Hardware-in-the-loop methods for real-time frequency-response measurements of on-board power distribution systems

Abstract

The operation of more electric aircraft is dependent on the embedded power grid. Therefore, the onboard power-distribution system must be reliable, having<br/>a high level of survivability, and promptly respond to any change in aircraft’s operation. Recent studies have presented a number of frequency-response-based tools with which to analyze both single- and multi-converter systems.<br/>The methods can be efficiently applied for on-board system analysis, stability assessment and adaptive control design. Most often, wideband measurement techniques have been applied to obtain the frequency response from a specific<br/>converter or a subsystem required for the analysis. In the methods, a broadband excitation such as a pseudo-random binary sequence (PRBS) is used as an external injection, and Fourier techniques are applied to extract the spectral<br/>information. This paper presents implementation techniques of the wideband methods using power-hardware-in-the-loop measurements based on OPAL-RT real-time simulator. The presented methods make it possible to modify<br/>the system characteristics, such as impedance behavior, in real time, thereby providing means for various stability and control design tools for on-board power distribution systems. Experimental measurements are shown from a<br/>high-power energy distribution system recently developed at DNV GL, Arnhem, Netherlands.