Transformer-less unified power flow controller in medium voltage distribution networks

A transformer-less unified power flow controller (UPFC) is a power electronic device consisting of series and shunt voltage source converters (VSCs) that are not connected to a common DC bus. It can control power flow in medium voltage (MV) distribution networks without the need for interfacing transformers. Hence there is a significant reduction in size and cost compared to a conventional UPFC. This paper investigates the operating range of a transformer-less UPFC in an MV distribution network and the required power ratings of the series and shunt converters. The results showed that a transformer-less UPFC is able to provide active power control using partially rated converters. However, its ability to control reactive power is limited by the current ratings of the converters. The analysis was verified using software simulation and hardware experiment.

Automated summary

A transformer-less UPFC is a power electronic device that uses series and shunt voltage source converters to control power flow in MV distribution networks. This study investigates its operating range and required power ratings. The results show that it can provide active power control using partially rated converters, but its abilities in reactive power control are limited by the converters' current ratings. The analysis is verified using software simulation and hardware experiment.