Reactive Power Control and SVG Coordinated Control Method for HVDC Transmission System

Abstract

This paper proposes a reactive power and SVG coordinated control method for a HVDC transmission system. The method includes calculating the reactive power ΔQ exchanged between the converter station and the AC system. Set the dead zone range of ΔQ and limit the output of ΔQ. Set the restriction condition of SVG’s ability to adjust and judge whether the reactive power emitted by SVG is restricted. Based on whether the reactive power sent by the SVG is limited and the limitation results of ΔQ, the input of the PI controller in the QPC module is calculated to complete the reactive power, and SVG coordinated control process. When this control method is adopted, the operating time of the converter greater than the rated angle is significantly reduced, the loss of the converter is effectively reduced. Meanwhile, the DC voltage rise and fall are stabilized, and the AC voltage fluctuations due to the passive switching are greatly reduced.