Evaluation of Current Measurement Accuracy for a Power Module with Integrated Shunt Resistors

Inhalt:
Measurement of the output current of voltage source inverters is often needed for control and overload detection. The integration of shunt resistors in power modules represents a simple, cost-effective and compact solution for this task. Challenges that have to be addressed with this approach are the trade-off between power losses and the amplitude of the sense voltage, voltage isolation, measurement tolerances and inductive coupling effects. In this paper, a standard 17 mm module with integrated shunt resistors is presented together with a δ-σ modulator for isolation and analog-to-digital conversion. The measurement accuracy is evaluated by simulations and measurements.