Logic optimization method for zero-sequence overcurrent protection of start-up and standby substations

A technology of zero-sequence overcurrent and optimization method, applied in the direction of emergency protection circuit devices, electrical components, etc., can solve the problems that cannot reflect the rapidity of protection, cannot quickly cut off faults, etc., and achieve the effect of reducing impact, saving costs, and obvious effects Effect

Inactive Publication Date: 2018-03-09
陕煤电力信阳有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

When the start-up substation is in the hot standby mode and a ground fault occurs in the branch, the protection cannot quickly cut off the fault, which does not reflect the rapidity of the protection

Method used

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  • Logic optimization method for zero-sequence overcurrent protection of start-up and standby substations
  • Logic optimization method for zero-sequence overcurrent protection of start-up and standby substations
  • Logic optimization method for zero-sequence overcurrent protection of start-up and standby substations

Examples

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Embodiment Construction

[0016] With a model of SFFZ10-CY-63000 / 220, a capacity of 63MVA, and a voltage ratio of 230KV / 6.3KV, it is used as a backup power supply for the utility power system of two 660MW ultra-supercritical units. The branch zero-sequence overcurrent protection has occurred many times in the standby transformer protection.

[0017] figure 1 It is a schematic diagram of one start-up turning into two sets of plant power to provide backup power, of which 601, 602, 603, 604 are backup branch switches; 611, 612, 613, 614 are incoming power supply incoming line switches. During normal operation, all working sections are powered by the high-factory substation, and the high-factory substation is powered by its own generator. The start-up substation is in the hot standby state, the incoming power switch is closed, and the standby branch switch is open. When the unit is overhauled, the high plant substation cannot supply power to the working section, and the fast switching device switches the...

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Abstract

The invention discloses a logic optimization method for zero-sequence overcurrent protection of a start-and-standby branch. According to the control logic, the logic diagram of the zero-sequence overcurrent section II remains unchanged or does not need to be configured, and only the zero-sequence overcurrent section I is optimized. . The optimized control logic adds low-voltage side branch current criterion, branch switch position contact, composite voltage element, branch zero-sequence overcurrent stage I protection action in terms of criteria, and an outlet method adds an outlet method two. The start-up standby transformer can shorten the protection action time no matter it is in the hot standby state or in the load condition. Through logic control optimization, when a ground fault occurs in the standby substation in the hot standby operation mode, the switch on the high voltage side of the standby transformer can be disconnected quickly, reducing the impact on the safe and stable operation of the power grid, and at the same time reducing the damage to the standby substation itself.

Description

technical field [0001] The invention relates to a protection method in an electric power system, in particular to a logic optimization method for zero-sequence overcurrent protection of a start-up transformer branch. Background technique [0002] In recent years, with the gradual increase of unit capacity, the increase of grid voltage, and the expansion of power supply range, the capacity of plant power load has also increased accordingly. For power plants, not only the safety and stability of power supply and consumption must be considered, but also the safety and stability of their own power generation equipment. [0003] The relay protection device refers to an automatic device that can reflect the failure or abnormal operation of the electrical components in the power system, and act and trip the short circuit or send a signal. The basic requirements of relay protection are reliability, selectivity, rapidity and sensitivity. Among these requirements, some complement ea...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H02H7/04
Inventor 蒲小琴
Owner 陕煤电力信阳有限公司
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