Conservative Power Theory Implementation in Shunt Active Power Filtering

This paper analyzes the current decomposition, in three-phase, three-wire systems, based on the Conservative Power Theory (CPT), and the application of these components in the active filtering. The CPT current decomposition gives the active component of the current, the reactive component, which can be compensated or not and the void current. It does not give the asymmetry current component, separately. For this reason, the active shunt compensators based on the CPT have the capability of compensating only parts of the non-active current, as needed. The reactive component can be compensated or not, but the void current, which contains the harmonic content, is normally compensated. A problem of the CPT, latter resolved, is the asymmetry current component which was not included in the first definitions. The aim of this paper is to analyze the performance of an experimental active compensator based on the early CPT definitions and a comparative study with the performances of the same compensator based on the improved CPT definitions.