Railroad Forums 

  • How does Amtrak monitor/charge electric use by NEC tenant agencies?

  • Discussion related to Amtrak also known as the National Railroad Passenger Corp.
Discussion related to Amtrak also known as the National Railroad Passenger Corp.

Moderators: GirlOnTheTrain, mtuandrew, Tadman

 #1586606  by rohr turbo
 
This comment by Mr. GBN in HHP8 discussion got me wondering..
Gilbert B Norman wrote: Fri Dec 10, 2021 2:30 pm ...MARC....and buy your power from us for which you can be sure we will gouge you...
So how is electric energy use by MARC, NJT, etc. metered? Are there meters in the electric motors/EMUs and do they wirelessly transmit to the central accounting system? Or is it done by formula (total usage divided by number of train-car-miles, etc.?) I know there are Power Directors to allocate electric distribution, but with multiple trains over NEC sections, is there the ability to centrally measure usage by individual trains? TIA
Last edited by rohr turbo on Fri Dec 10, 2021 9:31 pm, edited 2 times in total.
 #1586632  by Gilbert B Norman
 
I don't claim to know; but obviously there were mechanics in place since the '50's when there were publicly funded trains in the Philly area on both the PRR and RDG.

There definitely were "mechanics" in place on A-Day.

Anecdotally, I had learned that Amtrak is "not exactly benevolent" as a landlord providing access to the Corridor with Chessie and Topper (CP?; they make rates out of NY and Phila but do they have their own trains?); so it would figure they are likely same with the commuter agencies buying power from them.

We can be sure Metro North "returns the favor" between CP216 and 157 (or thereabouts) to Amtrak. :( . "The T" wanted no part of it operating all their trains with Diesel power.
 #1586671  by Ken W2KB
 
west point wrote: Fri Dec 10, 2021 9:52 pm What complicates the usage charges is for the power provided commercially you have the demand charges. Demand charges may apply and of course it would be at rush hours?

Yes. Electric utility demand charges are calculated on a monthly basis, typically based upon the highest usage in a 15 minute period. PSE&G also has a special provision for electric traction power. For example, the relevant High Tension Service in the currently effective PSE&G Electic Tariff: "BILLING DETERMINANTS:
Monthly Peak Demand:
The Monthly Peak Demand for each time period shall be determined by the registration of a demand meter furnished by Public Service. The customer’s Monthly Peak Demand in any month for each time period shall be the greatest average number of kilowatts delivered by Public Service during any fifteen-minute interval. Where the use of electric service is intermittent or subject to violent fluctuations, Public Service may base the customer’s Monthly Peak Demand for each time period upon five-minute intervals in lieu of intervals hereinbefore set forth." and "Where electric service is supplied for traction power to a rail rapid-transit system, for the purpose of determination of Monthly Peak Demands the hours 8 A.M. to 10 A.M. and 4 P.M. to 7 P.M. shall be included in the Off-Peak time period, and Public Service shall base the customer’s Monthly Peak Demand for each time period upon the greatest average number of kilowatts delivered by Public Service during any single coincident hour-ended sixty-minute interval during each time period, in lieu of fifteen-minute intervals. Where traction power is supplied at high voltage (230,000 volts) and such power is being provided during a limited period to supplant power normally supplied by another utility, that limited period shall be excluded for the purpose of
determining Monthly Peak Demand."
 #1586784  by Red Wing
 
Gilbert B Norman wrote: Sat Dec 11, 2021 8:18 am "The T" wanted no part of it operating all their trains with Diesel power.
Actually the T is looking at EMU's right now, Battery operated that can also use and be charged by the overhead:

https://www.commbuys.com/bso/external/b ... tUrl=close

They might get a different deal from Amtrak since the Commonwealth owns the ROW.
 #1596973  by farecard
 
Ken W2KB wrote: Sat Dec 11, 2021 3:41 pm
west point wrote: Fri Dec 10, 2021 9:52 pm What complicates the usage charges is for the power provided commercially you have the demand charges. Demand charges may apply and of course it would be at rush hours?

Yes. Electric utility demand charges are calculated on a monthly basis, typically based upon the highest usage in a 15 minute period. PSE&G also has a special provision for electric traction power.

And you can be sure that NEC pays through the nose.
It's the power customer the various PoC's surely hate.

First, it is single phase, not three phase power.
Second, it's feast or famine; they sit around providing idle levels,
then BANG, the Acela shows up demanding 10-15 MW,
and 60-90 seconds later it's gone.

This on the northern, 25KV/60Hz sections. On the antique 12.5/25 half, Amtrak buys power at 4-5 places and carries it along overhead. So the load is many consists, for half the trip.
 #1597119  by BandA
 
Red Wing wrote: Mon Dec 13, 2021 8:30 am
Gilbert B Norman wrote: Sat Dec 11, 2021 8:18 am "The T" wanted no part of it operating all their trains with Diesel power.
Actually the T is looking at EMU's right now, Battery operated that can also use and be charged by the overhead:

https://www.commbuys.com/bso/external/b ... tUrl=close

They might get a different deal from Amtrak since the Commonwealth owns the ROW.
In the 2016 time frame, MA was suing Amtrak over being jacked up by $30M in fees for NEC track that the MBTA owned! Earlier Amtrak vowed never to bid again on the MBTA CR contract. They've also had fights over stuff like Rte 128 Station maintenance, and shared yard space. Lately they seem all lovey-dovey.
 #1597304  by WhartonAndNorthern
 
farecard wrote: Tue May 03, 2022 1:29 pm And you can be sure that NEC pays through the nose.
It's the power customer the various PoC's surely hate.

First, it is single phase, not three phase power.
While Amtrak's own ex-PRR grid is single-phase 25 Hz and supplied by dedicated single-phase sources like Safe Harbor Dam, the utility converters are likely to be three phase input. I'm sure the original motor-generators were three-phase motors.
As for the 25 kV/60 Hz system, each phase is used to supply separate segments of the line, separated by phase gaps.
 #1597305  by Ken W2KB
 
WhartonAndNorthern wrote: Mon May 09, 2022 12:56 pm While Amtrak's own ex-PRR grid is single-phase 25 Hz and supplied by dedicated single-phase sources like Safe Harbor Dam, the utility converters are likely to be three phase input. I'm sure the original motor-generators were three-phase motors.
As for the 25 kV/60 Hz system, each phase is used to supply separate segments of the line, separated by phase gaps.
Yes, the solid state converters are also three phase input. The only motor generator I have seen in person is the one located in the PSE&G Metuchen Switching Station. I believe that 25MW rotary converter was refurbished about 10 years ago and is likely still in service. Amtrak at the time did not want to replace it with solid state since the rotating mass was excellent in withstanding transients in the New Jersey section of the NEC, which because of the large number of trains operating often resulted in some catenary electric system instability, such as when by coincidence multiple trains began to accelerate or brake simultaneously.
 #1597307  by farecard
 
As for the 25 kV/60 Hz system, each phase is used to supply separate segments of the line, separated by phase gaps.
From what I've read, the four substations are fed with single-phase 115 kV. That's all the PoCo cares about.
Amtrak at the time did not want to replace it with solid state since the rotating mass was excellent in withstanding transients in the New Jersey section of the NEC,
Also, the rotary converters do something unique. They ..eat.. the significant 3rd/etc. harmonic output of the varieties of solid-state converters, and loads, and use it to produce the needed 25Hz that the locomotives consume.

And oh yes, there's a buttload of stored energy in those spinning armatures.
 #1597458  by Greg Moore
 
There's something to be said for good old mechanical systems. I read an article once on how when they wanted to upgrade the analog computers on the Iowa class battleships, they ran into unexpected issues and the old stuff "just worked".
 #1597471  by TheOneKEA
 
farecard wrote: Mon May 09, 2022 1:41 pm
As for the 25 kV/60 Hz system, each phase is used to supply separate segments of the line, separated by phase gaps.
From what I've read, the four substations are fed with single-phase 115 kV. That's all the PoCo cares about.
I wonder why the traction substations were fed with single-phase 115kV, instead of two-phase at a higher phase-to-phase voltage. I have read that many 25kV electrification schemes in Europe will often connect to two phases instead of one, and balance the connections so that each three-member group of traction substations produces a relatively even loading on the transmission grid.
farecard wrote: Mon May 09, 2022 1:41 pm
Amtrak at the time did not want to replace it with solid state since the rotating mass was excellent in withstanding transients in the New Jersey section of the NEC,
Also, the rotary converters do something unique. They ..eat.. the significant 3rd/etc. harmonic output of the varieties of solid-state converters, and loads, and use it to produce the needed 25Hz that the locomotives consume.

And oh yes, there's a buttload of stored energy in those spinning armatures.
I have always wondered how much it would cost to build a 1930s-sized 25Hz generator with modern 21st-century metallurgy, construction techniques and computer controls, and use it on the southern part of the NEC to absorb the harmonics and some of the reactive power.
 #1599416  by cobra30689
 
TheOneKEA wrote: Wed May 11, 2022 6:25 pm
I wonder why the traction substations were fed with single-phase 115kV, instead of two-phase at a higher phase-to-phase voltage. I have read that many 25kV electrification schemes in Europe will often connect to two phases instead of one, and balance the connections so that each three-member group of traction substations produces a relatively even loading on the transmission grid.
Actually, it's 138kV (started out as 132kV) single phase with a 2-wire circuit. Each transmission line is 69kv (originally 66kV) to ground, and the transformers are grounded at the center tap. The original, 1915 44kV segment from PHL to Paoli was torn down years ago, and the main is now fed at both ends by the 138kV system at Zoo and Paoli. The original 132kV system was designed and rolled out in the mid '20's......PHL to Wilmington was the first to go up (1928 I think??). If you know the territory you can tell by the ancient round catenary poles that are still up today. It amazes me that, with exception of some upgrades at Metuchen, Lamokin and Ivy City.....the core system is basically exactly the same as it was from day 1. Although I often wonder what Amtrak and Conrail would have to have done if electric freight remained on the NEC (or Conrail electrified the Lehigh Line). Much of the capacity needed for the Acela's and commuter services today was excess released by the mass de-electrification of the freight routes. Good example of this......extending the wire from South Amboy to Matawan on the NJT Coast Line in 1982 became feasible after the Jamesburg Branch catenary was turned off.
 #1599425  by west point
 
Anyone on this thread. Just think of your home electrical system. Originally nominally 110 V leg to ground and 220 V leg to leg. Nowmost circuits are 125 and 250 V My own is a couple volts higher. PRR did the same going from 11,000 volts CAT to 11,500 after WW-2 and Amtrak taking it to 12,000 Volts CAT. Raised their high voltage service as well from 132 kV to 135 kV to 138 kV nominal (10)%.

Do not be confused by the listed voltages as it is nominal with a +/- allowable of 10%. So it is 12,000 to high 13,200 and low 10,800. If an ACS-64 is running regenerative braking and CAT voltage goes above 13,200 the motor will switch to dynamic braking. There are many reasons that the CAT voltages might go beyond these nominal limits . Amtrak has had several times when that happened causing a shutdown and reboot of the CAT power.

Have read unconfirmed posts that Amtrak is buying equipment to eventually bring the 25 hZ CAT to 12.5 kV nominal. But have no reason to either believe it or not.