The hybrid power flow controller - a new concept for flexible AC transmission

In this paper, two such topologies are presented. The first one consists of a shunt connected controllable source of reactive power, and two series connected voltage-sourced converters - one on each side of the shunt device. The second topology is a dual of the first; it is based on two shunt connected current-sourced converters around a series connected reactive compensator. In both cases the converters can exchange active power through a common DC circuit. Since both topologies make use of converters in addition to the (presumably existing) passive components, they can be regarded as hybrid, and the resulting FACTS controllers are thus named "hybrid power flow controllers", or HPFC. The analysis carried out that the HPFC offers performance characteristics similar to those of the UPFC. This paper presents some of the results. The rest of this paper is organized as follows. The HPFC topology that employs series VSCs is introduced. The steady state analysis is given and operating characteristics are derived. The dual topology, based on shunt connected current-sourced converters is presented