Current Sensing by means of Parasitic Inductances – Method Investigation and Inverter Application

In this paper, a low cost current sensing method by evaluating the voltage across parasitic inductances and resistances in a power semiconductor module is investigated. Some work has already been done in describing this method, especially for short circuit detection methods. This work, however, focuses on the application as current sensor for control purposes, where the module is used in an inverter configuration, first results included. It can be shown that such a sensor can provide input values for a reasonable and working current control. Here, different influences on the measurement signal have to be considered. For high accuracy, special attention has to be paid to the measurement position in the module, which is also topic of this work.