CN104538933B - A kind of motor differential protective system and method - Google Patents
A kind of motor differential protective system and method Download PDFInfo
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- CN104538933B CN104538933B CN201510027741.3A CN201510027741A CN104538933B CN 104538933 B CN104538933 B CN 104538933B CN 201510027741 A CN201510027741 A CN 201510027741A CN 104538933 B CN104538933 B CN 104538933B
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- motor
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- point current
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Abstract
The present invention discloses a kind of motor differential protective system and method, including with the motor protecting device and neutral point current harvester corresponding to one or more motor；The neutral point current of one or more motor is changed into data signal by neutral point current harvester; each group current signal is sent to by corresponding motor protecting device by communication mode; motor protecting device gathers respective motor generator terminal side electric current; the signal come is transmitted with reference to neutral point current harvester, differential protection function is completed after synchronizing processing.Such a system and method can solve the CT saturation problems caused by neutral point current collection cable is long, improve differential protection performance and the anti-error kinetic force of external area error, enhance the reliability of signal, simplify field connection, investment reduction.
Description
Technical field
The present invention relates to motor protection, in particular it relates to a kind of based on communication mode collection neutral point current letter
Number with the motor differential protective system and method that are combined by conventional method harvester side electric current.
Background technology
In power plant and industrial enterprise, motor is the essential equipment for ensureing technique normal operation, for
2000kW and the above capacity motor, it is desirable to install differential protection.
The control of operation and the stopping of high capacity motor is realized by breaker, in power plant and industrial enterprise, one section of mother
All breaker cabinet centralized arrangements of line are then arranged in different places, distance in switch gear room, motor according to the demand of technique
The supreme km of the tens of rice of breaker cabinet.
Generally, motor protecting device is installed on breaker cabinet, busbar voltage needed for protection device, electronic
Machine generator terminal electric current, circuit breaker position etc. can gather nearby out of this breaker cabinet.When needing differential protection, it is necessary to gather electricity
Motivation neutral point current, existing way are that neutral point current is accessed into motor protecting device by cable, as shown in figure 1,
Cable length is usually tens of rice to hundreds of meters, can reach km under a few cases, the increase of cable length means neutrality
The increase of point current transformer (abbreviation neutral point CT) secondary load, it is meant that neutral point CT progress of disease error increases.
Even if motor neutral point CT is with generator terminal CT homotypes, because the cable length of the two access motor protecting device is poor
Not larger, when causing motor normal operation, the out-of-balance current of motor protecting device increases；And work as motor neutral point
When CT secondary cables are long (such as larger than 300 meters), saturated phenomenon may occur by neutral point CT in starting process of motor.This
A little quick-actions and reliability for all having had a strong impact on motor differential protection.
The content of the invention
The purpose of the present invention, it is to provide a kind of motor differential protective system and method, solves a present motor
Or multiple motors differential protection is due to the long caused differential protection quick-action of neutral point CT secondary cables and reliability reduction
The problem of.
In order to reach above-mentioned purpose, solution of the invention is：
A kind of motor differential protective system, including one or more motor, and it is corresponding with the motor disconnected
Road device and motor protecting device；Including one or more neutral point current harvesters, the neutral point current harvester
It is connected with one or more motor, communication mode is used between the motor protecting device and neutral point current harvester
Connection；
The neutral point current harvester is used for the neutral point current for gathering the motor, and is converted to digital letter
Number, the motor protecting device is sent to by communication mode；Wherein, a neutral point current harvester collection one
The neutral point current of platform motor, or the neutral point current of collection multiple motors, it is electronic by each by communication mode
The neutral point current signal of machine is sent to corresponding motor protecting device；
The motor protecting device is used to gather the motor generator terminal side electric current, and is adopted according to the neutral point current
Acquisition means transmit the signal come, the motor neutral point current information are obtained, so as to complete differential protection function；
The motor generator terminal side electric current and the neutral point current are gathered by electromagnetic type current transformer；
Point-to-point communication can be used between the motor protecting device and neutral point current harvester, can also be adopted
Use network communication mode.
The invention also discloses a kind of motor differential protecting method, it is characterised in that：Including step：
Motor neutral point current collecting device gathers the neutral point current of one or more motor in real time, carries out modulus
Turn into neutral point current signal after conversion, wherein, when motor neutral point harvester gathers the neutral point electricity of a motor
During stream, the neutral point current signal is sent to the motor protection by the neutral point current harvester by communication mode
Device；When gathering the neutral point current of multiple motors, the neutral point current harvester will be each by communication mode
The neutral point current signal of platform motor is sent to corresponding motor protecting device；
Motor protecting device gathers the generator terminal side electric current of motor in real time, and carries out analog-to-digital conversion and turn into generator terminal side electric current
Signal；
When the motor protecting device obtains the neutral point current signal of respective motor and the generator terminal
After the current signal of side, two current signals are synchronized, finally complete differential protection.
Using technical scheme, have the advantages that：
(1) motor neutral point electric current in-situ digitalization, traditional neutral point electromagnetic type CT loads is reduced, are eliminated due to length
CT saturated phenomenons caused by cable；
(2) during motor normal operation, the out-of-balance current of motor protecting device is obviously reduced, therefore can reduce differential
Starting current threshold value is protected, improves the sensitivity of differential protection；
(3) probability of neutral point CT saturations is reduced, improves and internal fault differential protection occurs in the case of high current
Responsiveness；
(4) the anti-error kinetic force of external area error is improved；
(5) cable for differential protection can be saved significantly on, is reduced investment outlay, when multiple motors share a current acquisition
During device, effect becomes apparent from；
(6) live motor is more remote from a distance from motor generator terminal breaker, and above-mentioned advantage is more obvious.
Brief description of the drawings
Fig. 1 is existing motor protection wiring schematic diagram；
Fig. 2 is motor differential protection of the present invention and the one-to-one wiring schematic diagram of current collecting device；
Fig. 3 is motor differential protection of the present invention and current collecting device many-one, point-to-point wiring schematic diagram；
Fig. 4 is motor differential protection of the present invention and current collecting device many-one network connection schematic diagram.
Embodiment
Below with reference to accompanying drawing, embodiments of the invention are described in detail.
The present invention provides a kind of motor differential protective system, and its object being directed to is to need to install the electronic of differential protection
Machine.Coordinate shown in Fig. 2, motor protecting device is identical with the quantity of breaker and corresponds, each motor protecting device peace
In the breaker cabinet of corresponding breaker, pass through collection of the cable completion to the circuit breaker voltage, motor generator terminal
The collection of signal and the controls to breaker such as the collection of electric current, circuit breaker position；Motor neutral point for differential protection
Electric current accesses current collecting device by cable from neutral point current transformer, and current collecting device is after conversion by neutral point
Electric current is converted into data signal, and current collecting device, which is transmitted neutral point current signal to respective motor by communication mode, to be protected
In protection unit, communicated between motor protecting device and current collecting device by optical cable, communication cable or communication,
Host-host protocol is IEC61850-9-2 or IEC60044-8 or other proprietary protocols；Motor protecting device passes through re-sampling technology
The sampling instant of synchronous generator terminal electric current and neutral point current, complete motor differential protection.
Coordinate shown in Fig. 3, if several motor need to share a current collecting device, this implementation can be used
Example.Motor protecting device is identical with the quantity of breaker and corresponds, and each motor protecting device is arranged on corresponding
Breaker breaker cabinet in, collection to the circuit breaker voltage, the gathering of motor generator terminal electric current are completed by cable, broken
The collection of road device position signals and the control to breaker；Each motor neutral point electric current for differential protection passes through cable
Current collecting device is accessed from respective neutral point current transformer, current collecting device changes neutral point current after conversion
Into data signal, current collecting device is protected each neutral point current signal point-to-point transmission to respective motor by communication mode
In protection unit, led between each motor protecting device and current collecting device by optical cable, communication cable or communication
Letter, host-host protocol is IEC61850-9-2 or IEC60044-8 or other proprietary protocols；Every motor protecting device passes through again
The sampling instant of Sampling techniques synchronization generator terminal electric current and neutral point current, complete motor differential protection.
Coordinate shown in Fig. 4, if several motor share a current collecting device, this embodiment can be used.Electricity
Motivation protection device is identical with the quantity of breaker and corresponds, and each motor protecting device is arranged on corresponding open circuit
In the breaker cabinet of device, pass through collection of the cable completion to the circuit breaker voltage, the collection of motor generator terminal electric current, breaker position
The collection of signal and the control to breaker such as put；Each motor neutral point electric current for differential protection is by cable from respective
Neutral point current transformer accesses current collecting device, and neutral point current is converted into numeral by current collecting device after conversion
Signal, current collecting device, which is transmitted each neutral point current signal to respective motor by network mode by communication mode, to be protected
In protection unit, led between each motor protecting device and current collecting device by optical cable, communication cable or communication
Letter, host-host protocol is IEC60044-8 or other proprietary protocols, and every motor protecting device passes through re-sampling technology synchronous machine
The sampling instant of electric current and neutral point current is held, completes motor differential protection.
Certain power plant feed pump 2800kW, rated voltage 6.3kV, generator terminal side are that conventional 5P20 is mutual with neutral point current transformer
Sensor, no-load voltage ratio 400/1, motor step are electronic when motor starting from its corresponding about 900 meters of breaker cable distance
Machine protection device report difference throat floater is alarmed, and differential protection starting value setting valve is 0.7 times of motor rated current, differential
Protect insensitive and reliability relatively low.Using scheme shown in Fig. 2, property point installation current collecting device, is arranged in the motor
About 5 meters away from the motor remote positions, neutral point current transformer accesses current collecting device nearby, and current collecting device leads to
Cross optical cable to be connected with respective motor protection device, using IEC61850-9-2 transmission neutral point current samplings, differential protection rises
Dynamic value setting valve is reduced to the motor rated current for 0.3 times, and when motor start-up, comprehensive protecting device for motor is shown just
Often, indifference stream is alarmed.
The technological thought of above example only to illustrate the invention, it is impossible to protection scope of the present invention is limited with this, it is every
According to technological thought proposed by the present invention, any change done on the basis of technical scheme, the scope of the present invention is each fallen within
Within.
Claims (3)
1. a kind of motor differential protective system, it is characterized in that：Including one or more motor, and with the motor pair
The motor protecting device answered；Including one or more neutral point current harvesters, every neutral point current collection dress
Put and be connected with one or more motor, using logical between the motor protecting device and the neutral point current harvester
Letter mode connects；
The neutral point current harvester is used for the neutral point current for gathering the motor, and is converted to data signal, leads to
Cross communication mode and be sent to the motor protecting device；Wherein, a neutral point current harvester gathers an electricity
The neutral point current of motivation, or the neutral point current of collection multiple motors, by communication mode by each motor
Neutral point current signal is sent to corresponding motor protecting device；
The motor protecting device is used to gather the motor generator terminal side electric current, and is gathered and filled according to the neutral point current
The signal for transmitting and is put, the motor neutral point current information is obtained, so as to complete differential protection function；
Using point-to-point communication or using network between the motor protecting device and the neutral point current harvester
Communication mode.
A kind of 2. motor differential protective system as claimed in claim 1, it is characterised in that：The motor generator terminal side electric current
Gathered with the neutral point current by electromagnetic type current transformer.
A kind of 3. motor differential protecting method of motor differential protective system, it is characterised in that：Including step：
Motor neutral point current collecting device gathers the neutral point current of one or more motor in real time, carries out analog-to-digital conversion
Turn into neutral point current signal afterwards, wherein, when the neutral point current of motor neutral point harvester one motor of collection,
The neutral point current signal is sent to the motor protecting device by the neutral point current harvester by communication mode；
When gathering the neutral point current of multiple motors, the neutral point current harvester is electronic by each by communication mode
The neutral point current signal of machine is sent to corresponding motor protecting device；
Motor protecting device gathers the generator terminal side electric current of motor in real time, and carries out analog-to-digital conversion and believe as generator terminal side electric current
Number；
When the motor protecting device obtains the neutral point current signal and generator terminal side electricity of respective motor
After flowing signal, two current signals are synchronized, finally complete differential protection.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510027741.3A CN104538933B (en) | 2015-01-14 | 2015-01-20 | A kind of motor differential protective system and method |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2015100192082 | 2015-01-14 | ||
| CN201510019208 | 2015-01-14 | ||
| CN201510027741.3A CN104538933B (en) | 2015-01-14 | 2015-01-20 | A kind of motor differential protective system and method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN104538933A CN104538933A (en) | 2015-04-22 |
| CN104538933B true CN104538933B (en) | 2018-03-13 |
Family
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Family Applications (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201520040267.3U Withdrawn - After Issue CN204424875U (en) | 2015-01-14 | 2015-01-20 | A kind of motor differential protective system |
| CN201510027741.3A Active CN104538933B (en) | 2015-01-14 | 2015-01-20 | A kind of motor differential protective system and method |
Family Applications Before (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201520040267.3U Withdrawn - After Issue CN204424875U (en) | 2015-01-14 | 2015-01-20 | A kind of motor differential protective system |
Country Status (1)
| Country | Link |
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| CN (2) | CN204424875U (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN204424875U (en) * | 2015-01-14 | 2015-06-24 | 南京南瑞继保电气有限公司 | A kind of motor differential protective system |
| CN105140883A (en) * | 2015-07-07 | 2015-12-09 | 江苏金智科技股份有限公司 | Differential protection system applied to transformer circuit |
| CN107181237B (en) * | 2017-07-07 | 2018-11-13 | 南京南瑞继保电气有限公司 | A kind of pump-storage generator Back To Back Startup Procedure differential protecting method and system |
| CN108565835A (en) * | 2018-04-23 | 2018-09-21 | 华为技术有限公司 | Generator relay protecting method and circuit |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102025126A (en) * | 2011-01-19 | 2011-04-20 | 广东省电力设计研究院 | Relay protection method of transformer as well as system thereof |
| CN102623960A (en) * | 2012-04-12 | 2012-08-01 | 台州发电厂 | Variable-frequency motor protection device based on intelligent sensors |
| CN102916394A (en) * | 2011-12-24 | 2013-02-06 | 许继集团有限公司 | On-site transformer protection system used for intelligent transformer substation |
| CN204424875U (en) * | 2015-01-14 | 2015-06-24 | 南京南瑞继保电气有限公司 | A kind of motor differential protective system |
-
2015
- 2015-01-20 CN CN201520040267.3U patent/CN204424875U/en not_active Withdrawn - After Issue
- 2015-01-20 CN CN201510027741.3A patent/CN104538933B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102025126A (en) * | 2011-01-19 | 2011-04-20 | 广东省电力设计研究院 | Relay protection method of transformer as well as system thereof |
| CN102916394A (en) * | 2011-12-24 | 2013-02-06 | 许继集团有限公司 | On-site transformer protection system used for intelligent transformer substation |
| CN102623960A (en) * | 2012-04-12 | 2012-08-01 | 台州发电厂 | Variable-frequency motor protection device based on intelligent sensors |
| CN204424875U (en) * | 2015-01-14 | 2015-06-24 | 南京南瑞继保电气有限公司 | A kind of motor differential protective system |
Non-Patent Citations (1)
| Title |
|---|
| 交流高压电动机的保护配置方案与整定计算方法探讨;张强等;《自动化与仪器仪表》;20030228(第2期);50-53 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN104538933A (en) | 2015-04-22 |
| CN204424875U (en) | 2015-06-24 |
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