Parallel connection of two shunt active power filters with losses optimization

This paper describes a technique to reduce the converter losses in the shunt active power filter operation. In such technique, the reactive and harmonics compensation are separated in two shunt active power filters operating at different frequencies. The reactive power of the load is compensated by low frequency filter, while the power related with harmonics are compensated by high frequency filter. This technique provides some advantages in terms of losses and costs reduction when compared with standard solution. Both filters (low frequency and high frequency filters) are coupled in a combined topology in which they are connected in parallel connection scheme. Additionally, this paper gives the filter models, pulse-width modulation technique and control strategies are investigated, as well. Simulated and experimental results verify the theoretical studies.