基于MMC的柔性直流输电仿真与分析

Modeling and Simulation of Flexible HVDC Based on MMC

近年来,基于电压源换流器的柔性直流输电技术在我国得到了快速发展。为了分析研究双端柔性直流输电系统中参考值发生变化时,输电线路上流过的有功量和无功量的变化曲线,采用实时仿真软件RTDS进行了仿真分析,换流器采用模块化多电平换流器MMC,送端采用定有功功率和定交流电压的控制方式,受端采用定直流电压和定交流电压的控制方式,换流器MMC的调制方式采用最近电平逼近调制。分别调节系统中的有功量参考值和无功量参考值,观察调节前后有功量实际值和无功量实际值的变化曲线。仿真结果显示,调节系统中的有功量参考值主要对有功量的实际值产生影响而调节系统中的无功量参考值主要对无功量实际值产生影响。验证了该模型在仿真过程中具有有功、无功解耦控制的特点。

In recent years,the flexible HVDC based on voltage source inverter got rapid development in China. In or- der to analyze the change of the amount of active and reactive power curve of transmission lines when the reference value in two terminal HVDC system changes, the RTDS real-time simulation software is used for the analysis in this paper, the inverter adopts modular multilevel converter MMC, the sending end using the active power and voltage con- trol mode, the client using the constant DC voltage and rated voltage AC voltage control mode, the inverter using re- cent level approximation modulation of MMC. The active reference value and reactive reference value were controlled respectively and the actual value change curve of active and reactive power before and after the regulation was ob- served. The simulation results show that the active power reference value mainly affects the actual value of active power and reactive power reference value affects the actual value of reactive power. This model was verified to have the active and reactive power decoupling control characteristics in the simulation process.