Closed-loop control of three-phase four-leg inverters with the SHM-PWAM strategy

In this paper, a closed-loop control scheme with the SHM-PWAM strategy for three-phase four leg inverters has been proposed. The complexity of proposed control strategy is low for implementation. Recently developed PWAM strategy, is applied to the three-phase four-leg inverter. This leads to an increase in the system degrees of freedom in mitigating more harmonics compared to the conventional PWM-based strategies. The control signals of three-legs, mathematically expressed using Fourier-based equations to mitigate lower order non-triple harmonics, and the fourth les, produces the harmonics that are equal to the lower order triple harmonics which produced by the other legs. Simulation and experimental results show the superior performance of the proposed closed-loop control strategy.