Title :
Analytical calculation of the RMS current stress on the DC-link capacitor of voltage-PWM converter systems
Author :
Kolar, J.W. ; Round, S.D.
Author_Institution :
ETH Zurich, Power Electron. Syst. Lab., Zurich
fDate :
7/1/2006 12:00:00 AM
Abstract :
A simple analytical expression for the current stress on the DC-link capacitor caused by the load-side inverter of a voltage DC-link-converter system is derived. The DC-link capacitor-current RMS value is determined from the modulation depth and by the amplitude and the phase angle of the inverter output current assuming a sinusoidal inverter output current and a constant DC-link voltage. Despite neglecting the output-current ripple, the results of the analytical calculation are within 8% of measurements made from digital simulation and an experimental system, even if the output-current ripple is relatively high as in the case of low-frequency IGBT inverter systems. The simple analytical expression provides significant advantages over simulation methods for designing the DC-link capacitor of PWM converter systems
Keywords :
PWM invertors; PWM power convertors; capacitors; digital simulation; insulated gate bipolar transistors; DC-link capacitor; RMS current stress; analytical expression; digital simulation; low-frequency IGBT inverter system; modulation depth; output current amplitude; output-current ripple; phase angle; voltage-PWM converter system;
Journal_Title :
Electric Power Applications, IEE Proceedings -
