Practical evaluation of unbalance and harmonic distortion in power conditioning

This paper presents a method for assessing the quality improvement of the electric power obtained by using compensation equipment based in active power filters, APF. Power quality indicators that allow to separate the contribution to unbalance of each harmonic and interharmonic of voltages and currents are introduced, calculated with an enhanced procedure. To characterize the behavior of these indices, a parallel active compensator, and a series-parallel active compensator have been used for the compensation in a system with unbalance and distortion. The results obtained with an experimental platform designed for the purpose have allowed to verify the validity of the proposed procedure and they have shed new light on the interpretation of the indices of unbalance and harmonic distortion.