Solid-State Transformer Stability and Control Considerations


This paper addresses the stability issues and some control solutions in solid-state transformers (SST). An SST is built using three cascaded stages, including an ac-dc rectifier, a dual active bridge (DAB) converter, and a dc-ac inverter. Multistage cascaded converters are highly prone to instabilities due to the interaction between stages. Hence, the control system must be designed in a way that solves this detrimental interaction effect. Additionally, the stability issue can become even more complicated when a distributed energy storage device (DESD) and a distributed renewable energy resource (DRER) are added to the SST. In this paper, the stability of the SST is studied by applying the Middlebrook's criterion. To do so, the converters' small-signal models will be derived, and the frequency domain analyses is carried out to predict the time domain behavior of the SST. An average model of SST will be simulated in PSCAD to validate the stability analyses predictions.

Meeting Name

29th Annual IEEE Applied Power Electronics Conference and Exposition (2014: Mar. 16-20, Fort Worth, TX)


Electrical and Computer Engineering

Keywords and Phrases

Distributed Energy Storage Device; Distributed Renewable Energy Resource; Stability; Impedance; Rectifiers; Inverters; Transfer Functions; Stability Criteria; Power System Stability; Rectifiers; AC-DC Power Convertors; DC-AC Power Convertors; Frequency-Domain Analysis; Invertors; Power System Stability; Power Transformers

International Standard Book Number (ISBN)


International Standard Serial Number (ISSN)


Document Type

Article - Conference proceedings

Document Version


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© 2014 Institute of Electrical and Electronics Engineers (IEEE), All rights reserved.

Publication Date

01 Mar 2014