报告题目：Low-inertia Solid-State Transformer (SST) Modeling and Control

报告时间：2021年12月27日

报告地点：ZOOM

报告人：IEEE Fellow, Hui “Helen” Li

报告人简介：

Dr. Li is a professor of Electrical and Computer Engineering Department and leads power electronics research at Center for Advanced Power Systems (CAPS), Florida State University. Her research interests include solid-state transformers, multilevel converters, and WBG based power electronics for transportation and renewable energy grid applications. She is co-editor-in-chief of IEEE Transaction on Power Electronics from 2019-2021. She is a PELS Distinguished Lecturer of 2018-2019 and 2020-2021. She is the elected member at large of Administrative Committee of PELS from 2011-2013, 2015-2017, 2018-2020. She is a Fellow of the IEEE.

报告内容简介：

One goal pursued constantly by power electronics researchers is to reduce the size of capacitor and inductor in the converters to lower cost, size, and weight.  For solid-state transformers (SST) usually based on modular and/or multilevel configuration due to high voltage requirements, the benefits will be significant if cell capacitors and arm inductors size can be reduced. However, control becomes very challenging due to the stability issues inherent to the low-inertia systems. In addition, low-inertia SST has extra control challenges such as strong coupling between AC and DC stages as well as dramatically increased circulating energy compared to other low-inertia converters. Some methods have been proposed to address low-inertia SST control challenges, however, they are very complicated. In this talk, a novel modeling method is presented for a low-inertia DC solid-state transformer (SST) formed by inductor-less MMCs based on phase-shifted square-wave (PS-SWM) modulation. The developed model explicitly defines the circulating energy and remains accurate with an arm inductor-less operation. Based on the developed model, a hybrid PI + predictive control is designed to achieve fast and stable power flow control. Moreover, the control can achieve a “virtue inductance” function to suppress the low order harmonics of DC current caused by enlarged circulating energy due to low-inertia feature.