This paper comprehensivelyinvestigates the design trade-offs of a Modular Multilevel Converter (MMC) operations as an Arbitrary Wave shapesGenerator (AWG) to perform High Voltage (HV) dielectric testing of different grid assets. HV AWG applications pose unique operatingconditions to the MMC, which influences the selection of the various system parameters. This influence of the MMC system parameters is studied analytically, with MATLAB-Simulink simulations and a down-scaled MMC prototype. It is found that the Phase-Shift Carrier (PSC) modulation technique proves to be a superior modulation technique over Nearest Level Control (NLC). The correct choice of arm inductance and series damping resistance improves the harmonic performance of the output voltage waveform. The fast switching SiC MOSFETs are well suited to generate complex waveforms with high bandwidth. The adapted control system with the proportional controller can accurately generate the different waveforms with Total Harmonic Distortion (THD) less than 5%. The circulating current in the MMC is negligible for the HV AWG application, which explains why the submodule capacitor voltages are balanced even when asymmetric complex wave shapes are generated from the MMC. Additionally, the submodule capacitor ripple expression is derived for this unique application, and it matches well with the simulation and experimental results. For this application, submodule capacitance in the $\mu$ F range is sufficient to keep the ripple within 1% of its average value. Moreover, the challenges of realizing the full-scale MMC setup are discussed. The discussed design guidelines are applied to simulate the full-scale prototype with 67 submodules per arm.

中文翻译：

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用于常规和非常规高压测试的基于模块化多电平转换器的任意波形发生器的设计权衡

本文全面研究了模块化多电平转换器 (MMC) 操作作为任意波形发生器 (AWG) 对不同电网资产执行高压 (HV) 介电测试的设计权衡。HV AWG 应用对 MMC 提出了独特的操作条件，这会影响各种系统参数的选择。使用 MATLAB-Simulink 仿真和缩小比例的 MMC 原型，对 MMC 系统参数的这种影响进行了分析研究。发现相移载波 (PSC) 调制技术被证明是优于最近电平控制 (NLC) 的调制技术。臂电感和串联阻尼电阻的正确选择可以提高输出电压波形的谐波性能。快速开关 SiC MOSFET 非常适合生成具有高带宽的复杂波形。带有比例控制器的自适应控制系统可以准确地生成总谐波失真 (THD) 小于 5% 的不同波形。MMC 中的循环电流对于 HV AWG 应用可以忽略不计，这解释了为什么即使当 MMC 产生不对称的复杂波形时，子模块电容器电压也是平衡的。此外，子模块电容器纹波表达式是针对这一独特应用推导出来的，它与仿真和实验结果非常匹配。对于此应用，子模块电容在 MMC 中的循环电流对于 HV AWG 应用可以忽略不计，这解释了为什么即使当 MMC 产生不对称的复杂波形时，子模块电容器电压也是平衡的。此外，子模块电容器纹波表达式是针对这一独特应用推导出来的，它与仿真和实验结果非常匹配。对于此应用，子模块电容在 MMC 中的循环电流对于 HV AWG 应用可以忽略不计，这解释了为什么即使当 MMC 产生不对称的复杂波形时，子模块电容器电压也是平衡的。此外，子模块电容器纹波表达式是针对这一独特应用推导出来的，它与仿真和实验结果非常匹配。对于此应用，子模块电容在$\亩$ F 范围足以将纹波保持在其平均值的 1% 以内。此外，还讨论了实现全尺寸 MMC 设置的挑战。所讨论的设计指南用于模拟每臂具有 67 个子模块的全尺寸原型。