A method and system for traveling wave protection of hybrid direct current transmission line based on dual tree complex wavelet variation

A technology of hybrid DC and power transmission lines, applied in emergency protection circuit devices, electrical components, etc., to reduce translation sensitivity, improve accuracy, and solve the effect of insufficient sensitivity
CN109038515BActive Publication Date: 2022-01-07CHINA ELECTRIC POWER RES INST +1
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
CHINA ELECTRIC POWER RES INST
Publication Date
2022-01-07

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Abstract

The invention discloses a hybrid direct current transmission line traveling wave protection method and system based on dual tree complex wavelet changes, including: calculating the voltage difference modulus and voltage common modulus according to the collected positive and negative DC voltages; The wavelet transform calculates the dual tree complex wavelet transform of the voltage difference modulus, and judges whether the protection is started according to the high-sensitivity start judgment basis; when the protection is determined to start, according to the dual tree complex wavelet transform and the corresponding The fault extreme value of the hybrid DC transmission line is used to judge the fault type and carry out corresponding protection actions. The invention can quickly distinguish the faults of the hybrid direct current transmission line, and can reliably select fault poles, greatly reduces the translation sensitivity in the usual real wavelet transform, and can significantly improve the accuracy of fault analysis in long-distance transmission lines , to realize the rapid identification of hybrid DC transmission line faults.
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Description

technical field

[0001] The present invention relates to the technical field of relay protection of electrical technology, and more specifically, relates to a hybrid direct current transmission line traveling wave protection method and system based on dual tree complex wavelet variation. Background technique

[0002] The line commutated converter type HVDC transmission system (Line Commutated Converter, LCC-HVDC) based on thyristor technology has been widely used in long-distance large-capacity power transmission, asynchronous networking and other occasions, but it has the problem of commutation failure on the inverter side . The high-voltage DC transmission system (Voltage Source Converter, VSC-HVDC) based on the voltage source converter has been rapidly developed due to its independent control of active power and reactive power, the ability to work in passive systems, and not being affected by commutation failures. Development, but it has the disadvantages of high cost and...

Claims

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