Instantaneous phase-angle estimation algorithm under unbalanced voltage-sag conditions
SCIE
SCOPUS
- Title
- Instantaneous phase-angle estimation algorithm under unbalanced voltage-sag conditions
- Authors
- Song, HS; Nam, K
- Date Issued
- 2000-11
- Publisher
- IEE-INST ELEC ENG
- Abstract
- If a negative sequence is generated by voltage sag and/or unbalance, it appears as an oscillating error in a synchronous reference frame (SRF). In power conditioning equipment, the exact value of a positive sequence is needed to achieve the unity power factor and constant output voltage, whereas the exact value of a negative sequence is needed for unbalance compensation. To measure the positive sequence separately from the negative sequence, a low pass or notch filter having a narrow bandwidth is normally used. However, such a filter causes a lot of phase delay, thus the response time of the system tends to be lengthened. A method of estimating the positive- and the negative-sequence voltages separately is presented, without a significant delay, by utilising the weighted least-squares estimation (WLSE) method with the covariance resetting technique. A frequency update law is also proposed to accommodate the frequency varying environments. The authors demonstrate through simulation and experiment the superior performance of the proposed scheme in measuring the positive- and the negative-sequence voltages at the time of abrupt transition. This method can be applied to uninterruptable power supplies CUPS), pulsewidth modulation (PWM) AC/DC converters, active filters, AC voltage compensators etc.
- Keywords
- SCHEME
- URI
- https://oasis.postech.ac.kr/handle/2014.oak/19708
- DOI
- 10.1049/ip-gtd:20000716
- ISSN
- 1350-2360
- Article Type
- Article
- Citation
- IEE PROCEEDINGS-GENERATION TRANSMISSION AND DISTRIBUTION, vol. 147, no. 6, page. 409 - 415, 2000-11
- Files in This Item:
- There are no files associated with this item.
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.