Stability studies of critical DC power system component for More Electric Aircraft using μ sensitivity

Abstract

In this paper an approach for stability analysis of power systems for " More Electric Aircraft " (MEA) using µ sensitivity is proposed. The application of the proposed approach is illustrated via a regulated buck converter as a typical critical component in a power system. Due to the negative resistance at low frequencies the regulated buck converter could be unstable in combination with the input filter. A typical regulated buck converter is first modelled in the simulation package Dymola. The model equations are transferred to Maple or Matlab with a Dymola toolbox and symbolically linearized at steady state conditions. For computing µ sensitivity it is necessary to get a Linear Fractional Representation (LFR) of the buck converter. This is done by using the enhanced LFR Toolbox 2.0. Finally, the µ sensitivity is computed with the Robust Control Toolbox 3.1.1 of Mathworks. Compared with other methods for small signal stability, e.g. Middlebrook criterion and Modal Analysis, the µ sensitivity approach gives a much more global and direct result for the influence of all components on stability.

$\mu$ Approach to Robust Stability Domains in the Space of Parametric Uncertainties for a Power System With Ideal CPL

“…The authors in [4] have developed a software to make the process automatic in order to make the approach less laborious. Conversely, the SSV based µ method, that is presented in this work, has proven to produce reliable results in stability assessment of uncertain systems [9], [11], [12], [13]. Further, the µ approach excludes the need for extensive linearisation and parameter iterations.…”

“…In order to incorporate uncertainties when using classical methods, the eigenvalue method is typically combined with the Monte Carlo simulation. However, this probabilistic stability assessment approach can be employed to determine probability density functions of critical eigenvalues but cannot guarantee to identify the most critical system scenarios with respect to stability [9], [10]. In addition, the study [4] proposes an admittance space stability analysis method that incorporates parametric uncertainties in the application of the classical impedance-based Energy Source Analysis Consortium approach.…”

Toward Robust Stability of Aircraft Electrical Power Systems: Using a μ-Based Structural Singular Value to Analyze and Ensure Network Stability

“…However, applying single input single output (SISO) methods to multi input multi output systems (MIMO) may not produce reliable results, as reported in a number of studies [30], [31].…”

Fault Detection of Power Electronic Circuit using Wavelet Analysis in Modelica

“…It is well known that an output voltage regulated DC/DC power converter supplying constant power loads could de-stabilize the network stability due to the degraded performance of its input filter. The sensitivity study of input filter parameters concerning the network stability addressed in [2] reveals that the observation of degraded degree of the capacitor in the input filter can significantly increase the network reliability.…”