A transformer is a transformer. It doesn't care what the frequency is. It only has to be sized correctly. A circuit breaker is a circuit breaker. It does not care what the frequency is. It only has to be sized correctly.
Then I assume transformers don't have to be built in any way custom to run on 25 Hz? You can just use the exact same transformers you'd use for 60 Hz? (No, you can't, you have to size them differently. Looks like all the 25 Hz ones will run on 60 Hz, but not vice versa; in other words, they are all overweight for their power ratings -- continuing ongoing cost every time one is replaced.) Similar problems seem to arise with circuit breakers.
So the trains which Metro-North runs will just run on 25Hz without alteration?
So the SEPTA trains can run under 60Hz without alteration?
I've been told repeatedly that this is not the case. Please do feel free to tell me that Silverliner Vs will run on 60 Hz without alteration (well, I know they will in Denver), or that M8s will run on 25 Hz without blinking (less likely).
Or, in the alternative, I'd love to know all the specific parts which
are not the same are. You're so supposedly full of knowledge, I'm sure you can list them off. How about it? Prove that you actually know what you're talking about.
If it's all so easy to use the same equipment, I suggest you explain why it's supposedly so expensive to switch to 60 Hz. Maybe it's mainly the control circuitry which is different... that's bad enough.
Not non-standard equipment - their equipment is standard, off the shelf.
Outright false. Of course the extremely expensive frequency converters are strictly one-off custom jobs.
I really don't know what sort of circuit breakers Amtrak uses, but all the high-voltage designs I can think of require a rectifier somewhere in the process for measurement. Which means you're measuring different pulse patterns depending on the frequency. Which requires... care in designing your voltmeters.
*Everything* is going to have slightly different calculations for 25 Hz, from current transformers onward. Are you telling me that the equipment is basically "rounded up" to the next larger (or smaller) size of built-for-60Hz equipment, and the calibrations redone?
Even the *calculations* are still a continuing cost.
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jis said:
Typically one does such major conversions when there is a small island of an older system in a sea of newer standardized system. That certainly is not the case on the NEC (yet)
Really? It sure looks like a small island of an older system when viewing it from New York City.
Maybe it looks different when looking at it from Philadelphia.
Anyway, Jis is right, when they replaced the first of the frequency converters, that was the moment of poor decision-making.
Of course for the 60Hz obsessed, there is another way, which is to replace all the 60-25 converters in the setup by 60-60 converters (basically 3 phase to single phase using phase balances converters). That saves on the rewiring and just involves getting a bunch of converters.
... specifically, a sort of converter which is still used by someone other than Amtrak, and therefore still mass-produced.
Heck, 60-50 converters may still be used by other-than-Amtrak for all I know.
I guess the key problem is actually that the entire 25 Hz network is phase-synchronized, which makes it look like the entire network would have to be changed over in one go. It would not have to be. The first step would have been to put a phase break in somewhere in New Jersey. Sunnyside Frequency Converter seems to be the worst investment.
I don't know exactly how many years the payback is for standardization. I'm sure that in the 10-20 year time period it looks cheaper to just keep using obsolete standards. It just sickens me to see money misinvested this way when it's quite clear what the correct 200-year move is.
But I suppose that's the entire history of Amtrak, isn't it? There's never enough money to do anything *RIGHT* for the long term, so money keeps getting invested patching whatever-already-exists up, at a higher long term cost. Starting with the Heritage Fleet, and then the buy-it-quick Amfleets. Contrast any country which actually gives a damn about their rail system. (Britain is actually biting the bullet and replacing the mainline third rail system with overhead as it expires. Metro-North is... rebuilding unique-in-the-world underrunning third rail, because USA.)
Honestly, all kinds of things are happening to the power industry. Within 20 years, many of the utility companies are going to price themselves out of the market, as the trend is towards decentralization, solar power, and heavy use of batteries. Most generation, apart from hydro and wind, is going to end up being DC. Because of installed base, inverters for converting this to 50 Hz and 60 Hz and feeding it into the power grid will be mass produced; for converting to 25 Hz, not so much.
Committing hundreds of millions of dollars to frequency converters for a non-standard frequency.... well, I guess we're stuck with it for another five decades now that Amtrak has spent the money on so many of them already, but what a waste.
