Three-phase vector switching converters for power flow control

As congestion in AC power transmission systems increases due to technical limitations, environmental pressures, economic necessities and developmental demands, devices with ability to control power flow with much greater ease than presently possible would be highly desirable. Furthermore, devices that channel power flow in the network to fulfill contractual obligations for purchase agreements between power producers and consumers would facilitate improved operation of the power system in the emerging deregulated scenario. Generally, electronic control devices for directing power flow in AC systems have been realised using phase-controlled reactors in conjunction with switched capacitors, voltage source and current-source DC-link rectifiers/inverters have been applied on a point-to-point basis. Three phase vector switching converters are introduced as an alternative approach for realising power flow control in more complicated interconnections. These converters are seen to have the potential to be configured at arbitrary intertie points in a three-phase power system to route power flow in a complex power system. Operating principles, equivalent circuit models, simulation and experimental waveforms are presented along with examples.