A master thesis from Aalborg University
Development of Multirate Model and Analysis of Applicability to Wind Turbine Digital Fluid Power Transmissions
Term
4. term
Education
Publication year
2017
Submitted on
2017-06-01
Pages
221 pages
Abstract
Digital fluid power transmissions (DFPTs) are a promising alternative to drivetrains based on gearboxes and power electronics. One application is offshore wind turbines where the characteristics of high reliability and robustness of hydraulic systems are highly desirable. A DFPT consists of a digital displacement pump and motor connected to shared pressure lines, thereby forming the transmission. The decision to update the displacement of such machines occurs at a number of fixed shaft positions, why for variable-speed operation, the control rates of the machines are both asynchronous and non-uniform creating a multirate control problem. To obtain a linear control model, all dynamics are transformed to the spatial-domain. A new multirate modelling technique is hereafter derived by combining two existing multirate methods. From this multirate technique, the DFPT is linearly modelled and applicability of conventional control and analysis tools are evaluated. Based on this thesis’ results, it is concluded that multirate modelling and control of a DFPT is possible both in the time-domain and spatial-domain, but that the time-domain implementation of a spatialdomain control law is not straight forward.
Keywords
Documents
Colophon: This page is part of the AAU Student Projects portal, which is run by Aalborg University. Here, you can find and download publicly available bachelor's theses and master's projects from across the university dating from 2008 onwards. Student projects from before 2008 are available in printed form at Aalborg University Library.
If you have any questions about AAU Student Projects or the research registration, dissemination and analysis at Aalborg University, please feel free to contact the VBN team. You can also find more information in the AAU Student Projects FAQs.