Implementation of time-varying observers used in direct field orientation of motor drives by trapezoidal integration

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6 Scopus citations

Abstract

The paper discusses the problem of implementing the state observers associated with direct field orientation (DFO) of motor drives using trapezoidal integration (Tustin method). Typically, the discrete-time equations of observers are obtained by emulating the continuous-time equations using the Euler method (forward rectangular rule). With Euler integration, the resulting equations are simple and the realtime implementation requires low computational effort. However, Euler-based observers become inaccurate if a small sampling time cannot used or if the motor drive operates at high frequency - this is because, as the sampling time increases, the Euler approximation of the integral starts losing more and more area from under the curve. The Tustin method (trapezoidal integration) offers an interesting alternative - it is theoretically a more accurate integration method, however, it is more complicated. The paper discusses the emulation procedure required to discretize continuous-time observers based on trapezoidal integration. The permanent magnet synchronous motor (PMSM) is used as an example of a time-varying plant - the paper develops a trapezoidal integration based observer for the PMSM and compares this with an Euler-based observer in terms of computational complexity and performance. The two observers are simulated comparatively in order to establish the conditions when trapezoidal integration outperforms the Euler method.

Original languageEnglish (US)
Title of host publication6th IET International Conference on Power Electronics, Machines and Drives, PEMD 2012
PagesP162
Edition592 CP
DOIs
StatePublished - Aug 13 2012
Event6th IET International Conference on Power Electronics, Machines and Drives, PEMD 2012 - Bristol, United Kingdom
Duration: Mar 27 2012Mar 29 2012

Publication series

NameIET Conference Publications
Number592 CP
Volume2012

Other

Other6th IET International Conference on Power Electronics, Machines and Drives, PEMD 2012
CountryUnited Kingdom
CityBristol
Period3/27/123/29/12

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All Science Journal Classification (ASJC) codes

  • Electrical and Electronic Engineering

Cite this

Comanescu, M. (2012). Implementation of time-varying observers used in direct field orientation of motor drives by trapezoidal integration. In 6th IET International Conference on Power Electronics, Machines and Drives, PEMD 2012 (592 CP ed., pp. P162). (IET Conference Publications; Vol. 2012, No. 592 CP). https://doi.org/10.1049/cp.2012.0162