基于PSCAD仿真的柔性直流输电技术研究

Technical Study on Flexible DC Transmission Based on PSCAD Simulation

柔性直流输电技术是基于全控器件的新型高压直流输电(HVDC)技术,采用基于全控器件的电压源型换流器(VSC)和正弦脉宽调制(SPWM)技术进行无源逆变,解决了应用直流输电技术向无源负荷供电的问题。针对柔性直流输电的基本原理、VSC的数学模型和控制策略进行分析,研究了柔性直流输电系统的控制技术及其应用,并讨论了VSC的dq轴模型和几种基本控制方式。最后采用PSCAD软件建立了输电系统仿真模型,对向无源网络供电和两端供电这两种情况进行了仿真研究。仿真结果表明,柔性直流输电技术在两种情况下均能实现灵活可靠的控制。

Flexible direct-current transmission technology is a new HVDC technology based on full-controlled devices,voltage source converter（VSC） based on full-controlled devices and sinusoidal pulse width modulation（SPWM）technology are adopted for passive inverter to solve the issue i.e.direct current transmission technology is applied to supply the power to passive loads.The basic principle of flexible HVDC,the mathematical model of VSC and control strategy were analysed based on the research of the control technology of flexible HVDC system and its application,the dq axis model of VSC and several basic control methods were also discussed.Finally PSCAD software was used to establish a simulation model of the transmission system,and perform the simulation study on two cases i.e.power supply to passive network and two-sided current supply.The simulation results show that the flexible HVDC technology in both cases can achieve flexible and reliable control.