STATCOM Based on Cascade Multilevel Inverter
Static Synchronous Compensator (STATCOM) using the voltage source inverter (VSI) has been widely accepted as the current generation of the reactive power regulators of power system, improving the network steady-state and dynamic performances, regulates power factor, reduces losses and allows higher power flows in the exist line, assists in the post-fault recovery of transmission system. The cascade inverter not only can eliminate the bulky transformers compared with the conventional STATCOM, but also employ a sinusoid pulse width modular scheme: phase-shift. The use of the feedback linearization approach to design nonlinear controllers of power inverters is particularly interesting because it transforms a nonlinear system into a linear one in terms of its input–output relationship. Partial linearization may still be useful in some cases providing that the internal zero dynamics exhibit a proper transient performance.
J. L. Zhang "STATCOM Based on Cascade Multilevel Inverter", Applied Mechanics and Materials, Vols. 55-57, pp. 1365-1369, 2011