CN202353176U - Secondary over-voltage protection device for current transformer - Google Patents
Secondary over-voltage protection device for current transformer Download PDFInfo
- Publication number
- CN202353176U CN202353176U CN2011204540265U CN201120454026U CN202353176U CN 202353176 U CN202353176 U CN 202353176U CN 2011204540265 U CN2011204540265 U CN 2011204540265U CN 201120454026 U CN201120454026 U CN 201120454026U CN 202353176 U CN202353176 U CN 202353176U
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- circuit
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- electric current
- mutual inductance
- overvoltage protection
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Abstract
The utility model relates to a secondary over-voltage protection device for a current transformer. The device comprises a shell, and an over-voltage protection circuit, a resetting circuit, an alarming circuit, an indication circuit, a resetting key and a running indicator lamp which are accommodated in the shell; the resetting key and the running indicator lamp are arranged on the outer wall of the shell; the resetting key is electrically connected in series with the resetting circuit; the running indicator lamp is electrically connected in series with the indication circuit; the resetting circuit also comprises a resistor (R5), one end of the resistor (R5) is electrically connected with a power supply through the resetting key, and the other end of the resistor (R5) is electrically connected with one end of a resetting coil of a bistable relay of the over-voltage protection circuit; and the indication circuit also comprises a resistor (R9) and a diode, the anode of the diode is electrically connected with a corresponding contact of the bistable relay, and the cathode of the diode is electrically connected to the running indicator lamp through the resistor (R9). According to the secondary over-voltage protection device for the current transformer, an accident caused by the secondary open circuit of the current transformer can be effectively prevented.
Description
Technical field
The utility model relates to a kind of overvoltage protection, relates in particular to a kind of electric current mutual inductance secondary overvoltage protection.
Background technology
In electric power system, current transformer (CT) is widely used in the measurement and the control of primary current.The instrument transformer secondary side is in approximate short-circuit condition during operate as normal, and output voltage is very low.If secondary winding open circuit in running, or a winding flows through abnormal current (like lightning current, resonance overcurrent, electric capacity charging current, inductance starting current etc.), all can produce the overvoltage of thousands of volts even volts up to ten thousand at secondary side.This not only works the mischief to electrical secondary system insulation, also can make the too drastic and scaling loss of instrument transformer, even crisis staff's life security.
The utility model content
In view of this, be necessary to provide a kind of electric current mutual inductance secondary overvoltage protection, be intended to effectively to prevent cause accident because of the Current Transformer Secondary open circuit.
The utility model is achieved in that a kind of electric current mutual inductance secondary overvoltage protection, and it comprises housing; Be housed in overvoltage crowbar, reset circuit, warning circuit and indicating circuit in the said housing; Be arranged on reset key, relay indicating light on the said housing outer wall.Said reset key electrically is serially connected in the said reset circuit, and said relay indicating light electrically is serially connected in the said indicating circuit.Said reset circuit also comprises resistance (R5); One end of said resistance (R5) electrically connects via said reset key and a power supply; One end of the resetting coil of the other end of said resistance (R5) and the bistable relay of said overvoltage crowbar electrically connects, the electrical ground connection of the other end of the resetting coil of said bistable relay.Said indicating circuit also comprises resistance (R9) and diode, and the anode of said diode and the corresponding contacts of said bistable relay electrically connect, and the negative electrode of said diode is electrically connected at said relay indicating light via said resistance (R9).
Further improvement as such scheme; Said overvoltage crowbar comprises overvoltage detection circuit, rectifier bridge, filter circuit, voltage stabilizing circuit and bistable relay; Said voltage detecting circuit electrically connects via said rectifier bridge and said filter circuit; Said filter circuit electrically connects via the set coil of said voltage stabilizing circuit and said bistable relay; The resetting coil of said bistable relay and said reset circuit electrically connect; One of them contact of said bistable relay can be electrically connected at said warning circuit and said indicating circuit respectively, and one of another contact of said bistable relay connects the output earth terminal of said electric current mutual inductance secondary overvoltage protection, and the other end connects the output high-pressure side of said electric current mutual inductance secondary overvoltage protection.
Further improvement as such scheme; The electrical ground connection of input of said rectifier bridge; Said voltage detecting circuit comprises two piezo-resistances; In said two piezo-resistances one are serially connected with another input of said rectifier bridge, and another person's in said two piezo-resistances two ends are electrically connected at said two inputs respectively.
As the further improvement of such scheme, said filter circuit comprises electric capacity and a resistance, is electrically connected at two outputs of said rectifier bridge after said resistance and the said capacitances in series.
As the further improvement of such scheme, said voltage stabilizing circuit comprises that two ends are electrically connected at the piezo-resistance of two outputs of said rectifier bridge.
Further improvement as such scheme; Said warning circuit comprises diode, two resistance and buzzer; The anode of said diode and the corresponding contacts of said bistable relay electrically connect; The negative electrode of said diode is via the electrical ground connection in said two resistance, and also is electrically connected at said buzzer via another person in said two resistance.
Further improvement as such scheme; Said electric current mutual inductance secondary overvoltage protection also comprises test circuit; Said test circuit comprises two diodes, resistance and button; The anode of one in said two diodes and the corresponding contacts of said bistable relay electrically connect; The negative electrode of one in said two diodes and another person's in said two diodes negative electrode electrically connect, and another person's in said two diodes anode is electrically connected at a power supply via said button.
As the further improvement of such scheme, said electric current mutual inductance secondary overvoltage protection also comprises fly-wheel diode, and the two ends of said fly-wheel diode are electrically connected at two outputs of said rectifier bridge.
The utility model compared with prior art; Beneficial effect is: the electric current mutual inductance secondary overvoltage protection that the utility model provides is connected to the two ends of Current Transformer Secondary side when reality is used; Leakage Current is minimum during normal the operation; Be high-impedance state, because Leakage Current minimum (less than 1 μ A) influences accurately and can ignore with the table meter this loop protection operating value; When this secondary loop of mutual inductor open circuit or a winding occur being unusual overcurrent; The overvoltage that secondary winding produces is moved electric current mutual inductance secondary overvoltage protection rapidly, and with this Current Transformer Secondary side short circuit, shows trouble location on the panel of this current transformer automatically; And be furnished with the node signal of having no chance and export; After fault is got rid of, by the hand-reset button, normal operation input again again after circuit restores to the original state.
Description of drawings
The structural representation of the electric current mutual inductance secondary overvoltage protection that Fig. 1 provides for the utility model preferred embodiments.
Fig. 2 is the modular structure sketch map of electric current mutual inductance secondary overvoltage protection among Fig. 1.
Fig. 3 is the circuit diagram of electric current mutual inductance secondary overvoltage protection among Fig. 1.
Symbol description
| Electric current mutual inductance |
100 |
| |
10 |
| |
11 |
| |
12 |
| |
13 |
| |
14 |
| |
15 |
| |
16 |
| |
17 |
| |
18 |
| |
151 |
| Resetting |
153 |
| The |
155、157 |
| |
121、123 |
| |
124、126 |
| Electric capacity | C1 |
| Resistance | R1~R9 |
| Fly-wheel diode | D1 |
| Diode | D2~D4 |
| Buzzer | LS |
| Relay indicating light | LED1 |
| Power supply | Vcc |
| Button | K1、K2 |
Embodiment
For the purpose, technical scheme and the advantage that make the utility model is clearer,, the utility model is further elaborated below in conjunction with accompanying drawing and embodiment.Should be appreciated that specific embodiment described herein only in order to explanation the utility model, and be not used in qualification the utility model.
Please consult Fig. 1 to Fig. 3 in the lump, the structural representation of the electric current mutual inductance secondary overvoltage protection 100 that it provides for the utility model preferred embodiments, it comprises housing 200; Be housed in overvoltage crowbar 10, reset circuit 16, warning circuit 17 and indicating circuit 18 in the said housing 200; Be arranged on reset key K1, relay indicating light LED1 on said housing 200 outer walls.Said reset key K1 electrically is serially connected in the said reset circuit 16, and relay indicating light LED1 electrically is serially connected in the said indicating circuit 18.Said reset circuit 16 also comprises resistance R 5; One end of said resistance R 5 electrically connects via said reset key K1 and a power supply; One end of the resetting coil of the bistable relay 15 of the other end of said resistance R 5 and said overvoltage crowbar 10 electrically connects, the electrical ground connection of the other end of the resetting coil of said bistable relay 15.Said indicating circuit 18 also comprises resistance R 9 and diode D3, and the corresponding contacts of the anode of said diode D3 and said bistable relay 15 electrically connects, and the negative electrode of said diode D3 is electrically connected at said relay indicating light LED1 via said resistance R 9.
Indicating circuit 18 comprises resistance R 9, LED lamp LED1 and diode D3, and the corresponding contacts 155 of the anode of diode D3 and bistable relay 15 electrically connects, and the negative electrode of diode D3 is electrically connected at LED lamp LED1 via resistance R 9.In this execution mode, also be provided with test circuit, test circuit comprises diode D3, D4 and button K2, and the negative electrode of the negative electrode of diode D3 and diode D4 electrically connects, and the anode of diode D4 is electrically connected at power Vcc via button K2.
The operation principle of electric current mutual inductance secondary overvoltage protection 100 is following:
, reality is connected to the Current Transformer Secondary side two ends of (figure does not show) when using; Leakage Current is minimum during normal the operation; Be high-impedance state, because Leakage Current minimum (less than 1 μ A) influences accurately and can ignore with the table meter this loop protection operating value; When this secondary loop of mutual inductor open circuit or a winding occur being unusual overcurrent; The overvoltage that secondary winding produces is moved electric current mutual inductance secondary overvoltage protection 100 rapidly, and with this Current Transformer Secondary side short circuit, shows trouble location on the panel of this current transformer automatically; And be furnished with the node signal of having no chance and export; After fault is got rid of, by the hand-reset button, normal operation input again again after circuit restores to the original state.
The above is merely the preferred embodiment of the utility model; Not in order to restriction the utility model; Any modification of being done within all spirit and principles at the utility model, be equal to replacement and improvement etc., all should be included within the protection range of the utility model.
Claims (8)
1. an electric current mutual inductance secondary overvoltage protection is characterized in that it comprises housing; Be housed in overvoltage crowbar, reset circuit, warning circuit and indicating circuit in the said housing; Be arranged on reset key, relay indicating light on the said housing outer wall; Said reset key electrically is serially connected in the said reset circuit; Said relay indicating light electrically is serially connected in the said indicating circuit; Said reset circuit also comprises resistance (R5), and an end of said resistance (R5) electrically connects via said reset key and a power supply, and an end of the resetting coil of the other end of said resistance (R5) and the bistable relay of said overvoltage crowbar electrically connects; The electrical ground connection of the other end of the resetting coil of said bistable relay; Said indicating circuit also comprises resistance (R9) and diode, and the anode of said diode and the corresponding contacts of said bistable relay electrically connect, and the negative electrode of said diode is electrically connected at said relay indicating light via said resistance (R9).
2. electric current mutual inductance secondary overvoltage protection as claimed in claim 1; It is characterized in that; Said overvoltage crowbar comprises overvoltage detection circuit, rectifier bridge, filter circuit, voltage stabilizing circuit and bistable relay; Said voltage detecting circuit electrically connects via said rectifier bridge and said filter circuit; Said filter circuit electrically connects via the set coil of said voltage stabilizing circuit and said bistable relay; The resetting coil of said bistable relay and said reset circuit electrically connect; One of them contact of said bistable relay can be electrically connected at said warning circuit and said indicating circuit respectively, and one of another contact of said bistable relay connects the output earth terminal of said electric current mutual inductance secondary overvoltage protection, and the other end connects the output high-pressure side of said electric current mutual inductance secondary overvoltage protection.
3. electric current mutual inductance secondary overvoltage protection as claimed in claim 2; It is characterized in that; The electrical ground connection of input of said rectifier bridge; Said voltage detecting circuit comprises two piezo-resistances, and one in said two piezo-resistances are serially connected with another input of said rectifier bridge, and another person's in said two piezo-resistances two ends are electrically connected at said two inputs respectively.
4. electric current mutual inductance secondary overvoltage protection as claimed in claim 2 is characterized in that said filter circuit comprises electric capacity and a resistance, is electrically connected at two outputs of said rectifier bridge after said resistance and the said capacitances in series.
5. electric current mutual inductance secondary overvoltage protection as claimed in claim 2 is characterized in that said voltage stabilizing circuit comprises that two ends are electrically connected at the piezo-resistance of two outputs of said rectifier bridge.
6. electric current mutual inductance secondary overvoltage protection as claimed in claim 1; It is characterized in that; Said warning circuit comprises diode, two resistance and buzzer; The anode of said diode and the corresponding contacts of said bistable relay electrically connect, and the negative electrode of said diode is via the electrical ground connection in said two resistance, and also are electrically connected at said buzzer via another person in said two resistance.
7. electric current mutual inductance secondary overvoltage protection as claimed in claim 1; It is characterized in that; Said electric current mutual inductance secondary overvoltage protection also comprises test circuit; Said test circuit comprises two diodes, resistance and button; The anode of one in said two diodes and the corresponding contacts of said bistable relay electrically connect, and the negative electrode of one in said two diodes and another person's in said two diodes negative electrode electrically connect, and another person's in said two diodes anode is electrically connected at a power supply via said button.
8. electric current mutual inductance secondary overvoltage protection as claimed in claim 2 is characterized in that, said electric current mutual inductance secondary overvoltage protection also comprises fly-wheel diode, and the two ends of said fly-wheel diode are electrically connected at two outputs of said rectifier bridge.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011204540265U CN202353176U (en) | 2011-11-16 | 2011-11-16 | Secondary over-voltage protection device for current transformer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011204540265U CN202353176U (en) | 2011-11-16 | 2011-11-16 | Secondary over-voltage protection device for current transformer |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN202353176U true CN202353176U (en) | 2012-07-25 |
Family
ID=46542141
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2011204540265U Expired - Fee Related CN202353176U (en) | 2011-11-16 | 2011-11-16 | Secondary over-voltage protection device for current transformer |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN202353176U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103280769A (en) * | 2013-05-24 | 2013-09-04 | 国家电网公司 | Current transformer open circuit prevention protection device |
| CN105092940A (en) * | 2015-07-07 | 2015-11-25 | 国网上海市电力公司 | Alarming device for the electrification of a current transformer secondary circuit |
-
2011
- 2011-11-16 CN CN2011204540265U patent/CN202353176U/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103280769A (en) * | 2013-05-24 | 2013-09-04 | 国家电网公司 | Current transformer open circuit prevention protection device |
| CN105092940A (en) * | 2015-07-07 | 2015-11-25 | 国网上海市电力公司 | Alarming device for the electrification of a current transformer secondary circuit |
| CN105092940B (en) * | 2015-07-07 | 2018-09-28 | 国网上海市电力公司 | A kind of secondary loop of mutual inductor electrification alarming device |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20120725 Termination date: 20151116 |
|
| EXPY | Termination of patent right or utility model |