Symmetrical Shoot-Through Based Decoupled Control of Z-Source Inverter

Total harmonic distortion, produced with the existing PWM techniques for a Z-source inverter topology, is higher due to the unsymmetrical shoot-through, if separate controls of ac and dc sides are required. This paper proposes the concept of symmetrical shoot-through-based modulation and compares the performance with the case of the popular simple boost control. The proposed modulation method achieves a sinusoidal and symmetrical distribution of shoot-through states. This ensures an improved current and voltage profile at the output, along with the capability of decoupled control for the shoot-through and the modulation index control. The effectiveness of the proposed method has been demonstrated and validated through analysis, simulation, and experimentation. This concept can be applied to all the variants of Z-source-based power conversions.