CN109066590A - A kind of ground protection circuit and motor power supply system - Google Patents
A kind of ground protection circuit and motor power supply system Download PDFInfo
- Publication number
- CN109066590A CN109066590A CN201810879135.8A CN201810879135A CN109066590A CN 109066590 A CN109066590 A CN 109066590A CN 201810879135 A CN201810879135 A CN 201810879135A CN 109066590 A CN109066590 A CN 109066590A
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- China
- Prior art keywords
- contactor
- normally opened
- circuit
- power supply
- string
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Classifications
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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
- H02H7/08—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 for dynamo-electric motors
- H02H7/0833—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 for dynamo-electric motors for electric motors with control arrangements
- H02H7/0844—Fail safe control, e.g. by comparing control signal and controlled current, isolating motor on commutation error
-
- 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
- H02H7/08—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 for dynamo-electric motors
- H02H7/085—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 for dynamo-electric motors against excessive load
Landscapes
- Protection Of Generators And Motors (AREA)
- Emergency Protection Circuit Devices (AREA)
Abstract
The present invention provides a kind of ground protection circuit and motor power supply systems; wherein; ground protection circuit includes current detection circuit, breaker control circuit and/or contactor control loop; string is equipped with the secondary side and overcurrent relay coil of current transformer in current detection circuit, and the primary side of current transformer is located at the three-phase tie point of motor current supply circuit for going here and there to detect zero-sequence current；String is equipped with overcurrent relay normally opened contact and breaker shunt opening trip coil in breaker control circuit；String is equipped with contactor normally opened contact, overcurrent relay normally-closed contact and contactor coil in contactor control loop.Flexible design of the present invention is simple and practical, not only plays protective effect to electrical equipment upon the occurrence of a ground fault, but also also ensures the personal safety of operator, avoids the generation of safety accident, ensure that the normal operation of distribution system.
Description
Technical field
The invention belongs to electrical technology field, in particular to a kind of ground protection circuit and motor power supply system.
Background technique
Motor has penetrated into all trades and professions as a kind of driving machinery, its use, is industry, agricultural, national defense construction
The important guarantee being normally carried out with people's lives, with the high speed development of modern electronic technology, various motor protecting devices are answered
It transports and gives birth to, it is high sensitivity, cheap, strong operability, easy to maintain, before current every field has a wide range of applications
Scape.Therefore, the design studies for reinforcing motor protecting device are an important topics of current era.
Traditional motor protection mainly by installed in the current supply circuit of motor it is single be controlled by the controller connect
Tentaculum, when a failure occurs, control contactor disjunction are realized and are protected to disconnect the current supply circuit of motor, but the program
Defencive function it is single.When being overhauled not in time with electric line, when the reasons such as bad environments cause distribution system that ground fault occurs,
Very big electric current can be generated, since electric current is excessive at this time, may result in contactor can not normal disjunction, cannot cut off and match in time
Electrical circuit power supply will cause the electric shock accidents of the damage and service personnel of electrical equipment.
Summary of the invention
The purpose of the present invention is to provide a kind of ground protection circuit and motor power supply systems, for solving in the prior art
When distribution system earth current excessive the problem of causing safety accident.
To achieve the above object, the present invention provides a kind of ground protection circuits, including current detection circuit, breaker control
Circuit processed and/or contactor control loop, in the current detection circuit string be equipped with current transformer secondary side and overcurrent after
The primary side of electric apparatus coil, the current transformer is located at the three-phase tie point of motor current supply circuit for going here and there to detect zero sequence
Electric current；String is equipped with overcurrent relay normally opened contact and breaker shunt opening trip coil in the breaker control circuit；It is described to connect
String is equipped with contactor normally opened contact, overcurrent relay normally-closed contact and contactor coil in tentaculum control loop.
In order to facilitate the conducting of control contactor control loop, the contactor control loop, which is also gone here and there, is equipped with normally opened manually press
Button, the contactor normally opened contact are connected in parallel with the normally opened button manually.
It is described to connect in order to break down in contactor control loop or whens other situations turns off contactor control loop in time
Also string is equipped with manual normally closed button in tentaculum control loop, the normally closed button manually and the contactor normally opened contact, manually
The input terminal connection of normally opened button being connected in parallel a little.
The present invention also provides a kind of motor power supply systems, including motor current supply circuit, further include ground protection circuit, institute
Stating ground protection circuit includes current detection circuit, breaker control circuit and/or contactor control loop, the current detecting
String is equipped with the secondary side and overcurrent relay coil of current transformer in circuit, and the primary side string of the current transformer is located at electricity
To detect zero-sequence current at the three-phase tie point of machine current supply circuit；It is normal to be equipped with overcurrent relay for string in the breaker control circuit
Open contact and breaker shunt opening trip coil；String is equipped with contactor normally opened contact, overcurrent relay in the contactor control loop
Device normally-closed contact and contactor coil.
In order to which control selections disconnect breaker disconnection or contactor, the motor current supply circuit includes the first of parallel connection
It powers branch and the second power supply branch, string is equipped with breaker in the first power supply branch, goes here and there and sets in the second power supply branch
There is contactor, the first power supply branch is connect with the second power supply branch by change-over switch.
In order to facilitate the conducting of control contactor control loop, the contactor control loop, which is also gone here and there, is equipped with normally opened manually press
Button, the contactor normally opened contact are connected in parallel with the normally opened button manually.
It is described to connect in order to break down in contactor control loop or whens other situations turns off contactor control loop in time
Also string is equipped with manual normally closed button in tentaculum control loop, the normally closed button manually and the contactor normally opened contact, manually
The input terminal connection of normally opened button being connected in parallel a little.
The beneficial effects of the present invention are:
Ground protection circuit of the invention includes that current detection circuit, breaker control circuit and/or contactor control back
Road, string is equipped with the secondary side and overcurrent relay coil of current transformer in current detection circuit；It is gone here and there in breaker control circuit
Equipped with overcurrent relay normally opened contact and breaker shunt opening trip coil；String is equipped with the normally opened touching of contactor in contactor control loop
Point, overcurrent relay normally-closed contact and contactor coil, electric current of the overcurrent relay coil in motor current supply circuit reach
It is charged when to setting value, further to control cut-off breaker and/or contactor.Flexible design of the present invention is simple and practical, works as hair
Protective effect not only is played to electrical equipment when raw ground fault, but also also ensures the personal safety of operator, is avoided
The generation of safety accident, ensure that the normal operation of distribution system.
Detailed description of the invention
Fig. 1 is the structural schematic diagram of motor current supply circuit of the invention；
Fig. 2 is overcurrent relay wiring diagram；
Fig. 3 is overcurrent relay internal structure chart；
Fig. 4 is breaker shunt opening coil control loop structural schematic diagram；
Fig. 5 is contactor control loop structural schematic diagram.
Specific embodiment
A specific embodiment of the invention is further described with reference to the accompanying drawing:
The present invention provides a kind of motor power supply systems, including motor current supply circuit, further include ground protection circuit, ground connection
Protection circuit can be applicable in other electrical equipments such as motor.Ground protection circuit includes current detection circuit, breaker control
Circuit and/or contactor control loop, string is equipped with the secondary side and overcurrent relay line of current transformer in current detection circuit
Circle, the primary side string of current transformer are located at the three-phase tie point of motor current supply circuit to detect zero-sequence current；Breaker control
String is equipped with overcurrent relay normally opened contact and breaker shunt opening trip coil in circuit processed；String is equipped with and connects in contactor control loop
Tentaculum normally opened contact, overcurrent relay normally-closed contact and contactor coil.
Breaker and contactor in motor current supply circuit can be it is concatenated, as other embodiments, motor power supply
Circuit includes the first power supply branch and the second power supply branch in parallel, and string is equipped with breaker, the second power supply in the first power supply branch
String is equipped with contactor in branch, is connected between the first power supply branch and the second power supply branch by change-over switch.
When ground fault occurs for system, current transformer can detect zero-sequence current, when zero-sequence current reaches setting value,
Overcurrent relay normally opened contact closure, the electrification of breaker shunt opening trip coil, breaker disconnect；Alternatively, overcurrent relay is normally closed
Contact disconnects, contactor coil power loss, and contactor disconnects.But by the first power supply branch and contactor institute where breaker
The second power supply branch between be provided with change-over switch, so, can according to need selection and still broken by cut-off breaker
Open contactor make motor current supply circuit power off or simultaneously switch off several contactors of breaker make motor current supply circuit power off.
The contactor control loop of the present embodiment further includes contactor normally opened contact and normally opened button, contactor are normally opened manually
Contact is connected in parallel with manual normally opened button；Also string is equipped with manual normally closed button in the control loop, manual normally closed button with connect
The input terminal connection of tentaculum normally opened contact, manually normally opened button being connected in parallel a little.
Illustrate below with breaker and contactor are concatenated relationship, specific as depicted in figs. 1 and 2, motor power supply
Circuit includes circuit breaker Q F, contactor KM, electrothermal relay KH, further include string be located at motor D current supply circuit three-phase (U phase, V phase,
W phase) zero sequence current mutual inductor 1LH at tie point primary side, the two of overcurrent relay DLJ and zero sequence current mutual inductor 1LH
Secondary side connects to form current detection circuit, to detect the zero-sequence current in motor current supply circuit.The internal structure of overcurrent relay
As shown in figure 3, contact 1,3 is the normally opened contact of overcurrent relay DLJ, contact 5,7 is the normally-closed contact of overcurrent relay DLJ,
Contact 2,6 and contact 4,8 respectively constitute the Inside coil of overcurrent relay DLJ, are set by the series connection and parallel connection of Inside coil
Determine the action current of overcurrent relay.
As shown in figure 4, the motor ground protection circuit of the present embodiment includes breaker control circuit, breaker control circuit
In successively string be equipped with electrothermal relay FU, overcurrent relay DLJ normally opened contact and circuit breaker Q F shunt opening trip coil.When being grounded
When failure, zero sequence current mutual inductor can generate a zero-sequence current, when zero-sequence current is more than overcurrent relay setting value, overcurrent after
Electric apparatus coil electrification, then overcurrent relay normally opened contact 1,3 is closed, and breaker control circuit conducting makes point of circuit breaker Q F
It encourages tripping coil and obtains electric, drive the shunt release of breaker to act, disconnect the current supply circuit of motor, ensure that electrical equipment
And the safety of operator.
Further, the motor ground protection circuit of the present embodiment further includes contactor control loop, as shown in figure 5, should
Successively string is normally closed equipped with switch QA1, manual normally closed button SBT, manual normally opened button SBH, overcurrent relay DLJ in control loop
The coil of contact and contactor KM, the manual normally opened both ends button SBH are parallel with the normally opened contact of contactor KM.When generation ground connection event
When barrier, zero sequence current mutual inductor can generate a zero-sequence current, when zero-sequence current is more than overcurrent relay setting value, overcurrent relay
The electrification of device coil, then overcurrent relay normally-closed contact 5,7 disconnects, the contactor coil power loss in contactor control loop, right
Contacts of contactor in the motor current supply circuit answered disconnects, and disconnects the current supply circuit of motor, ensure that electrical equipment and operation
The safety of personnel.
Specific embodiment is presented above, but the present invention is not limited to embodiment described above.The present invention
Basic ideas be above-mentioned basic scheme, for those of ordinary skill in the art, introduction according to the present invention is designed each
The model of kind deformation, formula, parameter do not need to spend creative work.The case where not departing from the principle and spirit of the invention
Under to embodiment carry out variation, modification, replacement and deformation still fall in protection scope of the present invention.
Claims (7)
1. a kind of ground protection circuit, which is characterized in that including current detection circuit, breaker control circuit and/or contactor
Control loop, string is equipped with the secondary side and overcurrent relay coil of current transformer, the electric current in the current detection circuit
The primary side of mutual inductor is located at the three-phase tie point of motor current supply circuit for going here and there to detect zero-sequence current；The breaker control
String is equipped with overcurrent relay normally opened contact and breaker shunt opening trip coil in circuit processed；It goes here and there and sets in the contactor control loop
There are contactor normally opened contact, overcurrent relay normally-closed contact and contactor coil.
2. ground protection circuit according to claim 1, which is characterized in that the contactor control loop, which is also gone here and there, is equipped with hand
Normally opened button is moved, the contactor normally opened contact is connected in parallel with the normally opened button manually.
3. ground protection circuit according to claim 1 or 2, which is characterized in that also gone here and there in the contactor control loop
Equipped with manual normally closed button, the normally closed button manually and the contactor normally opened contact, manual normally opened button are connected in parallel
The input terminal connection of point.
4. a kind of motor power supply system, including motor current supply circuit, which is characterized in that it further include ground protection circuit, it is described to connect
It includes current detection circuit, breaker control circuit and/or contactor control loop, the current detection circuit that circuit is protected on ground
Middle string is equipped with the secondary side and overcurrent relay coil of current transformer, and the primary side string of the current transformer is located at motor confession
To detect zero-sequence current at the three-phase tie point of electrical circuit；String is equipped with the normally opened touching of overcurrent relay in the breaker control circuit
Point and breaker shunt opening trip coil；It is normal to be equipped with contactor normally opened contact, overcurrent relay for string in the contactor control loop
Closed contact and contactor coil.
5. motor power supply system according to claim 4, which is characterized in that the motor current supply circuit includes in parallel the
One power supply branch and second power supply branch, it is described first power supply branch in string be equipped with breaker, it is described second power supply branch in go here and there
Equipped with contactor, the first power supply branch is connect with the second power supply branch by change-over switch.
6. motor power supply system according to claim 4 or 5, which is characterized in that the contactor control loop, which is also gone here and there, to be set
There is manual normally opened button, the contactor normally opened contact is connected in parallel with the normally opened button manually.
7. motor power supply system according to claim 6, which is characterized in that also string is equipped in the contactor control loop
Manual normally closed button, the normally closed button manually and the contactor normally opened contact, manually normally opened button are connected in parallel a little
Input terminal connection.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810879135.8A CN109066590A (en) | 2018-08-03 | 2018-08-03 | A kind of ground protection circuit and motor power supply system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810879135.8A CN109066590A (en) | 2018-08-03 | 2018-08-03 | A kind of ground protection circuit and motor power supply system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN109066590A true CN109066590A (en) | 2018-12-21 |
Family
ID=64833173
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810879135.8A Pending CN109066590A (en) | 2018-08-03 | 2018-08-03 | A kind of ground protection circuit and motor power supply system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109066590A (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103746332A (en) * | 2014-01-24 | 2014-04-23 | 中山市明阳电器有限公司 | Ground protection device for molded case circuit breaker in main loop of power distribution device |
| CN204230865U (en) * | 2014-12-05 | 2015-03-25 | 常熟开关制造有限公司(原常熟开关厂） | A kind of motor protecting device |
| CN205017000U (en) * | 2015-10-10 | 2016-02-03 | 大唐华银株洲发电有限公司 | Power plant earth fault protection device |
| CN208522450U (en) * | 2018-08-03 | 2019-02-19 | 河南森源电气股份有限公司 | Ground protection circuit and motor power supply system |
-
2018
- 2018-08-03 CN CN201810879135.8A patent/CN109066590A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103746332A (en) * | 2014-01-24 | 2014-04-23 | 中山市明阳电器有限公司 | Ground protection device for molded case circuit breaker in main loop of power distribution device |
| CN204230865U (en) * | 2014-12-05 | 2015-03-25 | 常熟开关制造有限公司(原常熟开关厂） | A kind of motor protecting device |
| CN205017000U (en) * | 2015-10-10 | 2016-02-03 | 大唐华银株洲发电有限公司 | Power plant earth fault protection device |
| CN208522450U (en) * | 2018-08-03 | 2019-02-19 | 河南森源电气股份有限公司 | Ground protection circuit and motor power supply system |
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