Improving energy quality by voltage compensation and active power injection

This work discuss an active power filter configuration which allows voltage compensation as well as controlling the active power flow at the grid. The proposed configuration has an external power source tied to the DC bus thus allowing to deliver or to absorb energy. The steady-state characteristics, the design of the control law and experimental results are presented and discussed. In the experimental tests undervoltage-overvoltage compensation and power injecting-drawing for purely resistive and, strongly inductive load have been investigated. In all the cases, the proposed configuration provides load voltage regulation within the nominal specifications (notch depth below 10% and total harmonic distortion below 4%) whereas the average value of three-phase power fluctuates around the reference value specified for the active power.