Impedance Estimation Using Power Monitoring Feature for Tuning AFE Gains

Active Front End voltage source converters are widely used in industrial applications. Control loop gain setting is extremely important to maintain reliable operation of these converters to avoid resonance or bus over voltage issues. This paper presents a novel technique to estimate source impedance during drive pre-charge and transient operational mode. The technique can be extended to different drive power architecture which includes SCR/contactor based pre-charge. Transient method is implemented under a single and multiple drive at point of common coupling. Experimental results are used to validate these techniques. It is recommended to use a PQ meter to estimate and communicate grid information to multiple drives at the same time keeping system cost and accuracy of data into account.