An algorithm and implementation system for measuring impedance in the D-Q domain

As power electronics infiltrates the electric power distribution and conversion systems, stability issues become increasingly significant. The risk of instability due to the use of constant power loads stems from the implementation of controlled output power conversion systems. In three phase converters, these issues are difficult to measure. Although there have been developments in the determination of system stability at interfaces due to stability, a framework to perform measurements necessary for such a determination has not been fully developed. This paper presents a method to measure three phase impedances in the D-Q rotating reference frame for three phase AC systems and demonstrates the successful implementation and operation of such a system. Results are shown measuring a three phase passive load with a 2 kW source.