CN211206695U - Outer synchronous circuit for cable voltage-withstanding partial discharge test and cable partial discharge detection device - Google Patents
Outer synchronous circuit for cable voltage-withstanding partial discharge test and cable partial discharge detection device Download PDFInfo
- Publication number
- CN211206695U CN211206695U CN201921946588.4U CN201921946588U CN211206695U CN 211206695 U CN211206695 U CN 211206695U CN 201921946588 U CN201921946588 U CN 201921946588U CN 211206695 U CN211206695 U CN 211206695U
- Authority
- CN
- China
- Prior art keywords
- voltage
- cable
- partial discharge
- input
- discharge test
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Landscapes
- Testing Relating To Insulation (AREA)
Abstract
The utility model provides a test outer synchronous circuit is put in withstand voltage office of cable and detection device is put in cable office, this test outer synchronous circuit is put in withstand voltage office of cable keeps apart the output through the photoelectric coupler who inputs in the isolation unit to the power frequency signal of input, and the signal of gathering is more stable, can effectively prevent external electromagnetic interference coupling to the line input end, has strengthened the interference killing feature of circuit; and the isolated signals are compared and output by combining the voltage comparison unit, so that the acquisition of the cable power frequency signals is simply and efficiently realized, and the circuit and the device have simple structures and high reliability.
Description
Technical Field
The utility model belongs to the technical field of the partial discharge detection of cable, especially, relate to a detection device is put in withstand voltage office of cable and test outer synchronous circuit and cable office.
Background
In recent years, power cables are widely used in urban power grids for power transmission and distribution, and the cables become dominant products for transmitting power in cities. Due to the characteristics of the insulating material of the cable, various insulation defects may be generated in the operation process of the power cable due to the manufacturing process, the construction technology and the like of the cable, so that partial discharge, which is called partial discharge for short, is a great potential safety hazard in the operation of the power cable, is a symptom of the insulation degradation of the cable, and is one of important reasons for causing the insulation degradation. When the device is used for a certain period, partial discharge continues to develop to a certain extent, insulation breakdown is caused, and serious accidents of a power grid are caused. Therefore, the research on the partial discharge detection of the insulation defect of the crosslinked polyethylene cable is urgent, the potential insulation hazard of the cable can be detected timely and accurately, necessary countermeasures can be taken timely, the economic loss caused by accidents and the like can be reduced, and the method has very important practical significance.
In order to monitor the partial discharge condition of the high-voltage power transmission and distribution cable, an ultrahigh frequency partial discharge monitoring device is mostly adopted at present. When a partial discharge phenomenon occurs in the device, an ultrahigh frequency signal is generated, the high frequency signal is subjected to analog-to-digital conversion and analysis operation through the detection of the partial discharge sensor, and in the partial discharge signal acquisition unit, the acquired discharge pulse signal is superposed on the power frequency phase of the detection circuit to obtain a corresponding partial discharge pulse phase map so as to analyze the defect type of the partial discharge generation device. Therefore, the frequency bandwidth of the collected signal is very critical, however, the external synchronous signal of the existing monitoring device is converted into square wave through the operational amplifier sine wave by adopting direct coupling or transformer coupling, the method has complex circuit and low reliability, and the direct coupling is also easily interfered by external electromagnetic interference, so that the synchronous signal is unstable.
SUMMERY OF THE UTILITY MODEL
In view of the above-mentioned shortcomings of the prior art, an object of the present invention is to provide a cable partial discharge detection device for solving the above-mentioned technical problems.
In order to realize above-mentioned purpose and other relevant purposes, the utility model provides an outer synchronizing circuit of test is put in withstand voltage office of cable, include:
the input end of the input isolation unit is connected with a power frequency signal, and the output end of the input isolation unit outputs an isolated signal;
and the input end of the voltage comparison unit is connected with the output end of the input isolation unit, and the output end of the voltage comparison unit outputs a square wave signal.
Optionally, the input isolation unit includes a photoelectric coupling module, an input end of the photoelectric coupling module is connected to the power frequency signal, and an output end of the photoelectric coupling module is connected to an input end of the voltage comparison unit.
Optionally, the photoelectric coupling module includes two mutually independent photoelectric couplers, input ends of the two photoelectric couplers are connected in parallel, and output ends of the two photoelectric couplers are connected to an input end of the voltage comparison unit.
Optionally, the photocoupler includes at least one of a transistor output type photocoupler, a high-speed IC output type photocoupler, and a thyristor output type photocoupler.
Optionally, the input isolation unit further includes a plurality of voltage dividing resistors, and the power frequency signal is divided by the plurality of voltage dividing resistors and then is coupled to the input terminal of the photoelectric coupler.
Optionally, the voltage comparison unit includes a voltage comparator, a non-inverting input of the voltage comparator is connected to the output ends of the two photocouplers, and an inverting input of the voltage comparator is connected to the reference voltage.
Optionally, the voltage comparator comprises a push-pull output comparator.
Optionally, the voltage comparator comprises at least one of T L714, T L V3501, T L V2702.
In addition, for realizing above-mentioned purpose and other relevant purpose, the utility model also provides a detection device is put in cable office, including above-mentioned arbitrary one the withstand voltage office of cable put test outer synchronous circuit.
As above, the utility model discloses a test outer synchronizing circuit is put in withstand voltage office of cable has following beneficial effect:
the input isolation unit is used for isolating and outputting the input power frequency signal, the acquired signal is relatively stable, external electromagnetic interference can be effectively prevented from being coupled to the input end of the circuit, and the anti-interference performance of the circuit is enhanced; and the isolated signals are compared and output by combining the voltage comparison unit, so that the acquisition of the cable power frequency signals is simply and efficiently realized, and the circuit has a simple structure and high reliability.
Drawings
Fig. 1 is a block diagram of the outer synchronous circuit of the cable withstand voltage partial discharge test in the embodiment of the present invention.
Fig. 2 is a circuit diagram of the outer synchronous circuit of the cable withstand voltage partial discharge test in the embodiment of the present invention.
Description of the reference numerals
C1, C2, C3, C4, C5, C6, C7, C8, C9 and C10 capacitors
R1, R2, R3, R4, R5, R7, R8, R9, R10 and R11 resistors
U1 photoelectric coupling module
U2 voltage comparator
BUF _3V3 Voltage Signal
SYNC _3V3 SYNC signal
TRIGEROUT _ EN ENABLE VOLTAGE
TRIGEROUT square wave signal
1 output terminal of voltage comparator
2 inverting input terminal of voltage comparator
Non-inverting input terminal of 3 voltage comparator
Power supply cathode of 4-voltage comparator
8 voltage comparator power supply anode
Detailed Description
The following description of the embodiments of the present invention is provided for illustrative purposes, and other advantages and effects of the present invention will be readily apparent to those skilled in the art from the disclosure herein. The present invention can also be implemented or applied through other different specific embodiments, and various details in the present specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It is to be noted that the features in the following embodiments and examples may be combined with each other without conflict.
It should be noted that the drawings provided in the following embodiments are only for illustrating the basic concept of the present invention, and the components related to the present invention are only shown in the drawings rather than drawn according to the number, shape and size of the components in actual implementation, and the form, amount and ratio of the components in actual implementation may be changed at will, and the layout of the components may be more complicated.
As mentioned in the background, the external synchronization signal of the existing cable partial discharge monitoring device is converted into a square wave through an operational amplifier sine wave by direct coupling or transformer coupling, the method is complex in circuit and low in reliability, and the direct coupling is also easily interfered by external electromagnetic interference, which results in unstable synchronization signal.
Based on this, the utility model provides a synchronous circuit outside test is put in withstand voltage office of cable, as shown in fig. 1, it includes:
the input end of the input isolation unit is connected with a power frequency signal, and the output end of the input isolation unit outputs an isolated signal;
and the input end of the voltage comparison unit is connected with the output end of the input isolation unit, and the output end of the voltage comparison unit outputs a square wave signal.
In detail, as shown in fig. 2, the input isolation unit includes a photoelectric coupling module U1, an input terminal of the photoelectric coupling module U1 is connected to the power frequency signal, and an output terminal of the photoelectric coupling module U1 is connected to an input terminal of the voltage comparison unit. The photoelectric-photoelectric conversion is carried out through the photoelectric coupling module U1, so that the input power frequency signal can be effectively isolated and output, and the interference of external electromagnetic signals is avoided.
In more detail, as shown in fig. 2, the photo coupler module U1 includes two mutually independent photo couplers, input terminals of the two photo couplers are connected in parallel, and output terminals of the two photo couplers are connected to an input terminal of the voltage comparing unit. The photoelectric coupler comprises at least one of a transistor output type optical coupler, a high-speed IC output type optical coupler and a silicon controlled output type optical coupler, and can be flexibly selected by combining design requirements and cost.
The photoelectric coupling module U1 may be an existing dual optical coupler chip, such as a L TV-074 dual optical coupler.
In detail, as shown in fig. 2, the input isolation unit further includes voltage dividing resistors R1, R2, and R3, and after the power frequency signal in the cable connector is divided by the voltage dividing resistors R1, R2, and R3, the input terminals of the two photocouplers are connected in parallel at two ends of the resistor R2. Through the structural design that the input of two photoelectric couplers is connected in parallel, the bidirectional acquisition of power frequency signal current in the cable joint can be effectively realized, and the reliability and the practicability of the circuit are enhanced.
In detail, as shown in fig. 2, the voltage comparing unit includes a voltage comparator U2, a non-inverting input terminal 3 of the voltage comparator U2 is coupled to output terminals of two photo couplers, and an inverting input terminal 2 of the voltage comparator U2 is coupled to a reference voltage.
More specifically, the voltage comparison unit further includes resistors R3, R4, R5, R6, R7, R8, R9, R10 and R11, the enable voltage TRIGEROUT _ EN is grounded after passing through resistors R10, R4 and R5 which are connected in series in sequence, the output end of one photocoupler is connected to two ends of the resistor R4, the output end of the other photocoupler is connected to two ends of the resistor R5, one end of the resistor R6 is connected to the common end of the resistor R4 and the resistor R5, and the other end of the resistor R6 is connected to the non-inverting input end 3 of the voltage comparator U2; meanwhile, the enable voltage TRIGEROUT _ EN is grounded after passing through resistors R10, R7 and R8 which are sequentially connected in series, and the common end of the resistor R7 and the resistor R8 is connected with the inverting input end 2 of the voltage comparator U2; the output end 1 of the voltage comparator U2 outputs a square wave signal TRIGEROUT through a resistor R9.
The resistor R4 is equal to the resistor R7, and the resistor R5 is equal to the resistor R8.
Optionally, the voltage comparator U2 includes a push-pull output comparator, e.g., the voltage comparator U2 includes at least one of T L714, T L V3501, T L V2702.
In an embodiment of the present invention, as shown in fig. 2, the voltage comparator U2 is a structural design based on a T L V3501 dedicated chip, the voltage comparison unit further includes capacitors C1, C2, C3, C4, C5, C6, C7, C8, C9 and C10, the capacitor C10 is connected in parallel with the resistor R10, one end of the capacitor C10 is grounded, the other end of the capacitor C10 is connected to the common terminal of the resistor R10 and the resistor R10, the power supply cathode 4 of the voltage comparator U10 is grounded, the power supply anode 8 of the voltage comparator U10 is connected to the synchronization signal _3V 10V of the 3V, the synchronization signal SYNC _3V _ 10V is connected to the common terminal of the capacitor C10 and the common terminal 10, one end of the synchronization signal V10 is connected to the common terminal of the capacitor C10 and the common terminal of the capacitor C10V 10 and the common terminal of the signal V10, and the common terminal of the capacitor C10.
Optionally, the resistances of the resistors R1, R2, and R3 are all 10K Ω, the resistances of the resistors R4, R5, R7, R8, and R9 are all 20K Ω, the resistance of the resistor R6 is 100K Ω, the resistances of the resistors R10 and R11 are all 10 Ω, and the capacitances of the capacitors C1, C2, C3, C4, C5, C6, C7, C8, C9, and C10 are all 0.1 μ F.
As shown in fig. 2, when no signal of the input isolation unit is connected, the enable voltage TRIGEROUT _ EN is grounded through the resistors R10, R4, and R5 connected in series in sequence, and meanwhile, the enable voltage TRIGEROUT _ EN is grounded through the resistors R10, R7, and R8 connected in series in sequence, and the resistor R4 is equal to the resistor R7, and the resistor R5 is equal to the resistor R8, so that the common terminal voltage of the resistors R4 and R5 is equal to the common terminal voltage of the resistors R7 and R8; the common end voltage of the resistors R7 and R8 is used as reference voltage and is connected to the inverting input end of the voltage comparator U2; when a signal of the input isolation unit is accessed, a power frequency signal in a cable joint is divided by voltage dividing resistors R1, R2 and R3, voltage signals at two ends of the resistor R2 are converted from electricity to light to electricity by a photoelectric coupler in the photoelectric coupling module U1, and an isolated voltage signal, namely the voltage of the common terminal of the resistor R4 and the resistor R5, is obtained at the output end of the photoelectric coupling module U1; the common terminal voltage of the resistors R4 and R5 is connected to the non-inverting input end of the voltage comparator U2 after passing through the resistor R6, and is compared with the common terminal voltage of the resistors R7 and R8, and a square wave signal is obtained at the output end of the voltage comparator U2 and is output to the rear stage.
Furthermore, the utility model provides a detection device is put in cable office, it includes that the withstand voltage office of above-mentioned cable puts the outer synchronizing circuit of test, puts the structural design of the outer synchronizing circuit of test "input isolation unit + voltage comparison unit" through the withstand voltage office of above-mentioned cable, can simply, high-efficient, gather power frequency signal steadily and convert the square waveform into and export the back level, and this detection device is put in cable office with low costs and the reliability is high. The following processing circuit structure for the square wave signal in the cable partial discharge detection device may refer to the prior art, and is not described herein again.
In summary, in the cable voltage withstand partial discharge test external synchronization circuit and the cable partial discharge detection device provided by the utility model, the input power frequency signal is isolated and output through the photoelectric coupler in the input isolation unit, the acquired signal is stable, external electromagnetic interference can be effectively prevented from being coupled to the line input end, and the anti-interference performance of the circuit is enhanced; and the isolated signals are compared and output by combining the voltage comparison unit, so that the acquisition of the cable power frequency signals is simply and efficiently realized, and the circuit and the device have simple structures and high reliability.
The above embodiments are merely illustrative of the principles and effects of the present invention, and are not to be construed as limiting the invention. Modifications and variations can be made to the above-described embodiments by those skilled in the art without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which may be made by those skilled in the art without departing from the spirit and technical spirit of the present invention be covered by the claims of the present invention.
Claims (9)
1. The utility model provides an outer synchronizing circuit of withstand voltage partial discharge test of cable which characterized in that includes:
the input end of the input isolation unit is connected with a power frequency signal, and the output end of the input isolation unit outputs an isolated signal;
and the input end of the voltage comparison unit is connected with the output end of the input isolation unit, and the output end of the voltage comparison unit outputs a square wave signal.
2. The cable withstand voltage partial discharge test external synchronization circuit according to claim 1, wherein the input isolation unit comprises a photoelectric coupling module, an input end of the photoelectric coupling module is connected to the power frequency signal, and an output end of the photoelectric coupling module is connected to an input end of the voltage comparison unit.
3. The external synchronization circuit for cable withstand voltage partial discharge test according to claim 2, wherein the photoelectric coupling module comprises two mutually independent photoelectric couplers, input ends of the two photoelectric couplers are connected in parallel in a positive and negative manner, and output ends of the two photoelectric couplers are connected with input ends of the voltage comparison unit.
4. The cable withstand voltage partial discharge test external synchronous circuit according to claim 3, wherein the photocoupler includes at least one of a transistor output type photocoupler, a high-speed IC output type photocoupler, and a thyristor output type photocoupler.
5. The cable withstand voltage partial discharge test external synchronization circuit according to claim 4, wherein the input isolation unit further comprises a plurality of voltage dividing resistors, and the power frequency signal is divided by the voltage dividing resistors and then is connected to the input end of the photoelectric coupler.
6. The external synchronization circuit for cable withstand voltage partial discharge test according to claim 3, wherein the voltage comparison unit comprises a voltage comparator, a non-inverting input terminal of the voltage comparator is connected to output terminals of the two photocouplers, and an inverting input terminal of the voltage comparator is connected to a reference voltage.
7. The cable withstand voltage partial discharge test outer synchronization circuit according to claim 6, wherein the voltage comparator comprises a push-pull output comparator.
8. The cable withstand voltage partial discharge test outer synchronization circuit according to claim 7, wherein the voltage comparator comprises at least one of T L714, T L V3501, T L V2702.
9. A cable partial discharge detection device, characterized by comprising the cable withstand voltage partial discharge test external synchronization circuit according to any one of claims 1 to 8.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921946588.4U CN211206695U (en) | 2019-11-12 | 2019-11-12 | Outer synchronous circuit for cable voltage-withstanding partial discharge test and cable partial discharge detection device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921946588.4U CN211206695U (en) | 2019-11-12 | 2019-11-12 | Outer synchronous circuit for cable voltage-withstanding partial discharge test and cable partial discharge detection device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN211206695U true CN211206695U (en) | 2020-08-07 |
Family
ID=71852954
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201921946588.4U Active CN211206695U (en) | 2019-11-12 | 2019-11-12 | Outer synchronous circuit for cable voltage-withstanding partial discharge test and cable partial discharge detection device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN211206695U (en) |
-
2019
- 2019-11-12 CN CN201921946588.4U patent/CN211206695U/en active Active
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN203554436U (en) | Conducted interference isolation circuit for low-voltage circuit line carrier communication | |
| CN103308832A (en) | Partial discharge test device for high-voltage cable insulation middle joint and use method | |
| CN101930033A (en) | Test method without disconnection of capacitor voltage transformer | |
| CN104880652A (en) | Electrified partial discharge test system of switch cabinet and voltage signal extraction device thereof | |
| CN104215819A (en) | Monitoring device for gas insulated switchgear (GIS) thunder-and-lightening invasion overvoltage | |
| CN209446685U (en) | A kind of system for eliminating electrical fast transient (eft) interference | |
| CN201707395U (en) | Head-disassembling-free testing circuit of capacitance type voltage transformer | |
| CN203502582U (en) | GIS electronic transformer test system based on disconnecting switch switching-on and switching-off capacitive small current | |
| CN101614798A (en) | Polarity detection system of electronic transformer | |
| CN103823103A (en) | Overvoltage on-line monitoring device and method | |
| CN203940885U (en) | Cable sheath circulation on-Line Monitor Device | |
| CN204101619U (en) | A kind of for the superpotential monitoring device of GIS lightning ingress | |
| CN211206695U (en) | Outer synchronous circuit for cable voltage-withstanding partial discharge test and cable partial discharge detection device | |
| CN102710248A (en) | Isolated voltage acquisition circuit | |
| CN105092946A (en) | Three-phase circuit overvoltage monitoring system | |
| CN105092947B (en) | A kind of over-voltage monitoring system and method for three-phase circuit | |
| CN105353287A (en) | Partial discharge data acquisition circuit and apparatus | |
| CN204405728U (en) | Arrester discharge counter | |
| CN103364695A (en) | Local discharging on-line monitoring device of high-voltage cable | |
| CN105807193A (en) | Same-frequency same-phase voltage withstanding test device with safety sampling signals | |
| CN203455399U (en) | A CVT transient overvoltage sensor | |
| CN103018573A (en) | Field measurement system for dielectric loss value of crosslinked polyethylene power cable | |
| CN205176208U (en) | Partial discharge data acquisition circuit and monitoring facilities | |
| CN205176207U (en) | Partial discharge data acquisition circuit and equipment | |
| CN105334443A (en) | Partial discharge data collecting circuit and monitoring equipment |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CB03 | Change of inventor or designer information | ||
| CB03 | Change of inventor or designer information |
Inventor after: Gong Wei Inventor after: Zhang Xiuhong Inventor after: Zhou Kefa Inventor after: Wu Jie Inventor before: Zhang Xiuhong Inventor before: Gong Wei Inventor before: Wu Jie |
|
| CP02 | Change in the address of a patent holder | ||
| CP02 | Change in the address of a patent holder |
Address after: 4-1, 4 / F, block K, Shiqiaopu standard workshop, 52 Keyuan 4th Street, Jiulongpo District, Chongqing Patentee after: CHONGQING ZHENYUAN ELECTRICAL Co.,Ltd. Address before: 400039 factory building 1-8, building 6, No. 39 Xinggu Road, Jiulongpo District, Chongqing Patentee before: CHONGQING ZHENYUAN ELECTRICAL Co.,Ltd. |