CN102520386A - Calibration method of three-phase electric energy meter - Google Patents
Calibration method of three-phase electric energy meter Download PDFInfo
- Publication number
- CN102520386A CN102520386A CN2011104120511A CN201110412051A CN102520386A CN 102520386 A CN102520386 A CN 102520386A CN 2011104120511 A CN2011104120511 A CN 2011104120511A CN 201110412051 A CN201110412051 A CN 201110412051A CN 102520386 A CN102520386 A CN 102520386A
- Authority
- CN
- China
- Prior art keywords
- electric energy
- energy meter
- phase
- adjustment
- voltage
- Prior art date
Links
- 230000001360 synchronised Effects 0.000 claims abstract description 4
- 238000000034 methods Methods 0.000 claims description 16
- 230000000875 corresponding Effects 0.000 claims description 7
- 239000011159 matrix materials Substances 0.000 claims description 5
- 238000004891 communication Methods 0.000 claims description 2
- 238000004519 manufacturing process Methods 0.000 abstract description 5
- 241001417517 Scatophagidae Species 0.000 description 18
- 238000006243 chemical reactions Methods 0.000 description 4
- 281000052457 Interchannel companies 0.000 description 2
- 238000004364 calculation methods Methods 0.000 description 2
- 238000010586 diagrams Methods 0.000 description 2
- 101000018998 human Interleukin-4 Proteins 0.000 description 2
- 239000001981 lauryl tryptose broth Substances 0.000 description 2
- 230000011218 segmentation Effects 0.000 description 2
- 238000006467 substitution reactions Methods 0.000 description 2
- 229920000954 Polyglycolide Polymers 0.000 description 1
- 230000002596 correlated Effects 0.000 description 1
- 238000005516 engineering processes Methods 0.000 description 1
- 230000002708 enhancing Effects 0.000 description 1
- 235000010409 propane-1,2-diol alginate Nutrition 0.000 description 1
Abstract
Description
Technical field
The present invention relates to a kind of adjusting process of three-phase electric energy meter.
Background technology
In recent years, under the overall situation that intelligent grid is transformed, intelligent electric energy meter is as the indispensable equipment of intelligent grid; Demand is big, and in the production of traditional three-phase intelligent electric energy meter, pulse adjustment method is generally adopted in the intelligent electric energy meter adjustment; Pulse adjustment method has stable and accurate advantage, but pulse adjustment method need take great amount of time, particularly when the underloading point to high-precision electric energy meter carries out adjustment; Though can reduce the time of adjustment through the way that pulse is quickened, shortcoming such as the reliability of pulse accelerated process is not fine, and is not easy to operate; Thereby cause the production difficulty of three-phase intelligent electric energy meter big, efficient is low.
Summary of the invention
The purpose of this invention is to provide a kind of simply, fast, the adjusting process of three-phase electric energy meter accurately.
A kind of adjusting process of three-phase electric energy meter, its special feature is, comprises the steps:
(1), at first get an accuracy class and be higher than the electric current and voltage source of tested electric energy meter institute calling hierarchy, give the PC of electric current and voltage source with electric energy meter issue synch command for one, one as the matrix of reference with need the three-phase electric energy meter of adjustment;
(2), PC read matrix through the RS485 communication interface the measuring parameter data with synchronous by the three-phase electric energy meter of adjustment, realize by the parameter setting of adjustment electric energy meter;
(3), electric current and voltage source PF=0.5L; During the rated output voltage electric current; PC is to by the three-phase electric energy meter of adjustment broadcasting adjustment voltage, electric current and A, B, C phase channel gain and phase correction commands, and electric energy meter is accomplished the adjustment of above debug point according to the information in electric current and voltage source;
(4), electric current and voltage source PF=0.5L; Output rated voltage; The 20% current work point of rated current, PC is to being broadcasted underloading point A, B, C phase phase correction commands by the adjustment electric energy meter, and electric energy meter is accomplished the adjustment of the error of above underloading point according to the information in electric current and voltage source;
(5), electric current and voltage source electric current is unloaded; Output rated voltage; Electric energy meter is read unloaded effective value, performance number behind the PC broadcasting command, calculates the value that corresponding OFFSET value is inserted corresponding OFFSET register according to quiescent value again, accomplishes A, B, C phase OFFSET correction.
The present invention is the automatic adjusting process that adopts a kind of three-phase intelligent electric energy meter that the power calibration combines with traditional pulse calibration method, thereby reduces the production difficulty of three-phase intelligent electric energy meter greatly, enhances productivity.
Description of drawings
Accompanying drawing 1 is the process flow diagram of adjusting process of the present invention;
Accompanying drawing 2 is the logic theory block diagram of adjustment system of the present invention.
Embodiment
The principle of the inventive method is following:
1, normal voltage electric current and active power value are calculated:
(1), the voltage effective value register value of calculating and choice criteria
The voltage effective value register value of standard should both make things convenient for MCU to convert the LCD displayed value to during the voltagerating input, again in the zone of reasonableness of channel phases 1.0Ib.
When supposing voltagerating input Un, chip voltage passage input terminal voltage effective value is Vu, and calculated value is U Theoretical, be U through MCU conversion LCD displayed value Indicating value, the voltage effective value register value of standard is U Standard, U then StandardSelection should be satisfied following condition:
0.8<U Standard/ U Theoretical<1.2
K=U Standard/ U Theoretical, K should be integer and is convenient to the MCU conversion
Above-mentioned first condition guarantees U channel phases 1.0Ib a reasonable range, and choosing of second condition K should make things convenient for MCU to convert the effective value register value to the LCD displayed value.Wherein if PGA=1, U TheoreticalCan be calculated as follows:
U Theoretical=INT [(Vu/800) * 2^27]
(2), the current effective value register value of calculating and choice criteria
When calculating the specified input of electric current with same principle, the current effective value register value I of standard Standard
(3), calculate PF=1.0Ib, PF=0.5L Ib and PF=0.5L 0.2Ib, the active power register value of standard
Specified input, PF=1.0Ib, the active power effective value P of standard 1.0Ib=INT (U Standard* I Standard/ 2^31)
Specified input, PF=0.5L Ib, the active power effective value P of standard 0.5LIb=INT (U Standard* I Standard/ 2^32)
Specified input, PF=0.5L 0.2Ib, the active power effective value P of standard 0.2L0.5Ib=0.2INT (U Standard* I Standard/ 2^32)
2, HFConst calculates:
According to PF=1.0Ib, parameters such as the active power value P of standard, ammeter constant EC are calculated as follows theoretical HFConst value:
HFConst=INT[P*3.6*10^6*Fosc/(32*EC*Un*Ib*2^31)]
P:PF=1.0Ib is by 3) the active power register value of the standard calculated
Fosc: crystal frequency, recommend external 8.192Mhz crystal
Un: specified input voltage
Ib: the electric current of specified input
EC: ammeter constant
By result of calculation configuration HFConst1 and HFConst2 register.
3, channel phases 1.0Ib
The specified output in electric current and voltage source, suppose as 1 in to calculate A phase normal voltage effective value be UA, the normalized current effective value is IA, reading A phase virtual voltage effective value register value is that UA ', actual current effective value register value are IA ', then:
A phase voltage effective value error E rrUA=(UA '-UA)/UA
A phase current effective value error E rrIA=(IA '-IA)/IA
A phase U channel phases 1.0Ib can realize that the computing method of GSUA are following through configuration GSUA register:
USGain=(-ErrUA)/(1+ErrUA)
If USGain>=0, then GSUA=INT [USGain*2 15]
Otherwise USGain<0, then GSUA=INT [2 16+ USGain*2 15]
A phase I channel power correcting gain can be realized the same GSUA of method through configuration GSIA register
4, channel phases 0.5LIb
Electric current and voltage source configuration change is PF=0.5L Ib, and specified output is supposed as the mutually desirable active power of 1 calculating A is PA 0.5LIb, reading actual active power is PA 0.5LIbBe PA 0.5LIb', then the active power error brought by phase error of A is:
ErrPA=(PA 0.5LIb’-PA 0.5LIb)/PA 0.5LIb
This error can realize through configuration A phase U channel phases 0.5LIb register PHSUA or I channel phases 0.5LIb register PHSIA.Phase compensation formula: do as if A phase U, the interchannel angular difference of I
θ, then
If θ>0, the leading IA of expression UA; If θ<0, expression UA hysteresis IA.
To 50Hz, PHSUA and PHSIA register all have the relation of 0.017578 °/LSB.
If adjustment PHSUA register, PHSUA=0x80+INT (θ/0.017578 °) is arranged then
If adjust the PHSIA register and do not consider the segmentation correction, then have:
PHSIA_R1[7:0]=0x80-INT(θ/0.017578°)
5, channel phases 0.5L0.2Ib
Electric current and voltage source configuration change is PF=0.5L 0.2Ib, and specified output is supposed as the mutually desirable active power of 1 calculating A is PA 0.5L0.2Ib, reading actual active power is PA 0.5L0.2IbBe PA 0.5L0.2Ib', then the active power error brought by phase error of A is:
ErrPA=(PA 0.5L0.2Ib’-PA 0.5L0.2Ib)/PA 0.5L0.2Ib
This error can realize through configuration A phase U channel phases 0.5L0.2Ib register PHSUA or I channel phases 0.5L0.2Ib register PHSIA.Phase compensation formula: do as if A phase U, the interchannel angular difference of I
θ, then
If θ>0, the leading IA of expression UA; If θ<0, expression UA hysteresis IA.
To 50Hz, PHSUA and PHSIA register all have the relation of 0.017578 °/LSB.
If adjustment PHSUA register, PHSUA=0x80+INT (θ/0.017578 °) is arranged then
If adjust the PHSIA register and do not consider the segmentation correction, then have:
PHSIA_R1[7:0]=0x80-INT(θ/0.017578°)
6, according to above theory, produce some of the three-phase intelligent electric energy matrixs of various current specification, use during the intelligent electric energy meter adjustment that supplies different size.
7, in by the intelligent electric energy meter of adjustment, do corresponding adjustment according to above theory and realize program and signal procedure.
8, the control program of design PC end, so that PC realizes matrix, standard scale and by the control of adjustment table.
9, power calibration method for example
Suppose that a design 220V (Un), the specified input of 1.5A (In), table constant are the appearance table of 3200 (EC).Rated voltage Un=220V, requiring corresponding A DC input end signal amplitude is Vn=220mV; Rated current Ib=1.5A; Corresponding A DC input end signal amplitude is Vi=50mV, and the analog channel gain is 1 times.
(1), normal voltage effective value register value calculates and selects
A, voltage effective value register theoretical value when calculating specified input
According to formula U Theoretical=INT [(Vu/800) * 2^27], substitution Vn=220mV,
U Theoretical=INT [(220/800) * 2^27]=36909875
B, according to condition 0.8<U Standard/ U Theoretical<1.2, U TheoreticalReasonable choice range is 29527900~44291850
C, be U through MCU conversion LCD displayed value Indicating value=220V can select U StandardBe 44000000, MCU can change easily
(2), normalized current effective value register value calculates and selects
A, current effective value register theoretical value when calculating specified input
According to formula I Theoretical=INT [(Vi/800) * 2^27], substitution Vu=50mV,
I Theoretical=INT [(50/800) * 2^27]=8388608
B, according to condition 0.8<I Standard/ I Theoretical<1.2, I TheoreticalReasonable choice range is 6710886~10066329
C, be I through MCU conversion LCD displayed value Indicating value=1.5A can select I StandardBe 7500000, MCU can change easily
(3), PF=1.0Ib, PF=0.5LIb and PF=0.5L0.2Ib, standard active power register value calculates
Specified input, PF=1.0, the active power value of standard
P 1.0Ib=INT (U Standard* I Standard/ 2^31)=44000000*7500000/2^23=39339066
Specified input, PF=0.5L, the active power value of standard
P 0.5LIb=INT (U Standard* I Standard/ 2^32)=39339066/2=19669533
Specified input, PF=0.2L, the active power value of standard
P 0.5L0.2Ib=0.2INT (U Standard* I Standard/ 2^32)=19669533*0.2=3933906
(4), HFConst calculates and configuration
By formula: HFConst=INT [P*3.6*10^6*Fosc/ (32*EC*Un*Ib*2^31)]
=INT[(39339066*3.6*8.192*10^12)/(32*3200*220*1.5*2^31)]
=15987
=3E73H
So chip configuration HFConst1=HFConst2=3E73H
(5), channel phases 1.0Ib process
The specified output in electric current and voltage source; Read A phase voltage effective value register; Be assumed to be 37297350; So ErrUA=(UA '-UA)/UA=(37297350-44000000)/7500000=-0.152333, in register GSUA, write-ErrUA/ (1+ErrUA)=0.1321953*32768=4332, correction error can be controlled at 0.02%~0.03%.
Read A phase current effective value register; Be assumed to be 8299685; So ErrIA=(IA '-IA)/IA=(8299685-7500000)/7500000=0.106625;-ErrIA/ (1+ErrIA)=-0.0963515 writes INT [65536-0.0963515*32768]=F3ABH in register GSIA; Can proofread and correct current effective value like this is 7500000, and correction error can be controlled at 0.02%~0.03%.
After A phase voltage effective value and current effective value were proofreaied and correct and accomplished, be correlated with effective value, power etc. of active power/reactive power/first-harmonic were all proofreaied and correct completion.Because HFconst is the 3E73H that is extrapolated by standard active power, so A phase voltage error is also accomplished from NMO correction.
B phase and the interdependent photograph of C process are together proofreaied and correct.
(6), channel phases 0.5LIb process
Behind the intact channel phases 1.0Ib in school, change power factor into 0.5L Ib, the value of reading A phase active power register is 9526535,
ErrPA=(PA then 0.5LIb'-PA 0.5LIb)/PA 0.5LIb=(19526535-19669533)/19669533=-0.00727
θ=ArcSin(-(-0.00727)/1.732)=ArcSin0.0042=0.2406°。
PHSUA=128+INT [0.2406/0.017578]=142, converting 16 systems into is 0x8E
B phase and the interdependent photograph of C process are together proofreaied and correct.
(7), channel phases 0.5L0.2Ib process
Channel phases 0.5L0.2Ib reference channel phase place 0.5LIb process.
Claims (1)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN201110412051.1A CN102520386B (en) | 2011-12-12 | 2011-12-12 | Calibration method of three-phase electric energy meter |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN201110412051.1A CN102520386B (en) | 2011-12-12 | 2011-12-12 | Calibration method of three-phase electric energy meter |
Publications (2)
Publication Number | Publication Date |
---|---|
CN102520386A true CN102520386A (en) | 2012-06-27 |
CN102520386B CN102520386B (en) | 2014-01-22 |
Family
ID=46291371
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CN201110412051.1A CN102520386B (en) | 2011-12-12 | 2011-12-12 | Calibration method of three-phase electric energy meter |
Country Status (1)
Country | Link |
---|---|
CN (1) | CN102520386B (en) |
Cited By (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN103885026A (en) * | 2014-03-13 | 2014-06-25 | 威胜集团有限公司 | Electric energy meter calibrating method |
CN104020437A (en) * | 2014-06-21 | 2014-09-03 | 宁波三星电气股份有限公司 | Electric energy meter correction method |
CN104267370A (en) * | 2014-08-01 | 2015-01-07 | 云南电力试验研究院(集团)有限公司电力研究院 | Method for achieving compatible meter hanging of meter hanging bases for single-phase electric energy meters and three-phase electric energy meters |
CN104483650A (en) * | 2014-12-04 | 2015-04-01 | 厦门格绿能光电股份有限公司 | Calibration method for ammeter |
CN104503897A (en) * | 2014-10-21 | 2015-04-08 | 惠州市龙鼎盛电力科技有限公司 | Electric energy meter software design method capable of realizing multiple interaction modes |
CN106154206A (en) * | 2016-06-20 | 2016-11-23 | 华立科技股份有限公司 | Electric energy meter error bearing calibration |
CN106154208A (en) * | 2016-07-22 | 2016-11-23 | 溧阳市华鹏电力仪表有限公司 | The quick self-calibration system of a kind of guide tracked single-phase electric energy Watch Error and method for self-calibrating |
CN106249191A (en) * | 2016-08-19 | 2016-12-21 | 武汉盛帆电子股份有限公司 | The correction method of three-phase electric energy meter and device |
CN106842105A (en) * | 2017-02-14 | 2017-06-13 | 珠海中慧微电子股份有限公司 | A kind of method for reducing electric energy metering error |
CN107064852A (en) * | 2017-02-27 | 2017-08-18 | 北京博纳电气股份有限公司 | A kind of adjusting process of single-phase intelligent electric energy meter measuring accuracy |
CN107422292A (en) * | 2017-04-10 | 2017-12-01 | 华立科技股份有限公司 | Correction method for intelligent electric meter |
CN108051770A (en) * | 2017-11-09 | 2018-05-18 | 宁波三星医疗电气股份有限公司 | A kind of correction method of three-phase intelligent electric-energy meter |
CN109061546A (en) * | 2018-09-28 | 2018-12-21 | 广东雅达电子股份有限公司 | A kind of auto-adjustment device and method for electronic electric energy meter |
CN109557496A (en) * | 2017-09-27 | 2019-04-02 | 宁波三星医疗电气股份有限公司 | A kind of correction method of electric energy meter |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN101303401A (en) * | 2008-07-01 | 2008-11-12 | 长沙威胜电子有限公司 | RTC regulating apparatus of electrical energy meter and RTC automatic compensation correcting method |
CN101359042A (en) * | 2008-09-11 | 2009-02-04 | 江苏卡欧万泓电子有限公司 | Auto calibration method for single-phase electronic type electric energy meter |
CN101592717A (en) * | 2009-06-30 | 2009-12-02 | 深圳市科陆电子科技股份有限公司 | The method of automatically calibrating electrical instrument and system thereof |
CN101762801A (en) * | 2010-01-04 | 2010-06-30 | 山东电力研究院 | Device for detecting electric energy meter error under harmonic condition by adopting watt-second method, and detecting method |
-
2011
- 2011-12-12 CN CN201110412051.1A patent/CN102520386B/en active IP Right Grant
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN101303401A (en) * | 2008-07-01 | 2008-11-12 | 长沙威胜电子有限公司 | RTC regulating apparatus of electrical energy meter and RTC automatic compensation correcting method |
CN101359042A (en) * | 2008-09-11 | 2009-02-04 | 江苏卡欧万泓电子有限公司 | Auto calibration method for single-phase electronic type electric energy meter |
CN101592717A (en) * | 2009-06-30 | 2009-12-02 | 深圳市科陆电子科技股份有限公司 | The method of automatically calibrating electrical instrument and system thereof |
CN101762801A (en) * | 2010-01-04 | 2010-06-30 | 山东电力研究院 | Device for detecting electric energy meter error under harmonic condition by adopting watt-second method, and detecting method |
Non-Patent Citations (4)
Title |
---|
程田甜: "电能表检定装置系统设计与应用", 《科技资讯》 * |
陈向群: "电能表校表技术的发展", 《大众用电》 * |
马建: "一种新的电能表校验方法", 《电测与仪表》 * |
马睿松等: "JJG_597-2005_交流电能表检定装置检定规程", 《国家标准》 * |
Cited By (18)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN103885026A (en) * | 2014-03-13 | 2014-06-25 | 威胜集团有限公司 | Electric energy meter calibrating method |
CN103885026B (en) * | 2014-03-13 | 2016-07-13 | 威胜集团有限公司 | Electric energy meter calibrating method |
CN104020437A (en) * | 2014-06-21 | 2014-09-03 | 宁波三星电气股份有限公司 | Electric energy meter correction method |
CN104267370B (en) * | 2014-08-01 | 2017-07-28 | 云南电力试验研究院(集团)有限公司电力研究院 | The compatible pocket watch solution of list/three-phase electric energy meter pocket watch seat |
CN104267370A (en) * | 2014-08-01 | 2015-01-07 | 云南电力试验研究院(集团)有限公司电力研究院 | Method for achieving compatible meter hanging of meter hanging bases for single-phase electric energy meters and three-phase electric energy meters |
CN104503897A (en) * | 2014-10-21 | 2015-04-08 | 惠州市龙鼎盛电力科技有限公司 | Electric energy meter software design method capable of realizing multiple interaction modes |
CN104503897B (en) * | 2014-10-21 | 2017-07-21 | 惠州市龙鼎盛电力科技有限公司 | A kind of electric energy meter software design method that a variety of interactive modes can be achieved |
CN104483650A (en) * | 2014-12-04 | 2015-04-01 | 厦门格绿能光电股份有限公司 | Calibration method for ammeter |
CN106154206A (en) * | 2016-06-20 | 2016-11-23 | 华立科技股份有限公司 | Electric energy meter error bearing calibration |
CN106154208A (en) * | 2016-07-22 | 2016-11-23 | 溧阳市华鹏电力仪表有限公司 | The quick self-calibration system of a kind of guide tracked single-phase electric energy Watch Error and method for self-calibrating |
CN106249191A (en) * | 2016-08-19 | 2016-12-21 | 武汉盛帆电子股份有限公司 | The correction method of three-phase electric energy meter and device |
CN106842105A (en) * | 2017-02-14 | 2017-06-13 | 珠海中慧微电子股份有限公司 | A kind of method for reducing electric energy metering error |
CN106842105B (en) * | 2017-02-14 | 2019-05-07 | 珠海中慧微电子股份有限公司 | A method of reducing electric energy metering error |
CN107064852A (en) * | 2017-02-27 | 2017-08-18 | 北京博纳电气股份有限公司 | A kind of adjusting process of single-phase intelligent electric energy meter measuring accuracy |
CN107422292A (en) * | 2017-04-10 | 2017-12-01 | 华立科技股份有限公司 | Correction method for intelligent electric meter |
CN109557496A (en) * | 2017-09-27 | 2019-04-02 | 宁波三星医疗电气股份有限公司 | A kind of correction method of electric energy meter |
CN108051770A (en) * | 2017-11-09 | 2018-05-18 | 宁波三星医疗电气股份有限公司 | A kind of correction method of three-phase intelligent electric-energy meter |
CN109061546A (en) * | 2018-09-28 | 2018-12-21 | 广东雅达电子股份有限公司 | A kind of auto-adjustment device and method for electronic electric energy meter |
Also Published As
Publication number | Publication date |
---|---|
CN102520386B (en) | 2014-01-22 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
CN203327181U (en) | Multi-camera-module testing tool | |
CN102073029B (en) | Electronic mutual inductor test system and test method | |
CN100489555C (en) | Universal electric power mutual-inductor verification device | |
CN101231337B (en) | High-precision time synchronizing apparatus | |
CA2786242C (en) | Minimizing circulating current using time-aligned data | |
CN101718856B (en) | Calibration system of digital quantity input type electric energy meter | |
CN102841260B (en) | DC microresistivity measuring system | |
CN103630866A (en) | Transient characteristic detection system and transient characteristic detection method for electronic voltage transformers | |
CN101915903B (en) | Power meter calibrating system and power meter calibrating method for intelligent electric meter | |
CN101625383A (en) | On-line monitoring device for power quality | |
CN102981083B (en) | Self calibration equipment for monitoring power quality | |
CN106771556B (en) | A kind of AC power difference measurement system and method based on quantum techniques | |
CN203643596U (en) | Multi-meter-position three-phase electric energy meter detection system | |
CN101876693B (en) | Electric energy metering chip-based terminal calibration system | |
CN101281243B (en) | Device and method for testing equipotential closed loop electrical energy meter | |
CN102590784B (en) | Single-phase intelligent energy meter distributed correction method | |
CN202330688U (en) | Calibration device for radio frequency and mixed signal integrated circuit test system | |
CN101655544A (en) | Device for measuring and checking errors of digital mutual inductor | |
CN104808056B (en) | A kind of frequency characteristic test method and apparatus based on comparator conversion | |
CN101592717A (en) | The method of automatically calibrating electrical instrument and system thereof | |
CN102998525A (en) | Multifunctional single-phase electric energy measuring circuit and automatic ammeter calibrating method thereof | |
CN102253358A (en) | Method for correcting electric energy meter by using correction system, and correction system | |
CN104914304B (en) | Electric energy accurate measurement method and metering device under a kind of fluctuating load | |
CN202217149U (en) | High-precision electric time synchronizer | |
CN103630871A (en) | Testing device for dynamic characteristics of electronic energy meter |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PB01 | Publication | ||
C06 | Publication | ||
SE01 | Entry into force of request for substantive examination | ||
C10 | Entry into substantive examination | ||
GR01 | Patent grant | ||
C14 | Grant of patent or utility model | ||
CP01 | Change in the name or title of a patent holder |
Address after: 750021 the Ningxia Hui Autonomous Region Xixia District of Yinchuan Li Zi Yuan No. 6 North Street Patentee after: Ningxia LGG instrument Limited by Share Ltd Address before: 750021 the Ningxia Hui Autonomous Region Xixia District of Yinchuan Li Zi Yuan No. 6 North Street Patentee before: Ningxia Lgg Instrument Co., Ltd. |
|
C56 | Change in the name or address of the patentee |