Method for DC-link capacitance identification in voltage-source converters

A DC-link capacitance estimation method is presented for a three-phase voltage-source converter. The measured phase currents and DC-link voltage of the converter are used in formulation of the input and output signals for the estimator. The estimator is based on the ordinary least squares method. The capacitance can be estimated during the startup of the converter or while the converter is in normal operation. The proposed method is experimentally validated and the results indicate that the capacitance value is estimated with a good accuracy.