The paper briefly investigates the importance of power control of HVDC (high voltage direct current) control system in the HVDC projects and focus on the actual analysis and research on the realization of automatic power control in HVDC transmission. It has the important guiding significance for the implementation of automatic power control in HVDC transmission.

For the detection and location of power quality disturbance signal problem, a disturbance localization algorithm is proposed based on the mean sum of the square of S-transform amplitude, with this method the time of occurrence and duration of the disturbance signal is simulated. Simulation results show that the proposed algorithm is simple and effective, able to accurately analyze the disturbance signal, and the magnitude of voltage perturbation, voltage sag and voltage swell can be estimated.