Transient Stability Analysis of Renewable Power Generations via VSC-HVDC

Large power fluctuation may cause transient instability in renewable power generations (RPGs) via voltage source converter based high voltage direct current transmission (VSC-HVDC) system. First, this article establishes a reduced-order model of a system including grid-following RPGs and grid-forming VSC-HVDC, derives equivalent motion equations, and analyzes the dynamic coupling mechanism among different types of control units and their impacts on the system's transient stability. Then, a transient stability assessment method based on equivalent acceleration and deceleration areas is proposed. Furthermore, the power feasible region of such a system is constructed, and the influence of main circuit and control parameters on system stability is analyzed. Finally, the effectiveness of the proposed transient stability analysis method is validated through experimental results conducted on the real-time laboratory (RT-LAB) platform.