Investigation of residual current devices in high frequencies

In the paper, the results from the analysis of the working process of the residual current devices (RCD) in the frequencies over than 50 Hz (resp. 60 Hz), are presented. The main aim of the investigation is to estimate the applicability of the considered RCD in the systems including modern converting devices and its protective measures from the electric current breaking in the working frequencies over than 50 Hz (resp. 60 Hz). The paper finishes with conclusion remarks about advantages and disadvantages of the considered models of RCD.