Synchronous Voltage Source Inverter using FCMLI
The structure and control schemes of a STATic synchronous COMpensator (STATCOM) using Flying Capacitor Multi-Level Inverter (FCMLI) have been discussed in this paper. The STATCOM is realized by a synchronous Voltage Source Inverter (VSI), which generates three-phase ac voltages in phase with the transmission system voltage. Multilevel inverter structure of the VSI is used for the realization of the STATCOM. Three multilevel inverter structures (Diode clamped, cascade and flying voltage source) have been described in this work. The operation of these structures for the general inverter operation and compensation purposes has been studied. FCMLI is a special structure of the flying voltage source topology. A method for controlling the FCMLI is used which ensures that the flying capacitor voltages remain constant. The above inverter structures and control schemes of the STATCOM have been verified through digital computer simulation studies using PSCAD/EMTDC software package.