How to calculate or estimate the DC-Link capacitors for a motor driver

The capacitance of dc-link capacitor depend on many factors as below,
1. Capacitor material and type
2. Ripple current on capacitor
3. Temperature range, temperature profile, cooling
4. Input DC/AC ripple voltages, minimum input voltage
5. Allowed ripple voltage and frequency
6. Maximum power and current
7. pwm frequency for inverter
8. motor parameters, phase inductance

You can refer to this formula to simple calculate the capacitance C = Vbus / (32 ∗ L ∗ ΔV ∗ fpwm^2), the ΔV depends on voltage and current ripple, power.

Actually, this is a complex question, you can search more paper or thesis from website.

Hi,

  may i kow what is the "L" in the equation?

  thanks!

  kevin