Highlights
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2024-11-25 14:37 We tested a 350,000v DC circuit breaker from Hitachi which was fantastic to be able to do that.
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2024-11-25 14:37 Was it the Hitachi? Was it Hitachi or Mitsubishi which acquired the Abbas HVDC technology? Hitachi is basically former abb. Got it.
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2024-11-25 14:41 It arose out of a need for an independent body to assure quality in ships, making sure that ships and vessels were really seaworthy and that they could be insurable, so that cargoes that was transported in ships was insured and that safety was guaranteed. DMV was set up as a nonprofit organization that independently build out a set of technical standards to safeguard quality of vessels and to check this also during the building and later in life of those vessels.
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2024-11-25 14:43 We support developers with doing all the work that needs to be done for a developer to find the right POI and do all the interconnection application work and characterize it from an economic perspective.
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2024-11-25 14:46 Whereas for some of the HVDC work that we do, there are companies, bigger companies like WSP, Hatch, Burns and McDonnell.
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2024-11-25 14:47 It was all the oil and gas guys and the pipeline guys saying that obviously the way to get energy to shore was to make hydrogen offshore at wind farms and put it in pipelines and send it ashore. Whereas I suspect you and I would agree. Why would we do that?
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2024-11-26 16:40 In order for what we call real power or a real current to come out on the other side of the line, we need to first charge it up to a certain voltage or a certain current.
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2024-11-27 19:45 And that’s, I would say, probably the biggest benefit of hvdc. So let’s just take that apart for a second because, you know, just to the east of you where you’re sitting now in Quebec, at least just to the east by European standards, there is this massive H VAC transmission line set flowing down from James Bay’s massive hydro facilities down and actually leading even across the border. Now, historically, most transmission was high voltage alternating current. Why, given this advantage of hvdc, haven’t we been using it a lot more, a lot earlier? Well, everything has pros and cons, right?
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2024-11-27 19:45 So that could be one reason not to use hvdc. The other reason is that HVDC is very good or has been very good so far for point to point connections. So bringing large amounts of power over long distances between two points, but tapping off a little bit of power from that DC line and create, let’s say DC multi terminal system is more challenging. So this can be done traditionally for a few limited taps, maybe one or two taps in between the two end terminal stations, but not much more than that. Whereas with AC it is much simpler.
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2024-11-27 19:46 Remember that we were talking about this wave 60 times a second in North America or 50 times a second, the changes in Europe. That means that 120 times a second or 100 times a second the voltage or the current goes through zero. Right? AC circuit breakers work by making use of that naturally occurring zero crossing. At that moment, the current is zero already. And that gives you an opportunity to separate two contacts of the switch. And if you’ve designed the thing right, there’s enough distance between them, you can then withstand the voltage that will then appear across those two contacts without there being a further flash
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2024-11-27 19:46 D.C. we don’t have these naturally occurring current zeros. And unfortunately, if you were to have two mechanical contacts in the DC circuit breaker and there’s a DC current flowing through them, if you open them, the current will continue flowing and there will be a so called arc between the contacts. This is something that is a plasma. It’s hotter than the surface of the sun, somebody told me, which will steadily erode away the two contacts until the circuit breaker breaks down.
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2024-11-27 19:46 And it means that an HVDC circuit breaker is most likely orders of magnitude more expensive than an AC circuit breaker. And that means that you can probably not use it in the same way
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2024-11-27 19:47 Ideally, we’d like to be able to procure one terminal from Hitachi and another one from GE and maybe another one from Siemens and who knows what other vendors may come into the market in the future. And they all will have to play together nicely and they will also have to play together nicely with any HVDC circuit breakers from a different vendor that are located in that same grid. This really is where today’s challenge is in HVDC grid building, that the equipment delivered by different vendors is just not compatible.
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2024-11-27 19:47 if you were to go to Hitachi and ask them, can you build a multi terminal system that consists of only converters and an HVDC circuit breaker from Hitachi, that they can solve the technical challenge to do that in a reliable way. But the moment you do that in a multi vendor setting, we are not quite there yet.
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2024-11-27 19:46 It’s been around for a while. Right? We’ve all heard about the war of the currents, AC versus DC back in the day. DC has been around the block for a while. How HVDC and DC has evolved has largely been determined also by the different technologies that have been used to create DC from ac.