CN108132455A - Global error check system based on combining unit - Google Patents
Global error check system based on combining unit Download PDFInfo
- Publication number
- CN108132455A CN108132455A CN201711376152.1A CN201711376152A CN108132455A CN 108132455 A CN108132455 A CN 108132455A CN 201711376152 A CN201711376152 A CN 201711376152A CN 108132455 A CN108132455 A CN 108132455A
- Authority
- CN
- China
- Prior art keywords
- combining unit
- energy meter
- electric energy
- mutual inductor
- checked
- Prior art date
Links
- 238000005070 sampling Methods 0.000 claims abstract description 21
- 238000004364 calculation methods Methods 0.000 claims abstract description 9
- 230000005540 biological transmission Effects 0.000 claims abstract description 6
- 238000007689 inspection Methods 0.000 claims description 13
- 239000003365 glass fibers Substances 0.000 claims description 9
- 238000006243 chemical reactions Methods 0.000 claims description 8
- 239000000835 fibers Substances 0.000 claims description 8
- 230000003287 optical Effects 0.000 claims description 7
- 210000000056 organs Anatomy 0.000 claims description 6
- 238000001914 filtration Methods 0.000 claims description 3
- 238000009825 accumulation Methods 0.000 abstract description 5
- 230000000694 effects Effects 0.000 abstract description 2
- 238000010586 diagrams Methods 0.000 description 6
- 238000000034 methods Methods 0.000 description 5
- 238000004891 communication Methods 0.000 description 4
- 230000002633 protecting Effects 0.000 description 4
- 238000003780 insertion Methods 0.000 description 3
- 239000010410 layers Substances 0.000 description 3
- 241000723811 Soybean mosaic virus Species 0.000 description 2
- 238000004422 calculation algorithm Methods 0.000 description 2
- 230000001276 controlling effects Effects 0.000 description 2
- 238000004088 simulation Methods 0.000 description 2
- 241000272814 Anser sp. Species 0.000 description 1
- 241001269238 Data Species 0.000 description 1
- 210000000214 Mouth Anatomy 0.000 description 1
- 238000004458 analytical methods Methods 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000000875 corresponding Effects 0.000 description 1
- 238000005516 engineering processes Methods 0.000 description 1
- 239000000686 essences Substances 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 238000002955 isolation Methods 0.000 description 1
- 239000000203 mixtures Substances 0.000 description 1
- 230000001681 protective Effects 0.000 description 1
- 230000000630 rising Effects 0.000 description 1
- 230000001360 synchronised Effects 0.000 description 1
- 210000001519 tissues Anatomy 0.000 description 1
- 230000001131 transforming Effects 0.000 description 1
- 230000001052 transient Effects 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R35/00—Testing or calibrating of apparatus covered by the preceding groups
- G01R35/04—Testing or calibrating of apparatus covered by the preceding groups of instruments for measuring time integral of power or current
Abstract
Description
Technical field
The present invention relates to digital electricity meter metering school inspection technical field, particularly a kind of global errors based on combining unit Check system.
Background technology
Country is continuously increased in the scale of investment of digital transformer substation construction at present, the demand of electrical energy meter of digital transforming plant Amount also increases therewith, the application of electronic type voltage current transformer, intelligent primary equipment so that voltage and current signal is to be based on The digitalized electrical energy meter of the Ethernet digital quantity input of IEC61850 agreements has become the important of digital transformer substation electrical energy measurement Equipment.Although current Some Domestic research institution has had developed corresponding calibration equipment, method of calibration and verification dress Put it is varied, it is not unified enough, while there are no clear and definite for its technical indicator.
In traditional substation, electromagnetic transformer output is analog voltage current signal, and electric energy meter is by analog quantity Digital quantity is converted into, calculates electric energy.Essence all has occurred in electronic mutual inductor and digital electricity meter principle and interface mode Change.
And it is not yet put into effect currently for the relevant vertification regulation of digitalized electrical energy meter, therefore generally used in specific engineering In, the calibrating of digitalized electrical energy meter has references to JJG596《Electric multi-functional electric energy meter vertification regulation》The electronic type of middle defined Multifunctional electric energy meter detection load point carries out precision checking.
Existing method of calibration there are it is larger the drawbacks of, need in the independent extraction voltage current signal of combining unit extremely during verification Reserved verification interface, then connects small switch, the signal that electric energy meter is entered by combining unit is extracted, incoming fiber optic turns Parallel operation, but digital electricity meter can lose signal during middle converter works, and stop metering, cause metering loss.
Meanwhile there is presently no legal inspection procedure and unified and standard system, it is digitized electric energy metering device Composition error examine.
Invention content
In view of the drawbacks described above of the prior art, it is an object of the invention to provide a kind of entirety mistakes based on combining unit Poor check system carries out Electric energy accumulation based on electronic mutual inductor high sampling rate FT3 messages, is obviously improved the sampling of digital standard table It is worth rate, while digitalized electrical energy meter metering node error is fitted, ensures that standard digital electric energy meter can be to subwave, humorous These electric energy of wave are measured, and test result is closer to electric energy true value.Non-pulse method of calibration is used for integrated secondary device, It does not influence to protect the normal operation surveyed during metering verification, the operational reliability and stability of measuring equipment greatly improved.
It is realized the purpose of the present invention is technical solution in this way, a kind of global error verification based on combining unit System, it includes：Electronic mutual inductor, combining unit, digitalized electrical energy meter and multifunctional measurement and control device；
The electronic mutual inductor is connect with the combining unit, the signal transmission that electronic mutual inductor is detected To combining unit；
The combining unit is connect with digitalized electrical energy meter to be checked, and is tested to digitalized electrical energy meter to be checked；
The combining unit is connect with the error comparing calculation module in standard digital electric energy meter, and the combining unit is led to The error comparing calculation module is crossed to verify digitalized electrical energy meter to be checked；
The combining unit is also connect with multifunctional measurement and control device.
Further, combining unit insertion standard digital electric energy meter is formed after school inspection standard digital electric energy meter again It tests；
The signal that exchange conversion module exports in the inspection standard digital electric energy meter acquisition electronic mutual inductor of school；
School inspection standard digital electric energy meter receives the FT3 messages of other combining units output simultaneously, and by collected one Secondary signal and the FT3 messages received are exported to digitalized electrical energy meter to be checked or multifunctional measurement and control by the form of message frame and filled It puts.
Further, the electronic mutual inductor includes electronic current mutual inductor, electronic type voltage transformer；
The electronic mutual inductor is built-in with A/D modular converters, and the transfer principle of the A/D modular converters is as follows：
After analog signals are input to electronic mutual inductor, CPU systems are transferred to by low-pass filtering and analog-to-digital conversion module System；
Electric power loop and Sampling interrupt are extracted loop transfer to cpu system by optical fiber circuit 1；Cpu system feeds back to light again Fine circuit 2.
Further, the system also includes the verification having to global error, check system is as follows：
Current-voltage sampling equipment in combining unit carries out electronic mutual inductor signal of acquisition of signal, and will A signal passes through the fiber optical transceiver in standby transport to standard digital electric energy meter after acquisition；
The signal received is transmitted to optical fiber in standard digital electric energy meter by the fiber optical transceiver by metering Main control unit is parsed, and the main control unit simultaneously measures the signal after parsing.
Further, the system is as follows to digitalized electrical energy meter error school procuratorial organ to be checked formula：
In formula：γ is relative error；WXThe electric energy recorded by digitalized electrical energy meter to be checked；WNFor theoretical energy value.
Further, when derived digital signal output follows the sample values of 860.92 agreement of DL/T 860.91 or DL/T Frame, then the system is as follows to digitalized electrical energy meter error school procuratorial organ to be checked formula：
In formula：t1-t1’<1s, t2-t2 '<1s；γ is relative error；WN1Energy value for the t1 moment；WN2For the t2 moment Energy value；WX1The electric energy recorded by the digitalized electrical energy meter to be checked metering node t1 ' moment；WX2For digitalized electric energy to be checked The electric energy that the meter amount node t2 ' moment is recorded.
By adopting the above-described technical solution, the present invention has the advantage that：
(1) Electric energy accumulation is carried out based on electronic mutual inductor high sampling rate FT3 messages, is obviously improved the sampling of digital standard table It is worth rate, while digitalized electrical energy meter metering node error is fitted, ensures that standard digital electric energy meter can be to subwave, humorous These electric energy of wave are measured, and test result is closer to electric energy true value；
(2) for integrated secondary device using non-pulse method of calibration, metering does not influence to protect the normal operation surveyed when verifying, The operational reliability and stability of measuring equipment greatly improved；
(3) seniority top digit A/D chip and oversampling technique can be used in standard digital electric energy meter, and bandwidth is high, standard digital It is high to change measuring accuracy of electric energy meter；
(4) 6 ranks or more can be used in the asynchronous algorithm of standard digital electric energy meter, and asynchronous Algorithm Error approaches zero；
(5) technologies such as the automatic switchover of multi gear position and FIR filter, measurement dynamic range can be used in standard digital electric energy meter Greatly, signal-to-noise ratio is low；
(6) standard digital electric energy meter be based on high sampling rate can individually add up multiple harmonic, can to analog quantity electric energy meter into Row fundamental energy is accumulated and the verification of harmonic electric energy accumulation.
Other advantages, target and the feature of the present invention will be illustrated in the following description to a certain extent, and And to a certain extent, based on will be apparent to those skilled in the art to investigating hereafter, Huo Zheke To be instructed from the practice of the present invention.The target and other advantages of the present invention can be wanted by following specification and right Book is sought to realize and obtain.
Description of the drawings
The description of the drawings of the present invention is as follows：
Fig. 1 is the system schematic of the global error check system based on combining unit.
Fig. 2 is that the combining unit of the global error check system based on combining unit examines schematic diagram.
Fig. 3 is A/D modular converter schematic diagrames built in the electric mutual inductor of the global error check system based on combining unit.
Fig. 4 is that standard digital electric energy meter schematic diagram is examined in the school of the global error check system based on combining unit.
Fig. 5 is the global error test schematic diagram of the global error check system based on combining unit.
Fig. 6 measures node to digitalized electrical energy meter to be checked for the global error check system based on combining unit and carries out school inspection Functional block diagram.
Fig. 7 is that the digitalized electrical energy meter to be checked metering node of the global error check system based on combining unit carries out school inspection System diagram.
Fig. 8 is that the synchronizing signal of the global error check system based on combining unit inputs schematic diagram.
Specific embodiment
The invention will be further described with reference to the accompanying drawings and examples.
Embodiment：As shown in Figures 1 to 8；A kind of global error check system based on combining unit, it includes：Electricity Minor mutual inductor, combining unit, digitalized electrical energy meter and multifunctional measurement and control device；
The electronic mutual inductor is connect with the combining unit, the signal transmission that electronic mutual inductor is detected To combining unit；
The combining unit is connect with digitalized electrical energy meter to be checked, and is tested to digitalized electrical energy meter to be checked；
The combining unit is connect with the error comparing calculation module in standard digital electric energy meter, and the combining unit is led to The error comparing calculation module is crossed to verify digitalized electrical energy meter to be checked；
The combining unit is also connect with multifunctional measurement and control device.
The electronic mutual inductor includes electronic current mutual inductor, electronic type voltage transformer；
The electronic mutual inductor is built-in with A/D modular converters, and the transfer principle of the A/D modular converters is as follows：
After analog signals are input to electronic mutual inductor, CPU systems are transferred to by low-pass filtering and analog-to-digital conversion module System；
Electric power loop and Sampling interrupt are extracted loop transfer to cpu system by optical fiber circuit 1；Cpu system feeds back to light again Fine circuit 2.
It is examined again after combining unit insertion standard digital electric energy meter is formed school inspection standard digital electric energy meter It tests；
The signal that exchange conversion module exports in the inspection standard digital electric energy meter acquisition electronic mutual inductor of school；
School inspection standard digital electric energy meter receives the FT3 messages of other combining units output simultaneously, and by collected one Secondary signal and the FT3 messages received are exported to digitalized electrical energy meter to be checked or multifunctional measurement and control by the form of message frame and filled It puts.
After combining unit insertion digital standard table, on the one hand it is mainly used for receiving the digital signal of collector and from electricity The analog signal of magnetic-type mutual inductor directly carries out Electric energy accumulation, on the one hand these signals is merged, IEC 61850-9- after processing 2LE agreements are transferred to digital table or multifunctional measurement and control device.The function of device is as follows：
(1) data that up to No. 12 collectors transmit are received and processed.The A/D sampling sections of combining unit, can sample The analog signal on most 6 tunnels of exchange conversion module output
(2) receiving station end synchronizing signal synchronizes each road A/D samplings.
(3) the FT3 messages of other combining units output are received.
(4) power supply status of isolation collector is received, adjusts the output of Laser Power Devices as needed
After the data that merging treatment is acquired, meet 100BASE-FX as defined in IEEE 802.3 or 10BASE-F L with 3 tunnels Mode externally provides data acquisition signal, can also use the message of FT3 forms transmission IEC60044-8 prescribed forms.
The system also includes the verification having to global error, check system is as follows：
Current-voltage sampling equipment in combining unit carries out electronic mutual inductor signal of acquisition of signal, and will A signal passes through the fiber optical transceiver in standby transport to standard digital electric energy meter after acquisition；
The signal received is transmitted to optical fiber in standard digital electric energy meter by the fiber optical transceiver by metering Main control unit is parsed, and the main control unit simultaneously measures the signal after parsing.
At present, global error is mainly made of several aspects：Digital electricity meter error, electronic mutual inductor error, due to It is transmitted using optical fiber, no additional loops error.Wherein the error of electronic mutual inductor is made of 2 parts, before a part is AD conversion error is held, one is combining unit round-off error.Now consider digital standard table being directly embedded into combining unit device. Three-phase load be theoretically it is balanced, in fact, primary system trend, i.e. three-phase current, three-phase voltage value and it is off-gauge just Chord curve, standard scale is directly using FT3 data, generally per 200 points of cycle, relative to the number of every 80 point sampling value of cycle reception For word table, precision can improve an accuracy class, be conducive to verify out system global error.
Principle based on combining unit tester：Primary processor is used to read the collector data of FPGA offers, according to conjunction And the configuration information tissue treatment data of unit.Primary processor is provided out 4 tunnels and meets 100BASE-FX as defined in IEEE802.3 Or 10BASE-F L interface.
Secondary processor is FPGA, for controlling A/D conversions, receiving the up to data of No. 12 collector modules, reception together Step signal sends and receivees FT3 messages, and data are exchanged by internal dual port RAM and primary processor.
A/D sampling sections can convert 6 tunnel analog signals of module output with Sample AC.Return with collector input signal And latter sends out.
Simulation of data processing provides in device alarm signal to power module and shares one group with power alarm and output relay Contact.
If a secondary device receives the data of several combining units output simultaneously, these combining units need Synchronous working, when synchronizing signal is lost, combining unit will inform secondary device by the flag bit in message.
Using optical fiber interface, Fig. 8 shows the shape of optical signal for synchronizing signal input.Wherein,
(1) synchronization point is signal rising edge, and triggering luminous power is the 50% of maximum luminous power；
(2) clock frequency：1Hz；
(3) combining unit checks the reasonability of signal；
(4) pulse duration th>10μs；
(5) pulse spacing tl>500ms。
Whole system is using integrated secondary device non-pulse method of calibration：
Integrated secondary device device is integrated with the functions such as combiner, protection, observing and controlling, metering, belongs to All-in-One device, measures school Mainly consider not influence to protect the normal operation surveyed when testing.
Integrated secondary device has simulation small-signal acquisition interface, supports the protective wire of low-voltage-grade electronic mutual inductor The millivolt level output of circle and the volt grade output of measuring coil, have the energy for receiving or sending IEC60044-8/FT3 protocol datas Power, and compartment is provided and synchronizes input interface.100M fiber optic Ethernet mouths with reception or transmission IEC61850-9-1 agreements, Process layer GOOSE nets can be can access in the seamless connections such as digital electric energy meter, device integrated intelligent terminal function.Device can be with Station level is communicated with IEC61850 standard modes,
In terms of metering, major function is as follows：
1) it realizes full electrical measurement, a variety of three-phase power parameters can be measured.Measured value can be shown on device MMI in real time Show, also can teletransmission to electrical energy collecting device.
2) there is distant place communication function.DL/T645-2007 or DL/T is carried out by included RS-485 communication interfaces 645-1997 is communicated, and metrical information, parameter setting can be uploaded to background monitoring host, realizes distant place centralized management and prison Control, user easily can carry out systematic parameter programming using communication.3) 61850MMTR logical nodes are supported, guarantor can be passed through The communication port and 61850 main websites for protecting CPU communicate.
Digitalized electric energy metering node is generally by sending user's report subscribed in timing, to update the electricity in acquisition terminal Energy datum, such report generally comprise：Active energy, reactive energy, data update time, data update time are accurate to 2 - 24 power seconds, considerably beyond equipment time accuracy；Therefore reference number electric energy meter standard digital power source method verification side Method can carry out metering verification by obtaining IEC61850-8-1 standard reports data.
Derived digital signal exports the sample values frame for following 860.92 agreement of DL/T 860.91 or DL/T, and the number It can be set according to voltage, the amplitude of current signal and the phase representated by frame according to practical requirement, the parameter according to configuration obtains To theoretical energy value WN, electric energy measurement value W is obtained from tested electric energyX；The system is to digitalized electrical energy meter error school procuratorial organ to be checked Formula is as follows：
In formula：γ is relative error；WXThe electric energy recorded by digitalized electrical energy meter to be checked；WNFor theoretical energy value.
Derived digital signal exports the sample values frame for following 860.92 agreement of DL/T 860.91 or DL/T, and the number It can be set according to voltage, the amplitude of current signal and the phase representated by frame according to practical requirement, stably and controllable, error calculation Utensil has stable time counter, and the energy value W at t1 moment is respectively obtained according to the sample values frame receivedN1, the t2 moment Energy value WN2, and pass through receive message from tested digitalized electric energy metering node obtain t1 ' moment electric energy measurement values WX1、t2’ Moment electric energy measurement value WX2, t1 and t1 ' moment, t2 and t2 ' moment do not need to strict conformance, as long as keeping suitable：t1- t1’<1s, t2-t2 '<1s；Then the system is as follows to digitalized electrical energy meter error school procuratorial organ to be checked formula：
In formula：t1-t1’<1s, t2-t2 '<1s；γ is relative error；WN1Energy value for the t1 moment；WN2For the t2 moment Energy value；WX1The electric energy recorded by the digitalized electrical energy meter to be checked metering node t1 ' moment；WX2For digitalized electric energy to be checked The electric energy that the meter amount node t2 ' moment is recorded.
As shown in fig. 7, it is digitized electrical energy measurement node school according to above-mentioned integrated secondary device non-pulse method of calibration It tests, when carrying out field-checking, Error Calculator (or similar devices) is handed over as long as accessing metering in substation nearby with station level It changes planes (MMS messages), you can receive the report of measured numberization metering node, access layer switch is spaced in substation nearby (SMV messages), you can sampling value message is received, without opening the equipment cabinet being closed, to access electrical energy pulse and sampling It is worth message, and batch calibrating can be carried out, it is convenient and efficient；And experiment when in, can also set up two switch networks：Station level is handed over It changes planes (MMS messages), be spaced layer switch (SMV messages), can also carry out batch verification.
Whole verification error analysis：
According to Shannon's sampling theorem, in the transfer process for carrying out analog/digital signal, when sample frequency is more than in signal At 2 times of highest frequency, the digital signal after sampling completely remains the information in original signal, actually at least big It, generally will be to 4 times or more, otherwise due to the quantization error of A/D and the initial phase of Computing precision and sampled point in 2 times The reasons such as position are difficult to restore, for example 2 points sampled are just just fallen at 0 degree and the zero passage of 180 degree when 2 times, in this way The sampled value of A/D is 0, and signal can not restore completely.
During real load check, because under the transient process or distorting loads of power grid be possible to down to 1Hz signal, and we one As can only be integrated with several primitive period signals, such low frequency signal just has a truncated error, and different sample rates is by table It is now different precision.So when the signal period of fundamental wave is 50Hz, and the harmonic wave for only existing integral multiple (is less than sample rate As 1/2), the precision of different sample rates is only.As tester still uses 80 point sampling of every cycle of combining unit, dot product It is 1.3337% with error, such as directly uses FT3 data, it is assumed that when being 256, data is then -0.142%.
The active power error of different sample rates is as shown in table 1 below by Matlab phantom errors.
1 phantom error of table
Finally illustrate, the above embodiments are merely illustrative of the technical solutions of the present invention and it is unrestricted, although with reference to compared with The present invention is described in detail in good embodiment, it will be understood by those of ordinary skill in the art that, it can be to the skill of the present invention Art scheme is modified or replaced equivalently, and without departing from the objective and range of the technical program, should all be covered in the present invention Right in.
Claims (6)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201711376152.1A CN108132455A (en) | 2017-12-19 | 2017-12-19 | Global error check system based on combining unit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201711376152.1A CN108132455A (en) | 2017-12-19 | 2017-12-19 | Global error check system based on combining unit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN108132455A true CN108132455A (en) | 2018-06-08 |
Family
ID=62390796
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201711376152.1A CN108132455A (en) | 2017-12-19 | 2017-12-19 | Global error check system based on combining unit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN108132455A (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102608450A (en) * | 2012-02-24 | 2012-07-25 | 江苏凌创电气自动化股份有限公司 | Testing and verifying system appropriate for intelligent transformer substation and verifying method |
| CN103792508A (en) * | 2014-01-27 | 2014-05-14 | 国家电网公司 | Error test system and method for digitized metering device |
| CN104062625A (en) * | 2014-06-27 | 2014-09-24 | 国家电网公司 | Digital electric energy metering device calibration equipment and method thereof |
| US20150141064A1 (en) * | 2004-11-18 | 2015-05-21 | Powersense A/S | Compensation of simple fiber optic faraday effect sensors |
| CN204694837U (en) * | 2015-06-26 | 2015-10-07 | 国家电网公司 | Pick-up unit |
-
2017
- 2017-12-19 CN CN201711376152.1A patent/CN108132455A/en active Search and Examination
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20150141064A1 (en) * | 2004-11-18 | 2015-05-21 | Powersense A/S | Compensation of simple fiber optic faraday effect sensors |
| CN102608450A (en) * | 2012-02-24 | 2012-07-25 | 江苏凌创电气自动化股份有限公司 | Testing and verifying system appropriate for intelligent transformer substation and verifying method |
| CN103792508A (en) * | 2014-01-27 | 2014-05-14 | 国家电网公司 | Error test system and method for digitized metering device |
| CN104062625A (en) * | 2014-06-27 | 2014-09-24 | 国家电网公司 | Digital electric energy metering device calibration equipment and method thereof |
| CN204694837U (en) * | 2015-06-26 | 2015-10-07 | 国家电网公司 | Pick-up unit |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Albu et al. | Syncretic use of smart meters for power quality monitoring in emerging networks | |
| CN101498757B (en) | Real-time dynamic monitoring and recording equipment of power system | |
| CN101334439B (en) | Electric parameter data integrated collection apparatus | |
| CN104267374B (en) | Metering device on-line checking and status assessing system | |
| CN201327517Y (en) | Integrated detection device of electric power terminal | |
| CN101534021B (en) | Multimode data acquisitions and processing method applied to power automation system | |
| CN101493485B (en) | On-line monitoring system for capacitive equipment dielectric loss angle | |
| CN103278791B (en) | The electronic mutual inductor amplitude phase error check system that Networkable detects | |
| CN102608450B (en) | Testing and verifying system appropriate for intelligent transformer substation and verifying method | |
| CN102928040B (en) | Ship lock Multi-channel water level measuring system and filtering method | |
| CN101149425B (en) | Electronic electric energy meter debugging, checkout automated system | |
| CN201742158U (en) | Online monitoring device for power transformer | |
| CN101458286B (en) | Phasor measuring set based on in situ spectroscopic analysis and applied wide domain measuring system | |
| CN103792508B (en) | The error testing system of the digitized measurement device and method of testing | |
| CN102255637B (en) | Carrier communication test equipment | |
| CN102073029B (en) | Electronic mutual inductor test system and test method | |
| CN202057784U (en) | Online calibrating and digital online monitoring system for electric energy meter | |
| CN101515015B (en) | Power quality monitoring and recording device of power system | |
| CN102401871B (en) | Failure message integrated device based on FPGA and ARM hardware platform | |
| CN102819004B (en) | Comprehensive detecting and analyzing platform for performance of digital electric energy metering systems of intelligent transformer substations | |
| CN102305922B (en) | On-load detection method and device for intelligent optical fiber electric energy meter in substation | |
| CN202486199U (en) | Data acquisition unit of electronic type mutual inductor | |
| CN102401864B (en) | Laboratory simulation detection device for low-voltage meter reading system | |
| RU2577245C2 (en) | Merging unit and method of operating merging unit | |
| CN101231320B (en) | Undervoltage meter system detecting device based on virtual electric energy meter module |
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 |