A matrix N×M multiphase converter is a simple structure incorporating N×M bi-directional switches, connecting N input phases to M output phases and able to convert input voltages into output voltages of any shape and frequency. However, commutation problems and complicated control algorithms keep it from being utilized on a large scale. This paper gives a solution to the control system of the multiphase matrix converters for power system application. The practical application of multiphase matrix converters (MC) in power systems involves the study of application requirements, possible converter topologies and the development of new, reliable control algorithms. The MC is working as a connection device between power systems or as an interconnection device within the power system. The proposed tasks performed by the MC in the power system are power flow control and power flow oscillation dumping. The device can be viewed as new FACTS device-series power system connector, based on straightforward energy conversion.