CN107769162B - Unit protection tripping device of power plant based on 3/2 connection condition - Google Patents
Unit protection tripping device of power plant based on 3/2 connection condition Download PDFInfo
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- CN107769162B CN107769162B CN201711176182.8A CN201711176182A CN107769162B CN 107769162 B CN107769162 B CN 107769162B CN 201711176182 A CN201711176182 A CN 201711176182A CN 107769162 B CN107769162 B CN 107769162B
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency 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
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H1/00—Details of emergency protective circuit arrangements
- H02H1/0061—Details of emergency protective circuit arrangements concerning transmission of signals
- H02H1/0069—Details of emergency protective circuit arrangements concerning transmission of signals by means of light or heat rays
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- Remote Monitoring And Control Of Power-Distribution Networks (AREA)
Abstract
本发明涉及发电厂机组保护技术领域，是一种基于3/2接线条件发电厂的机组保护跳闸装置，其第一发变组保护装置、发变组非电量保护装置的第一组出口、第一高压启动备用变压器保护装置和高压启动备用变压器非电量保护装置第一组出口均与第一光纤传输模块电连接，第一光纤传输模块与第三光纤传输模块通信连接，第三光纤传输模块分别与发变组高压断路器操作箱的第一路跳闸回路TJR接点和高压启动备用变压器断路器操作箱的第一路跳闸回路TJR接点电连接。本发明结构合理而紧凑，使用方便，利用了光纤通信解决了以往发变组保护装置到断路器操作箱的跳闸电缆过长导致机组误跳闸的问题，使跳闸回路不受电缆距离长短及直流一点接地或交流窜入的影响。
The present invention relates to the technical field of power plant unit protection, and is a unit protection tripping device for a power plant based on 3/2 wiring conditions, wherein the first generator-transformer group protection device, the first group of outlets of the generator-transformer group non-electrical quantity protection device, the first high-voltage start-up standby transformer protection device, and the first group of outlets of the high-voltage start-up standby transformer non-electrical quantity protection device are all electrically connected to a first optical fiber transmission module, the first optical fiber transmission module is communicatively connected to a third optical fiber transmission module, and the third optical fiber transmission module is electrically connected to a first tripping circuit TJR contact of a high-voltage circuit breaker operating box of a generator-transformer group and a first tripping circuit TJR contact of a high-voltage start-up standby transformer circuit breaker operating box, respectively. The present invention has a reasonable and compact structure, is easy to use, and utilizes optical fiber communication to solve the problem of the unit tripping caused by the excessive length of the tripping cable from the generator-transformer group protection device to the circuit breaker operating box, so that the tripping circuit is not affected by the length of the cable distance and the direct current single-point grounding or the alternating current intrusion.
Description
Technical Field
The invention relates to the technical field of unit protection of power plants, in particular to a unit protection tripping device of a power plant based on a 3/2 wiring condition.
Background
In a 3/2-wire power plant, a breaker operation box is disposed in a protection room of a booster station, and the distance between the protection room of a booster station network and a unit is long. The unit protection tripping is realized by connecting an action outlet of the unit protection to a relay of a breaker operation box TJR. The frequent occurrence of multiple unit false tripping events in China during the process is shown to be mostly caused by overlong tripping cables from the generator-transformer unit protection device to the breaker operation box, the secondary trip cable from the transformer group protection device to the breaker operation box is too long, and the secondary trip cable is grounded at one point of direct current or the alternating current can cause protection misoperation, and the secondary trip cable can be generally divided into 3 cases: 1) When the voltage of the positive electrode and the negative electrode of the direct current system deviates from the ground, a point grounding moment occurs in the direct current system, and protection misoperation can be caused; 2) When the voltage fluctuation of the positive electrode and the negative electrode of the direct current system is too large, the protection misoperation can be caused at the moment that one point of the direct current system is grounded; 3) When an alternating current power source is led into the positive electrode or the negative electrode of the direct current system, protection misoperation can be caused.
Aiming at the found problems, partial power generation enterprises reform the secondary circuit, the relay in the operation box is replaced by a high-power relay, or the high-power relay is additionally arranged at the position of the power generation group protection device, and then the auxiliary contact of the high-power relay is connected to the control cabinet of the switching station to realize tripping. However, this method cannot fundamentally solve the problem, if the high-power relay is placed at the protection screen of the transformer group, the voltage division is excessive due to the overlong cable from the high-power relay to the control cabinet of the booster station, so that the action voltage of the circuit breaker is in a critical state and the phenomenon of non-full phase or burning auxiliary contacts occurs, if the high-power relay is placed at the screen cabinet of the operation box of the protection chamber of the booster station, the protection misoperation tripping is caused due to the excessive capacitor discharge power of the long-distance cable at the instant of grounding at one point of direct current.
Disclosure of Invention
The invention provides a unit protection tripping device based on a 3/2 wiring condition power plant, which overcomes the defects of the prior art, and can effectively solve the problem that in the 3/2 wiring mode power plant, the tripping cable from the unit protection device to a breaker operation box is overlong, and the unit is easy to trip by mistake.
The technical scheme of the invention is realized by the following measures: the unit protection tripping device based on the 3/2 wiring condition power plant comprises a first generator set protection device, a second generator set protection device, a first high-voltage starting standby transformer protection device, a second high-voltage starting standby transformer protection device, a high-voltage starting standby transformer non-electric quantity protection device, a generator set non-electric quantity protection device, a first optical fiber transmission module, a second optical fiber transmission module, a third optical fiber transmission module, a fourth optical fiber transmission module, a generator set high-voltage circuit breaker operation box and a high-voltage starting standby transformer circuit breaker operation box which are arranged in a booster station protection chamber, wherein a protection action joint of the first generator set protection device, a first set outlet of the generator set non-electric quantity protection device, a protection action joint of the first high-voltage starting standby transformer protection device and a first set outlet of the high-voltage starting standby transformer non-electric quantity protection device are all electrically connected with the first optical fiber transmission module, the first optical fiber transmission module is in communication connection with a third optical fiber transmission module, the third optical fiber transmission module is respectively and electrically connected with a first trip circuit TJR contact of a high-voltage circuit breaker operation box of a power generation group and a first trip circuit TJR contact of a high-voltage starting standby transformer circuit breaker operation box, a protection action contact of a second power generation group protection device, a second group outlet of a power generation group non-electric quantity protection device, a protection action contact of a second high-voltage starting standby transformer protection device and a second group outlet of a high-voltage starting standby transformer non-electric quantity protection device are all electrically connected with a second optical fiber transmission module, the second optical fiber transmission module is in communication connection with a fourth optical fiber transmission module, the fourth optical fiber transmission module is respectively and electrically connected with the second trip circuit TJR contact of the transformer group high-voltage circuit breaker operation box and the second trip circuit TJR contact of the high-voltage starting standby transformer circuit breaker operation box.
The following are further optimizations and/or improvements to the above-described inventive solution:
The first optical fiber transmission module may include a first optical fiber interface device, a first PCM device, and a first SDH device, where the protection action contact of the first power generation group protection device, the first group outlet of the power generation group non-electric quantity protection device, the protection action contact of the first high-voltage starting standby transformer protection device, and the first group outlet of the high-voltage starting standby transformer non-electric quantity protection device are all electrically connected to the first optical fiber interface device, the first optical fiber interface device is in communication connection with the first PCM device, and the first PCM device is in communication connection with the first SDH device.
The third optical fiber transmission module may include a third optical fiber interface device, a third PCM device, and a third SDH device, where the first SDH device is in communication connection with the third SDH device, the third SDH device is in communication connection with the third PCM device, the third PCM device is in communication connection with the third optical fiber interface device, and the third optical fiber interface device is electrically connected to the first trip circuit TJR contact of the high-voltage circuit breaker operation box of the power generation set and the first trip circuit TJR contact of the high-voltage starting standby transformer circuit breaker operation box, respectively.
The second optical fiber transmission module may include a second optical fiber interface device, a second PCM device, and a second SDH device, where the protection action contact of the second power generation and transformation group protection device, the second group outlet of the power generation and transformation group non-electric quantity protection device, the protection action contact of the second high-voltage starting standby transformer protection device, and the second group outlet of the high-voltage starting standby transformer non-electric quantity protection device are all electrically connected to the second optical fiber interface device, the second optical fiber interface device is communicatively connected to the second PCM device, and the second PCM device is communicatively connected to the second SDH device.
The fourth optical fiber transmission module may include a fourth optical fiber interface device, a fourth PCM device, and a fourth SDH device, where the second SDH device is in communication connection with the fourth SDH device, the fourth SDH device is in communication connection with the fourth PCM device, the fourth PCM device is in communication connection with the fourth optical fiber interface device, and the fourth optical fiber interface device is electrically connected to the second trip circuit TJR contact of the high-voltage circuit breaker operation box of the power generation set and the second trip circuit TJR contact of the high-voltage starting standby transformer circuit breaker operation box, respectively.
The first optical fiber interface device and the first PCM device, the second optical fiber interface device and the second PCM device, the third optical fiber interface device and the third PCM device, and the fourth optical fiber interface device and the fourth PCM device may all be connected through twisted pair communication.
The first PCM device and the first SDH device, the second PCM device and the second SDH device, the third PCM device and the third SDH device and the fourth PCM device and the fourth SDH device can be connected through tail fiber communication.
The first SDH equipment and the third SDH equipment and the second SDH equipment and the fourth SDH equipment can be connected through optical cable communication.
According to the invention, the first power generation group protection device, the power generation group non-electric quantity protection device, the first high-voltage starting standby transformer protection device and the high-voltage starting standby transformer non-electric quantity protection device are electrically connected with the first trip circuit TJR contact of the power generation group high-voltage circuit breaker operation box and the first trip circuit TJR contact of the high-voltage starting standby transformer circuit breaker operation box through the first optical fiber transmission module and the third optical fiber transmission module, so that trip operation is realized, the second power generation group protection device, the power generation group non-electric quantity protection device, the second high-voltage starting standby transformer protection device and the second trip circuit TJR contact of the power generation group high-voltage circuit breaker operation box and the second trip circuit TJR contact of the high-voltage starting standby transformer circuit breaker operation box are electrically connected through the second optical fiber transmission module and the fourth optical fiber transmission module, the trip operation problem of a unit caused by a trip cable from the power generation group protection device to the circuit breaker operation box is effectively solved, the trip operation of a power plant is not influenced by the direct current or direct current distance of a direct current or a bit of a trip circuit is not influenced, and the trip operation of a power plant can be performed accurately.
Drawings
Fig. 1 is a schematic circuit diagram of a preferred embodiment of the present invention.
Fig. 2 is a schematic diagram of a power supply circuit of an optical fiber transmission module according to a preferred embodiment of the present invention.
Detailed Description
The present invention is not limited by the following examples, and specific embodiments can be determined according to the technical scheme and practical situations of the present invention.
The invention is further described below with reference to examples and figures:
As shown in fig. 1 and 2, the unit protection tripping device of the power plant based on 3/2 wiring condition comprises a first power generation unit protection device, a second power generation unit protection device, a first high-voltage starting standby transformer protection device, a second high-voltage starting standby transformer protection device, a high-voltage starting standby transformer non-electric quantity protection device, a power generation unit non-electric quantity protection device, a first optical fiber transmission module, a second optical fiber transmission module, a third optical fiber transmission module, a fourth optical fiber transmission module, a power generation unit high-voltage circuit breaker operation box and a high-voltage starting standby transformer circuit breaker operation box which are arranged in a booster station protection chamber, wherein a protection action contact of the first power generation unit protection device, a first group outlet of the power generation unit non-electric quantity protection device, a protection action contact of the first high-voltage starting standby transformer protection device and a first group outlet of the high-voltage starting standby transformer non-electric quantity protection device are all electrically connected with the first optical fiber transmission module, the first optical fiber transmission module is in communication connection with a third optical fiber transmission module, the third optical fiber transmission module is respectively and electrically connected with a first trip circuit TJR contact of a high-voltage circuit breaker operation box of a power generation group and a first trip circuit TJR contact of a high-voltage starting standby transformer circuit breaker operation box, a protection action contact of a second power generation group protection device, a second group outlet of a power generation group non-electric quantity protection device, a protection action contact of a second high-voltage starting standby transformer protection device and a second group outlet of a high-voltage starting standby transformer non-electric quantity protection device are all electrically connected with a second optical fiber transmission module, the second optical fiber transmission module is in communication connection with a fourth optical fiber transmission module, the fourth optical fiber transmission module is respectively and electrically connected with the second trip circuit TJR contact of the transformer group high-voltage circuit breaker operation box and the second trip circuit TJR contact of the high-voltage starting standby transformer circuit breaker operation box.
The first transformer group protection device, the second transformer group protection device, the first high-voltage starting standby transformer protection device, the second high-voltage starting standby transformer protection device, the high-voltage starting standby transformer non-electric quantity protection device, the transformer group high-voltage circuit breaker operation box and the high-voltage starting standby transformer circuit breaker operation box are all known technologies. Because the high-voltage starting standby transformer protection device in the unit protection chamber is provided with two sets of electric quantity protection devices and one set of non-electric quantity protection device, the power generation and transformation group protection device is also provided with two sets of electric quantity protection devices and one set of non-electric quantity protection device, two sets of optical fiber transmission modules are arranged in the unit protection chamber, and two sets of optical fiber transmission modules are also arranged in the corresponding booster station protection chamber. Meanwhile, the first optical fiber transmission module of the unit protection chamber supplies power through a direct current section of the unit direct current system; the second optical fiber transmission module is powered by a direct current second section of the unit direct current system. The third optical fiber transmission module of the booster station protection chamber supplies power through a direct current section of a direct current system of the booster station protection chamber; the fourth optical fiber transmission module is powered by a direct current second section of the direct current system of the booster station protection room.
According to the invention, the first power generation group protection device, the power generation group non-electric quantity protection device, the first high-voltage starting standby transformer protection device and the high-voltage starting standby transformer non-electric quantity protection device are electrically connected with the first trip circuit TJR contact of the power generation group high-voltage circuit breaker operation box and the first trip circuit TJR contact of the high-voltage starting standby transformer circuit breaker operation box through the first optical fiber transmission module and the third optical fiber transmission module, so that trip operation is realized, the second power generation group protection device, the power generation group non-electric quantity protection device, the second high-voltage starting standby transformer protection device and the second trip circuit TJR contact of the power generation group high-voltage circuit breaker operation box and the second trip circuit TJR contact of the high-voltage starting standby transformer circuit breaker operation box are electrically connected through the second optical fiber transmission module and the fourth optical fiber transmission module, the trip operation problem of a unit caused by a trip cable from the power generation group protection device to the circuit breaker operation box is effectively solved, the trip operation of a power plant is not influenced by the direct current or direct current distance of a direct current or a bit of a trip circuit is not influenced, and the trip operation of a power plant can be performed accurately.
The unit protection tripping device of the power plant based on the 3/2 wiring condition can be further optimized or/and improved according to actual needs:
As shown in fig. 1 and 2, the first optical fiber transmission module includes a first optical fiber interface device, a first PCM device and a first SDH device, where the protection action contact of the first power generation group protection device, the first group outlet of the power generation group non-electric quantity protection device, the protection action contact of the first high-voltage starting standby transformer protection device and the first group outlet of the high-voltage starting standby transformer non-electric quantity protection device are all electrically connected with the first optical fiber interface device, the first optical fiber interface device is in communication connection with the first PCM device, and the first PCM device is in communication connection with the first SDH device. The first optical fiber interface device, the first PCM device and the first SDH device are all known technologies, and the PCM device is integrated service access equipment, and is used for transmitting and extending analog signals, digital signals and data through optical fibers, twisted pairs or microwaves; the SDH equipment is optical transmission equipment and is used for realizing functions such as intercommunication among the equipment, greatly improving the utilization rate of network resources, reducing the management and maintenance cost and realizing flexible, reliable and efficient network operation and maintenance.
As shown in fig. 1 and 2, the third optical fiber transmission module includes a third optical fiber interface device, a third PCM device and a third SDH device, where the first SDH device is in communication connection with the third SDH device, the third SDH device is in communication connection with the third PCM device, the third PCM device is in communication connection with the third optical fiber interface device, and the third optical fiber interface device is electrically connected with the first trip circuit TJR contact of the high-voltage circuit breaker operation box of the power generation set and the first trip circuit TJR contact of the high-voltage starting standby transformer circuit breaker operation box respectively.
As shown in fig. 1 and 2, the second optical fiber transmission module includes a second optical fiber interface device, a second PCM device and a second SDH device, where the protection action contact of the second power generation and transformation group protection device, the second group outlet of the power generation and transformation group non-electric quantity protection device, the protection action contact of the second high-voltage starting standby transformer protection device and the second group outlet of the high-voltage starting standby transformer non-electric quantity protection device are all electrically connected with the second optical fiber interface device, the second optical fiber interface device is in communication connection with the second PCM device, and the second PCM device is in communication connection with the second SDH device.
As shown in fig. 1 and 2, the fourth optical fiber transmission module includes a fourth optical fiber interface device, a fourth PCM device and a fourth SDH device, where the second SDH device is in communication connection with the fourth SDH device, the fourth SDH device is in communication connection with the fourth PCM device, the fourth PCM device is in communication connection with the fourth optical fiber interface device, and the fourth optical fiber interface device is electrically connected to the second trip circuit TJR contact of the high-voltage circuit breaker operation box of the power generation set and the second trip circuit TJR contact of the high-voltage starting standby transformer circuit breaker operation box respectively.
As shown in fig. 1 and 2, the first optical fiber interface device is connected with the first PCM device, the second optical fiber interface device is connected with the second PCM device, the third optical fiber interface device is connected with the third PCM device, and the fourth optical fiber interface device is connected with the fourth PCM device through twisted pair communication.
As shown in fig. 1 and 2, the first PCM device is connected with the first SDH device, the second PCM device is connected with the second SDH device, the third PCM device is connected with the third SDH device, and the fourth PCM device is connected with the fourth SDH device through tail fiber communication.
As shown in fig. 1 and 2, the first SDH device and the third SDH device, and the second SDH device and the fourth SDH device are all connected through optical cable communication.
The technical characteristics form the optimal embodiment of the invention, have stronger adaptability and optimal implementation effect, and can increase or decrease unnecessary technical characteristics according to actual needs so as to meet the requirements of different situations.
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| CN201711176182.8A CN107769162B (en) | 2017-11-22 | 2017-11-22 | Unit protection tripping device of power plant based on 3/2 connection condition |
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| CN201711176182.8A CN107769162B (en) | 2017-11-22 | 2017-11-22 | Unit protection tripping device of power plant based on 3/2 connection condition |
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| CN107769162A CN107769162A (en) | 2018-03-06 |
| CN107769162B true CN107769162B (en) | 2024-06-25 |
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| CN109167338B (en) * | 2018-08-16 | 2020-04-28 | 岭澳核电有限公司 | Generator-transformer unit protection control method and device for nuclear power unit |
| CN109088444B (en) * | 2018-08-28 | 2020-07-21 | 国网湖南省电力有限公司 | Optimization method for non-full-phase protection action performance of direct-current receiving-end phase modulator |
| CN112383034B (en) * | 2020-10-30 | 2022-07-22 | 南京南瑞继保电气有限公司 | Operation relay device, converter transformer protection tripping system and tripping method |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN207910444U (en) * | 2017-11-22 | 2018-09-25 | 国网新疆电力有限公司电力科学研究院 | Generator protection tripgear based on 3/2 wiring condition power plant |
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| JP4352267B2 (en) * | 2005-06-27 | 2009-10-28 | 日立Ｇｅニュークリア・エナジー株式会社 | Digital protection relay system for generator main circuit |
| WO2010012301A1 (en) * | 2008-07-30 | 2010-02-04 | Abb Research Ltd | Generator circuit breaker with fiber-optic current sensor |
| CN202231412U (en) * | 2011-09-30 | 2012-05-23 | 湖南晟通科技集团有限公司 | Power generation and transformation group non-electric quantity protection remote transmission tripping device |
| CN102570413B (en) * | 2012-01-04 | 2014-11-19 | 广东省电力设计研究院 | Compensatory protection and linked tripping device for submarine cable |
| CN102570391A (en) * | 2012-03-13 | 2012-07-11 | 南京南瑞继保电气有限公司 | Configuration realization method for transformer protection |
| CN205407404U (en) * | 2016-03-17 | 2016-07-27 | 中国神华能源股份有限公司 | A an equipment and a system of change group for sending out switching of power of change group |
| CN205790973U (en) * | 2016-06-17 | 2016-12-07 | 广东电网有限责任公司揭阳供电局 | The electric power system of transformer lines unit connection |
| CN106300262B (en) * | 2016-08-26 | 2019-02-05 | 大唐黄岛发电有限责任公司 | A kind of 220kV grade transformer protection method for substation's remote power-feeding |
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| CN207910444U (en) * | 2017-11-22 | 2018-09-25 | 国网新疆电力有限公司电力科学研究院 | Generator protection tripgear based on 3/2 wiring condition power plant |
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