To resolve the surplus power problem in modular multilevel converter-based high-voltage direct current (MMC-HVDC) systems during onshore AC grid faults

this paper first calculates and validates the rationality of the energy warning threshold and develops an adaptive operating energy value

thus addressing the sub-module overvoltage issue arising from distance-related delays and control transition lags. Then

it analyzes the dynamic output characteristics of the grid-side converter (GSC) during low-voltage ride-through (LVRT) and presents a precise voltage-reduction control strategy for offshore converter stations. This strategy

based on feedback from the DC voltage change rate

enables effective load reduction in wind turbines. Finally

this paper proposes a LVRT strategy that integrates coordinated control of precise wind turbine load reduction and sub-module capacitor energy

effectively addressing the underutilization of system energy margin and the high investment in energy-dissipating devices during fault periods. In this study

a simulation model is developed in MATLAB/Simulink to validate the effectiveness of the proposed method

with comparisons against existing approaches. The simulation results demonstrate that the proposed method can significantly reduce

or even eliminate

the need to activate energy-dissipating devices. It also exhibits adaptability to maximize the utilization of the MMC-HVDC system’s energy margin under different fault conditions. Notably

under mild fault conditions

the method preserves a portion of the energy margin after fault clearance

thereby effectively mitigating secondary voltage sags and enhancing the system’s LVRT performance.