DC/DC converter: 0-60V to 60V

BradtheRad said:

If your motor draws 1500 W at 60 V, then it draws 26 A and has a net impedance of 2.3 ohms.

I find that if I start out my simulation with a 2.5 Farad capacitor, its output drops to 42 V at 18 A after two seconds. Power is about half what you started with.
Therefore if you want 60 V continuous output then your boost converter must draw 80 A bursts at a 50 percent duty cycle.

how did you calculate this?

f you use continuous conduction mode, it permits you to use a coil with a lower inductive saturation current rating.

Click to expand...

what does this mean?

Click to expand...

jumpjack said:

BradtheRad said:

Therefore if you want 60 V continuous output then your boost converter must draw 80 A bursts at a 50 percent duty cycle.

how did you calculate this?

Click to expand...

I let the simulator calculate for me.
Otherwise I could have used the RC time constant formula.

I used my brain for a rough calculation to get the 80 A figure. I guessed that the converter will operate at 50 percent duty cycle. Therefore to maintain 1500 W when the incoming volt level has dropped to half, you'll need 4 times the amperes during the switch-On period.

My figures are rough since there will be losses, but it gives you an idea how difficult it will be to achieve your goal.

I wrote:
If you use continuous conduction mode, it permits you to use a coil with a lower inductive saturation current rating.

You wrote:

what does this mean?

Click to expand...

This is a mode of switching a coil at a fast enough rate that it never fully discharges.

CCM is in contrast to discontinuous mode. In DCM the coil discharges and is idle for part of the cycle. (You probably will not use discontinuous mode for this project.)

CCM versus DCM is an operating parameter for a switched-coil converter.

Click to expand...