Evaluation of the Ride-Through Capability of an Active-Front-End Adjustable Speed Drive under Real Grid Conditions

Better quality of the input currents, unity power factor and regenerative capability are not the only benefits of equipping an Adjustable Speed Drive (ASD) with an active front-end-stage. Controlling the power inflow may enable also the reduction of the dc-link energy storage, which will then lead to the replacement of the electrolytic capacitors with film capacitors, which have lower energy density meaning that the volume is similar, but will increase the ASD lifetime. In these circumstances, operation under unbalanced and distorted supply voltage as well as high dynamic operation of the ASD makes the control task more challenging. The aim of this paper is to investigate the ride-through capability of an ASD with active front-end under real grid conditions and in view of the minimum dc-link storage. Experiments validate the theoretical analysis.