To test high-voltage (HV) equipment with increasingly complex transients obtained from various power system studies, this article demonstrates a hardware implementation of a medium-voltage (MV) submodule (SM) to be used in a modular multilevel converter (MMC)-based HV arbitrary wave shape generator (AWG). The MV SM is scalable with its own onboard auxiliary power supply (APS), and it is constructed by connecting three full-bridge SMs in series from the commercially available component. The designed MV SM can be operated for a wide voltage range of 0.8–2.7 kV to incorporate different test objects ranging from HV insulation material to MV equipment and generate a wide output range of 0.12–1.2 kV. Considering the hardware nonidealities in the APS, gate driver, and switches, the series operation of three SMs is ensured using an arm energy controller. Based on the current-based model of APS, SM capacitance design criteria are updated for variable-frequency output waveform, and the minimum dc-link voltage is calculated for the proper start-up of this scalable MMC module. Apart from the variable voltage per SM, the HV AWG application poses different conditions, such as a low value of SM capacitance value and the HV dc sources with a current rating of a few tens of milliamperes. Hence, this article proposes exclusive design guidelines for the proper start-up, steady-state, and shutdown operation of the MMC-based AWG. In addition, this article dives deeper analytically into the soft start-up algorithm to understand its working principle and to design the average charging current within the limit for any number of SMs of the arm. In the end, their performance is showcased with a single MV SM per arm, operating at a different voltage (0.8–2.7 kV) and frequency levels (1–600 Hz) and generating different wave shapes, such as triangular, sinusoidal with different harmonics, and pulse waveforms. In addition, the fault ride-through capability is verified for the MMC-based HV AWG.

中文翻译：

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基于模块化多电平转换器的任意波形发生器的可扩展串联子模块演示，用于现成组件的高压测试

为了测试从各种电力系统研究中获得的日益复杂的瞬态高压 (HV) 设备，本文演示了用于模块化多电平转换器 (MMC) 的中压 (MV) 子模块 (SM) 的硬件实现 -基于高压任意波形发生器（AWG）。MV SM 可通过其自己的板载辅助电源 (APS) 进行扩展，它是通过将商用组件中的三个全桥 SM 串联连接而成的。设计的中压 SM 可在 0.8–2.7 kV 的宽电压范围内运行，以纳入从高压绝缘材料到中压设备的不同测试对象，并产生 0.12–1.2 kV 的宽输出范围。考虑到 APS、栅极驱动器和开关中的硬件非理想性，使用 ARM 能量控制器确保三个 SM 的串联运行。基于基于电流的 APS 模型，针对可变频率输出波形更新了 SM 电容设计标准，并计算了最小直流母线电压，以便正确启动该可扩展 MMC 模块。除了每个 SM 的电压可变之外，HV AWG 应用还提出了不同的条件，例如 SM 电容值较低以及额定电流为几十毫安的高压直流源。因此，本文针对基于 MMC 的 AWG 的正确启动、稳态和关闭操作提出了独家设计指南。此外，本文对软启动算法进行了更深入的分析，以了解其工作原理，并为该臂的任意数量的 SM 设计限制内的平均充电电流。到底，它们的性能通过每臂一个 MV SM 来展示，在不同的电压 (0.8–2.7 kV) 和频率水平 (1–600 Hz) 下运行，并生成不同的波形，例如具有不同谐波的三角波、正弦波和脉冲波形。此外，还验证了基于 MMC 的高压 AWG 的故障穿越能力。