Comparison of Methods for DC Link Voltage Measuring of a Module in a UPS Based on a Modular Multilevel Design

A modular multilevel scheme for constructing energy converters and storage devices requires measuring the voltage in the DC link of each module for its correct operation. In this case during the voltage measurement, there must be a galvanic isolation. In the presented article, several methods will be proposed for determining the voltage in the DC link of the module, among them there will be both direct and indirect. At the end, the presented schemes will be compared in terms of ease of implementation and accessibility.