A distribution network relay protection system based on current-limiting step-difference coordination
A technology of relay protection and differential coordination, applied in emergency protection circuit devices for limiting overcurrent/overvoltage, emergency protection devices for automatic disconnection, emergency protection circuit devices, etc., can solve the problem of urban distribution network relays. Difficulty in protection coordination, etc., to reduce the short-circuit current level and damage to the system and equipment, act quickly, and operate reliably
Active Publication Date: 2019-09-03
STATE GRID SHAANXI ELECTRIC POWER RES INST +2
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[0013] In order to solve the above problems, the present invention provides a distribution network relay protection system based on current-limiting step-difference coordination to realize high-selectivity relay protection of urban distribution network, thereby solving the problem of urban distribution network relay protection with short power supply radius. Difficulty with protection
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[0054] The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments.
[0055] In the present invention, each 10kV outgoing line circuit breaker in the substation is equipped with an automatic current limiting device for outgoing lines, which can be arranged in the switch cabinet. The protection device at the outlet circuit breaker is equipped with no delay current protection function, and its current setting value is I SET,S .
[0056] refer to figure 1 , the automatic current-limiting device for outgoing lines includes a three-phase current-limiting impedance Z and a three-phase vacuum contactor S connected in series, which are connected in parallel on both sides of the fracture of the 10kV outgoing line circuit breaker B, and controlled by the first controller C 1 control. During normal operation, the circuit breaker B is in the closing state, the vacuum contactor S is also in the closing state, and the cur...
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The invention discloses a current-limiting-difference-matching-based relay protection system of a distribution network. The principle of the relay protection system is as follows: current-limiting protection devices are arranged at a transformer substation outgoing breaker and an interconnection switch; when an inter-phase short circuit fault occurs, the current-limiting protection device of the outgoing breaker carries out current limiting quickly and, together with a protection device arranged at a feeder section switch, is used for realizing multi-stage difference relay protection cooperation; if an instantaneous fault occurs, re-closing is carried out for power supply recovery by the primary reclosing function of the current-limiting protection device and the feeder section switch; ifa permanent fault occurs, the current-limiting protection device is arranged at the interconnection switch and thus isolation of a fault region and power supply recovery of a perfect region are realized under the current-limiting condition. Compared with the distribution automation technology, relay protection can be carried out quickly and relay protection operation becomes reliable. The current-limiting-difference-matching-based relay protection system is suitable for an overhead distribution network and a cable distribution network.
Description
technical field [0001] The invention belongs to the technical field of relay protection for distribution networks, and in particular relates to a high-selectivity relay protection system for urban distribution networks based on the cooperation of primary equipment and secondary equipment. Background technique [0002] At present, many achievements have been made in the relay protection of urban distribution network with short power supply radius. The following is a detailed introduction: [0003] 1. Traditional segmented overcurrent protection. [0004] Current increase is the basic feature of short-circuit faults in power systems, and the protection realized by using this feature is also the earliest applied relay protection principle. Current protection belongs to stage type or multi-stage protection with step action characteristics. Its selectivity is guaranteed by the cooperation of upper and lower protection settings and action time. The number of protection stages is ...
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IPC IPC(8): H02H7/26H02H9/02H02H3/06
Inventor 刘健张志华张小庆锁军卢鹏张钰声薛建
Owner STATE GRID SHAANXI ELECTRIC POWER RES INST