This paper proposes a novel framework for modular multilevel converter (MMC) current harmonic emission estimation from medium voltage (MV) charging stations. The framework is enlightened by wave decomposition, exploiting an analytical derivation of the emission, without a time-domain model. Accordingly, voltage harmonic distribution in grids can be estimated with a frequency-domain model, using the estimated voltage-dependent current emission in the iterations. Compared to conventional time-domain simulation, such method not only enables analytical harmonic estimation integrated with a large load-flow model, but also benefits from the potential of distributed computation. A 10.5 kV grid-tied single-phase half-bridge MMC simulation case on PLECS has been implemented and investigated for comparison. Corresponding results revealed that the estimated harmonic series kept the absolute average difference to the PLECS model lower than 0.02% and a correlation ratio higher than 99.990% with the simulated ones. The effectiveness of the proposed estimation framework is successfully verified.

中文翻译：

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中压充电站模块化多电平转换器的谐波电流排放估算

本文提出了一种用于中压 (MV) 充电站的模块化多电平转换器 (MMC) 电流谐波排放估算的新框架。该框架受到波分解的启发，利用发射的分析推导，没有时域模型。因此，可以使用频域模型估计电网中的电压谐波分布，在迭代中使用估计的电压相关电流发射。与传统的时域仿真相比，这种方法不仅能够将分析谐波估计与大潮流模型相结合，而且还受益于分布式计算的潜力。PLECS 上的 10.5 kV 并网单相半桥 MMC 仿真案例已经实施并进行了比较研究。相应的结果表明，估计的谐波级数与PLECS模型的绝对平均差值低于0.02%，与模拟值的相关率高于99.990%。成功验证了所提出的估计框架的有效性。