CAREER: Accelerated Insulation Aging due to Fast, Repetitive Voltage Pulses from Wide Bandgap Power Electronics

摘要：到2030年，预计80%的电力将通过电力电子系统传输。与硅基模块相比，能够承受更高电压和电流的宽带隙功率模块是减小电力电子系统尺寸和重量的最有希望的解决方案。这些宽带隙功率模块构成了电力电子系统的强大构建模块，基于宽带隙的转换器/电力电子构建模块被设想广泛应用于电网的低压和中压应用，并可能在高压直流和柔性交流传输系统的高压应用中。宽带隙器件的优点之一是其转换速率和开关频率远高于硅基器件。然而，从绝缘方面来看，频率和转换率是电压脉冲的两个最关键的因素，它们会影响暴露在这种电压脉冲下的绝缘系统的退化程度。上升时间越短，寿命越短。此外，寿命随着频率的增加而急剧减少。因此，尽管宽带隙器件正在彻底改变电力电子学，但电气绝缘系统还没有为这种革命做好准备；如果不解决绝缘问题，由于电气化部件的故障率急剧增加，电子电力革命将失败。该研究计划率先克服了基于宽带隙的电压脉冲下绝缘系统的加速老化问题，其目标是在大气压下表征、建模和减轻这种绝缘退化问题。综合教育计划将有助于培养下一代高电场和电气绝缘工程师/研究人员，这些工程师/研究人员需要保持美国电力电子和电力系统劳动力的竞争活力，以应对两大趋势：(1)各种应用中的高功率密度设计；(2)电力电子产品的使用日益增加，导致加速老化问题。该教育计划还包括向K-12年级的学生和代表性不足的群体伸出援手。由于暴露于新兴的基于宽带隙的电力电子系统产生的高转换率（范围从数十到数百千伏/μs）和重复（频率范围从数百kHz到MHz）电压脉冲，电力系统组件中绝缘系统的加速老化和退化是接受和利用宽带隙功率模块的最重要障碍之一。本研究旨在通过“基于理论的多物理场”方法(1)表征，(2)建模，以及(3)缓解加速老化问题。通过全面的实验研究，对加速老化问题进行表征，并将实验数据用于验证所建立的多物理场模型。此外，将通过将开发和实验验证的模型确定解决加速老化问题的最佳缓解方法。此外，将开发用于旋转机器、变压器、电缆和传输线的高频电磁瞬变模型，以确定(i)过电压，（ii）电应力和（iii）不同部件（包括电机和变压器绕组）的热应力，以及电机和电缆终端在宽带隙电压加号下的应力分级系统。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Title: CAREER: Accelerated Insulation Aging due to Fast, Repetitive Voltage Pulses from Wide Bandgap Power Electronics Abstract: By 2030, it is expected that 80% of all electric power will flow through power electronics systems. Wide bandgap power modules that can tolerate higher voltages and currents than silicon-based modules are the most promising solution to reducing the size and weight of power electronics systems. These wide-bandgap power modules constitute powerful building blocks for power electronics systems, and wide bandgap-based converter/power electronics building blocks are envisaged to be widely used in power grids in low- and medium-voltage applications and possibly in high-voltage applications for high-voltage direct current and flexible alternating current transmission systems. One of the merits of wide bandgap devices is that their slew rates and switching frequencies are much higher than silicon-based devices. However, from the insulation side, frequency and slew rate are two of the most critical factors of a voltage pulse, influencing the level of degradation of the insulation systems that are exposed to such voltage pulses. The shorter the rise time, the shorter the lifetime. Furthermore, lifetime dramatically decreases with increasing frequency. Thus, although wide bandgap devices are revolutionizing power electronics, electrical insulating systems are not prepared for such a revolution; without addressing insulation issues, the electronic power revolution will fail due to dramatically increased failure rates of electrification components. This research plan pioneers overcoming the accelerated aging of insulation systems under wide bandgap-based voltage pulses, and its goal is to characterize, model, and mitigate this insulation degradation issue under atmospheric pressure. The integrated education plan will help to train the next generation of high electric field and electrical insulation engineers/ researchers, who are needed to maintain the competitive vitality of the U.S. power electronics and power system workforce regarding the two trends toward (I) high-power-density designs in various applications and (II) the increasing use of power electronics, leading to the accelerated aging issue. The education plan also includes outreach to students in grades K-12 and underrepresented groups.Accelerated aging and degradation of insulation systems in power system components as a consequence of exposure to the high slew rates (ranging from tens to hundreds of kV/μs) and repetitive (frequencies ranging from hundreds of kHz to MHz) voltage pulses that originate from emerging wide bandgap-based power electronics systems are one of the most significant barriers for the acceptance and utilization of wide bandgap power modules. This research endeavor aims to (1) characterize, (2) model, through a “theoretical-based Multiphysics” approach, and (3) mitigate the accelerated aging problem. Through comprehensive experimental investigations, the accelerated aging issue will be characterized, and the experimental data will also be used to validate the Multiphysics models developed. Furthermore, optimal mitigation methods to solve the accelerated aging problem will be determined through the models that will be developed and verified experimentally. Moreover, high-frequency electromagnetic transient models for rotating machines, transformers, cables, and transmission lines will be developed to determine (i) overvoltages, (ii) electrical stress, and (iii) thermal stress on different components including motor and transformer windings, and stress grading systems in electrical motors and cable terminations under wide bandgap-based voltage pluses.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.