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I need to rectify 200 V at 30 kHz for a resistive load of 3-4 kW. I use a 1200 V/60 A Schottky diode bridge. I have some 6800 uF/450 V capacitors. Can I use them, or should I use other values? Is there any formula to compute other values (voltage, frequency, load)?

Wave form - not sure, but not sinus. Output ripple - not important, as long the load is resistive. Capacitor is only for optimizing the output.

So, I should test the rectifier with increasing loads, in order to keep in the diode-s range. Should I test the bridge with the 6800 capacitors?

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    \$\begingroup\$ Welcome! What's your input voltage waveform? Sine? Square? What's your output voltage ripple requirement? Have you tried to simulate your circuit? \$\endgroup\$
    – winny
    Commented Oct 9, 2023 at 7:52
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    \$\begingroup\$ Have you tried simulating your circuit to see what ripple voltage you get and what is acceptable? \$\endgroup\$
    – Andy aka
    Commented Oct 9, 2023 at 8:05
  • \$\begingroup\$ What is the reason to feed the resistive load buffered DC? \$\endgroup\$
    – greybeard
    Commented Oct 9, 2023 at 8:23
  • \$\begingroup\$ With DC I can measure the output voltage. With AC al 30KHz, I do not have oscilloscope, nor an adapter for DMM. \$\endgroup\$
    – Pilgrim
    Commented Oct 9, 2023 at 9:27

2 Answers 2

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Here is a simulation with some components values ... (without specs).

The diode bridge should withstand some kA for "some" millisecond (starting phase ...) ...
and then +/- 120 A peak ...

enter image description here

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It is recommended to consider several factors, including current requirements, input and output voltage fluctuations, load characteristics, and required ripple levels. You can estimate the required capacitance using the following simplified formula:

C=I⋅ΔVf⋅VrC=f⋅Vr​I⋅ΔV​

in:

 C: C is the required capacitance in farads.
 I: I is the load current in amps.
 ΔV: ΔV is the desired output voltage ripple in volts.
 f: f is the switching frequency in Hertz.
 Vr: Vr​ is the rated voltage of the capacitor in volts.
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    \$\begingroup\$ Why is Vr included? Is C=IDVfVrC correct? Thank you. \$\endgroup\$
    – Pilgrim
    Commented Oct 9, 2023 at 8:38
  • \$\begingroup\$ (Down-voters please comment what in particular makes a post not useful.) \$\endgroup\$
    – greybeard
    Commented Oct 9, 2023 at 10:04
  • \$\begingroup\$ @greybeard - Hi, Please note that, as explained here, downvoters do not have to explain their votes. \$\endgroup\$
    – SamGibson ♦
    Commented Oct 9, 2023 at 15:36
  • \$\begingroup\$ FredMorgan - Analysis suggests your answer may have been copied from elsewhere. This site rule explains that any content copied or adapted from elsewhere must be correctly referenced. || Therefore, if your answer was copied from elsewhere, please edit it and add the required reference to the source. If it was not copied from elsewhere, please edit it and explain the formula you gave, as it does not seem correct. Thanks. \$\endgroup\$
    – SamGibson ♦
    Commented Oct 9, 2023 at 15:41

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