Characteristic-harmonic-based protection method and system for high-voltage direct current transmission line

A DC line, high-voltage DC technology, applied in the direction of automatic disconnection of emergency protection devices, circuit devices, emergency protection circuit devices, etc., can solve the problems of complex algorithm, large amount of calculation, etc. poor sex effect
CN102623968AActive Publication Date: 2012-08-01SHANGHAI JIAO TONG UNIV
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Patent Information

Authority / Receiving Office
CN ยท China
Current Assignee / Owner
SHANGHAI JIAO TONG UNIV
Publication Date
2012-08-01

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Abstract

The invention discloses a characteristic-harmonic-based protection method and a characteristic-harmonic-based protection system for a high-voltage direct current transmission line. The characteristic-harmonic-based protection method for the high-voltage direct current transmission line comprises the following steps of: synchronously sampling direct currents on the two sides of the high-voltage direct current transmission line to obtain real-time current data, and performing discrete Fourier transform to obtain current characteristic harmonics at the two ends of the line; and counting the number Nn.m of characteristic current harmonics, calculating a weighted index IH.M, and performing logic judgment on the weighted index IH.M, the number Nn.m of the characteristic current harmonics and set values IH.set and Nn.set to obtain a failure type. The influence of distributed capacitive current can be avoided, and the shortcomings of the conventional differential protection for the high-voltage direct current transmission line are overcome; and moreover, the method and the system are high in resistance to transition resistance, simple in operation, easy to implement and high in working speed and reliability, and special requirements on sampling frequency are avoided.
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Description

technical field

[0001] The present invention relates to a method and device in the technical field of relay protection for DC transmission lines in electric power systems, in particular to a characteristic harmonic-based HVDC transmission line protection method and system for EHV / UHV DC transmission lines. Background technique

[0002] High-voltage direct current (HVDC) transmission occupies an important position in long-distance and high-power transmission because of its advantages such as large transmission power and good control performance. Developed countries in the world regard it as the main method for large-capacity, long-distance power transmission and asynchronous networking. means. In my country, since the completion of the Zhoushan DC transmission project in 1987, the number of DC transmission projects in my country has been increasing day by day. With the construction of a strong smart grid that "transmits power from west to east, mutual supply between north an...

Claims

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