Driving a 48V 400W DC motor from a single phase 220V 50Hz AC: Comparison between two topologies.

Discussion in 'The Projects Forum' started by BlackMelon, Apr 12, 2016.

  1. BlackMelon

    Thread Starter Member

    Mar 19, 2015
    31
    0
    Hello,

    In my mind, there are two ways to do this. However, I don't know pros, cons, and cost-effectiveness of each.

    http://lh6.ggpht.com/_X6JnoL0U4BY/S26tzJ3HCtI/AAAAAAAASCI/p_k2WzgjVb4/tmp166_thumb.jpg?imgmax=800
    The link above presents driving one from SCRs. The 4 SCRs can't reverse the motor's direction, thereby requiring another four to do so. However, as shown, the topology is work best with 3 phase.

    The other way is using a bridge rectifier and a dc-dc converter to convert 220V to 48Vdc. Subsequently, a h-bridge mosfet driver is conneted to 48Vdc to drive my motor. This allow me to control both speed and direction. However, the converter requires a transformer for safety. I'm afraid that the transformer will dump the overall efficiency down.

    Which way should I take? Is this a trading off between smoothness of dc voltage across the motor and the overall efficiency?

    Thanks
    BlackMelon
     
  2. MaxHeadRoom

    Expert

    Jul 18, 2013
    10,493
    2,363
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