CN111398857A - Single-phase earth fault detection system of line selection device for arc suppression coil grounding system - Google Patents
Single-phase earth fault detection system of line selection device for arc suppression coil grounding system Download PDFInfo
- Publication number
- CN111398857A CN111398857A CN202010375511.7A CN202010375511A CN111398857A CN 111398857 A CN111398857 A CN 111398857A CN 202010375511 A CN202010375511 A CN 202010375511A CN 111398857 A CN111398857 A CN 111398857A
- Authority
- CN
- China
- Prior art keywords
- module
- fault
- phase
- selection device
- line selection
- 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.)
- Pending
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R35/00—Testing or calibrating of apparatus covered by the other groups of this subclass
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Emergency Protection Circuit Devices (AREA)
Abstract
The invention relates to a single-phase earth fault detection system of a line selection device for an arc suppression coil grounding system, which comprises: the main three-phase bus is connected with two groups of slave three-phase buses; a test three-phase bus connected to the slave three-phase bus; the detection unit includes: the circuit comprises a current transformer, a line parameter conversion module and a grounding parameter conversion module; a signal feedback unit, the signal feedback unit comprising: the system comprises a data acquisition module, a main control processing chip, a result output module, a fault judgment module, a signal sending module and a background server, wherein the judgment result of the fault judgment module is sent to the background server through the signal sending module. The fault information is generated by the fault judging module and is sent to the background server through the signal sending module so as to prompt testing personnel.
Description
Technical Field
The invention relates to the technical field of power detection, in particular to a single-phase earth fault detection system of a line selection device for an arc suppression coil grounding system.
Background
The 10-35KV medium-voltage system in our country is the main component of the power grid, generally consists of 10KV and 35KV buses of a 35KV transformer substation and a 110KV transformer substation, is mainly used for urban and rural power distribution networks, most of the systems adopt a neutral point ungrounded mode and an arc suppression coil grounded mode, when single-phase grounding occurs, the symmetry of system voltage is not damaged, great harm is not caused to power supply equipment, a fault line is allowed to continue to operate for a period of time, normal power supply is not influenced, but if single-phase grounding faults are not processed in time, as the voltage of two phases of a non-fault phase opposite to the ground is increased, weak insulation links are possibly broken down, and are developed into interphase short circuits, so that accidents are enlarged, and the safe operation of the power grid is influenced. In an electric power system, line ground faults account for more than 70% of total faults, and short-circuit faults are mostly single-phase ground to be converted into multi-phase ground. Therefore, when a single-phase earth fault occurs, the fault line must be detected and cut off correctly and timely.
In order to ensure the accuracy, safety and stability of the line selection device, the performance of the line selection device needs to be detected before the line selection device leaves a factory, so that the performance of the line selection device and the accuracy of line selection are detected, but the detection process aiming at the line selection device in the current market is complex, and no method is provided for ensuring the accuracy and reliability of line selection of the line selection device.
Disclosure of Invention
In order to solve the technical problem, the invention provides a single-phase earth fault detection system of a line selection device for an arc suppression coil grounding system, which has the advantage of more convenient detection process.
In order to achieve the purpose, the technical scheme of the invention is as follows:
a single-phase earth fault detection system of a line selection device for an arc suppression coil grounding system comprises:
the main three-phase bus is connected with a control switch, the main three-phase bus is connected with two groups of slave three-phase buses, the two groups of slave three-phase buses are connected with voltage conversion modules, one of the voltage conversion modules is connected with an arc suppression coil, and the arc suppression coil is grounded;
the test three-phase buses are connected with the slave three-phase buses, the two groups of test three-phase buses are connected through a connector, and both the two groups of test three-phase buses are connected with a voltage transformer;
a plurality of with the detection circuitry that test three-phase bus is connected, each detection circuitry is connected with detecting element, detecting element includes: the grounding parameter conversion module is connected with the line parameter conversion module and is used for converting circuit parameters when a line selection device to be tested is grounded, the grounding parameter conversion module is connected with a test switch, and the current transformer and the test switch are connected with the line selection device to be tested;
the signal feedback unit is connected with the detection unit and comprises: the device comprises a data acquisition module, a main control processing chip, a result output module, a fault judgment module, a signal sending module and a background server, wherein the data acquisition module is connected with the detection unit and used for acquiring test parameters of the line parameter conversion module and the grounding parameter conversion module, the main control processing chip is connected with the data acquisition module and used for analyzing and processing the test parameters, the result output module is connected with the main control processing chip, the fault judgment module is connected with the result output module and used for obtaining fault conditions according to output results of the result output module, the signal sending module is connected with the fault judgment module, the background server is connected with the signal sending module, and judgment results of the fault judgment module are sent to the background server through the signal sending module.
When the technical scheme is implemented, when detection is carried out, the line selection device to be detected is connected into the detection unit, voltage is converted into passing voltage through the voltage transformer, the line selection device to be detected is controlled to be in communication connection with the detection unit through the test switch, circuit parameters of a detection circuit are detected and converted into test parameters through the circuit parameter conversion module, the circuit parameters when the line selection device to be detected is grounded are detected and converted into the test parameters through the grounding parameter conversion module so as to judge single-phase grounding faults of the line selection device to be detected, then the data acquisition module acquires test data and reversely and transmits the test data and the test parameters to the main control processing chip, the test data are analyzed and processed through the main control processing chip, an analysis result is output through the result output module, and the fault judgment module receives the analysis result and generates fault information according to the analysis result, and send the module to the backstage server through the signal, in order to point out the tester, through the above-mentioned process, make the test procedure more convenient and fast, detection efficiency is high.
As a preferable aspect of the present invention, the fault determining module includes: the data temporary storage module is used for temporarily storing the output result of the result output module, the fault information pre-storage module is connected with the data temporary storage module and pre-stores fault information, the data temporary storage module and the fault information pre-storage module are connected with the fault corresponding module which is used for temporarily storing the output result in the data temporary storage module and pre-stores the fault information in the fault information pre-storage module, and the fault output module is used for outputting the fault information corresponding to the fault corresponding module.
According to the technical scheme, the data temporary storage module temporarily stores the output result of the result output module for the subsequent judgment process, the fault corresponding module compares the output result with fault information prestored in the fault information prestored module to obtain fault information corresponding to the output result, and the fault information is output through the fault output module, so that the fault detection judgment process is completed, and then data in the data temporary storage module is released to wait for storing the next output result.
As a preferred scheme of the present invention, the main control processing chip is further connected to a storage module for storing test parameters.
According to the technical scheme, the test parameters are stored through the storage module, so that the subsequent fault judgment process can be conveniently carried out.
As a preferred scheme of the present invention, the fault determination module is further connected to a fault location detection module.
According to the technical scheme, the fault position of the line selection device to be detected is judged while the fault type is judged by the fault judging module through the fault position detecting module, so that the detection personnel can judge quickly.
As a preferable aspect of the present invention, a signal amplifying unit is further connected between the detecting unit and the signal feedback unit.
According to the technical scheme, the test parameters of the line parameter conversion module and the grounding parameter conversion module are amplified through the signal amplification unit, so that the signal feedback unit can conveniently process the parameters.
As a preferable scheme of the invention, the signal sending module is also connected with a communication interface module, and the communication interface module comprises an MII interface, an RMII interface, an RS232 interface, an RS485 interface, a CAN Bus, an M-Bus, an MDOBUS, an I2C Bus, an SPI interface, Bluetooth, a L ORA wireless module and a ZigBee wireless module.
By the technical scheme, various connection modes can be provided to connect with the background server.
As a preferred scheme of the present invention, the background server is further connected to an alarm module, and when the background server receives the fault information, the alarm module is controlled to send an alarm signal.
According to the technical scheme, the alarm module sends the alarm signal to prompt detection personnel, and the detection efficiency is improved.
In a preferred embodiment of the present invention, a protector is further connected to the three-phase bus.
In conclusion, the invention has the following beneficial effects:
the embodiment of the invention provides a single-phase ground fault detection system of a line selection device for an arc suppression coil grounding system, when detection is carried out, the line selection device to be detected is connected into a detection unit, voltage is converted into the line selection device to be detected through a voltage transformer to provide passing voltage, the line selection device to be detected is controlled to be in communication connection with the detection unit through a test switch, circuit parameters of a detection circuit are detected and converted into test parameters through a circuit parameter conversion module, the circuit parameters when the line selection device to be detected is grounded are detected and converted into the test parameters through a ground parameter conversion module to judge the single-phase ground fault of the line selection device to be detected, then test data and retrograde are acquired by a data acquisition module and are sent to a main control processing chip, the test data are analyzed and processed by the main control processing chip, and then an analysis result is output by a result output module, the fault judgment module receives the analysis result, generates fault information according to the analysis result, and sends the fault information to the background server through the signal sending module to prompt a tester.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.
Fig. 1 is a schematic structural diagram of an embodiment of the present invention.
Fig. 2 is a schematic circuit diagram of a power module and a detection unit according to an embodiment of the invention.
1. A main three-phase bus; 11. a control switch; 12. from a three-phase bus; 13. a voltage conversion module; 14. an arc suppression coil; 15. a protector; 2. testing a three-phase bus; 21. a communicator; 22. a voltage transformer; 3. a line selection device to be tested; 4. detecting a line; 5. a detection unit; 51. a current transformer; 52. a line parameter conversion module; 53. a grounding parameter conversion module; 54. a test switch; 6. a signal feedback unit; 61. a data acquisition module; 62. a main control processing chip; 621. a storage module; 63. a result output module; 64. a fault judgment module; 641. a data temporary storage module; 642. a fault information prestoring module; 643. a fault correspondence module; 644. a fault output module; 65. a signal transmitting module; 66. a background server; 67. a fault location detection module; 68. a communication interface module; 69. an alarm module; 7. a signal amplifying unit.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Examples
A single-phase earth fault detection system of a line selection device for an arc suppression coil 14 grounding system comprises: the system comprises a main three-phase bus 1 connected with a mains supply, wherein the main three-phase bus 1 is connected with a control switch 11, the main three-phase bus 1 is connected with two groups of slave three-phase buses 12, the two groups of slave three-phase buses 12 are also connected with a protector 15, the protector 15 can adopt a fuse, the two groups of slave three-phase buses 12 are connected with voltage conversion modules 13, one voltage conversion module 13 is connected with an arc suppression coil 14, and the arc suppression coil 14 is grounded; the test three-phase bus 2 is connected with the slave three-phase bus 12, the two groups of test three-phase buses 2 are connected through a connector 21, and the two groups of test three-phase buses 2 are both connected with a voltage transformer 22; the detection lines 4 are connected with the test three-phase bus 2, and each detection line 4 is connected with a detection unit 5; and a signal feedback unit 6 connected to the detection unit 5.
Specifically, the detection unit 5 includes: the circuit parameter testing device comprises a current transformer 51 connected with the detection line 4, a line parameter conversion module 52 connected with the detection line 4 and used for converting circuit parameters of the detection line 4, and a grounding parameter conversion module 53 connected with the line parameter conversion module 52 and used for converting circuit parameters when the line selection device 3 to be tested is grounded, wherein the grounding parameter conversion module 53 is connected with a test switch 54, and the current transformer 51 and the test switch 54 are connected with the line selection device 3 to be tested.
The signal feedback unit 6 includes: the system comprises a data acquisition module 61 connected with the detection unit 5 and used for acquiring test parameters of the line parameter conversion module 52 and the grounding parameter conversion module 53, a main control processing chip 62 connected with the data acquisition module 61 and used for analyzing and processing the test parameters, a result output module 63 connected with the main control processing chip 62, a fault judgment module 64 connected with the result output module 63 and used for obtaining a fault condition according to an output result of the result output module 63, a signal sending module 65 connected with the fault judgment module 64, and a background server 66 connected with the signal sending module 65, wherein a judgment result of the fault judgment module 64 is sent to the background server 66 through the signal sending module 65.
The failure determination module 64 includes: the fault diagnosis module comprises a data temporary storage module 641 for temporarily storing the output result of the result output module 63, a fault information pre-storing module 642 connected with the data temporary storage module 641 and pre-storing fault information, a fault corresponding module 643 connected with the data temporary storage module 641 and the fault information pre-storing module 642 and used for corresponding the output result temporarily stored in the data temporary storage module 641 with the fault information pre-stored in the fault information pre-storing module 642, and a fault output module 644 used for outputting the fault information corresponding to the fault corresponding module 643.
The data temporary storage module 641 temporarily stores the output result of the result output module 63 for the subsequent determination process, the fault correspondence module 643 compares the output result with the fault information pre-stored in the fault information pre-storage module 642 to obtain the fault information corresponding to the output result, the fault information is output through the fault output module 644, so as to complete the fault detection determination process, and then the data in the data temporary storage module 641 is released to wait for storing the next output result.
Further, the main control processing chip 62 is further connected with a storage module 621 for storing test parameters, the test parameters are stored through the storage module 621, so that the subsequent fault determination process is performed, meanwhile, the fault determination module 64 is further connected with a fault position detection module 67, and when the fault determination module 64 determines the fault type, the fault position of the line selection device 3 to be detected is determined through the fault position detection module 67, so that the detection personnel can rapidly determine the fault type.
Further, a signal amplifying unit 7 is connected between the detecting unit 5 and the signal feedback unit 6, and the signal amplifying unit 7 amplifies the test parameters of the line parameter converting module 52 and the grounding parameter converting module 53, so that the signal feedback unit 6 can conveniently perform parameter processing.
The signal sending module 65 is further connected with a communication interface module 68, and the communication interface module 68 comprises an MII interface, an RMII interface, an RS232 interface, an RS485 interface, a CAN Bus, an M-Bus, an MDOBUS, an I2C Bus, an SPI interface, a bluetooth, a L ORA wireless module, and a ZigBee wireless module, and CAN provide various connection modes to connect with the background server 66.
The background server 66 is further connected with an alarm module 69, and when the background server 66 receives the fault information, the alarm module 69 is controlled to send an alarm signal, and the alarm module 69 sends the alarm signal to prompt a detection person, so that the detection efficiency is improved.
During detection, the line selection device 3 to be detected is connected into the detection unit 5, voltage is converted into passing voltage through the voltage transformer 22, the line selection device 3 to be detected is controlled to be in communication connection with the detection unit 5 through the test switch 54, circuit parameters of the detection circuit 4 are detected and converted into test parameters through the circuit parameter conversion module 52, the circuit parameters when the line selection device 3 to be detected is grounded are detected and converted into the test parameters through the grounding parameter conversion module 53, so as to judge the single-phase grounding fault of the line selection device 3 to be detected, then the test data and the reverse line are collected and sent to the main control processing chip 62 through the data collection module 61, the analysis result is output through the result output module 63 after the test data is analyzed and processed through the main control processing chip 62, the fault judgment module 64 receives the analysis result and generates fault information according to the analysis result, and the data is sent to the background server 66 through the signal sending module 65 to prompt the tester, so that the testing process is more convenient and faster, and the detection efficiency is high.
In the foregoing embodiments, the descriptions of the respective embodiments have respective emphasis, and for parts that are not described in detail in a certain embodiment, reference may be made to related descriptions of other embodiments.
It should be noted that, for simplicity of description, the above-mentioned method embodiments are described as a series of acts or combination of acts, but those skilled in the art will recognize that the present invention is not limited by the order of acts, as some steps may occur in other orders or concurrently in accordance with the invention. Further, those skilled in the art should also appreciate that the embodiments described in the specification are preferred embodiments and that the acts and modules referred to are not necessarily required by the invention.
In the embodiments provided in the present application, it should be understood that the disclosed apparatus may be implemented in other manners. For example, the above-described embodiments of the apparatus are merely illustrative, and for example, the above-described division of the units is only one type of division of logical functions, and other divisions may be realized in practice, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or communication connection may be an indirect coupling or communication connection between devices or units through some interfaces, and may be in a telecommunication or other form.
The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.
The above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; although the present invention is described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.
Claims (8)
1. The utility model provides an arc suppression coil is single-phase earth fault detecting system of route selection device for ground system which characterized in that includes:
the main three-phase bus is connected with a control switch, the main three-phase bus is connected with two groups of slave three-phase buses, the two groups of slave three-phase buses are connected with voltage conversion modules, one of the voltage conversion modules is connected with an arc suppression coil, and the arc suppression coil is grounded;
the test three-phase buses are connected with the slave three-phase buses, the two groups of test three-phase buses are connected through a connector, and both the two groups of test three-phase buses are connected with a voltage transformer;
a plurality of with the detection circuitry that test three-phase bus is connected, each detection circuitry is connected with detecting element, detecting element includes: the grounding parameter conversion module is connected with the line parameter conversion module and is used for converting circuit parameters when a line selection device to be tested is grounded, the grounding parameter conversion module is connected with a test switch, and the current transformer and the test switch are connected with the line selection device to be tested;
the signal feedback unit is connected with the detection unit and comprises: the device comprises a data acquisition module, a main control processing chip, a result output module, a fault judgment module, a signal sending module and a background server, wherein the data acquisition module is connected with the detection unit and used for acquiring test parameters of the line parameter conversion module and the grounding parameter conversion module, the main control processing chip is connected with the data acquisition module and used for analyzing and processing the test parameters, the result output module is connected with the main control processing chip, the fault judgment module is connected with the result output module and used for obtaining fault conditions according to output results of the result output module, the signal sending module is connected with the fault judgment module, the background server is connected with the signal sending module, and judgment results of the fault judgment module are sent to the background server through the signal sending module.
2. The system for detecting a single-phase ground fault of a line selection device for an arc suppression coil grounding system according to claim 1, wherein the fault determination module comprises: the data temporary storage module is used for temporarily storing the output result of the result output module, the fault information pre-storage module is connected with the data temporary storage module and pre-stores fault information, the data temporary storage module and the fault information pre-storage module are connected with the fault corresponding module which is used for temporarily storing the output result in the data temporary storage module and pre-stores the fault information in the fault information pre-storage module, and the fault output module is used for outputting the fault information corresponding to the fault corresponding module.
3. The system for detecting the single-phase ground fault of the line selection device for the arc suppression coil grounding system according to claim 2, wherein the main control processing chip is further connected with a storage module for storing test parameters.
4. The system for detecting the single-phase earth fault of the line selection device for the arc suppression coil grounding system according to claim 2 or 3, wherein the fault judgment module is further connected with a fault position detection module.
5. The system for detecting the single-phase ground fault of the line selection device for the arc suppression coil grounding system according to claim 4, wherein a signal amplification unit is further connected between the detection unit and the signal feedback unit.
6. The single-phase ground fault detection system of the line selection device for the arc suppression coil grounding system is characterized in that the signal transmission module is further connected with a communication interface module, and the communication interface module comprises an MII interface, an RMII interface, an RS232 interface, an RS485 interface, a CAN Bus, an M-Bus, an MDOBUS, an I2C Bus, an SPI interface, Bluetooth, a L ORA wireless module and a ZigBee wireless module.
7. The single-phase ground fault detection system of the line selection device for the arc suppression coil grounding system as claimed in claim 2, wherein an alarm module is further connected to the background server, and when the background server receives the fault information, the alarm module is controlled to send an alarm signal.
8. The system for detecting a single-phase ground fault of a line selection device for an arc suppression coil grounding system according to claim 1, wherein a protector is further connected to the three-phase bus.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010375511.7A CN111398857A (en) | 2020-05-07 | 2020-05-07 | Single-phase earth fault detection system of line selection device for arc suppression coil grounding system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010375511.7A CN111398857A (en) | 2020-05-07 | 2020-05-07 | Single-phase earth fault detection system of line selection device for arc suppression coil grounding system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN111398857A true CN111398857A (en) | 2020-07-10 |
Family
ID=71431950
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010375511.7A Pending CN111398857A (en) | 2020-05-07 | 2020-05-07 | Single-phase earth fault detection system of line selection device for arc suppression coil grounding system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111398857A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112305387A (en) * | 2020-10-31 | 2021-02-02 | 贵州电网有限责任公司 | Ground insulation detection and diagnosis system |
-
2020
- 2020-05-07 CN CN202010375511.7A patent/CN111398857A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112305387A (en) * | 2020-10-31 | 2021-02-02 | 贵州电网有限责任公司 | Ground insulation detection and diagnosis system |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103605015B (en) | High-precision electric parameter measurement dry-type reactor on-Line Monitor Device and method | |
| CN205665347U (en) | 10kV distribution lines broken string fault detection and positioning system based on three phase voltage electric current | |
| CN105866615A (en) | 10kV power distribution line disconnection fault judging method based on three-phase voltage current | |
| CN109490686B (en) | Phase failure detection method and system for power transmission and transformation equipment of nuclear power plant | |
| CN107491569B (en) | Transformer substation system fault online simulation method based on IEC61850 standard GOOSE and SV technology | |
| CN108132425A (en) | Power grid distribution line failure on-line monitoring method and system | |
| CN113030715B (en) | Residual current operated circuit breaker performance detection device and fault judgment method | |
| CN103983895B (en) | The online N line multipoint earth faults detection method of PT secondary circuit | |
| CN102540009A (en) | Fault locating system of power distribution network | |
| CN108287295A (en) | Power circuit earth fault location lookup method and system | |
| CN108732467A (en) | A kind of one-phase earthing failure in electric distribution network detection positioning system | |
| CN111398857A (en) | Single-phase earth fault detection system of line selection device for arc suppression coil grounding system | |
| CN204154848U (en) | A kind of Secondary Circuit of Potential Transformer multipoint earth faults on-Line Monitor Device | |
| CN203164360U (en) | Transformer device insulation online monitoring system | |
| CN212111743U (en) | Single-phase earth fault detection system of line selection device for neutral point ungrounded system | |
| CN111624440A (en) | Single phase grounding fault line selection device in neutral point through arc suppression coil grounding system | |
| CN212111744U (en) | Single-phase earth fault detection system of line selection device for arc suppression coil grounding system | |
| CN203811747U (en) | A small current grounding line selection system | |
| CN110749802A (en) | Fault positioning method and system for low-voltage distribution network | |
| CN105203886A (en) | Capacitive type current transformer online detection device and method | |
| CN205450179U (en) | Failure monitoring system based on distribution network monitored control system | |
| CN104931859A (en) | Fault monitoring device based on distributed wave recording | |
| CN215641682U (en) | Residual current operated circuit breaker performance detection device | |
| CN114089010A (en) | High-stability electric meter capable of testing leakage current and testing system thereof | |
| CN204495930U (en) | A kind of intelligent type automatic electrical test system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |