Article 7622 (48 more) in sci.energy: From: gecr@igc.org (Cutter Information) Subject: GE's New Efficient HVAC Motor Message-ID: <1466300073@igc.org> Date: 2 Jul 92 16:54:00 GMT Sender: Notesfile to Usenet Gateway Lines: 34 On June 30, General Electric introduced a new "ECM Programmable Motor" that it says is 20% more efficient than standard induction motors. The new motor would be used in HVAC applications (furnaces, air conditioners and chillers, etc.) and in refrigerators and automobile air conditioners. ECM stands for "Electronically Commutated Motor," which is a fancy way of saying "brushless DC." I'm writing up a short blurb about the motor for my newsletter, but wanted to toss out a question to the sci.energy community first. GE's information material on the new motor keeps comparing it with standard induction motors, but it doesn't really say how it --MORE--(56%) compares with other brushless DC motors that may be in use in HVAC equipment today. Other than the fact that you can program the new motor with a personal computer -- to set things like voltage, frequency, rotation, ramp rate, blower delay, speed, torque, and airflow control -- which allows GE to offer a single "standard" model for multiple uses, I can't figure out what's so new and revolutionary about the motor. Is the significance simply that GE has found a way to make brushless DC motors cheaper and more attractive to original equipment manufacturers? Or is the new "ECM Programmable Motor" itself actually more efficient than other brushless DC motors on the market today? I'd appreciate hearing from anyone who is familiar with the new motor. Thanks, Brad Hurley Editor Global Environmental Change Report End of article 7622 (of 7647)--what next? [npq] Article 7667 (59 more) in sci.energy: From: keil@apollo.hp.com (Mark Keil) Subject: Re: GE's New Efficient HVAC Motor Message-ID: Date: 8 Jul 92 18:17:02 GMT References: <1466300073@igc.org> Sender: usenet@apollo.hp.com (Usenet News) Organization: Hewlett-Packard Corporation, Chelmsford, MA Lines: 40 Nntp-Posting-Host: thor.ch.apollo.hp.com In article <1466300073@igc.org> gecr@igc.org (Cutter Information) writes: > > [stuff deleted] > Is the significance > simply that GE has found a way to make brushless DC motors > cheaper and more attractive to original equipment > manufacturers? Or is the new "ECM Programmable Motor" itself > actually more efficient than other brushless DC motors on the > market today? I'd appreciate hearing from anyone who is > familiar with the new motor. I am not familar with the motor in question, but... --MORE--(44%) What make you think that it must have brushes? It may have some kind of shaft encoder. If you know the orentation of the rotor at each instant in time, then you will know just when to energize the stator for the effect that you desire. If you have active control of the stator, then you know how much energy you imparted to the rotor. If you also track the angular momemtum of the rotor, you can calculate the torque load on the motor at each instant, and thus taylor the delevered power to exactly match the load, at the highest possible efficiency at all times. If you can control ramp rate, that almost implies knowledge of shaft position. This kind of control could be employed with most any standard induction motor, with the addition of a shaft encoder, processor & power electronics. I suspect that this the latest step in bringing control technology to mass produced aockage motors. You need to ask GE for more info. --MORE--(89%) What is the cost differential over standard induction motors? Mark -- Mark Keil HP/Apollo Computer, Chelmsford MA 01824 +1 508-256-6600 x4542 keil@apollo.hp.com / {decvax,mit-erl,yale}!apollo!kei l End of article 7667 (of 7672)--what next? [npq] From: gary@ke4zv.uucp (Gary Coffman) Subject: Re: GE's New Efficient HVAC Motor Message-ID: <1992Jul10.135149.10690@ke4zv.uucp> Date: 10 Jul 92 13:51:49 GMT References: <1466300073@igc.org> Reply-To: gary@ke4zv.UUCP (Gary Coffman) Organization: Gannett Technologies Group Lines: 44 In article keil@apollo.hp.com (Mark Keil) writes: >In article <1466300073@igc.org> gecr@igc.org (Cutter Information) writes: >> >> [stuff deleted] >> Is the significance >> simply that GE has found a way to make brushless DC motors >> cheaper and more attractive to original equipment >> manufacturers? Or is the new "ECM Programmable Motor" itself >> actually more efficient than other brushless DC motors on the >> market today? I'd appreciate hearing from anyone who is >> familiar with the new motor. > > I am not familar with the motor in question, but... > What make you think that it must have brushes? --MORE--(43%) A failure of reading comprehension perhaps? He did state the motor *was* brushless. > It may have some kind of shaft encoder. > If you know the orentation of the rotor at each instant in time, > then you will know just when to energize the stator for the > effect that you desire. > If you have active control of the stator, then you know how > much energy you imparted to the rotor. If you also track the > angular momemtum of the rotor, you can calculate the torque > load on the motor at each instant, and thus taylor the delevered > power to exactly match the load, at the highest possible efficiency > at all times. That *is* how brushless DC motors work, of course that's what *he* said. > This kind of control could be employed with most any standard induction motor, > with the addition of a shaft encoder, processor & power electronics. > I suspect that this the latest step in bringing control technology > to mass produced aockage motors. --MORE--(83%) Uh, *AC* induction motors don't need any of that rigamarole. They automatically are locked to the product of their number of poles and the AC line frequency. To vary their speed you simply vary the frequency of the applied drive. Their torque curve gets pretty nasty at very low speeds though. That's why controlled brushless DC motors are often preferred for wide speed/torque range applications. Gary End of article 7685 (of 7690)--what next? [npq]