Quick Take: Researchers are hailing the new smart transformer built at the North Carolina FREEDM Center. In fact, the Massachusetts Institute of Technology called it one of the 10 most important innovations of 2010. But even its biggest fans admit it may be years before it begins to make an impact. That's because cautious utilities must first field test it multiple times over multiple years before they will be willing to give it a try. Too bad our industry doesn't have more facilities (and more stomach) for shared-cost facilities and shared pilots. Sure, EPRI does its best, but most utilities shy away from the fast-track testing and shared results that are widely used in cable and telecom. – By Jesse Berst
Researchers at the FREEDM Systems Center on the North Carolina State University Centennial Campus have come up with what they call a "smart transformer" capable of managing electricity flow in both directions and interconnections with rooftop solar installations and plug-in EVs. While the digital transformer is far from ready to make an appearance on an electrical grid near you, MIT calls it one of the 10 most important technology developments of 2010, according to a news article in the News & Observer newspaper.
Referring to the solid state transformer, Stephen Cass, special projects editor at the MIT Technology Review, was quoted in the article as saying "Think of it as an Internet router for the electrical grid. This contribution fits into that transformational ideal in that it will enable other changes."
FREEDM Center director Alex Huang said "This technology is probably five years ahead of its time. We are pushing electronics into the power grid."
The smart transformer works in the lab, but there are hurdles to overcome before utilities will be ready to buy it. Its components can hold up for about 20 years, about half of the life span of today's transformers, and they're expensive.
And independent Raleigh, N.C. industry consultant Chad Eckhardt, also quoted in the article, said mass production of technologies like the smart transformer will need to attract interest from global industry giants like ABB, Eaton, Siemens or GE – and that utilities will need to agree to field test them first.
Jesse Berst is the founder and chief analyst of Smart Grid News.com. He consults to smart grid companies seeking market entry advice and M&A advisory. A frequent keynoter at industry events in the US and abroad, he also serves on the Advisory Council of Pacific Northwest National Laboratory's Energy & Environment directorate.
Just what does this transformer do that exiting transformers do not do? The article does not tell us.
John
John Shaw - 06/20/2011 - 18:58
"Smart" transformer
I have the same question as John, and did some searching. From what littile I found, it looks like the "smart transformer" is actually a transformer that includes power electronics to convert between DC and AC. The long term goal is DC distribution at the service level, and the ability to convert DC-supplied power, such as from solar or EVs, to AC to distribute to the grid. As such, I'd think of this as "LVDC" as opposed to a "smart transformer".
Rich Hunt - 06/21/2011 - 06:29
Transformer Life, etc.
A couple of problems:
1. 20-year life of components is probably not going to be acceptable. That doesn't equal 20-year life of the assembled device. Of course, starry-eyed purveyors of technology using the right buzzwords don't care, but utilities do. Even if you concede that political obeisance to the efficiency gods will force transformer changeouts to much lower loss conventional transformers within the next 10-15 years, any replacements will have to equal today's transformer longevity. So far as I know, no utility has seen enough failures of old transformers (greater than 50 years in-service) to justify systematic replacement due to age, which tells me most of them not removed for other reasons are still in service.
2. Whining about the lack of fast-track testing using this example should be ignored. Fact is, most of the technology installed by the telecom and cable industries will be replaced within no more than 5-15 years due to obsolescence, so who cares if it lasts 50 years? It's hard to see how the smartest transformer in the world will generate enough dollars for closely regulated electric utilities to adopt that thinking.
Dave Gilmer - 06/21/2011 - 06:39
Smart Transformer - UPS
This smart transformer looks like a UPS. I am having trouble seeing how the Utility benifits in providing a UPS for the customer. It will be an expensive solution to save minimal conversion losses and provide power in the rare event (say 10 hrs a year) that the utilty has an outage. The $ dont make sence. I also have problems with their asumption that dumb transformer only send power one direction. It is for safety reasons that Utilites shy away from letting customers inject into the grid. Linemen could get killed.
Ken Kagy - 06/21/2011 - 06:45
Smart Transformer as multi-port microgrid interface
This "smart transformer" is a multiport, bi-directional inverter. It basically converts the input to higher voltage DC (OK 1,000 Vdc is technically still LVDC) and runs it through a very small transformer at high frequency (for low loss on the magnetics, small size) and inverts it back on the other end. It is more efficient and can actually do AC or DC on the ports (and have more than 2 ports). To say it's like a UPS is somewhat oversimplified and ignores the lack of DC storage (Although you could make it a three-port device and put DC storage on one port.) The FREEDM center approach is utility targeted, but IMHO the real value will be a smart transformer that this article alluded to at the building (or campus) microgrid.
It makes a lot of sense on the house/building side of the smart-grid where you could run DC from the PV array MPPT to storage and avoid the multiple penalties from three conversion (PV DC/AC, AC/DC to store, DC to AC to use stored energy - ~15% loss). Keep it all DC from the PV array to storage and then a single DC/AC conversion from storage for ~10% more efficiency (read available energy). I don't see this being a Utility investment, but a home/building owner one.
Finally, the self-islanding will be required (could even be built into this building-level "smart transformer" device) and we have to stop treating distribution as one-way. With microgrids on the other side of smart-meters, distribution is turning into transmission. It's not a matter of if, but when. So let's not outlaw end-user generation. Let's accept the inevitable and deal directly with the safety implications, because microgrids are here to stay and there are going to be new failure modes that come with microgrids.
Guy AlLee - 06/21/2011 - 08:39
Smart Transformer
The real change in the grid of the future will be flexibility of service offered to customers; from almost none today (except maybe service current rating and a few tariff riders) to any designer whim of the customer. This transformer may approach the Smart Phone options telecom sells today, at the specific customer's expense. Customers opt for many enhancements over simple voice calling and pay for the add-ons. If a customer wants to pay to integrate her PV system, ride through brief outages, or otherwise improve the perceived quality or flexibility of service then these new devices may help satisfy that need. If it were all about the money, who would own an iPhone?
Ray Hayes - 06/21/2011 - 08:42
What does it really do?
Before we go around hailing this smart Transformer as the next best thing since sliced bread, I suggest someone make a real comparison between today's transformer (the old fashioned kind) and this smart transformer. My big concern is that in our hurry to call everything "Smart" something, we will continue down this path of over-promising and under-delivering. The questions to start with would be:
1) Is it really a transformer - Does it transform from one voltage to another? If so how well and how realiably will this perform?
2) when we compare losses and so on - are we comparing with a transfomer of similar capacity?
I am sure others can come up with more questions. I prefer apples to apples comparisons before we start talking about DC-homes and so on. DC homes are in the future - let us solve today's problems first.
Mani
Mani Vadari - 06/21/2011 - 10:06
Off-grid solar
Why can't the homeowner be required to have an off-grid battery storage bank and charge that with the solar array, tap that until it's low, and then automatically switch to the grid?
Darlene Holmberg - 06/21/2011 - 10:18
LVDC
Damn Rich Hunt, it seems that you respond to nearly every question on every forum related to Smart Grid. Or it could just be a lot of Rich Hunts are in the Smart Grid Business (But how many work for GE?). Anyway, I agree with your name for the device.
Darlene Holmberg, the answer to your question is in the comments before yours.
Ratcoon - 06/21/2011 - 14:10
DC replaces AC?
The original article also states: "It's widely believed that when the Smart Grid is developed, the nation will shift away from AC (alternating current) to DC (direct current) electricity."
It would be illuminating(!) to know who these "believers" are. There are advantages to running DC in the home for low power appliances, but anything high power would still require high voltage, and therefore AC. There is an awful lot of inertia to changing embedded technology, and insufficient advantages/incentives to users at present.
Also highly unlikely that transmission and distribution will ever move away from AC. Have the authors redefined the Smart Grid for their own purpose, as solely being within the domestic home? Tesla was a visionary in his own lifetime, and is yet to be beaten by new technology.
John McDermott - 06/21/2011 - 14:46
transmission isn't distribution, AC was for broadcast
I agree with Guy AlLee that the real application is on "the house/building side of the smart-grid where you could run DC from the PV array MPPT to storage and avoid the multiple penalties from three conversion (PV DC/AC, AC/DC to store, DC to AC to use stored energy - ~15% loss). Keep it all DC from the PV array to storage and then a single DC/AC conversion from storage for ~10% more efficiency (read available energy). I don't see this being a Utility investment, but a home/building owner one."
Also agree with John McDermott that there are "advantages to running DC in the home for low power appliances" by which we mean IEEE 802.3at, nothing else. It's not true that "anything high power would still require high voltage, and therefore AC" - there are DC freezers, fridges, etc., and many of these always-on DC devices are inherently efficient.
That said agree that "there is an awful lot of inertia to changing embedded technology, and insufficient advantages/incentives to users at present." More a question of incentives I think.
As for "transmission and distribution" these are two different problems. Transmission is going DC now with low-resistance long-haul cables. I too find it hard to believe that distribution "will ever move away from AC" at current superconductor prices but if everything else goes DC, well, it's possible it would make sense on a micro-grid with widely distributed batteries, generators, and with the power consumed by mostly DC devices.
Quite a few businesses or specialty buildings could go all DC though, especially if they use lots of batteries. Small warehouses or depots for instance using electric drive forklifts, centrally controlled lighting and so on, could probably go DC and break even if they could get the run lengths of the cables short enough.
Calling DC inevitable in distribution and likely to monopolize residential use however is a reach. I expect IEEE P1901 and AC power plugs to be around until 2100 somewhere in North America. Then again there is probably knob-and-tube wiring in use somewhere still, so that may not be an endorsement.
Tesla? His original vision was to broadcast power, remember. And AC makes broadcasting it easier but that isn't the topology of the future grid I think.
Stephen N. Bord - 06/21/2011 - 17:00
how we can say this transformer is smart?
sir could you please tell how we consider this is a smart transformer?
Three new demonstration projects caught our attention - a smart grid effort in Albuquerque's business district, a rapid recovery transformer study in Texas and a trial involving low voltage current sensor technologies in the UK. They also got us to thinking: At this stage in the smart grid build out, if you could design a demonstration project, what would it entail? That's our latest Tuesday Topic; click for the details.
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