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Introduction of Adaptive Active Filters in HVDC Systems

Göransson, Tor (1993) In MSc Theses
Department of Automatic Control
Abstract
When converting electric power from AC to DC, a 12-pulse converter is often used. Unfortunately, the converter creates harmonics superimposed on the DC voltage. These are removed by filters. A passive filter is normally used, but active filters may be added for improved performance. However, the drift in component values due to fluctuations in temperature and the change in load, makes it difficult to obtain filters with consistently good performance. Initially, tests and measurements are required to adjust the filters to the environment. To circumvent these drawbacks, adaption and adjustment during operation is needed. Different adaptive control concepts are investigated in this report. Two of them, feedforward with estimation using the... (More)
When converting electric power from AC to DC, a 12-pulse converter is often used. Unfortunately, the converter creates harmonics superimposed on the DC voltage. These are removed by filters. A passive filter is normally used, but active filters may be added for improved performance. However, the drift in component values due to fluctuations in temperature and the change in load, makes it difficult to obtain filters with consistently good performance. Initially, tests and measurements are required to adjust the filters to the environment. To circumvent these drawbacks, adaption and adjustment during operation is needed. Different adaptive control concepts are investigated in this report. Two of them, feedforward with estimation using the MIT rule and feedback using an indirect self-tuning regulator, are also tested in simulations. The ability to estimate the whole system, including the effect of reflections from the transmission net, is partially analyzed. Estimation is done using the recursive least-mean-square algorithm and the stochastic approximation algorithm. Many problems can arise in designing adaptive controllers for a HVDC system. In this report, some of them are discussed and different solutions are suggested. (Less)
Please use this url to cite or link to this publication:
author
Göransson, Tor
supervisor
organization
year
type
H3 - Professional qualifications (4 Years - )
subject
keywords
HVDC, Active fiters, Adaptive control, Parameter estimation
publication/series
MSc Theses
report number
TFRT-5492
ISSN
0280-5316
language
English
id
8849089
date added to LUP
2016-03-25 20:48:17
date last changed
2016-03-25 20:48:17
@misc{8849089,
  abstract     = {When converting electric power from AC to DC, a 12-pulse converter is often used. Unfortunately, the converter creates harmonics superimposed on the DC voltage. These are removed by filters. A passive filter is normally used, but active filters may be added for improved performance. However, the drift in component values due to fluctuations in temperature and the change in load, makes it difficult to obtain filters with consistently good performance. Initially, tests and measurements are required to adjust the filters to the environment. To circumvent these drawbacks, adaption and adjustment during operation is needed. Different adaptive control concepts are investigated in this report. Two of them, feedforward with estimation using the MIT rule and feedback using an indirect self-tuning regulator, are also tested in simulations. The ability to estimate the whole system, including the effect of reflections from the transmission net, is partially analyzed. Estimation is done using the recursive least-mean-square algorithm and the stochastic approximation algorithm. Many problems can arise in designing adaptive controllers for a HVDC system. In this report, some of them are discussed and different solutions are suggested.},
  author       = {Göransson, Tor},
  issn         = {0280-5316},
  keyword      = {HVDC,Active fiters,Adaptive control,Parameter estimation},
  language     = {eng},
  note         = {Student Paper},
  series       = {MSc Theses},
  title        = {Introduction of Adaptive Active Filters in HVDC Systems},
  year         = {1993},
}