Pole-placement control strategy for 4-leg voltage-source inverters

Four-leg inverters are used in critical applications like UPS systems and satellite earth stations. Consequently, generation of balanced voltages, with sinusoidal waveform, is necessary for these inverters. Most papers dealing with 4-leg inverters suggest classic controllers, such as PI controller, for the system. However, the transient performance of the closed-loop system does not become, accurately, adjustable and acceptable, in some cases. This paper proposes Pole Placement control strategy, via state feedback, for 4-leg voltage-source inverters to adjust the transient performance of the closed-loop system. Simulation results validate the theoretical results and proposed control strategy.