CN113283068A - Method for improving alternating current sampling precision and reliability of relay protection device - Google Patents
Method for improving alternating current sampling precision and reliability of relay protection device Download PDFInfo
- Publication number
- CN113283068A CN113283068A CN202110542503.1A CN202110542503A CN113283068A CN 113283068 A CN113283068 A CN 113283068A CN 202110542503 A CN202110542503 A CN 202110542503A CN 113283068 A CN113283068 A CN 113283068A
- Authority
- CN
- China
- Prior art keywords
- protection device
- relay protection
- sampling
- port1
- condition
- 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.)
- Granted
Links
Images
Classifications
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F30/00—Computer-aided design [CAD]
- G06F30/20—Design optimisation, verification or simulation
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F2119/00—Details relating to the type or aim of the analysis or the optimisation
- G06F2119/02—Reliability analysis or reliability optimisation; Failure analysis, e.g. worst case scenario performance, failure mode and effects analysis [FMEA]
Landscapes
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- General Physics & Mathematics (AREA)
- Theoretical Computer Science (AREA)
- Emergency Protection Circuit Devices (AREA)
- Computer Hardware Design (AREA)
- Evolutionary Computation (AREA)
- Geometry (AREA)
- General Engineering & Computer Science (AREA)
- Testing Electric Properties And Detecting Electric Faults (AREA)
Abstract
The invention provides a method for improving alternating current sampling precision and reliability of a relay protection device, which comprises the following steps: s1, establishing a test platform, and S2, setting test conditions; s3, the PC is in communication connection with the relay protection device; s4, after the connection is successful, carrying out clock matching operation of the PC and the relay protection device; s5, carrying out simulation wave recording operation to obtain a wave recording file; s6, converting the wave recording file into a data file arranged according to the COMTRADE rule by utilizing wave recording analysis software, wherein the data format is ASCII code; and S7, calculating the sampling precision of each sampling channel according to the test conditions in the step S2, if the precision requirement is met, considering that the alternating current sampling precision of the relay protection device reaches the standard, and if the precision requirement is not met, repeatedly circulating the steps S1 to S7. The invention improves the alternating current sampling precision of the relay protection device, effectively prevents the malfunction and the refusal of the relay protection device and greatly improves the operation reliability of the relay protection device.
Description
Technical Field
The invention belongs to the field of relay protection, and particularly relates to a method for improving alternating current sampling precision and reliability of a relay protection device.
Background
At present, the analog quantity acquisition technology of the traction substation is rapidly developed, is one of core technologies of the relay protection of a traction power supply system, and is also a cornerstone of the traction substation for intellectualization, in-situ integration and multifunctional integrated high-speed development; analog quantity input signals of the relay protection device of the traction power supply system comprise voltage quantity, current quantity and the like of a secondary loop system, and then the relay protection device can perform protection actions such as tripping outlet, closing, alarming and the like through a protection algorithm; the design of the analog quantity acquisition system is in the middle of the design of the relay protection device of the traction substation, the performance of the analog quantity acquisition system is directly related to the sensitivity of a protection algorithm, and if the sampling precision is low, the relay protection device has the risk of misoperation or failure; therefore, under the development trend of intellectualization, in-situ and multi-functional unification of the traction substation, higher requirements are put forward on the reliability of analog quantity acquisition.
Generally, the performance of an analog quantity acquisition system is verified from the perspective of hardware circuit design, so that the sampling precision of the analog quantity acquisition system is increased to meet the requirement of noise immunity; or a qualified third-party inspection mechanism performs testing, and once a problem occurs in the testing, the testing is repeatedly modified, which not only consumes manpower and material resources, but also modifies the design scheme due to the fact that the requirement cannot be met, and the like, so that a method for improving the alternating current sampling precision and reliability of the relay protection device is urgently needed.
Disclosure of Invention
In view of this, the present invention is directed to a method for improving ac sampling accuracy and reliability of a relay protection device, so as to solve the problem of low ac sampling accuracy of the conventional relay protection device.
In order to achieve the purpose, the technical scheme of the invention is realized as follows:
a method for improving AC sampling precision and reliability of a relay protection device comprises the following steps:
s1, establishing a relay protection device alternating current sampling test platform, wherein the relay protection device alternating current sampling test platform comprises a relay protection device and a PC;
s2, setting a test condition of an alternating current sampling channel of the relay protection device;
s3, opening maintenance software at the PC end, and establishing communication connection with the relay protection device;
s4, after the connection is successful, performing clock matching operation of the PC and the relay protection device to ensure that the time of the relay protection device is consistent with that of the PC;
s5, performing analog wave recording operation by using maintenance software, acquiring original sampling value data of each synchronous sampling channel, and storing the original sampling value data into a wave recording file of the relay protection device;
s6, reading the stored wave recording file in the wave recording file of the relay protection device in the step S5 to a PC (personal computer) end, and converting the wave recording file into a data file arranged according to a rule by utilizing wave recording analysis software;
s7, opening the wave recording data file converted in the step S6, calculating the sampling precision of each sampling channel according to the test conditions in the step S2, judging whether the precision requirements are met, if the precision requirements are met, considering that the AC sampling precision of the relay protection device reaches the standard and has high reliability, and if the precision requirements are not met, repeating the steps S1 to S7 until the AC sampling precision of the relay protection device reaches the standard and has high reliability.
Further, in step S1, the relay protection device includes an ac sampling module, an EEPROM for storing a recording file, and a first communication device;
the PC comprises a communication device II and is provided with maintenance software and wave recording analysis software;
and the first communication device is connected with the second communication device and is used for communication between the PC and the relay protection device.
Furthermore, the alternating current sampling module comprises a mutual inductor, the output end of the secondary side of the mutual inductor is connected with the alternating current sampling analog-to-digital conversion module, and the alternating current sampling analog-to-digital conversion module is connected with the FPGA.
Further, the transformer includes a port on a primary side input 1, a port2, and ports on a secondary side output 3 and AGND.
Further, the test conditions in step S2 include:
under the condition one, port3 and AGND are shorted at room temperature;
applying a 3V direct-current voltage signal between the port3 and the AGND at room temperature;
condition three, shorting port1 and port2 at room temperature;
the condition four, low temperature-40 ℃, short connecting port1 and port 2;
fifth, high temperature 70 ℃, port1 and port2 are shorted;
under the sixth condition, at room temperature, port1 and port2 are short-circuited, and the immunity of the electrical fast transient pulse group is tested on port1 and port2, wherein the pulse repetition rate is set to be 5 kHz;
under the seventh condition, at room temperature, port1 and port2 are short-circuited, and the immunity of the electrical fast transient pulse group is tested on port1 and port2, wherein the pulse repetition rate is set to be 100 kHz;
at room temperature, 5A traffic is applied between port1 and port 2;
under the ninth condition, 5A traffic flow is applied between the port1 and the port2 at room temperature, the port1 and the port2 are subjected to electric fast transient pulse group immunity test, and the pulse repetition rate is set to be 5 kHz;
at room temperature, applying 5A traffic volume between port1 and port2, and performing an electrical fast transient burst immunity test on port1 and port2, with the pulse repetition rate set at 100 kHz.
Further, the accuracy requirement in step S7 includes:
in the case of the first condition, the precision requirement is not more than +/-0.1% under the first condition to the fifth condition;
in case two, under the condition six to the condition ten, the accuracy is required to be not more than ± 1%.
Compared with the prior art, the method for improving the alternating current sampling precision and reliability of the relay protection device has the following beneficial effects:
according to the invention, the established alternating current sampling test platform of the relay protection device is subjected to extreme condition pressure test under different test conditions, data reading, conversion and analysis are carried out at the PC terminal, the sampling precision of the alternating current analog quantity acquisition module of the tested relay protection device is obtained, the sampling precision is not more than +/-0.1% under the test conditions, the error of the action value is not more than +/-1%, and the design scheme of a hardware circuit is improved and verified through repeated tests, so that the alternating current sampling precision of the relay protection device is improved, the manpower and test cost are reduced, the misoperation, the rejection and the like of the relay protection device are effectively prevented, and the operation reliability of the relay protection device is greatly improved.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an embodiment of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:
fig. 1 is a flowchart of a method for improving ac sampling accuracy and reliability of a relay protection device according to an embodiment of the present invention;
fig. 2 is a block diagram of an ac sampling test platform of a relay protection device according to an embodiment of the present invention;
fig. 3 is a block diagram of an ac sampling module according to an embodiment of the present invention.
Detailed Description
It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict.
In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on those shown in the drawings, and are used only for convenience in describing the present invention and for simplicity in description, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be construed as limiting the present invention. Furthermore, the terms "first", "second", etc. are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first," "second," etc. may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless otherwise specified.
In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art through specific situations.
The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.
Referring to fig. 1 to fig. 3, a method for improving ac sampling accuracy and reliability of a relay protection device includes the following steps:
s1, establishing a relay protection device alternating current sampling test platform, wherein the relay protection device alternating current sampling test platform comprises a relay protection device and a PC;
s2, setting a test condition of an alternating current sampling channel of the relay protection device;
s3, opening maintenance software at the PC end, and establishing communication connection with the relay protection device;
s4, after the connection is successful, performing clock matching operation of the PC and the relay protection device to ensure that the time of the relay protection device is consistent with that of the PC;
s5, performing analog wave recording operation by using maintenance software, acquiring original sampling value data of each synchronous sampling channel, and storing the original sampling value data into a wave recording file of the relay protection device;
s6, reading the stored wave recording file in the wave recording file of the relay protection device in the step S5 to a PC (personal computer) end, and converting the wave recording file into a data file arranged according to the COMTRADE rule by utilizing wave recording analysis software, wherein the data format is ASCII (American standard code for information interchange) code;
s7, opening the wave recording data file converted in the step S6, calculating the sampling precision of each sampling channel according to the test conditions in the step S2, judging whether the precision requirements are met, if the precision requirements are met, considering that the AC sampling precision of the relay protection device reaches the standard and has high reliability, and if the precision requirements are not met, repeating the steps S1 to S7 until the AC sampling precision of the relay protection device reaches the standard and has high reliability.
The relay protection device in the step S1 includes an ac sampling module, an EEPROM for storing a recording file, and a first communication device, where the first communication device includes an ethernet a;
the PC comprises a second communication device, the second communication device comprises an Ethernet A', maintenance software and recording analysis software are installed on the second communication device, the maintenance software comprises an analog recording module and is used for controlling the alternating current sampling module to perform analog recording operation, the recording analysis software can be used for converting recording files into data files which are arranged according to the COMTRADE rule, and the data format is ASCII codes;
and the first communication device is connected with the second communication device and is used for communication between the PC and the relay protection device.
The alternating current sampling module comprises a mutual inductor which is used for converting external alternating current input into analog quantity input small signals suitable for being identified by the alternating current sampling analog-digital conversion module, the output end of the secondary side of the mutual inductor is connected with the alternating current sampling analog-digital conversion module, the alternating current sampling analog-digital conversion module has the functions of signal conditioning and analog-digital conversion, and the alternating current sampling analog-digital conversion module is connected with the FPGA and is used for caching digital quantity data converted by the alternating current sub-analog-digital conversion module.
The transformer includes a primary side input port1, a port2, and secondary side output ports 3 and AGND.
The test conditions in step S2 include:
under the condition one, port3 and AGND are shorted at room temperature;
applying a 3V direct-current voltage signal between the port3 and the AGND at room temperature;
condition three, shorting port1 and port2 at room temperature;
the condition four, low temperature-40 ℃, short connecting port1 and port 2;
fifth, high temperature 70 ℃, port1 and port2 are shorted;
under the sixth condition, at room temperature, port1 and port2 are short-circuited, and the immunity of the electrical fast transient pulse group is tested on port1 and port2, wherein the pulse repetition rate is set to be 5 kHz;
under the seventh condition, at room temperature, port1 and port2 are short-circuited, and the immunity of the electrical fast transient pulse group is tested on port1 and port2, wherein the pulse repetition rate is set to be 100 kHz;
at room temperature, 5A traffic is applied between port1 and port 2;
under the ninth condition, 5A traffic flow is applied between the port1 and the port2 at room temperature, the port1 and the port2 are subjected to electric fast transient pulse group immunity test, and the pulse repetition rate is set to be 5 kHz;
at room temperature, applying 5A traffic volume between port1 and port2, and performing an electrical fast transient burst immunity test on port1 and port2, with the pulse repetition rate set at 100 kHz.
The accuracy requirement in step S7 includes:
in the case of the first condition, the precision requirement is not more than +/-0.1% under the first condition to the fifth condition;
in case two, under the condition six to the condition ten, the accuracy is required to be not more than ± 1%.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.
Claims (6)
1. A method for improving AC sampling precision and reliability of a relay protection device is characterized by comprising the following steps:
s1, establishing a relay protection device alternating current sampling test platform, wherein the relay protection device alternating current sampling test platform comprises a relay protection device and a PC;
s2, setting a test condition of an alternating current sampling channel of the relay protection device;
s3, opening maintenance software at the PC end, and establishing communication connection with the relay protection device;
s4, after the connection is successful, performing clock matching operation between the PC end and the relay protection device to ensure that the time of the relay protection device is consistent with that of the PC;
s5, performing analog wave recording operation by using maintenance software, acquiring original sampling value data of each synchronous sampling channel, and storing the original sampling value data into a wave recording file of the relay protection device;
s6, reading the stored wave recording file in the wave recording file of the relay protection device in the step S5 to a PC (personal computer) end, and converting the wave recording file into a data file arranged according to a rule by utilizing wave recording analysis software;
s7, opening the wave recording data file converted in the step S6, calculating the sampling precision of each sampling channel according to the test conditions in the step S2, judging whether the precision requirements are met, if the precision requirements are met, considering that the AC sampling precision of the relay protection device reaches the standard and has high reliability, and if the precision requirements are not met, repeating the steps S1 to S7 until the AC sampling precision of the relay protection device reaches the standard and has high reliability.
2. The method for improving the alternating current sampling precision and reliability of the relay protection device according to claim 1, wherein the method comprises the following steps: in step S1, the relay protection device includes an ac sampling module, an EEPROM for storing a recording file, and a first communication device;
the PC comprises a communication device II and is provided with maintenance software and wave recording analysis software;
and the first communication device is connected with the second communication device and is used for communication between the PC and the relay protection device.
3. The method for improving the alternating current sampling precision and reliability of the relay protection device according to claim 2, wherein the method comprises the following steps: the AC sampling module comprises a mutual inductor, the output end of the secondary side of the mutual inductor is connected with the AC sampling A/D conversion module, and the AC sampling A/D conversion module is connected with the FPGA.
4. The method for improving the AC sampling precision and reliability of the relay protection device according to claim 3, wherein the method comprises the following steps: the transformer includes a primary side input port1, a port2, and secondary side output ports 3 and AGND.
5. The method for improving the AC sampling precision and reliability of the relay protection device according to claim 4, wherein the method comprises the following steps: the test conditions in step S2 include:
under the condition one, port3 and AGND are shorted at room temperature;
applying a 3V direct-current voltage signal between the port3 and the AGND at room temperature;
condition three, shorting port1 and port2 at room temperature;
the condition four, low temperature-40 ℃, short connecting port1 and port 2;
fifth, high temperature 70 ℃, port1 and port2 are shorted;
under the sixth condition, at room temperature, port1 and port2 are short-circuited, and the immunity of the electrical fast transient pulse group is tested on port1 and port2, wherein the pulse repetition rate is set to be 5 kHz;
under the seventh condition, at room temperature, port1 and port2 are short-circuited, and the immunity of the electrical fast transient pulse group is tested on port1 and port2, wherein the pulse repetition rate is set to be 100 kHz;
at room temperature, 5A traffic is applied between port1 and port 2;
under the ninth condition, 5A traffic flow is applied between the port1 and the port2 at room temperature, the port1 and the port2 are subjected to electric fast transient pulse group immunity test, and the pulse repetition rate is set to be 5 kHz;
at room temperature, applying 5A traffic volume between port1 and port2, and performing an electrical fast transient burst immunity test on port1 and port2, with the pulse repetition rate set at 100 kHz.
6. The method for improving the AC sampling precision and reliability of the relay protection device according to claim 5, wherein the method comprises the following steps: the accuracy requirement in step S7 includes:
in the case of the first condition, the precision requirement is not more than +/-0.1% under the first condition to the fifth condition;
in case two, under the condition six to the condition ten, the accuracy is required to be not more than ± 1%.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110542503.1A CN113283068B (en) | 2021-05-18 | 2021-05-18 | Method for improving alternating current sampling precision and reliability of relay protection device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110542503.1A CN113283068B (en) | 2021-05-18 | 2021-05-18 | Method for improving alternating current sampling precision and reliability of relay protection device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113283068A true CN113283068A (en) | 2021-08-20 |
| CN113283068B CN113283068B (en) | 2023-05-16 |
Family
ID=77279701
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110542503.1A Active CN113283068B (en) | 2021-05-18 | 2021-05-18 | Method for improving alternating current sampling precision and reliability of relay protection device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113283068B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114113847A (en) * | 2021-11-23 | 2022-03-01 | 天津凯发电气股份有限公司 | Testing method and device for relay protection CPU plug-in |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1917323A (en) * | 2006-09-01 | 2007-02-21 | 清华大学 | Method for raising measuring precision of microcomputer protective relay device |
| CN103558465A (en) * | 2013-10-29 | 2014-02-05 | 国家电网公司 | Method for on-line precision calibration of 10kV protecting device |
| CN104101790A (en) * | 2013-04-11 | 2014-10-15 | 云南电网公司曲靖供电局 | Relay protection AC sampling test system |
| CN105372611A (en) * | 2015-11-27 | 2016-03-02 | 许昌许继软件技术有限公司 | Reliability verification method for SV data acquired based on wave recording device |
| CN106199258A (en) * | 2016-06-30 | 2016-12-07 | 国网上海市电力公司 | A kind of microcomputer protective relay Auto-Test System |
| CN108226838A (en) * | 2017-11-28 | 2018-06-29 | 南京南瑞继保电气有限公司 | A kind of method realized protection supervisory equipment precision and automatically corrected |
| CN109101714A (en) * | 2018-08-02 | 2018-12-28 | 云南电网有限责任公司昆明供电局 | A method of verifying protective relaying device logic function |
| CN109406993A (en) * | 2018-10-11 | 2019-03-01 | 国网江苏省电力有限公司电力科学研究院 | Relay protection automatic test approach, apparatus and system based on recorded wave file playback |
| CN112557986A (en) * | 2020-12-07 | 2021-03-26 | 国网青海省电力公司电力科学研究院 | Method and device for checking sampling precision of fault recording and computer equipment |
-
2021
- 2021-05-18 CN CN202110542503.1A patent/CN113283068B/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1917323A (en) * | 2006-09-01 | 2007-02-21 | 清华大学 | Method for raising measuring precision of microcomputer protective relay device |
| CN104101790A (en) * | 2013-04-11 | 2014-10-15 | 云南电网公司曲靖供电局 | Relay protection AC sampling test system |
| CN103558465A (en) * | 2013-10-29 | 2014-02-05 | 国家电网公司 | Method for on-line precision calibration of 10kV protecting device |
| CN105372611A (en) * | 2015-11-27 | 2016-03-02 | 许昌许继软件技术有限公司 | Reliability verification method for SV data acquired based on wave recording device |
| CN106199258A (en) * | 2016-06-30 | 2016-12-07 | 国网上海市电力公司 | A kind of microcomputer protective relay Auto-Test System |
| CN108226838A (en) * | 2017-11-28 | 2018-06-29 | 南京南瑞继保电气有限公司 | A kind of method realized protection supervisory equipment precision and automatically corrected |
| CN109101714A (en) * | 2018-08-02 | 2018-12-28 | 云南电网有限责任公司昆明供电局 | A method of verifying protective relaying device logic function |
| CN109406993A (en) * | 2018-10-11 | 2019-03-01 | 国网江苏省电力有限公司电力科学研究院 | Relay protection automatic test approach, apparatus and system based on recorded wave file playback |
| CN112557986A (en) * | 2020-12-07 | 2021-03-26 | 国网青海省电力公司电力科学研究院 | Method and device for checking sampling precision of fault recording and computer equipment |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114113847A (en) * | 2021-11-23 | 2022-03-01 | 天津凯发电气股份有限公司 | Testing method and device for relay protection CPU plug-in |
| CN114113847B (en) * | 2021-11-23 | 2024-04-12 | 天津凯发电气股份有限公司 | Test method and device for relay protection CPU plug-in |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113283068B (en) | 2023-05-16 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN107807290B (en) | Direct current charging pile detection system and detection method | |
| CN110161331B (en) | Detection platform for primary and secondary fusion complete equipment and control method | |
| MX2010012327A (en) | Individualized self-monitoring system for transformers in power measurement installations and method of self-monitoring and diagnosis of transformers in power measurement installations. | |
| CN206618845U (en) | Power supply module for communication test system | |
| CN105790443A (en) | SCD virtual terminal connection automatic testing system and method for intelligent substation | |
| CN109752588A (en) | Electric machine controller DC bus-bar voltage signal sampling and monitoring circuit and method | |
| CN113283068A (en) | Method for improving alternating current sampling precision and reliability of relay protection device | |
| CN102288849B (en) | Highway addressable remote transducer (HART) loop fault diagnosis instrument and method | |
| CN103792398A (en) | Error-prevention universal circuit board testing adapter | |
| US20160282419A1 (en) | Device and method for testing a vehicle battery | |
| CN108037461B (en) | Quick test system and survey test panel of two electric core battery protection shields | |
| CN209746093U (en) | Universal relay protection measurement and control device | |
| CN107612642A (en) | A kind of signal band and out-of-band interference level method of testing | |
| CN113589043B (en) | System and method for detecting secondary fusion and deep fusion power distribution equipment | |
| CN214122341U (en) | Rod position detector testing device and rod position detector tester | |
| CN110554291A (en) | Partial discharge signal envelope detection device | |
| CN214473712U (en) | One-key type full-automatic tester for insulation standardization between branches | |
| CN209746092U (en) | Novel relay protection testing device | |
| CN113203921A (en) | One-key type full-automatic tester for insulation standardization between branches | |
| CN107562985B (en) | Parameter determination and modeling method for coupling unit of alternating current-direct current conversion circuit | |
| CN219179488U (en) | High-voltage acquisition and insulation parameter detection device and insulation detection device | |
| CN218387498U (en) | Non-signaling test circuit of low-voltage power line broadband carrier communication unit | |
| CN220820110U (en) | Electricity testing device based on wireless carrier power supply communication | |
| CN219799586U (en) | Instrument for testing audio output level of recording interface of railway wireless train tuning radio station | |
| CN109975736B (en) | Mutual inductor error testing system in GIS based on frequency conversion anti-interference technology |
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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |