Title:
PHASE DIFFERENCE PROTECTION METHOD AND SYSTEM BASED ON MAGNETO-OPTICAL MEASUREMENT ELEMENT
Document Type and Number:
WIPO Patent Application WO/2021/147163
Kind Code:
A1
Abstract:
Disclosed are a phase difference protection method and system based on a magneto-optical measurement element. The method comprises: placing an element with a magneto-optical effect near an alternating-current line or a cable; inputting polarized light with a constant light intensity into the magneto-optical element by means of an optical fiber; the magnetic field generated by the line current enabling a polarization plane of the polarized light to rotate, such that the light intensity of the output polarized light is changed after the output polarized light passes through a polarization analyzer, and the periodically changed light intensity is generated by the periodic alternating current; and comparing waveform phases of light intensities at two ends thereof to realize phase difference protection. By means of the phase difference principle, only the light intensity phase needs to be measured, and the requirements for the amplitude measurement precision is not high, such that the influence of vibration, temperature changes. etc. on the amplitude measurement precision of a magneto-optical element does not cause a reduction in the protection performance.
Inventors:
LIU SHIMING (CN)
ZHAO YONGSEN (CN)
WANG BO (CN)
NAN TIANQI (CN)
HAN BO (CN)
ZHAO YONGSEN (CN)
WANG BO (CN)
NAN TIANQI (CN)
HAN BO (CN)
Application Number:
PCT/CN2020/080436
Publication Date:
July 29, 2021
Filing Date:
March 20, 2020
Export Citation:
Assignee:
UNIV SHANDONG (CN)
International Classes:
H02H7/26; G01R15/24; H02H3/30
Foreign References:
| CN103715650A | 2014-04-09 | |||
| CN1862903A | 2006-11-15 | |||
| CN103730884A | 2014-04-16 | |||
| CN1623261A | 2005-06-01 | |||
| JP2001050988A | 2001-02-23 |
Attorney, Agent or Firm:
JINAN SHENGDA INTELLECTUAL PROPERTY AGENCY CO., LTD. (CN)
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