Pseudo random binary signal for MIMO frequency response identification of a magnetically levitated rotor system

Abstract

High-speed machine technology with magnetically levitated rotor systems has become interesting solution in modern compressor, pump and turbo applications. Often, the commissioning of such machines is system identification-based with injected artificially generated excitation. In this paper a statistically uncorrelated PRBS design is proposed for multi-input multi-output MIMO system that gives the possibility to utilize same PRBS signal for all inputs. The proposed routine is validated with an experimental high-speed generator with active magnetic bearings (AMBs). The obtained frequency responses are validated by comparing the results with the mathematical model.

Design and verification of a hermetic high-speed turbogenerator concept for biomass and waste heat recovery applications

“…As part of the testing plan, measurements of the rotor operational dynamics were made. Based on the experimentally determined frequency responses at a number of fixed speeds, the first forward whirling mode frequencies of the rotor were identified using the approach proposed in [46]. The identified forward whirling mode frequencies are plotted with red crosses in the Campbell effect of unbalanced magnetic pull (UMP).…”