A Novel Single-Phase AC–AC Converter for Circuit Breaker Testing Application

This paper presents a novel single-phase ac-ac converter with power factor correction and output current control for circuit-breaker testing according to the IEC 60898 standard. The important advantages of the proposed circuit are low component count and fast responses for the standard requirement, especially a current step at the beginning of the test. The proposed single-phase ac-ac converter can operate in either buck or boost mode to accommodate the need for a wide range of output current while satisfying the ramping and step current requirements in the standard. The control circuits consist of two parts, dc voltage control of dc-link capacitors and ac output current controls operating simultaneously. The proposed circuit is verified through both computer simulation and hardware experiment. An example of a 50 A circuit breaker testing according to the IEC 60898 is demonstrated in the paper.