Nine IGBTs based UPFC topology and control for renewable power integration

This paper proposes an integrated unified power flow controller (UPFC) with only nine IGBTs to improve grid compliance of renewable (i.e., wind and solar) power generation systems. The integrated UPFC has two AC outputs, which are served as an AC injected voltage source (DC-AC inverter) and an AC current source (AC-DC rectifier), respectively. The modulation of the UPFC is developed to provide sufficient voltage for power flow control as well as minimizing system rating. Then operating range of the developed UPFC is analyzed with a given system power rating. Furthermore, voltage oriented control of the UPFC is introduced to achieve independent control of real and reactive power. A 2-MVA simulation model is built to demonstrate the operating performance of the proposed UPFC configuration.