Development and Field Demonstration of a Series Power Flow Controller for Distribution Grids

Series power flow controllers can be a cost-effective solution to improve distribution grids efficiency and resilience by turning radial feeders into a loop topology in a controllable and secure way. In this context, this paper presents the development and field demonstration of a 500-kVA series power flow controller in an actual 13.8kV distribution grid. Because a series power flow controller has to withstand only a fraction of the line voltage, the power rating of the series converter is only a small portion of the power it can manipulate (20% in the developed equipment compared to 200% in a back-to-back solution). Experimental results show that the equipment can help alleviate overloaded feeders by transferring their power to an adjacent one, improving the terminal voltage profile. This is done while preventing harmonics from flowing between the feeders. The equipment field installation shows that it can be extensively applied in actual distribution grids for power quality improvements and realtime power manipulation.