基于电压源换流器的高压直流输电系统离散化建模与仿真研究

基于电压源换流器的高压直流输电(voltage source converter based high voltage direct current transmission,VSC-HVDC)的工业控制系统通常为微机控制器,该控制器的控制对象是系统的离散化模型。为此提出了一种在dq0同步旋转坐标系下的VSC-HVDC离散化状态空间模型。在此基础上建立了VSC电流内环离散化控制器和外环控制器,并实现了有功电流和无功电流的解耦控制;为提高VSC-HVDC的外环控制器响应速度,在外环控制器中引入了前馈控制。基于电磁暂态仿真软件PSCAD/EMTDC建立了VSC-HVDC模型及其离散化控制器模型。仿真结果验证了离散模型的正确性以及控制策略的有效性。

Discretization Modeling and Simulation Study of HVDC Power Transmission System Based on Voltage Source Converters

Minicomputer controllers are usually used in the industrial control systems of voltage source converter based high voltage direct current transmission(VSC-HVDC)and the controlled objects are discretized models of VSC-HVDC.For this purpose a discretized state space model of VSC-HVDC under d-q-0 synchronous rotating coordinate system is proposed.On this basis the inner-loop current discrete controller and the outer-loop controller of VSC are built and the decoupling control for active and reactive currents are implemented.To accelerate the response speed of outer-loop controllers of VSC,the feed-forward control is led into outer-loop controller.Based on electromagnetic transient simulation software PSCAD/EMTDC,a VSC-HVDC model and a model for its discretized controller are built.Simulation results verified that the proposed discretized model is correct and the control strategy is effective.