Abstract:Emergency load shedding when serious HVDC transmission fault happens are necessary measures to prevent frequency drop of receiving-side power network.Combined with the characteristics of the stability control and marketing load control,it proposes a load control system using the load which can be interrupted as the object of precise control.It compares advantages and disadvantages of the load control by stability control device and load control by the marketing system and then introduces the overall architecture of precise load control system.It focus on the functional position of the system,load control principle and prevention for system malfunction and rejection.The precise load control system proposed in this paper has been completed and put into operation in Jiangsu Power Grid,which realizes accurate control of 3.5 million kilowatt per second and emergency control capability of 1 million kilowatt per millisecond.