Aluminum electrolytic and DC film capacitors are widely used in all types of inverter power systems, from variable-speed drives to welders, UPS systems, and inverters for renewable energy.

Learn the considerations involved in selecting the right types of bus capacitors for such power systems, mainly in terms of ripple current handling and low-impedance energy storage that maintains low ripple voltage.

The information provided in this 24-page paper will help engineers select DC link capacitors that maximize efficiency and end-product reliability.

 

  • Review of the basic power conversion scheme
  • Analysis of Energy Source Contributions to DC Link Ripple Current and Ripple Voltage
  • Analysis of Inverter Contributions to DC Link Ripple Current and Ripple Voltage
  • Spectral Analysis and Joule Heating Effects of Pulse Rep Rate, Shape, and Spacing
  • General expression for DC Link ripple current for PWM inverter with balanced 3-phase output
  • Resources for selecting the right capacitor
  • Example of 3-phase, 10 horsepower motor drive