Fault Operating Condition of Modular Multilevel Converter-Based HVDC Using Lyapunov Method Compensators

In this paper, the input-output feedback linearization (IOFL) theory is applied to modular multilevel converter (MMC) dynamics to design the initial control strategy. Then, direct Lyapunov method is used to complete the control strategy by attaining several effective low pass filters (LPFs). In the process of achieving LPFs, global stability of the considered MMC-based high voltage dc (HVDC) system is guaranteed through the d and q components of both MMC output and circulating currents dynamics. To this end, the errors of proposed control functions with suitable Lyapunov coefficients are used to shape the energy function. Simulation results in MATLAB/SIMULINK environment are provided to verify effectiveness of the proposed control strategy at reaching a good dynamic response for a MMC-based HVDC system under fault condition.