Harmonic stability analysis of offshore wind farm with component connection method

In this paper, an eigenvalue-based harmonic stability analysis method for offshore wind farm is proposed. Considering the internal cable connection layout, a component connection method (CCM) is adopted to divide the system into individual blocks as current controller of converters, LCL filters, collection system cable impedance, transmission cable impedance and grid impedance. By using this method, each block can be modelled independently and then be integrated into a whole state space matrix which contains sparse and diagonal matrix. Compared with the traditional state space formulation process, this method is superior in reducing the computational cost. A 4 by 4 wind turbines wind farm is selected as the study case and the proposed method is validated by comparing the results obtained from time domain simulation software — Power System Computer Aided Design (PSCAD).