Hello to all my power electronic Gurus,

I was reading this paper

https://www.kalbeck.com/asset/630/Whitepaper SalconeBond.pdf

on properly sizing a dclink capacitor, i understood most of it, but there were a few things that were still unclear.

In the example which was shown on Page 4, Vbus is 325v, Inductance is 100uH, and a switching frequency of 10 Khz,

If we calculate the ripple current at 50% duty cycle it comes to around 28.7Amps(RMS) as per the given formula:

delta_i = (0.25*Vbus)/(f*L)

The author further says that " If an electrolytic capacitor were sized for this application it would require a 5,000uF / 450V capacitor to meet the ripple current requirement at 10 kHz switching frequency". How did he arrive at the 5000uF value? I dont see any equation between Capacitance and ripple current.

Could someone please explain this...

Thanks

I was reading this paper

https://www.kalbeck.com/asset/630/Whitepaper SalconeBond.pdf

on properly sizing a dclink capacitor, i understood most of it, but there were a few things that were still unclear.

In the example which was shown on Page 4, Vbus is 325v, Inductance is 100uH, and a switching frequency of 10 Khz,

If we calculate the ripple current at 50% duty cycle it comes to around 28.7Amps(RMS) as per the given formula:

delta_i = (0.25*Vbus)/(f*L)

The author further says that " If an electrolytic capacitor were sized for this application it would require a 5,000uF / 450V capacitor to meet the ripple current requirement at 10 kHz switching frequency". How did he arrive at the 5000uF value? I dont see any equation between Capacitance and ripple current.

Could someone please explain this...

Thanks

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