CN112087048B - High-voltage plant branch zero-sequence protection configuration system and method - Google Patents

High-voltage plant branch zero-sequence protection configuration system and method Download PDF

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Publication number
CN112087048B
CN112087048B CN202010929883.XA CN202010929883A CN112087048B CN 112087048 B CN112087048 B CN 112087048B CN 202010929883 A CN202010929883 A CN 202010929883A CN 112087048 B CN112087048 B CN 112087048B
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voltage
bus
plant
low
substation
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CN112087048A (en
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周亚群
张钢
赵婷婷
都劲松
曹浩军
吴晋
吕尚霖
刘欢
付东岩
刘瞻
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Xian Thermal Power Research Institute Co Ltd
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Xian Thermal Power Research Institute Co Ltd
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    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02JCIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J9/00Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting
    • H02J9/04Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting in which the distribution system is disconnected from the normal source and connected to a standby source
    • H02J9/06Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting in which the distribution system is disconnected from the normal source and connected to a standby source with automatic change-over, e.g. UPS systems
    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02HEMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H7/00Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
    • H02H7/04Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for transformers
    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02JCIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00Circuit arrangements for ac mains or ac distribution networks
    • H02J3/007Arrangements for selectively connecting the load or loads to one or several among a plurality of power lines or power sources
    • H02J3/0073Arrangements for selectively connecting the load or loads to one or several among a plurality of power lines or power sources for providing alternative feeding paths between load and source when the main path fails, e.g. transformers, busbars

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Business, Economics & Management (AREA)
  • Emergency Management (AREA)
  • Supply And Distribution Of Alternating Current (AREA)

Abstract

The invention discloses a high-voltage plant branch zero-sequence protection configuration system and a method, which comprises a high-voltage plant high-voltage side closed bus, a high-voltage plant transformer, a high-voltage plant low-voltage side closed bus, a high-voltage plant bus working incoming line switch lower port CT, a high-voltage plant bus, a high-voltage plant low-voltage side neutral point zero-sequence CT, a high-voltage plant low-voltage side neutral point grounding resistor and a high-voltage plant branch protection device.

Description

High-voltage plant branch zero-sequence protection configuration system and method
Technical Field
The invention belongs to the technical field of electrical protection, and relates to a high-voltage plant transformer branch zero-sequence protection configuration system and method.
Background
When the generator set normally operates, high-voltage service can be changed into a generator set to provide service power, a high-voltage standby power supply is configured to be used as a unit standby power supply, and power switching is realized between the two power supplies through a quick switching device.
For a system that a neutral point on the low-voltage side of a high-voltage substation is grounded through a small resistor, the zero-sequence protection of the branch of the high-voltage substation adopts a zero-sequence current principle, a zero-sequence current element usually only selects the zero-sequence current of the neutral point on the low-voltage side of the high-voltage substation, and the zero-sequence current protection is divided into two time limits. According to the DLT1502 Relay protection setting calculation guide rule for plants, for a system with a neutral point grounded through a small resistor, a first time limit of variable branch zero-sequence protection for a high-voltage plant is operated to switch a local branch circuit breaker and a locked standby power supply, and a second time limit of branch zero-sequence protection is operated to switch a shutdown and a started standby power supply, wherein the first time limit of branch zero-sequence protection is matched and set with the longest action time of the next-stage zero-sequence overcurrent protection, and the second time limit of branch zero-sequence protection is matched and set with the first time limit of branch zero-sequence protection.
According to the configuration mode of the variable branch zero-sequence protection for the high-voltage plant, when a fault point is located between a branch circuit breaker and a high-voltage plant bus, the branch zero-sequence protection acts in a time limit mode, and the outlet mode is that the branch circuit breaker is tripped, a standby power supply is locked for switching, and the fault is cut off; when a fault point is positioned between a high-voltage station transformer low-voltage winding and a branch circuit breaker, the branch zero sequence protection acts for a time limit, the outlet mode is switching of a tripping branch circuit breaker and a locking standby power supply, after the first time limit acts, because the branch zero sequence fault still exists, the branch zero sequence protection acts for a second time limit, the outlet mode is switching of a shutdown and starting of the standby power supply, but before the second time limit acts, the branch zero sequence is always in an acting state for the first time limit, the standby power supply is switched to a locking state before the second time limit acts, and meanwhile, when the protection locking of a fast switching device is lost, the standby power supply can be switched again only after manual resetting or automatic resetting of the fast switching device after 10s of time delay, so when the second time limit acts, the starting of the standby power supply is failed to switch, and the station power supply is lost. The fault point is located between a high-voltage station transformer low-voltage winding and a branch circuit breaker, the first time limit and the second time limit of branch zero sequence protection both act correctly, but when the two time limits act, the case of failure in starting the switching of the standby power supply is caused because the protection locking fast switching of the fast switching device cannot be restored in time. Therefore, the system and the method for the high-voltage plant transformer branch zero-sequence protection configuration have important significance.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provides a high-voltage plant transformer branch zero-sequence protection configuration system and a method, which can judge the position of a fault point so as to select different protection outlet modes.
In order to achieve the above purpose, the high-voltage substation branch zero-sequence protection configuration system of the present invention includes a high-voltage substation side closed bus, a high-voltage substation low-voltage side closed bus, a high-voltage substation bus working incoming line switch lower port CT, a high-voltage substation bus, a high-voltage substation low-voltage side neutral point zero-sequence CT, a high-voltage substation low-voltage side neutral point grounding resistor, and a high-voltage substation protection device;
the high-voltage station transformer substation protection device comprises a high-voltage station transformer substation, a high-voltage station transformer substation closed bus, a high-voltage station bus working incoming line switch, a high-voltage station transformer substation incoming line switch lower port CT (current transformer) and a high-voltage station transformer substation closed bus working incoming line switch, wherein the high-voltage station transformer substation closed bus is connected with the high-voltage station transformer substation, the high-voltage station transformer substation closed bus working incoming line switch lower port CT is installed on a line between the high-voltage station transformer substation closed line switch and the high-voltage station transformer substation bus, a low-voltage side neutral point is grounded through a high-voltage station transformer substation low-voltage side neutral point grounding resistor, a high-voltage station transformer substation low-voltage side neutral point zero sequence CT is installed on a line between a low-voltage side neutral point of the high-voltage station transformer substation and a high-voltage station transformer substation low-voltage side neutral point grounding resistor, and the high-voltage station transformer substation closed bus working incoming line switch lower port CT is connected with a high-voltage station transformer substation protection device.
The wiring mode of the high-voltage station transformer high-voltage winding is a delta-shaped wiring mode, and the wiring mode of the high-voltage station transformer low-voltage winding is a Y-shaped wiring mode.
A high-voltage plant branch zero-sequence protection configuration method comprises the following steps:
switching into high-voltage substation variable branch zero-sequence protection, when the zero-sequence current of a neutral point zero-sequence CT (current transformer) on the low-voltage side of the high-voltage substation is greater than a setting value and the self-produced zero-sequence current of a CT (current transformer) on the lower port of a bus working incoming line switch for the high-voltage substation is less than the setting value, tripping a fault area between a low-voltage winding of the high-voltage substation transformer and the bus working incoming line switch for the high-voltage substation through protecting a time limit outlet, and starting standby power supply switching while the outlet mode is shutdown;
and (3) switching into the zero sequence protection of the branch of the high-voltage substation, when the zero sequence current of the neutral point zero sequence CT on the low-voltage side of the high-voltage substation is greater than a setting value and the zero sequence current of the CT self-produced at the lower port of the bus working incoming line switch of the high-voltage substation is greater than the setting value, tripping the fault region between the bus working incoming line switch of the high-voltage substation and the bus of the high-voltage substation through protecting a time limit outlet, and simultaneously locking the switching of the standby power supply, wherein the outlet mode is that the bus working incoming line switch of the high-voltage substation is tripped.
The invention has the following beneficial effects:
when the high-voltage substation variable branch zero-sequence protection configuration system and the method are operated specifically, a high-voltage substation bus working incoming switch lower port CT is installed at a high-voltage substation bus working incoming switch lower port, and self-produced zero-sequence current of the high-voltage substation bus working incoming switch lower port CT is introduced into the high-voltage substation variable branch zero-sequence protection to serve as one of branch zero-sequence protection current criteria. The high-voltage station-use bus working incoming line switch is used as a demarcation point, the high-voltage station-use bus working incoming line switch is used for generating zero sequence current by CT through the lower port of the high-voltage station-use bus working incoming line switch, and the high-voltage station-use variable low-voltage winding to the high-voltage station-use bus working incoming line switch, the second part is from the high-voltage station-use bus working incoming line switch to the high-voltage station-use bus, in addition, when the fault is positioned from the high-voltage station-use variable low-voltage winding to the high-voltage station-use bus working incoming line switch, the outlet mode is shutdown, and the standby power supply switching is started; when the fault is located from the high-voltage station bus working incoming line switch to the high-voltage station bus, the outlet mode is the high-voltage station bus working incoming line switch, meanwhile, the standby power supply is locked for switching, and the selection of different protection outlet modes is realized through the position differentiation of the fault point.
Drawings
FIG. 1 is a diagram of a protection arrangement of the present invention;
FIG. 2 is a protection logic diagram of the present invention;
FIG. 3 is a diagram of a prior art protection arrangement;
fig. 4 is a prior art protection logic diagram.
The high-voltage station transformer substation comprises a high-voltage station transformer substation, a low-voltage station transformer substation, a high-voltage station transformer substation closed bus, a high-voltage station transformer substation working incoming line switch, a high-voltage station transformer substation low-voltage side neutral point zero sequence CT, a high-voltage station transformer substation low-voltage side neutral point grounding resistor and a high-voltage station transformer substation protection device, wherein the high-voltage station transformer substation closed bus is 1, the high-voltage station transformer substation is 2, the low-voltage station transformer substation is 3, the high-voltage station transformer substation working incoming line switch is 4, the high-voltage station transformer substation low-voltage side neutral point zero sequence CT is 5, the high-voltage station transformer substation low-voltage side neutral point grounding resistor is 6, the high-voltage station transformer substation protection device is 7.
Detailed Description
The invention is described in further detail below with reference to the accompanying drawings:
referring to fig. 1, the high-voltage substation branch zero-sequence protection configuration system according to the present invention includes a high-voltage substation side closed bus 1, a high-voltage substation 2, a high-voltage substation low-voltage side closed bus 3, a high-voltage substation bus working incoming line switch 4, a high-voltage substation bus working incoming line switch lower port CT5, a high-voltage substation bus 6, a high-voltage substation low-voltage side neutral point zero-sequence CT7, a high-voltage substation low-voltage side neutral point ground resistor 8, and a high-voltage substation protection device 9; the high-voltage station transformer substation is characterized in that a high-voltage station transformer substation 2 high-voltage station transformer substation side closed bus 1 is connected with a high-voltage station transformer substation 6 through a high-voltage station transformer substation 2, a high-voltage station transformer substation side closed bus 3 and a high-voltage station transformer substation working incoming line switch 4, a high-voltage station transformer substation incoming line switch lower port CT5 is installed on a line between the high-voltage station transformer substation working incoming line switch 4 and the high-voltage station transformer substation 6, a low-voltage side neutral point of the high-voltage station transformer substation 2 is grounded through a high-voltage station transformer substation low-voltage side neutral point grounding resistor 8, a high-voltage station transformer substation low-voltage side neutral point CT7 is installed on a line between the low-voltage side neutral point of the high-voltage station transformer substation 2 and the high-voltage station transformer substation low-voltage side neutral point grounding resistor 8, a high-voltage station transformer substation protection device 9 is connected with a secondary side of the high-voltage station transformer substation busbar working incoming line switch lower port CT5 and a secondary side of the high-voltage station transformer substation low-voltage side neutral point CT7, wherein the high-voltage station transformer substation 2 high-voltage winding is connected in a delta type wiring manner, the wiring mode of the high-voltage station transformer 2 low-voltage winding is a Y-type wiring mode.
A high-voltage plant is with changing the zero sequence protection configuration method of the branch, through the high-voltage plant bus work incoming line switch lower port CT 5's self-produced zero sequence current, judge the high-voltage plant is with changing the zero sequence protection fault area of the branch, realize different outlet tripping modes, the protection outlet is only a time limit, the time limit is according to cooperating with the longest action time of the next level of zero sequence overcurrent protection to set, refer to fig. 2, include the following steps specifically:
the method comprises the steps that the high-voltage substation is put into branch zero-sequence protection, when the zero-sequence current of a neutral point zero-sequence CT7 on the low-voltage side of the high-voltage substation is larger than a setting value, and the self-produced zero-sequence current of a lower port CT5 of a bus working incoming line switch for the high-voltage substation is smaller than the setting value, a fault area is tripped between a low-voltage winding of a high-voltage substation 2 and a bus working incoming line switch 4 through a protection time limit outlet, the outlet mode is shutdown, and meanwhile, the standby power supply is started to be switched;
and (3) putting into high-voltage substation variable branch zero sequence protection, when the zero sequence current of the neutral point zero sequence CT7 on the low-voltage side of the high-voltage substation is greater than a setting value and the zero sequence current produced by the lower port CT5 of the bus working incoming line switch for the high-voltage substation is greater than the setting value, tripping the fault area between the bus working incoming line switch 4 for the high-voltage substation and the bus 6 for the high-voltage substation through protecting a time limit outlet, wherein the outlet mode is to trip the bus working incoming line switch 4 for the high-voltage substation, and simultaneously locking the standby power supply for switching.
Fig. 3 is a diagram of a conventional high-voltage plant variable branch zero-sequence protection configuration, a logic diagram is shown in fig. 4, the high-voltage plant variable branch zero-sequence protection adopts a zero-sequence current principle, a zero-sequence current element only selects a high-voltage plant variable low-voltage side neutral point zero-sequence current, the zero-sequence current protection is divided into two time limits, wherein one time limit is matched and set with the longest action time of the next-stage zero-sequence overcurrent protection, an outlet mode is a high-jump voltage plant bus working inlet switch, the standby power supply switching is locked, if a fault still exists after one time limit action, the two time limits protect action, the outlet mode is a shutdown, and the standby power supply switching is started.

Claims (1)

1. The high-voltage plant variable branch zero-sequence protection configuration method is characterized by being based on a high-voltage plant variable branch zero-sequence protection configuration system, wherein the high-voltage plant variable branch zero-sequence protection configuration system comprises a high-voltage plant variable high-voltage side closed bus (1), a high-voltage plant variable (2), a high-voltage plant variable low-voltage side closed bus (3), a high-voltage plant bus working incoming line switch (4), a high-voltage plant bus working incoming line switch lower port CT (5), a high-voltage plant bus (6), a high-voltage plant variable low-voltage side neutral point zero-sequence CT (7), a high-voltage plant variable low-voltage side neutral point grounding resistor (8) and a high-voltage plant variable protection device (9);
the high-voltage station high-voltage side enclosed bus (1) is connected with a high-voltage station bus (6) through a high-voltage station transformer (2), a high-voltage station low-voltage side enclosed bus (3) and a high-voltage station bus working incoming line switch (4), a lower port CT (5) of a bus working incoming switch for a high-voltage plant is arranged on a line between the bus working incoming switch (4) for the high-voltage plant and a bus (6) for the high-voltage plant, a low-voltage side neutral point of a transformer (2) for the high-voltage plant is grounded through a low-voltage side neutral point grounding resistor (8) for the high-voltage plant, a low-voltage side neutral point zero sequence CT (7) of the transformer for the high-voltage plant is arranged on a line between the low-voltage side neutral point of the transformer (2) for the high-voltage plant and a low-voltage side neutral point grounding resistor (8) for the high-voltage plant, the high-voltage station transformer protection device (9) is connected with the secondary side of a lower port CT (5) of a working inlet wire switch of a high-voltage station bus and the secondary side of a neutral point zero sequence CT (7) of a low-voltage side of the high-voltage station transformer;
the wiring mode of the high-voltage winding of the high-voltage station transformer (2) is a delta-shaped wiring mode, and the wiring mode of the low-voltage winding of the high-voltage station transformer (2) is a Y-shaped wiring mode;
the method comprises the following steps:
the method comprises the steps that the high-voltage station transformer branch zero sequence protection is put into use, when the zero sequence current of a neutral point zero sequence CT (7) on the low-voltage side of the high-voltage station transformer is larger than a setting value, and the self-produced zero sequence current of a lower port CT (5) of a bus working incoming line switch for the high-voltage station is smaller than the setting value, a fault area is arranged between a low-voltage winding of a high-voltage station transformer (2) and a bus working incoming line switch (4) for the high-voltage station transformer, a time limit outlet is protected to trip, the outlet mode is shutdown, and meanwhile, the standby power supply is started to be switched;
and (2) putting into high-voltage substation variable branch zero sequence protection, when the zero sequence current of a neutral point zero sequence CT (7) on the low-voltage side of the high-voltage substation variable is greater than a setting value and the self-produced zero sequence current of a lower port CT (5) of a bus working incoming line switch for the high-voltage substation is greater than the setting value, a fault area is tripped between the bus working incoming line switch (4) for the high-voltage substation and a bus (6) for the high-voltage substation through a protection time limit outlet, the outlet mode is that the bus working incoming line switch (4) for the high-voltage substation is tripped, and the standby power supply is locked for switching.
CN202010929883.XA 2020-09-07 2020-09-07 High-voltage plant branch zero-sequence protection configuration system and method Active CN112087048B (en)

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RU2589716C1 (en) * 2015-05-22 2016-07-10 Роман Александрович Шестак Method for offset of magnetisation current rush during connection under voltage for transformer differential protection
RU171206U1 (en) * 2016-10-31 2017-05-24 Общество с ограниченной ответственностью "Релематика" DEVICE FOR PROTECTING ELECTRIC TRANSMISSION LINES FROM SINGLE-PHASE EARTH CLOSES IN A THREE-PHASE NETWORK WITH INSULATED NEUTRAL
CN108718076A (en) * 2018-07-02 2018-10-30 润电新能源(英德)有限公司 Ground connection becomes relay protecting method and ground connection becomes protective device
CN108776284A (en) * 2018-03-29 2018-11-09 广东电网有限责任公司惠州供电局 A kind of small resistance grounding system single phase earthing protection method compared based on zero-sequence current
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RU2589716C1 (en) * 2015-05-22 2016-07-10 Роман Александрович Шестак Method for offset of magnetisation current rush during connection under voltage for transformer differential protection
RU171206U1 (en) * 2016-10-31 2017-05-24 Общество с ограниченной ответственностью "Релематика" DEVICE FOR PROTECTING ELECTRIC TRANSMISSION LINES FROM SINGLE-PHASE EARTH CLOSES IN A THREE-PHASE NETWORK WITH INSULATED NEUTRAL
CN108776284A (en) * 2018-03-29 2018-11-09 广东电网有限责任公司惠州供电局 A kind of small resistance grounding system single phase earthing protection method compared based on zero-sequence current
CN108718076A (en) * 2018-07-02 2018-10-30 润电新能源(英德)有限公司 Ground connection becomes relay protecting method and ground connection becomes protective device
CN109980614A (en) * 2019-03-29 2019-07-05 广东电网有限责任公司 A kind of distribution line zero-sequenceprotection direction-adaptive method of discrimination

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