Announcement

Collapse
No announcement yet.

AC waterpump with solar panels

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • #46
    I would mention, our latest locomotives use AC traction motors with an electronic drive, which
    can pull really hard from a stall on up. So the technology to do such things is known, but it
    isn't just a bunch of standard components thrown together. Bruce Roe

    Comment


    • #47
      Originally posted by bcroe View Post
      I would mention, our latest locomotives use AC traction motors with an electronic drive, which
      can pull really hard from a stall on up. So the technology to do such things is known, but it
      isn't just a bunch of standard components thrown together. Bruce Roe
      Bruce I am out of my element here but are you referring to some of the new GE Evolution series? I know there are some locomotives using AC motors and most are found in India and Europe. They have been slow to appear in the USA because of the extreme cost. I have heard BNSF and CSX has a few now days for heavy transportation for coal and other heavy loads.

      I have really wanted to get a look at the VFD Inverter those beast use.I assume they drive 6 to 8 motors?
      MSEE, PE

      Comment


      • #48
        In Europe there are some of those locomotives in service since late 80's and powered by cable above @ 27000v .
        They use one motor per each wheel , or atleast some of the models.
        The most advanced like the French TGV does Marseille to Paris less than 2 hrs, faster than the plane.

        Comment


        • #49
          Originally posted by Raul View Post
          In Europe there are some of those locomotives in service since late 80's and powered by cable above @ 27000v .
          They use one motor per each wheel , or atleast some of the models.
          The most advanced like the French TGV does Marseille to Paris less than 2 hrs, faster than the plane.
          Raul that is not what I am asking. I understand what you are saying but does not apply. You are speaking of light rail or passenger rail service. For Light Rail you can use overhead lines. We do that in the USA mostly in the North East part of the country and around Chicago. Some rail service like like in NYC are using the Third Rail to supply power.

          I am asking about Diesel/Electric Heavy Transportation, not light rail passenger. Diesel/Electric here for decades and even today is mostly done with DC Traction Motors. Diesel engine turns a AC generator and the the AC is ran through rectifiers and ran to the DC motors.

          I think back in 2005 GE introduced some AC Locomotives. AC has not been used here much because it is extremely expensive to implement. The VFD Inverters prices have come down in the last 12 years and now some operators like CSX and BNSF have purchased and using a few AC locomotives for very heavy loads like coal, oil, and commodities. When you are running 4 locomotives with 6500 HP engines is way beyond what over head lines can transport over any significant distance. Only way to do that is with the generators on the locomotive diesel engines. Like DC Traction motors the diesel still turns a AC generator, rectified to DC, then the VFD converts DC back to AC to run the traction motors. Dependin gon th esize a locomotive uses 6 to 8 motors, one for each axle.

          US environmental policy and the falling expense of implementing AC locomotives has changed the economic situation here. The Employment Prevention Agency (EPA) emission policy is getting stricter on Rail emissions. To meet those demands GE is now offering AC Drive trains because AC motors are more efficient than DC, thus uses less fuel. Like all policies they have unintended consequences. In this case it raises the price of everything. The fuel savings does not offset the cost of using AC motors up to now. Those cost are passed onto consumers as rail service does most of the long distance transportation in the USA and trucks are used for the last leg, or perishable commodities.

          As for passenger rail service is not used much in the USA as it is not profitable and no companies offer passenger rail service. All of it to my knowledge is operated by goberment and heavily subsidised by tax payers.
          MSEE, PE

          Comment


          • #50
            Originally posted by Sunking View Post
            As for passenger rail service is not used much in the USA as it is not profitable and no companies offer passenger rail service. All of it to my knowledge is operated by goberment and heavily subsidised by tax payers.
            Passenger rail service in the U.S. is gov. subsidized and not profitable, with intercity service for the most part only available via Amtrak on private railroad rights of way/tracks. However, it can be a nice, if somewhat expensive way to travel as long as you're not on a timetable to get somewhere on anything like a reliable schedule. Seems to me like a faint echo of past glory that's continuously fading due to changes in what folks expect and want in travel. About as anachronistic as seeing a horse/buggy going down the road in Amish country.

            Comment


            • #51
              I'm not up on all the details, but I have read overviews of the technology. Railroads might have
              been invented over there, but they were perfected as freight haulers right here. A box car over
              there has 4 wheels; ours have 8. I don't see how the European coupler system can match the
              efficiency of our knuckle couplers.

              Diesel locomotives started around 600 hp and some are 10 times that now. My understanding is
              each 3 axle truck had 2 motors, but lately there is so much power they are using 3 motors per
              truck. I have read stories by engineers about the AC motor locomotives hauling heavy freight;
              they do the job well. With electronic traction control, probably better.

              The same evolution of high powered semiconductors that made these great GTIs practical is
              changing transmitters, locomotives, and a lot of other stuff. I only worked DC in the telco biz,
              but AC is being revolutionized too. Bruce Roe

              Comment


              • #52
                Originally posted by bcroe View Post
                The same evolution of high powered semiconductors that made these great GTIs practical is
                changing transmitters, locomotives, and a lot of other stuff. I only worked DC in the telco biz,
                but AC is being revolutionized too. Bruce Roe
                AC motors is pretty much a mature technology and has been for many decades along with DC motors. DC motors have been the choice up to now, and still very popular understandable so because they are so easy and inexpensive to control.

                There are some giant sized synchronous motors out there. Does not require a VFD naturally, but big nonetheless. Ironically the largest electric motors out there are used in petroleum refineries. Largest motor I know of is 66,000 hp that runs at 1800 RPM used in Delaware City Repower Project to turn cola into syngas. It is used to run a fan to pump air into a burner. Another way many folks do not know about is DOD and DOE run nuclear power and use the heat off reactors to make syngas for military, and generate electricity. Kind of easy to figure out which nuke plants do this because they have heavy rail to bring coal in and pipe lines to ship the product out.

                But I agree the advancement in high voltage semiconductors is changing the face of 3-phase AC Induction motors. But as for the motors themselves nothing new, they are just getting larger. The only real advancement I know of is the USN is testing a new High Temperature Superconductor Ship motor rated at 49,000 hp running at 120 RPM @ 2.9 million Newton Meters of torque. That is one hell of a titty twister. . What is unique about it is 1/3 the size and weight of conventional 4 pole monster motors.

                As a cost comparative though in my experience with racing golf carts is for about $1000 I can equip you with a 20 hp DC motor and 500 amp PWM speed controller. Want AC with that cart is going to cost you $3000 for a 16 hp 550 amp VFD Inverter. My current cart uses a HPEV 35 running at 144 volts with a 500 amp controller. It is a 35 hp continuous power motor. But do not let that fool you as it produces a Flat torque curve from 0 rpm to 6000 RPM of 90 Ft/lbs of torque and Flat 102 hp from 6000 RPM to 11,000 RPM. No transmission needed and I have it speed limited to 7000 RPM or 75 mph. In the 8th mile wil beat even a Telsa Roadster or gas car you want to race with. It wil scare the chit out of you. With my fat but in it only weighs 960 pounds.
                Last edited by Sunking; 02-20-2017, 08:52 PM.
                MSEE, PE

                Comment


                • #53
                  Originally posted by Sunking View Post

                  But I agree the advancement in high voltage semiconductors is changing the face of 3-phase AC Induction motors. But as for the motors themselves nothing new, they are just getting larger. The only real advancement I know of is the USN is testing a new High Temperature Superconductor Ship motor rated at 49,000 hp running at 120 RPM @ 2.9 million Newton Meters of torque. That is one hell of a titty twister. . What is unique about it is 1/3 the size and weight of conventional 4 pole monster motors.

                  As a cost comparative though in my experience with racing golf carts is for about $1000 I can equip you with a 20 hp DC motor and 500 amp PWM speed controller. Want AC with that cart is going to cost you $3000 for a 16 hp 550 amp VFD Inverter. My current cart uses a HPEV 35 running at 144 volts with a 500 amp controller. It is a 35 hp continuous power motor. But do not let that fool you as it produces a Flat torque curve from 0 rpm to 6000 RPM of 90 Ft/lbs of torque and Flat 102 hp from 6000 RPM to 11,000 RPM. No transmission needed and I have it speed limited to 7000 RPM or 75 mph. In the 8th mile wil beat even a Telsa Roadster or gas car you want to race with. It wil scare the chit out of you. With my fat but in it only weighs 960 pounds.
                  Super conduction is another thing changing the rules. Maybe we will have DC transmission at near
                  100% efficiency and no distance limit. I'd hate to see a military motor quit because they ran out of
                  liquid hydrogen. Fermi Lab (walking distance from my last loc) managed to be the worlds most
                  powerful accelerator for decades using super conducting magnets. They had the worlds largest
                  liquid hydrogen plant.

                  There is no physical reason a quick car shouldn't be electric, with the right components. I won't be
                  racing any golf cars myself. Bruce Roe

                  Comment

                  Working...
                  X