PROJECT TITLE :

Stability Boundary Analysis in Single-Phase Grid-Connected Inverters with PLL by LTP Theory - 2017

ABSTRACT:

Stability analysis of power converters in ac networks is advanced due to the nonlinear nature of the conversion systems. Whereas interactions of converters in dc networks will be studied by linearizing regarding the operating point, the extension of the identical approach to ac systems poses serious challenges, especially for single-part or unbalanced 3-phase systems. A general technique for stability analysis of power converters suitable for single-part or unbalanced ac networks is presented during this paper, based on linear time periodic theory. A single-phase grid-connected inverter with part-locked loop (PLL) is considered as case study. It is demonstrated that the steadiness boundaries will be precisely evaluated by the proposed methodology, despite the nonlinearity introduced by the PLL. Simulation and experimental results from a 10-kW laboratory prototype are provided to substantiate the effectiveness of the proposed analysis.