This paper presents a new transformer, i.e., the Custom Power Active Transformer (CPAT) - which integrates shunt and series equivalent circuits within the transformer's magnetic structure. Thus, it provides power system services using a single transformer. The CPAT equipped with a power converter can be utilized in distribution systems to control grid-current and load-voltage waveforms while operating as a step-up or step-down transformer between the grid and load. Moreover, it can provide other services that any typical shunt-series compensation arrangement provides. Design and analysis of a single-phase CPAT is presented showing the effect of coupling between windings and transformer parameters affecting CPAT operation. In this paper, control of the CPAT in a Unified Power Quality Controller (UPQC) application is investigated to attenuate grid-current and load-voltage harmonics as well as compensate for reactive power requirements and attenuate grid inrush current. Through simulation and experimental implementation, the merits and performance of the CPAT were validated.

Peer Reviewed