A Review on Impedance Modeling of Grid-Connected Renewable Energy Generation System

With the increasing proportion of renewable energy generation in the power grid, the stability issues induced by its grid connection becomes more and more important. The impedance-based approach has become an important method to analyze such issues because of its unique advantages. This paper gives a comprehensive review on impedance modeling of the grid-connected renewable energy generation system. Several commonly used impedance modeling methods are studied, including the dq-frame linearization and the harmonic linearization methods and their development. Then, the impedance modeling of the photovoltaic power generation system, direct-drive wind turbine, and doubly-fed wind turbine is introduced.