Abstract This paper demonstrates the presence of spurious power generation or losses in two commonly used Modular Multilevel Converter (MMC) models: the Arm Equivalent Model (AEM) and the Average Value Model (AVM). Such power does not represent any physical phenomenon and appears due to numerical effects. It is demonstrated that spurious power is present when the model equations are not solved simultaneously with the surrounding electrical circuit equations, which is the case when the AEM and AVM are implemented using control system blocks. Depending on operating conditions and simulation parameters, such power can represent a significant part of the total converter station losses or even surpass them, thus making simulation results inaccurate. Several solutions to eliminate the spurious power are proposed for the AEM and AVM. Their effects are demonstrated in steady-state and transient conditions on a point-to-point MMC-HVDC simulation test case.

中文翻译：

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模块化多电平转换器模型中的杂散功率及其消除

摘要 本文展示了两种常用的模块化多电平转换器 (MMC) 模型中存在的杂散发电或损耗：Arm 等效模型 (AEM) 和平均值模型 (AVM)。这种力量并不代表任何物理现象，而是由于数值效应而出现。结果表明，当模型方程没有与周围的电路方程同时求解时，就会出现寄生功率，这就是使用控制系统块实现 AEM 和 AVM 时的情况。根据运行条件和仿真参数，这种功率可能占换流站总损耗的很大一部分，甚至超过它们，从而使仿真结果不准确。为 AEM 和 AVM 提出了几种消除杂散功率的解决方案。