carnej1 The Railpower Green Goat locomotives captured and reused dynamic brake energy in addition to using an onboard genset to charge the batteries and there were a fair number of production units built. However problems (fires especially) with the units lead/acid batteries caused most carriers to remove them from service. I'm not sure if any of them are still operating in the battery/diesel/electric configuration although I'm aware that some have been rebuilt as more conventional genset locomotives.
My understanding was that the Green Goat was a disaster in any switching service that involved 'kicking' cars -- where you had rapid acceleration of a load followed by rapid deceleration. This neither suits output from lead-acid cells nor charging them regeneratively at high/uncontrolled rate. I don't think their designer really quite understood what switch engines were expected to do, or that if they loaded like dash-7 GEs it might take all day to get a couple of hours worth of work done.
From what I understand, many current genset designs are not much better, specifically through having no ability to 'predictively' spool up and load down additional prime movers just in advance of a 'kick'. I would think this an obvious design feature to add, but haven't seen evidence so far.
CPM500 Motor driven (A/C) blowers were introduced on the EMD 70 Series...and on the GE Dash-8. CPM500
Motor driven (A/C) blowers were introduced on the EMD 70 Series...and on the GE Dash-8.
CPM500
AC Electric Motor driven traction motor blowers started at EMD with the DC-motored SD70 variants, But the SD70MAC locomotives continued to use mechanically linked traction motor blowers until the advent of the SD70ACe. The SD80MAC and SD90MAC locomotives also had the AC electric motor driven blowers.
timz On a 1960s-1970s EMD the traction motor blower is driven directly by the diesel-- so in full dynamic the diesel has to be running at... Run 5 speed? Or faster? to cool the motors. Dunno when EMD quit that.
On a 1960s-1970s EMD the traction motor blower is driven directly by the diesel-- so in full dynamic the diesel has to be running at... Run 5 speed? Or faster? to cool the motors.
Dunno when EMD quit that.
BaltACD M636C BaltACD M636C It doesn't have to be heat - GE built an ES44 derivative loco with batteries charged by dynamic braking, although that seems to have dropped out of sight recently. M636C I was speaking of diesel-electrics, where the electricity generated in dynamic braking can only be disapated as heat. So the battery equipped ES44 was not diesel-electric? M636C While the 'test' battery equipped locomotive was a diesel electric, personally I doubt that the battery was able to store all the energy that was created in the normal dynamic braking usage cycle - especially in territories where DB is used for 8 or 10 miles, released for a mile or two and then reapplied for another 8 or 10 miles. Once the energy is stored in the battery, how is the energy withdrawn from the battery and used as a additional power source for the locomotive, with how much actual benefit. It can be done, but at what cost and at what level of reliability. To my limited knowledge, battery storage of DB energy has never progressed beyond the testing stage.
M636C BaltACD M636C It doesn't have to be heat - GE built an ES44 derivative loco with batteries charged by dynamic braking, although that seems to have dropped out of sight recently. M636C I was speaking of diesel-electrics, where the electricity generated in dynamic braking can only be disapated as heat. So the battery equipped ES44 was not diesel-electric? M636C
BaltACD M636C It doesn't have to be heat - GE built an ES44 derivative loco with batteries charged by dynamic braking, although that seems to have dropped out of sight recently. M636C I was speaking of diesel-electrics, where the electricity generated in dynamic braking can only be disapated as heat.
M636C It doesn't have to be heat - GE built an ES44 derivative loco with batteries charged by dynamic braking, although that seems to have dropped out of sight recently. M636C
It doesn't have to be heat - GE built an ES44 derivative loco with batteries charged by dynamic braking, although that seems to have dropped out of sight recently.
M636C
I was speaking of diesel-electrics, where the electricity generated in dynamic braking can only be disapated as heat.
So the battery equipped ES44 was not diesel-electric?
While the 'test' battery equipped locomotive was a diesel electric, personally I doubt that the battery was able to store all the energy that was created in the normal dynamic braking usage cycle - especially in territories where DB is used for 8 or 10 miles, released for a mile or two and then reapplied for another 8 or 10 miles.
Once the energy is stored in the battery, how is the energy withdrawn from the battery and used as a additional power source for the locomotive, with how much actual benefit. It can be done, but at what cost and at what level of reliability.
To my limited knowledge, battery storage of DB energy has never progressed beyond the testing stage.
The Railpower Green Goat locomotives captured and reused dynamic brake energy in addition to using an onboard genset to charge the batteries and there were a fair number of production units built.
However problems (fires especially) with the units lead/acid batteries caused most carriers to remove them from service. I'm not sure if any of them are still operating in the battery/diesel/electric configuration although I'm aware that some have been rebuilt as more conventional genset locomotives.
The GE built Powerhaul units operating in the UK also recapture energy from the Dynamic brakes on a smaller scale and use it to run the engine auxiliary systems and recharge the batteries but not for traction..
"I Often Dream of Trains"-From the Album of the Same Name by Robyn Hitchcock
Never too old to have a happy childhood!
There is a lot of mystery as to whether or not the GE Hybrid demonstrator locomotive (which was def. a Diesel Electric as it was an "engine dominant hybrid" setup) ever operated with the energy storage system fully functional.
The unit was outshopped at a time when GE determined that lithium ion batteries would not hold up to the stresses encountered by a have freight locomotive.
GE then developed it's own line of Molten Salt batteries that were supposed to be optimized for locomotive usage, but then marketed them for other applications and had low sales. They significantly cut production on the battery line and it doesn't seem that the hybrid locomotive program is active currently.
Glad you brought that up...I have often wondered what could be done with the "power" generated during D Braking.
Perhaps it is an untapped potential.?
And yes...I was only thinking of the Diesel Electrics.
M636C BaltACD Paul_D_North_Jr timz On a 1960s-1970s EMD the traction motor blower is driven directly by the diesel-- so in full dynamic the diesel has to be running at... Run 5 speed? Or faster? to cool the motors. Dunno when EMD quit that. I was surprised to hear that much noise coming from the helpers on a downgrade train rounding Horse Shoe Curve a few years back. Couldn't see them well enough to make a positive ID, but SD40's or a rebuild to those specs are likely. - Paul North. Braking - no matter how it's done - takes kinetic engergy from the moving train and turns it into heat. Brake shoes applied with pressure against the wheel treads create heat as they slow the train. Dynamic brakes, turning the traction motors into generator also create heat - heat that has to be disapated by blowing high volumes of cooling air through the 'generators' as well as having the current generated by the 'generators' disapated in resistor grids that also need cooling to be kept from overheating. It doesn't have to be heat - GE built an ES44 derivative loco with batteries charged by dynamic braking, although that seems to have dropped out of sight recently. In an electric locomotive, the current can be returned to the overhead line, and the process is called regenerative rather than dynamic braking. If you can see the driver's console in a commuter train, I enjoy watching the ammeter as we approach a station. It drops back to zero as power is cut, then goes even higher as the regenerative braking cuts in and oscillates as the train slows almost to a stand and drops to zero again as the air brakes cut in. This is computer controlled to minimise the use of the air brakes. The best view is in the underground where the illuminated dials show up most clearly. M636C
BaltACD Paul_D_North_Jr timz On a 1960s-1970s EMD the traction motor blower is driven directly by the diesel-- so in full dynamic the diesel has to be running at... Run 5 speed? Or faster? to cool the motors. Dunno when EMD quit that. I was surprised to hear that much noise coming from the helpers on a downgrade train rounding Horse Shoe Curve a few years back. Couldn't see them well enough to make a positive ID, but SD40's or a rebuild to those specs are likely. - Paul North. Braking - no matter how it's done - takes kinetic engergy from the moving train and turns it into heat. Brake shoes applied with pressure against the wheel treads create heat as they slow the train. Dynamic brakes, turning the traction motors into generator also create heat - heat that has to be disapated by blowing high volumes of cooling air through the 'generators' as well as having the current generated by the 'generators' disapated in resistor grids that also need cooling to be kept from overheating.
Paul_D_North_Jr timz On a 1960s-1970s EMD the traction motor blower is driven directly by the diesel-- so in full dynamic the diesel has to be running at... Run 5 speed? Or faster? to cool the motors. Dunno when EMD quit that. I was surprised to hear that much noise coming from the helpers on a downgrade train rounding Horse Shoe Curve a few years back. Couldn't see them well enough to make a positive ID, but SD40's or a rebuild to those specs are likely. - Paul North.
I was surprised to hear that much noise coming from the helpers on a downgrade train rounding Horse Shoe Curve a few years back. Couldn't see them well enough to make a positive ID, but SD40's or a rebuild to those specs are likely.
- Paul North.
Braking - no matter how it's done - takes kinetic engergy from the moving train and turns it into heat. Brake shoes applied with pressure against the wheel treads create heat as they slow the train.
Dynamic brakes, turning the traction motors into generator also create heat - heat that has to be disapated by blowing high volumes of cooling air through the 'generators' as well as having the current generated by the 'generators' disapated in resistor grids that also need cooling to be kept from overheating.
In an electric locomotive, the current can be returned to the overhead line, and the process is called regenerative rather than dynamic braking.
If you can see the driver's console in a commuter train, I enjoy watching the ammeter as we approach a station. It drops back to zero as power is cut, then goes even higher as the regenerative braking cuts in and oscillates as the train slows almost to a stand and drops to zero again as the air brakes cut in. This is computer controlled to minimise the use of the air brakes. The best view is in the underground where the illuminated dials show up most clearly.
timzOn a 1960s-1970s EMD the traction motor blower is driven directly by the diesel-- so in full dynamic the diesel has to be running at... Run 5 speed? Or faster? to cool the motors. Dunno when EMD quit that.
The newer SD70's rev up to what sounds like Notch 3 or 4 when in dynamics, but only do so once the dynamics are loading a certain amount... maybe 300 amps or something like that.
On GEVO's the engine also revs, but not as much I think. Their dynamic fans also speed up and slow down depending on how much the dynamics are loading.
Greetings from Alberta
-an Articulate Malcontent
Our EMDs and ALCOs both spool up for dynamics.
Larry Resident Microferroequinologist (at least at my house) Everyone goes home; Safety begins with you My Opinion. Standard Disclaimers Apply. No Expiration Date Come ride the rails with me! There's one thing about humility - the moment you think you've got it, you've lost it...
OK...interesting.
Thanks Again
The locos with dynamics that I run automatically go to Notch 4 when the dynamics are set up. This generates the field in the traction motors that's used to turn them into generators.
Don't know about ACs.
When going down grade, what is the diesel doing.....is it just idling into the generator (or whatever rpm is required to generate needed power), while being disconnected from the motors.?
Thank You
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