模块化多电平换流器快速能量等效建模

为解决模块化多电平换流器(modularmultilevel converter,MMC)电磁暂态仿真效率低的问题,提出一种针对MMC桥臂及子模块等效的快速能量等效模型,具有建模过程简单,方法可靠的优点。通过对MMC桥臂进行受控源等效,保证换流器的外部特性一致,并使得桥臂与子模块间电气解耦;再利用桥臂与子模块只有二次信息交换的特点,对子模块进行开关简化与能量等效建模,简化了仿真电路,减少电路中的非线性元件。在PSCAD/EMTDC仿真平台上对所提仿真建模方法进行验证,对比详细模型提速效果可以达到1736倍以上,结果表明所提快速能量等效模型的有效性,能够保证高仿真精度,并在仿真效率上极大的提升。

Fast Energy Equivalent Modeling of Modular Multilevel Converter

In order to further improve electromagnetic transients of modular multilevel converter in simulation, a fast energy equivalent model, simple and reliable, for converter-arm and sub-module is proposed. Specifically, the converter-arm is equivalent to a controlled source, ensuring that the converter has the same external characteristics and electrically decoupling the sub-module from the arm. This model simplifies sub-module switch and performs energy equivalence, using electrical independence features of the sub-modules. The proposed method also simplifies simulation circuit and reduces the number of nonlinear components in the circuit. The proposed simulation model is verified on PSCAD/EMTDC platform, showing that it is 1736 times faster than the detailed one. Results show effectiveness of the proposed fast energy equivalent model, guaranteeing high simulation accuracy and greatly improving simulation efficiency.