• Fulltext


        Click here to view fulltext PDF

      Permanent link:

    • Keywords


      Current control; current stress; diode-clamped inverter; full-bridge inverter; half-bridge inverter; multi-level inverter; proportional-resonant controller; sinusoidal modulation; vector control; voltage ripple

    • Abstract


      The sizing of the DC-link capacitor in a three-level inverter is based on the RMS current flowing through it. This paper analyses the DC-link capacitor RMS current in a neutral-point clamped (NPC) inverter and expresses the same as a function of modulation index, line-side current amplitude and power factor. Analytical closed-form expressions are derived for the capacitor RMS current for single-phase half-bridge,single-phase full-bridge and three-phase three-leg topologies of a three-level inverter. The worst-case capacitor current stress is determined for each topology based on the analytical expressions. Further, analytical expressions are derived for the RMS values of low-frequency and high-frequency capacitor currents. These expressions are then used to estimate voltage ripple across the DC capacitor for sinusoidally modulated three-phase NPC inverter. The analytical expressions for the RMS current and voltage ripple are validated experimentally over a wide range of operating points.

    • Author Affiliations



      1. Department of Electrical Engineering, Indian Institute of Science, Bangalore 560012, India
      2. Department of Electrical and Electronics Engineering, National Institute of Technology Goa, Farmagudi, Ponda 403401, India
    • Dates

  • Sadhana | News

    • Editorial Note on Continuous Article Publication

      Posted on July 25, 2019

      Click here for Editorial Note on CAP Mode

© 2017-2019 Indian Academy of Sciences, Bengaluru.