Design Of SSDC And Optimization Of PI Parameters Of Constant Current Controller In HVDC

This paper studies the problems of how to use additional controller to suppress the sub-synchronous oscillation caused by the constant current controller and how to optimize PI parameters of the constant current controller in HVDC.The paper begins with the description of the control system structure of HVDC, which includes its basic structure and the basic control modes. Besides, we do a comparison among the common dynamic performance indicators, and deduce the transfer function of constant current controller on rectifier side and constant y controller on inverter side separately. Then based on the analysis of sub-synchronous caused by HVDC control system, we compare different designs of SSDC and design the SSDC using time-domain simulation method combined with the test signal method. The simulation result shows that SSDC can inhibit sub-synchronous effectively and improve security and stability of the system. Meantime, to resolve the optimization of PI parameter in HVDC, we propose to use adaptive particle swarm algorithm to optimize PI parameters, by writing algorithm in MATLAB and optimizing PI parameters based on the transfer function of constant current controller. Finally, taking constant current controller in CIGRE standard test of PSCAD for example, and the results verify the effectiveness and practicality of the method.