A Damping Controller Design for D-PMSG-based Wind Farm Integrated With LCC-HVDC System Based on Damping Path

In recent years, large-scale new power equipment will transmit power to the load center through the line-commutated-converter based high voltage direct current (LCC-HVDC) transmission. The interaction between new energy equipment and LCC-HVDC increases the risk of subsynchronous oscillation (SSO), so it is urgent to carry out related research. To solve the above problems, we quantitatively evaluates the damping characteristics of subsynchronous interaction between different subsystems in direct-drive permanent magnet synchronous generator (D-PMSG)-based wind farm through the LCC-HVDC transmission system through damping path analysis, and proposes an additional damping controller design method based on damping path analysis results from the perspective of path damping compensation. Firstly, the damping characteristics of SSO mode led by LCC-HVDC DC inductor are analyzed by referring to the damping coefficient in the damping torque method. Then, we plot the closed-loop transfer function block diagram about three damping paths together, then their damping characteristics in the system are decomposed. Then, based on the quantitative analysis results of the internal damping path of the system, a method of additional damping controller based on the damping path is proposed to suppress the risk of SSO in the system. Finally, taking the system we analyzed above as an example, the effectiveness of the additional damping controller design method based on damping path is designed and verified by simulation.