Power command compensation structure to improve the dynamic performance for single phase transformer-less photovoltaic inverters with dynamic power decoupling

摘要

This paper proposes a scheme to improve the system transient performance by implementing a power command compensation structure in a single phase transformer less photovoltaic inverter with dynamic power decoupling. The drawback of the original control scheme in the transient performance is analyzed and shown in simulation results. The mechanism of the proposed control scheme is discussed in detail. The analysis and benefits of the proposed scheme are validated on a single-phase grid-connected inverter prototype employing SiC MOSFETs and DSP28335 for control implementation. Compared with the original control scheme, the improved scheme can realize a significant improvement in the transient response and can in turn decrease the dc link voltage maximum value by 35%, achieving higher efficiency and cost reduction.