The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 05, 2000
Filed:
Jul. 13, 1998
Isao Koda, Aichi, JP;
Masakazu Tsukamoto, Aichi, JP;
Yasuhiro Fuwa, Aichi, JP;
Shoji Nishimura, Kyoto, JP;
Yoshifumi Minowa, Kyoto, JP;
Yasuyuki Natsuda, Kyoto, JP;
Nissin Electric Co., Ltd., Kyoto, JP;
Chuba Electric Power Co., Inc., Nagoya, JP;
Abstract
Single-phase currents at two frequencies f.alpha. and f.beta. (f.alpha.<n.multidot.fs<f.beta.) of non-integral multiples of a system fundamental wave frequency fs sandwiching an targeted harmonic (frequency n.multidot.fs) are injected between two phases of a three-phase power system as interharmonic currents. A frequency analysis of measurement current and measurement voltage of each phase in the system is carried out and a positive-phase-sequence current I1, a positive-phase-sequence voltage V1, a negative-phase-sequence current I2, and a negative-phase-sequence voltage V2 are detected for each of the two frequencies f.alpha. and f.beta. in the system based on injecting of the interharmonic currents. Positive-phase-sequence and negative-phase-sequence admittances Y1 and Y2 or positive-phase-sequence and negative-phase-sequence impedances Z1 and Z2 are found for each of the frequencies f.alpha. and f.beta. in the system as Y1=I1/V1 and Y2=I2/V2 or Z1=V1/I1 and Z2=V2/I2. Interpolation operation is performed for finding positive-phase-sequence and negative-phase-sequence admittances or positive-phase-sequence and negative-phase-sequence impedances for the targeted harmonic in the system from the admittances Y1 and Y2 or the impedances Z1 and Z2 for the frequencies f.alpha. and f.beta..