CAPACITANCE ESTIMATION SYSTEM OF DC LINK CAPACITOR FOR SINGLE PHASE PULSE WIDTH MODULATION CONVERTER

摘要

PURPOSE: A capacitance estimation system of a dc link capacitor for single phase pulse width modulation(PWM) converter is provided to improve productivity by determining the replacement time of a capacitor in advance by estimating a capacitance state in on-line. CONSTITUTION: An inductor(L) is connected to the backend of an input power source(es). A PWM converter converts AC voltage outputted from the input power source into DC voltage. The capacitor(C) is connected to the backend of the PWM converter and smooths the DC voltage. A voltage controller produces a second current command using the difference of the voltage of capacitor and a first voltage command. The current controller outputs the voltage command from the error current value.