My DC motor's nameplate says:

VOLTS: 125


HP: 4 HP

RPM: 5000 RPM


I chose this IGBT IKW50N60DTP to drive the motor with a PWM frequency of 5 kHz using a single-quadrant chopper.

My question is: For the power calculations, do I need the max load current of 27A (average IGBT current value?), even if I don't plan to reach that value of current?

I'm following this app note to do my power calculations and it suggests I need the IGBT average and RMS current.

  • 2
    \$\begingroup\$ Unless you accelerate very slowly (rate of V/f ) the surge current while starting is 45A for 4HP @ 125V regardless of the load due to the DCR of the motor coil. \$\endgroup\$ – Sunnyskyguy EE75 Dec 15 '18 at 16:34

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