mainting or exceeding the standard of life we are all used to. We will be keeping a close eye as things develop as this major initiative is something SPS would very much like to be part of and is very well placed both in terms of experience and facilities.

Second V2G Workshop

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Our Technical Partner Dr Charlie Elliott attended the second Cenex / Level Vehicle to Grid (V2G) workshop held in Nottingham on 6th February. It was a follow on event from the one in 2018 and it was great to see presentations on the outcome from real world installations abroad and in the UK. As last year there was some healthy debate as to the real world commercial feasibility of V2G in the UK. In other countries certain markets for services have artifically high prices which makes V2G a much simpler proposition.

Courtesy of a £30M Innovate UK funded project there is a lot of activity in this area at the moment which is great to see but also a bit frustrating for a UK based power electronics design and manufacturing company not even contacted to be involved!! One project in particular promises to install up to 1k V2G systems for domestic use. Sadly the core power electronics of this and other systems within the IUK project are being bought in from abroad presumably as there was thought to be insufficient time/budget/knowledge to carry out the development in the UK. Driving down the price of the hardware for V2G is essential to make it commercially viable. SPS is exceptionally well-placed to carry out such work given its existing experience in bidirectional grid-tied inverters and DCDC converters built up over many years. It has also previously worked on DC rapid chargers for EVs. SPS is currently investigating sources of funding / partners for such activity. If you are interested then please do get in contact.

Another sucessful project delivered!!

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Our Technical Partner Dr. Charlie Elliott has just come back from Brazil where he sucessfully commissioned an ultra-compact high-efficiency motor-drive inverter based on SiC MOSFETs. This 15kW system hit 98% efficiency which is fairly special in it’s own right. If you then add the fact that the system has to work at 330 bar pressure on the bottom of the sea bed then you probably have a world first!! Charlie was testing the system flooded with pressure compensating oil in a special test chamber in Rio de Janeiro.

LCV 2018

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Out Technical Partner Dr. Charlie Elliott decided to get in the spirit of things and take his own 30kWh Nissan Leaf to LCV this year. It wasn’t just for the free parking (although he has been in Yorkshire for over 30 years so something must have rubbed off by now) but also as a bit of a show of solidarity. Two stops for 20 mins each on the way there and back to rapid charge was no issue at all with a coffee and a few e-mails written each time. Charging was free at the event and he even made use of the measured mile at Milbrook to see how the leaf did – a ton wasnt a problem! He reported that LCV has grown again and it was great to see so many UK based outfits working hard in the Low Carbon Vehicle sector. We may have to think about taking a stand next year.

3rd SiC MOSFET based project won!!

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We are delighted to report that we have just kicked off another significant project using SiC MOSFETs. In the past 18 months we have been working on two SiC based motor drive systems. One is for an EV project where the attraction of SiC is the power density and part load efficiency benefits. The latter in particular is essential as it offers potential for reduction in battery pack capacity/size/cost or alternatively additional range.  The other existing project is for an ultra high-efficiency motor drive where size is especially important and cost less so.

This new project is for higher power 500 kVA static-power conversion system where being able to switch at 20 kHz and above is essential to reduce the size of filtering components and eliminate switching frequency audible noise. Up at these kinds of power / current levels there is no choice but to parallel commercially available power modules. This brings it’s own challenges in terms of gate drive function and power circuit layout to ensure sharing of losses and to eliminate the potential for the modules to oscillate against each other. SPS will be using it’s wealth of experience in core power electronics technology and it’s extensive laboratory equipment to carry out this work for our client.

PCIM 2018

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We are not exhibiting at PCIM this year as PEMD was so close but our Technical Partner (Dr. Charlie Elliott) is going to visit. This key exhibition is a great opportunity to see the very latest in new technologies and meet with many key suppliers. Charlie spends a considerable about of time maintaining our excellent direct links with many power semiconductor, passive component, signal level control, isolation, sensor and ancillary component technology companies. This assists SPS in providing cutting-edge future-proof designs for its customers and also ensures that if any technical issues are identified with components that they can be resolved as rapidly as possible.

PEMD 2018

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We are now back from the PEMD 2018 Conference and Exhibition which was held last week at the ACC in Liverpool. As expected we had warm welcome from the folks on the other side of the Pennines. Liverpool docks is a fantastic area to visit. Well worth a long weekend.  The event was well attended and we had plenty of interest in our stand showing the huge diverse range of power electronics we have been involved in.

The papers presented were on a very broad range of topics. For me one of the stand-out areas being looked at by Sheffield University was in the area of using piezoelectric devices as resonant electric transformers at lower powers. A transformer with no windings with power transferred by vibration!! There was also a very interesting tutorial discussion on which of the various power semiconductor technologies is the “best” at 600V. For sure that is an interesting battleground.

What a busy week!!

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The week commencing 29th January was a tad busy for our Technical Partner Dr Charlie Elliott!!

Tuesday 30th was the Reinforcing the Grid for the Roll Out of Electrical Vehicles event in London. A very well attended event with interesting and diverse talks. It was particularly interesting to hear from National Grid who think that provided simple charging delay is used so not everybody charges starting at 5-6pm, the increase in demand is very manageable. They think with 150 or so clusters of rapid chargers along key roads (which are often close to the HV grid) a very high percentage of the population will be covered and really range anxiety should become a thing of the past.

Wednesday 31st was the Vehicle To Grid event organised by Cenex and LEVEL in Nottingham.  There were a wide range of talks and it was clear that there is still much debate about how people will be able to generate revenue from V2G. One thing is for certain is that it is a great opportunity and that specialist kit available at a sensible price needs to be developed. Watch this space as V2G is a perfect space for SPS given it’s past experience and capabilities!!

Thursday 1st February was the Power Electronics Grand Challenges meeting in Birmingham organised by Innovate UK Knowledge Transfer Network, Power Electronics UK and the Compound Semiconductor Applications Catapult. This meeting was held to discuss direction for potential work with the CSA Catapult and to review whether the 3 grand challenges previously identified with PEUK were still valid. There was much lively debate and the possibility of rolling in the high power requirements for electric powered short haul flights was thrown into the mix. Very interesting times!!!

Charlie commented that it is very clear that new and challenging Power Electronics applications are being identified all the time. Bring it on!!