Estimation Algorithm of Equivalent Series Resistance of DC Input Capacitor in Single-Phase DC-AC Converter Based on Least Mean Square Approach

In this research, the internal resistance of the input capacitor in the DC/AC single-phase converter, equivalent series resistance (ESR), is estimated by the least mean square method. This paper firstly applied the LMS algorithm to identify the amplitude of the equivalent series resistance of the dc-link capacitor of the dc-ac converters, by using signals of capacitor voltage and current. In addition, conditions for optimal performance were confirmed by adjusting the sampling time of the data. The error was analyzed by comparing the estimated and measured using the algorithm. As a result, it was confirmed that the estimation accuracy was relatively high at 98 % at a capacitor capacity. Furthermore, the algorithm of this paper compared the accuracy according to sampling time and data section. Accordingly, it was confirmed which of the two factors had a greater effect on accuracy. This result is a contribution to this paper. It was confirmed that the sampling time had a greater effect than the section of the data.