Power Supply Suggestions?

Discussion in 'General Electronics Chat' started by railguy, Jul 3, 2008.

  1. railguy

    Thread Starter New Member

    Jul 3, 2008

    We are in the preliminary stages of designing a test fixture for the testing of traction motors for a rail vehicle. The motors will be mounted in the truck assembly (bogie), but not on the vehicle, ie no large load to move. Basically they will be connected to the transmission, axles, wheels, but the wheels will be allowed to spin free on the test stand.

    The motors are 3-phase with the following specs (from spec sheet):
    Nominal Output: 90kW (120.7hp)
    Number of phases: 3
    Number of poles: 4
    Stator winding connection: Y
    Nominal voltage L-L: 3x400 V
    Nominal current: 163 A
    Nominal speed: 1973 RPM
    Nominal frequency: 67 Hz
    Maximum speed: 4800 RPM
    Power factor: 0.85

    Equivalent Circuit (68oF)
    R1 = 0.0184
    R2 = 0.0187
    L1 = 0.325 mH
    L21 = 0.173 mH
    Lh = 8.24 mH

    I’m trying to get an idea of what type of power supply we would need. Now the motors will need to be powered to spin the axles/wheels, but will not be moving the entire vehicle. Currently, four of these 90kW output motors can move the vehicle which weighs over 80,000lbs, so I’m guessing it would take a bit less to power one of these to test it.

    I have access to a GPD 505 V-B 041 Adjustable Frequency Drive.
    Input: 3PH 380-460V 50/60Hz 46A
    Output: AC 0-460V, 0-400Hz, 41A-VT

    Any suggestions or ideas about using this to test the motors? Any other power supply suggestions would also be a big help. I haven’t had a lot of time to look closely at this, but I figured maybe I could get some help here to get the ball rolling.

    Thanks in advance.
  2. Pich

    Senior Member

    Mar 11, 2008
    The drive you have available may work to test the motor using a longer ramp time at no load but you will need VFD rated for the motor to check it under load.