一种典型混联直流输电系统的运行特性分析

Operating Characteristic for a Typical Hybrid HVDC Transmission System

混合型高压直流输电能够充分利用晶闸管换流器和电压源换流器的优点,具有良好的发展前景。为研究混联式直流电网的控制策略和运行特性,建立了整流侧采用模块化多电平换流器,逆变侧采用晶闸管换流器的四端双极混联式结构,推导其数学模型,并设计了相应的控制策略,在PSCAD/EMTDC中对该混联式直流电网的启动过程和运行特性进行了仿真分析,证明了所提出控制策略的有效性。

Hybrid HVDC can take full advantage of the thyristor converter and voltage source converter,and it has a good development prospects. In order to analysis the control strategy and operating characteristic of hybrid DC grid,a four terminal bipolar＇s hybrid grid structure is established,whose rectifier side is modular multilevel converter and inverter side is thyristor converter,the mathematical model is derived and corresponding control strategy is designed. The start-up process and operating characteristic of hybrid DC grid are simulated and analyzed in PSCAD/EMTDC,which demonstrates the effectiveness of the proposed control strategy.