Evaluation of Nonlinearity and Complexity in SSTs Systems


This paper addresses the complexity and nonlinear dynamics that may arise in solid state transformers (SST). SST in contrast to the conventional transformer is prone to nonlinear and complex dynamics due to incorporation of power electronic (PE) converter and devices. This is because of nonlinear nature, interdependence and coupling, and feedbacks (e.g. control) of these converters. In this paper, the nonlinear and complex behavior of a SST connected to the power grid will be investigated by presenting some test results in normal or extreme operation of system. Then a methodology of complexity quantification will be proposed, which is a refinement of a popular measure called approximate entropy (ApEn). This methodology will be used to interpret some complex behavior of SST system. The detailed model and control scheme of SST including AC/DC rectifier, Dual Active Bridge (DAB) converter and DC/AC inverter are developed to enable dynamic system level simulation.

Meeting Name

6th IEEE International Systems Conference (2012: Mar. 19-22, Vancouver, Canada)


Electrical and Computer Engineering

Keywords and Phrases

AC/DC Rectifiers; Approximate Entropy; Complex Behavior; Complex Dynamics; Complexity; Control Schemes; Conventional Transformer; DC/AC Inverters; Detailed Models; Dual Active Bridges; Non-Linearity; Nonlinear Nature; Power Grids; Solid State Transformer (SST); SSTs; System Level Simulation; Convergence Of Numerical Methods; Dynamics; Electric Rectifiers; Entropy; Nonlinear Feedback; Nonlinear Dynamics; Stability

International Standard Book Number (ISBN)

978-1467307505; 978-1467307482

Document Type

Article - Conference proceedings

Document Version


File Type





© 2012 Institute of Electrical and Electronics Engineers (IEEE), All rights reserved.

Publication Date

01 Mar 2012