CN112068061A - Electronic transformer error measuring device and method - Google Patents
Electronic transformer error measuring device and method Download PDFInfo
- Publication number
- CN112068061A CN112068061A CN202010870712.4A CN202010870712A CN112068061A CN 112068061 A CN112068061 A CN 112068061A CN 202010870712 A CN202010870712 A CN 202010870712A CN 112068061 A CN112068061 A CN 112068061A
- Authority
- CN
- China
- Prior art keywords
- data
- electrical energy
- electronic transformer
- sampling data
- tested
- 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
- 238000000034 method Methods 0.000 title claims abstract description 46
- 238000005070 sampling Methods 0.000 claims abstract description 169
- 238000005259 measurement Methods 0.000 claims abstract description 114
- 238000012545 processing Methods 0.000 claims abstract description 100
- 238000004364 calculation method Methods 0.000 claims abstract description 35
- 230000001360 synchronised effect Effects 0.000 claims abstract description 23
- 238000012360 testing method Methods 0.000 claims abstract description 17
- 238000012544 monitoring process Methods 0.000 claims abstract description 16
- 230000010363 phase shift Effects 0.000 claims description 16
- 230000000737 periodic effect Effects 0.000 claims description 14
- 230000008569 process Effects 0.000 claims description 7
- 239000000126 substance Substances 0.000 claims description 7
- 238000001914 filtration Methods 0.000 claims description 6
- 238000000691 measurement method Methods 0.000 claims description 5
- 238000006243 chemical reaction Methods 0.000 claims description 4
- PHTXVQQRWJXYPP-UHFFFAOYSA-N ethyltrifluoromethylaminoindane Chemical compound C1=C(C(F)(F)F)C=C2CC(NCC)CC2=C1 PHTXVQQRWJXYPP-UHFFFAOYSA-N 0.000 claims 1
- 238000010586 diagram Methods 0.000 description 16
- 230000006870 function Effects 0.000 description 12
- 238000004590 computer program Methods 0.000 description 7
- 230000005540 biological transmission Effects 0.000 description 4
- 238000004422 calculation algorithm Methods 0.000 description 4
- 239000000835 fiber Substances 0.000 description 4
- 230000003287 optical effect Effects 0.000 description 4
- 238000003860 storage Methods 0.000 description 4
- 230000008859 change Effects 0.000 description 3
- 238000004458 analytical method Methods 0.000 description 2
- 238000010276 construction Methods 0.000 description 2
- 238000013461 design Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000001228 spectrum Methods 0.000 description 2
- 238000005253 cladding Methods 0.000 description 1
- 238000012937 correction Methods 0.000 description 1
- 238000007405 data analysis Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
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
- G01R35/02—Testing or calibrating of apparatus covered by the other groups of this subclass of auxiliary devices, e.g. of instrument transformers according to prescribed transformation ratio, phase angle, or wattage rating
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Measurement Of Current Or Voltage (AREA)
Abstract
The invention discloses an error measuring device and method for an electronic transformer, which comprises the following steps: when the synchronous photoelectric clock source sends a test instruction to the upper computer, a pulse per second signal is sent to a merging unit and a data acquisition module of the electronic transformer to be tested; the online monitoring module receives a network message data frame sent by the merging unit of the electronic transformer to be tested after receiving the pulse per second signal, and analyzes the network message data frame to obtain tested electrical energy sampling data of the electronic transformer to be tested; the data acquisition module acquires the electric energy data of the standard electronic transformer after receiving the pulse per second signal so as to acquire reference electric energy sampling data; and the error calculation module respectively carries out asynchronous measurement processing on the measured electrical energy sampling data and the reference electrical energy sampling data, and calculates the error of the electronic transformer to be measured according to the measured electrical energy sampling data subjected to the asynchronous measurement processing and the reference electrical energy sampling data subjected to the asynchronous measurement processing.
Description
Technical Field
The invention relates to the technical field of high-voltage measuring equipment, in particular to an electronic transformer error measuring device and method.
Background
Since the intelligent construction of a power grid, electronic transformers are developed in a unified and strong smart power grid target provided by the construction of the power grid. An electronic transformer is an electrical apparatus consisting of one or more current or voltage sensors connected to a transmission system and to a secondary converter, for transmitting a signal proportional to a "measured quantity" for use by measuring instruments, meters and relay protection or control devices. The error measuring device of the electronic transformer is based on the principle that a standard transformer is compared with the electronic transformer to be measured to calibrate whether the measured quantity has errors or not.
The scenes and reasons for errors in measurement are: 1) when the merging unit of the standard transformer sampling device and the tested transformer receives the synchronous signal of the optical/electrical second pulse source, certain delay is generated, and errors are caused. 2) Any type of calibration device inevitably uses electronic components such as a collector, a gain amplifier, an ADC (analog-to-digital converter), a light source, and the like. The complex electromagnetic environment and temperature in the field can cause certain influence. 3) The frequency of the power grid is not accurate to 50Hz, and because the error (ratio difference and angle difference) algorithm of the sampling device is DFT conversion, frequency fluctuation can cause non-whole period sampling, and the frequency spectrum leakage of the converted and restored signals is caused. 4) Some inherent structures of the tested product, such as an active Rogowski coil current transformer, are greatly influenced by temperature of a matched integrator operational amplifier.
In order to solve the above problems, the main technical ideas at present are as follows: firstly, the hardware anti-interference capability of the device is improved through type selection. If the electronic device is selected as a device with small offset voltage (Vos), bias current (IB) and gain change rate under the change of ambient temperature; the data transmission fiber mainly adopts the fiber core and the cladding of the imported fiber, the thermal expansion coefficient of the fiber is small, and the error is not influenced by serious linear birefringence. However, the cost of the hardware for type selection is increased sharply, the economy is poor, and the problem cannot be solved fundamentally; and secondly, correcting through a software algorithm. And inputting a standard wave into the device according to the field use environment, monitoring the output waveform and the standard wave distortion, and feeding the standard wave distortion back to the upper computer to perform software error correction. However, this method can only be used as a temporary measure, because the accuracy is affected to different degrees due to different running environments, medium types, testing methods and wiring positions during the testing of the mutual inductor each time, and the software modification steps are complicated and have no field operability.
From the above analysis, it can be seen that: the existing measurement technical measures of the electronic transformer have certain defects. Therefore, there is a need to develop innovative research aimed at this technical problem, proposing a simpler, reliable and economical way.
Disclosure of Invention
The invention provides an electronic transformer error measuring device and method, and aims to solve the problem of how to accurately measure errors of an electronic transformer.
In order to solve the above-mentioned problems, according to an aspect of the present invention, there is provided an electronic transformer error measuring apparatus, the apparatus including:
the synchronous photoelectric clock source is used for sending a pulse per second signal to a merging unit and a data acquisition module of the electronic transformer to be tested when the upper computer sends a test instruction;
the online monitoring module is used for receiving a network message data frame sent by the merging unit of the electronic transformer to be tested after receiving the pulse per second signal, and analyzing the network message data frame to obtain tested electrical energy sampling data of the electronic transformer to be tested;
the data acquisition module is used for acquiring the electric energy data of the standard electronic transformer after receiving the pulse per second signal so as to acquire reference electric energy sampling data;
and the error calculation module is used for respectively performing asynchronous measurement processing on the measured electrical energy sampling data and the reference electrical energy sampling data, and calculating the error of the electronic transformer to be measured according to the measured electrical energy sampling data subjected to the asynchronous measurement processing and the reference electrical energy sampling data subjected to the asynchronous measurement processing.
Preferably, wherein the apparatus further comprises:
and the soft synchronization module is used for acquiring a CPU (Central processing Unit) timestamp when the upper computer sends a test instruction, comparing the CPU timestamp with the time for acquiring the tested electrical energy sampling data and the time for acquiring the reference electrical energy sampling data by the data acquisition module respectively after acquiring the tested electrical energy sampling data and the reference electrical energy sampling data, and filtering redundant electrical energy sampling data generated due to different hardware time sequences in the tested electrical energy sampling data and the reference electrical energy sampling data according to a comparison result to ensure the synchronization of the data.
Preferably, the error calculation module further includes:
and the phase shifting unit is used for performing Hilbert phase shifting processing on the sampled data of the detected electrical energy before performing asynchronous measurement processing on the sampled data of the detected electrical energy when the electronic transformer to be detected is of a Rockwell coil structure.
Preferably, the error calculation module performs asynchronous measurement processing on the measured electrical energy sample data and the reference electrical energy sample data respectively by using the following method, and includes:
for input signals
Performing first iterative computation by adopting a complex rectangle product to obtain a first iterative result:
the method for performing iteration for a preset number of times according to the first iteration result to acquire data subjected to asynchronous processing comprises the following steps:
wherein the content of the first and second substances,
the data is obtained after the nth iteration of the periodic signal corresponding to the tested electrical energy sampling data and is subjected to asynchronous measurement processing;
obtaining data which is obtained after the nth iteration of the periodic signal corresponding to the reference electric energy sampling data and is subjected to asynchronous measurement processing;
a weighting factor for the nth iteration; i is a serial number and is started as i0And i ═ i0,…,i0+N；f＝fNS+fΔF is the power frequency, fNSFor sampling the corresponding frequency, fΔFor frequency deviation, M is the number of harmonics, M is the total number of harmonics, AmFor each of the amplitudes of the harmonics,
for each harmonic phase, TNS＝1/fNSFor the sampling time, at [ T ]0,T0+nTNS]Equal interval sampling nN +1 times, T0For the sampling start, N is the period, and N is the sampling point for each period.
Preferably, the error calculation module calculates the error of the electronic transformer to be tested according to the sampled data of the measured electrical energy subjected to the asynchronous measurement processing and the sampled data of the reference electrical energy subjected to the asynchronous measurement processing, and includes:
wherein A ismThe ratio difference of the electronic transformer to be detected is obtained;
to the electron to be measuredAngular difference of the formula transformers;
data is sampled for measured electrical energy that is subject to an unsynchronized measurement process,
and sampling data for the reference electric energy subjected to asynchronous measurement processing.
According to another aspect of the invention, an electronic transformer error measurement method is provided, which includes:
when the upper computer sends a test instruction, sending a pulse per second signal to a merging unit and a data acquisition module of the electronic transformer to be tested;
receiving a network message data frame sent by a merging unit of the electronic transformer to be tested after receiving the pulse per second signal, and analyzing the network message data frame to obtain tested electrical energy sampling data of the electronic transformer to be tested;
acquiring electric energy data of a standard electronic transformer after receiving the pulse per second signal to acquire reference electric energy sampling data;
and respectively carrying out asynchronous measurement processing on the measured electrical energy sampling data and the reference electrical energy sampling data, and calculating the error of the electronic transformer to be measured according to the measured electrical energy sampling data subjected to asynchronous measurement processing and the reference electrical energy sampling data subjected to asynchronous measurement processing.
Preferably, wherein the method further comprises:
the method comprises the steps of obtaining a CPU time stamp when an upper computer sends a test instruction, comparing the CPU time stamp with the time when an online monitoring module obtains tested electrical energy sampling data and the time when a data acquisition module obtains reference electrical energy sampling data after obtaining the tested electrical energy sampling data and the reference electrical energy sampling data, and filtering redundant electrical energy sampling data generated due to different hardware time sequences in the tested electrical energy sampling data and the reference electrical energy sampling data according to a comparison result to ensure synchronization of data.
Preferably, the error calculation module further includes:
when the electronic transformer to be tested is of a Rockwell coil structure, before asynchronous measurement processing is carried out on the sampled data of the tested electrical energy, Hilbert phase shift conversion processing is carried out on the sampled data of the tested electrical energy.
Preferably, the method performs asynchronous measurement processing on the measured electrical energy sample data and the reference electrical energy sample data respectively by using the following method, and includes:
for input signals
Performing first iterative computation by adopting a complex rectangle product to obtain a first iterative result:
the method for performing iteration for a preset number of times according to the first iteration result to acquire data subjected to asynchronous processing comprises the following steps:
wherein the content of the first and second substances,
the data is obtained after the nth iteration of the periodic signal corresponding to the tested electrical energy sampling data and is subjected to asynchronous measurement processing;
obtaining data which is obtained after the nth iteration of the periodic signal corresponding to the reference electric energy sampling data and is subjected to asynchronous measurement processing;
a weighting factor for the nth iteration; i is a serial number and is started as i0And i ═ i0,…,i0+N；f＝fNS+fΔF is the power frequency, fNSFor sampling the corresponding frequency, fΔFor frequency deviation, M is the number of harmonics, M is the total number of harmonics, AmFor each of the amplitudes of the harmonics,
for each harmonic phase, TNS＝1/fNSFor the sampling time, at [ T ]0,T0+nTNS]Equal interval sampling nN +1 times, T0For the sampling start, N is the period, and N is the sampling point for each period.
Preferably, the calculating the error of the electronic transformer to be tested according to the sampled data of the measured electrical energy subjected to the asynchronous measurement processing and the sampled data of the reference electrical energy subjected to the asynchronous measurement processing includes:
wherein A ismThe ratio difference of the electronic transformer to be detected is obtained;
the angular difference of the electronic transformer to be detected is obtained;
for measured electrical energy production by asynchronous measurement processingThe data of the sample is processed by the data processing device,
and sampling data for the reference electric energy subjected to asynchronous measurement processing.
The invention provides an error measuring device and method for an electronic transformer, wherein a digital quantity of a standard electronic transformer after A/D sampling is used as a reference signal; the digital frame sent by the merging unit of the tested electronic transformer of the Ethernet interface is used as a tested signal; synchronizing the two paths of signals by clock second pulse; the two-path synchronous sampling results are sent to the error measuring device for comparison, functions of soft synchronization, Hilbert phase shift, asynchronous measurement and the like are added in the structure of the error measuring device with the general design, so that the accuracy of measurement under a power frequency signal of 50Hz is met, the function of accurately measuring errors when the frequency fluctuates (49.5-50.5 Hz) under interference factors such as electromagnetic environment, temperature, inherent structure and synchronous source influence is achieved, the precision requirement of error data is met, and the method has the advantages of being simple in structure, small in product service life influence, good in economical efficiency and the like.
Drawings
A more complete understanding of exemplary embodiments of the present invention may be had by reference to the following drawings in which:
fig. 1 is a schematic structural diagram of an electronic transformer error measurement apparatus 100 according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of signal synchronization measurement according to an embodiment of the present invention;
FIG. 3 is a schematic diagram of performing an error calculation according to an embodiment of the present invention;
FIG. 4 is an exemplary graph of error measurement using an electronic transformer error measurement device according to an embodiment of the present invention;
FIG. 5 is a schematic diagram of an error measurement apparatus of an electronic transformer according to an embodiment of the present invention;
FIG. 6 is a flowchart illustrating an operation of an error measurement apparatus of an electronic transformer according to an embodiment of the present invention;
fig. 7 is a flowchart of an electronic transformer error measurement method 700 according to an embodiment of the invention.
Detailed Description
The exemplary embodiments of the present invention will now be described with reference to the accompanying drawings, however, the present invention may be embodied in many different forms and is not limited to the embodiments described herein, which are provided for complete and complete disclosure of the present invention and to fully convey the scope of the present invention to those skilled in the art. The terminology used in the exemplary embodiments illustrated in the accompanying drawings is not intended to be limiting of the invention. In the drawings, the same units/elements are denoted by the same reference numerals.
Unless otherwise defined, terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Further, it will be understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense.
Fig. 1 is a schematic structural diagram of an electronic transformer error measurement apparatus 100 according to an embodiment of the present invention. As shown in fig. 1, in the error measuring apparatus for an electronic transformer according to the embodiment of the present invention, a digital value obtained by a standard electronic transformer after a/D sampling is used as a reference signal; the digital frame sent by the merging unit of the tested electronic transformer of the Ethernet interface is used as a tested signal; synchronizing the two paths of signals by clock second pulse; the two-path synchronous sampling results are sent to the error measuring device for comparison, functions of soft synchronization, Hilbert phase shift, asynchronous measurement and the like are added in the structure of the error measuring device with the general design, so that the accuracy of measurement under a power frequency signal of 50Hz is met, the function of accurately measuring errors when the frequency fluctuates (49.5-50.5 Hz) under interference factors such as electromagnetic environment, temperature, inherent structure and synchronous source influence is achieved, the precision requirement of error data is met, and the method has the advantages of being simple in structure, small in product service life influence, good in economical efficiency and the like. The electronic transformer error measuring device 100 provided by the embodiment of the invention comprises: the system comprises a synchronous photoelectric clock source 101, an online monitoring module 102, a data acquisition module 103 and an error calculation module 104.
Preferably, the synchronous photoelectric clock source 101 is configured to send a pulse per second signal to a merging unit and a data acquisition module of the electronic transformer to be tested when the host computer sends the test instruction.
Preferably, the online monitoring module 102 is configured to receive a network message data frame sent by the merging unit of the electronic transformer to be tested after receiving the pulse per second signal, and analyze the network message data frame to obtain the sampled data of the measured electrical energy of the electronic transformer to be tested.
Preferably, the data acquisition module 103 is configured to acquire the electric energy data of the standard electronic transformer after receiving the pulse per second signal, so as to acquire reference electric energy sampling data.
In the embodiment of the invention, when an upper computer sends a request to a measuring device, a synchronous photoelectric clock source sends a clock second pulse signal, a receiving thread of a network message data frame sent by a merging unit of an electronic transformer to be measured is started, the network message data frame sent by the merging unit of the electronic transformer to be measured after receiving the second pulse signal is received by an online monitoring module, and the obtained network message data frame is analyzed by an IEC61850-9-2 protocol to obtain a real-time electric energy sampling value of the electronic transformer to be measured as a measured signal of error measurement; and meanwhile, after the synchronous photoelectric clock source sends out a clock pulse signal, a data acquisition module is started to acquire data of the standard electronic transformer, and a real-time electric energy sampling value of the standard electronic transformer is obtained and is used as a reference signal for error measurement.
Preferably, wherein the apparatus further comprises:
and the soft synchronization module is used for acquiring a CPU (Central processing Unit) timestamp when the upper computer sends a test instruction, comparing the CPU timestamp with the time for acquiring the tested electrical energy sampling data and the time for acquiring the reference electrical energy sampling data by the data acquisition module respectively after acquiring the tested electrical energy sampling data and the reference electrical energy sampling data, and filtering redundant electrical energy sampling data generated due to different hardware time sequences in the tested electrical energy sampling data and the reference electrical energy sampling data according to a comparison result to ensure the synchronization of the data.
In the embodiment of the present invention, the electronic transformer may be a current transformer or a voltage transformer. The error measurement has higher synchronization requirements on the data of the measured signal and the reference signal, and the data acquisition module and the tested transformer merging unit of the device generate certain delay when receiving the synchronous signal of the optical/electrical pulse per second source, so that corresponding calculation errors are caused. Specifically, as shown in fig. 2, when the upper computer sends a test instruction to the device, the soft synchronization module obtains a current 64-bit CPU timestamp, and after the data acquisition module and the merging unit receive a falling edge of a clock synchronization signal (which is a TTL level signal), the data acquisition module starts acquisition and reception of a reference signal and a signal to be tested. In order to ensure the real-time performance of two paths of signals, the characteristic that a counter is set to zero after receiving a synchronization pulse in a merging unit of the electronic transformer is utilized, a soft synchronization module compares a CPU time stamp, and after sampling data generated due to different hardware time sequences before the time stamp is filtered out is sent by an upper computer, synchronous pulse sending and CPU time stamp obtaining are simultaneously executed. And after the device receives the synchronous pulse, the A/D sampling signal and two threads corresponding to the signals for acquiring the merging unit message are synchronously executed. Starting an ADC chip during A/D sampling; and the message acquisition is a message for reading the data analysis of the network port. Therefore, a certain time difference exists between the time when the two signals receive the instruction to start working and the time when the two signals formally start sampling. The time stamp is equivalent to a reference sampling point, and is compared with the 'received data frame time' and the 'sampling start time' in the bank 2, and a certain existing time difference is calculated. For example, the comparison timestamp of the A/D sampling path is-10 ms, and the comparison timestamp of the data frame path is-15 ms, then the data sampled earlier by the A/D sampling path in 5ms is removed, so that the data synchronism is ensured, and the memory overhead is reduced.
Preferably, the error calculation module 104 is configured to perform asynchronous measurement processing on the measured electrical energy sampling data and the reference electrical energy sampling data respectively, and calculate an error of the electronic transformer to be measured according to the measured electrical energy sampling data subjected to the asynchronous measurement processing and the reference electrical energy sampling data subjected to the asynchronous measurement processing.
Preferably, the error calculation module further includes:
and the phase shifting unit is used for performing Hilbert phase shifting processing on the sampled data of the detected electrical energy before performing asynchronous measurement processing on the sampled data of the detected electrical energy when the electronic transformer to be detected is of a Rockwell coil structure.
Preferably, the error calculation module performs asynchronous measurement processing on the measured electrical energy sample data and the reference electrical energy sample data respectively by using the following method, and includes:
for input signals
Performing first iterative computation by adopting a complex rectangle product to obtain a first iterative result:
the method for performing iteration for a preset number of times according to the first iteration result to acquire data subjected to asynchronous processing comprises the following steps:
wherein the content of the first and second substances,
the data is obtained after the nth iteration of the periodic signal corresponding to the tested electrical energy sampling data and is subjected to asynchronous measurement processing;
obtaining data which is obtained after the nth iteration of the periodic signal corresponding to the reference electric energy sampling data and is subjected to asynchronous measurement processing;
a weighting factor for the nth iteration; i is a serial number and is started as i0And i ═ i0,…,i0+N；f＝fNS+fΔF is the power frequency, fNSFor sampling the corresponding frequency, fΔFor frequency deviation, M is the number of harmonics, M is the total number of harmonics, AmFor each of the amplitudes of the harmonics,
for each harmonic phase, TNS＝1/fNSFor the sampling time, at [ T ]0,T0+nTNS]Equal interval sampling nN +1 times, T0For the sampling start, N is the period, and N is the sampling point for each period.
Preferably, the error calculation module calculates the error of the electronic transformer to be tested according to the sampled data of the measured electrical energy subjected to the asynchronous measurement processing and the sampled data of the reference electrical energy subjected to the asynchronous measurement processing, and includes:
wherein A ismThe ratio difference of the electronic transformer to be detected is obtained;
to the electron to be measuredAngular difference of the formula transformers;
data is sampled for measured electrical energy that is subject to an unsynchronized measurement process,
and sampling data for the reference electric energy subjected to asynchronous measurement processing.
FIG. 3 is a schematic diagram of performing error calculations according to an embodiment of the present invention. As shown in fig. 3, the measured signal and the reference signal are sent to an error calculation module, the error calculation module completes the calculation of the error of the measured transformer, and the module mainly comprises a hilbert phase shift processing stage, an asynchronous measurement processing stage and an error calculation stage.
The Hilbert phase shift processing is used for a Rogowski coil structure in an electronic transformer to be measured, a voltage signal in a proportional relation with the differential of primary current is directly output from the secondary side of the transformer of the structure, and an integrator needs to be added on the output side of the transformer. Currently, an active integrator is mostly used, and an operational amplifier for realizing the integrator is easily influenced by temperature, so that errors of measurement results are caused. The present invention therefore contemplates the use of a hilbert transform to implement the function of a digital integrator. If the original signal can be represented as,
the hubert transformed signal is then:
as can be seen from the frequency domain form of the hilbert transform, there is Y (ω) ═ X (ω) H (ω).
Wherein:
describing a hilbert transform of a signal may be accomplished by passing the signal through an all-pass phase shift network that produces a phase shift that lags 90 ° for all positive frequency components of the signal and 90 ° for all negative frequency components, i.e., the hilbert transform may function as a digital integrator that is phase shifted 90 °. Therefore, after the output voltage signal of the Rogowski coil enters the error calculation module to carry out Hilbert phase shift processing, the output signal is effectively restored to the shape of the current to be measured.
It should be noted that the hilbert phase shift processing is only applied to the measured signal, and the measured signal enters into the asynchronous measurement processing stage after the hilbert phase shift processing; the reference signal is directly processed in the asynchronous measurement processing stage without phase shift processing.
In the embodiment of the invention, the sampling value is processed by asynchronous measurement in consideration of the problem that signal errors are caused by external electromagnetic interference, temperature and frequency deviation. Namely, on the basis of synchronous equal-interval sampling, the frequency number of sampling periods is properly increased, and weighted average processing is carried out on the sampling data, so that the problem of spectrum leakage in signal reduction can be effectively solved. The asynchronous measurement has no requirement on the starting point of the first sampling, and the frequency of the measured signal is allowed to change within a certain frequency range, so that an approximate value can be known in advance.
It inputs a signal:
wherein f ═ fNS+fΔ，fNSFor sampling the corresponding frequency, fΔFor frequency deviation, m is the harmonic order. A. themFor each of the amplitudes of the harmonics,
for each harmonic phase, TNS＝1/fNSIs the sampling time. In [ T ]0,T0+nTNS]N +1 times with equal spacing (where T0As the starting point for sampling, N is the period, and N is the sampling point for each period).
Firstly, performing first iterative computation by adopting a complex rectangle product to respectively obtain:
then, starting subsequent iterative computations to obtain:
wherein the content of the first and second substances,
the data is obtained after the nth iteration of the periodic signal corresponding to the tested electrical energy sampling data and is subjected to asynchronous measurement processing;
obtaining data which is obtained after the nth iteration of the periodic signal corresponding to the reference electric energy sampling data and is subjected to asynchronous measurement processing;
the weighting coefficient i of the nth iteration is a serial number and is initially i0And i ═ i0,…,i0+ N; generally, better results can be obtained by iterating more than 4 times in actual work, and the measurement speed of the device is influenced by too many iteration times.
Due to asynchronous algorithm to synchronous sampling deviation fΔThe method is sensitive, and the accuracy of the asynchronous algorithm is higher when the synchronous deviation is smaller. Therefore, when using asynchronous algorithms: f. ofNS＞＞|fΔL, actual deviation f of the gridΔIf the asynchronous requirement is satisfied, f is generallyΔ/fNS< 0.01, not satisfyingThe limitation of this condition leads to a significant increase in the error of the higher harmonics. In actual work, fNS is power frequency 50Hz, and the allowable fluctuation frequency range (49.5-50.5 Hz) of the power grid meets the requirement of asynchronous measurement.
In the embodiment of the invention, after the two-path signal processing is processed by asynchronous measurement, the error calculation stage is entered. And (3) calculating the ratio difference and the angular difference by applying a DFT definition formula to obtain final error data, wherein the method comprises the following steps:
wherein A ismThe ratio difference of the electronic transformer to be detected is obtained;
the angular difference of the electronic transformer to be detected is obtained;
data is sampled for measured electrical energy that is subject to an unsynchronized measurement process,
and sampling data for the reference electric energy subjected to asynchronous measurement processing.
In the embodiment of the invention, the online monitoring module has the functions of voltage monitoring and message analysis, and adopts the IEC61850-9-2 protocol to analyze the data frames sent by the merging unit of the electronic transformer to be tested and simultaneously display the messages, so that the transmission performance state of the electronic transformer can be monitored online in real time.
Fig. 4 is an exemplary diagram of measuring an error using an error measuring apparatus of an electronic transformer according to an embodiment of the present invention. As shown in fig. 4, taking a current transformer as an example, 1 is a standard current transformer, 2 is an electronic current transformer to be measured, 3 is a merging unit, and 4 is an electronic transformer error measuring device.
The digital quantity of the secondary analog signal of the standard current transformer after A/D sampling is used as a reference signal; the digital frame sent by the merging unit of the tested electronic transformer of the Ethernet interface is used as a tested signal; the clock second pulse synchronizes the two signals. And sending the two paths of synchronous sampling results into an error measuring device for comparison, and calculating the ratio and the phase angle error of the electronic current transformer to be measured.
Fig. 5 is a measurement schematic diagram of an error measurement apparatus of an electronic transformer according to an embodiment of the invention. As shown in fig. 5, 5 is a synchronous photoelectric clock source, 6 is a data acquisition module, 7 is a soft synchronization module, 8 is an online monitoring module, and 9 is an error calculation module (including three parts, hilbert phase shift, asynchronous measurement and error calculation).
As shown in fig. 4, 5, and 6, the embodiment of the present invention adds an anti-interference function to the existing electronic transformer error measurement, and can be used in a digital substation, which is affected by various factors (electromagnetic environment, temperature, inherent structure, and synchronous source) and has a prominent error measurement problem, to measure the bus voltage and the line voltage and realize real-time monitoring of the grid voltage. When the error measuring device initiates a measurement request, the soft synchronization module 7 acquires a current 64-bit CPU timestamp, and the synchronous optical/electrical clock source 5 sends a pulse-per-second signal to the electronic transformer merging unit 3 and the acquisition module 6. The merging unit 3 receives the sync pulse and sends the message data to the device while setting its own internal counter to zero, which is the received data frame time T1. The online monitoring module analyzes the network message data frame sent by the merging unit through an IEC61850-9-2 protocol to obtain a real-time voltage/current sampling value of the tested mutual inductor as a tested signal for error measurement, and can simultaneously display a message and perform online monitoring on the transmission performance state of the electronic mutual inductor in real time. And the data acquisition module 6 starts to acquire data of the standard transformer after receiving the synchronous pulse, wherein the sampling time is T2, and the real-time voltage/current sampling value of the standard transformer is obtained and used as a reference signal for error measurement. The soft synchronization module 7 compares the CPU time stamps, and filters out the sampling data generated before the T1 and T2 time stamps due to different hardware time sequences, thereby effectively ensuring data synchronization and reducing memory overhead. The measured signal and the reference signal after the soft synchronization processing are sent to an error calculation module 9 for processing, and the calculation of the ratio and the phase angle error of the measured electronic transformer is completed. The error calculation module mainly comprises a Hilbert (Hilbert) phase shift, asynchronous measurement and error calculation. When the electronic transformer to be measured is a Rogowski coil structure, a measured signal is subjected to digital integration through Hilbert (Hilbert) phase shift in the error calculation module 9 and then sent to the asynchronous measurement module 8. When the electronic transformer to be measured is of other structure, the measured signal is directly sent to the asynchronous measurement module 8. The reference signal is fed directly to the unsynchronised measurement module 8. The two paths of signals are processed by asynchronous measurement and then sent to an error calculation module 9 for calculation of the ratio difference and the angular difference, and final error data are obtained and transmitted to an upper computer through an Ethernet interface for display and storage.
Fig. 7 is a flowchart of an electronic transformer error measurement method 700 according to an embodiment of the invention. The method 700 for measuring the error of the electronic transformer starts from step 701, and sends a pulse per second signal to a merging unit and a data acquisition module of the electronic transformer to be measured when the upper computer sends a test instruction in step 701.
In step 702, a network message data frame sent by the merging unit of the electronic transformer to be tested after receiving the pulse per second signal is received, and the network message data frame is analyzed to obtain the tested electrical energy sampling data of the electronic transformer to be tested.
In step 703, after receiving the pulse per second signal, acquiring power data of a standard electronic transformer to obtain reference power sampling data.
Preferably, wherein the method further comprises:
the method comprises the steps of obtaining a CPU time stamp when an upper computer sends a test instruction, comparing the CPU time stamp with the time when an online monitoring module obtains tested electrical energy sampling data and the time when a data acquisition module obtains reference electrical energy sampling data after obtaining the tested electrical energy sampling data and the reference electrical energy sampling data, and filtering redundant electrical energy sampling data generated due to different hardware time sequences in the tested electrical energy sampling data and the reference electrical energy sampling data according to a comparison result to ensure synchronization of data.
In step 704, the measured electrical energy sampling data and the reference electrical energy sampling data are subjected to asynchronous measurement processing, and the error of the electronic transformer to be measured is calculated according to the measured electrical energy sampling data subjected to asynchronous measurement processing and the reference electrical energy sampling data subjected to asynchronous measurement processing.
Preferably, the error calculation module further includes:
when the electronic transformer to be tested is of a Rockwell coil structure, before asynchronous measurement processing is carried out on the sampled data of the tested electrical energy, Hilbert phase shift conversion processing is carried out on the sampled data of the tested electrical energy.
Preferably, the method performs asynchronous measurement processing on the measured electrical energy sample data and the reference electrical energy sample data respectively by using the following method, and includes:
for input signals
Performing first iterative computation by adopting a complex rectangle product to obtain a first iterative result:
the method for performing iteration for a preset number of times according to the first iteration result to acquire data subjected to asynchronous processing comprises the following steps:
wherein the content of the first and second substances,
the data is obtained after the nth iteration of the periodic signal corresponding to the tested electrical energy sampling data and is subjected to asynchronous measurement processing;
obtaining data which is obtained after the nth iteration of the periodic signal corresponding to the reference electric energy sampling data and is subjected to asynchronous measurement processing;
a weighting factor for the nth iteration; i is a serial number and is started as i0And i ═ i0,…,i0+N；f＝fNS+fΔF is the power frequency, fNSFor sampling the corresponding frequency, fΔFor frequency deviation, M is the number of harmonics, M is the total number of harmonics, AmFor each of the amplitudes of the harmonics,
for each harmonic phase, TNS＝1/fNSFor the sampling time, at [ T ]0,T0+nTNS]Equal interval sampling nN +1 times, T0For the sampling start, N is the period, and N is the sampling point for each period.
Preferably, the calculating the error of the electronic transformer to be tested according to the sampled data of the measured electrical energy subjected to the asynchronous measurement processing and the sampled data of the reference electrical energy subjected to the asynchronous measurement processing includes:
wherein A ismThe ratio difference of the electronic transformer to be detected is obtained;
the angular difference of the electronic transformer to be detected is obtained;
data is sampled for measured electrical energy that is subject to an unsynchronized measurement process,
and sampling data for the reference electric energy subjected to asynchronous measurement processing.
The electronic transformer error measurement method 700 according to the embodiment of the present invention corresponds to the electronic transformer error measurement apparatus 100 according to another embodiment of the present invention, and is not described herein again.
The invention has been described with reference to a few embodiments. However, other embodiments of the invention than the one disclosed above are equally possible within the scope of the invention, as would be apparent to a person skilled in the art from the appended patent claims.
Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise herein. All references to "a/an/the [ device, component, etc ]" are to be interpreted openly as referring to at least one instance of said device, component, etc., unless explicitly stated otherwise. The steps of any method disclosed herein do not have to be performed in the exact order disclosed, unless explicitly stated.
As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.
The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
Finally, it should be noted that: the above embodiments are only for illustrating the technical solutions of the present invention and not for limiting the same, and although the present invention is described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: modifications and equivalents may be made to the embodiments of the invention without departing from the spirit and scope of the invention, which is to be covered by the claims.
Claims (10)
1. An electronic transformer error measurement device, the device comprising:
the synchronous photoelectric clock source is used for sending a pulse per second signal to a merging unit and a data acquisition module of the electronic transformer to be tested when the upper computer sends a test instruction;
the online monitoring module is used for receiving a network message data frame sent by the merging unit of the electronic transformer to be tested after receiving the pulse per second signal, and analyzing the network message data frame to obtain tested electrical energy sampling data of the electronic transformer to be tested;
the data acquisition module is used for acquiring the electric energy data of the standard electronic transformer after receiving the pulse per second signal so as to acquire reference electric energy sampling data;
and the error calculation module is used for respectively performing asynchronous measurement processing on the measured electrical energy sampling data and the reference electrical energy sampling data, and calculating the error of the electronic transformer to be measured according to the measured electrical energy sampling data subjected to the asynchronous measurement processing and the reference electrical energy sampling data subjected to the asynchronous measurement processing.
2. The apparatus of claim 1, further comprising:
and the soft synchronization module is used for acquiring a CPU (Central processing Unit) timestamp when the upper computer sends a test instruction, comparing the CPU timestamp with the time for acquiring the tested electrical energy sampling data and the time for acquiring the reference electrical energy sampling data by the data acquisition module respectively after acquiring the tested electrical energy sampling data and the reference electrical energy sampling data, and filtering redundant electrical energy sampling data generated due to different hardware time sequences in the tested electrical energy sampling data and the reference electrical energy sampling data according to a comparison result to ensure the synchronization of the data.
3. The apparatus of claim 1, wherein the error calculation module further comprises:
and the phase shifting unit is used for performing Hilbert phase shifting processing on the sampled data of the detected electrical energy before performing asynchronous measurement processing on the sampled data of the detected electrical energy when the electronic transformer to be detected is of a Rockwell coil structure.
4. The apparatus of claim 1, wherein the error calculation module performs asynchronous measurement processing on the measured electrical energy sample data and the reference electrical energy sample data by performing asynchronous measurement processing on the measured electrical energy sample data and the reference electrical energy sample data respectively in the following manner, comprising:
for input signals
Performing first iterative computation by adopting a complex rectangle product to obtain a first iterative result:
the method for performing iteration for a preset number of times according to the first iteration result to acquire data subjected to asynchronous processing comprises the following steps:
wherein the content of the first and second substances,
the data is obtained after the nth iteration of the periodic signal corresponding to the tested electrical energy sampling data and is subjected to asynchronous measurement processing;
obtaining data which is obtained after the nth iteration of the periodic signal corresponding to the reference electric energy sampling data and is subjected to asynchronous measurement processing;
a weighting factor for the nth iteration; i is a serial number and is started as i0And i ═ i0,…,i0+N；f＝fNS+fΔF is the power frequency, fNSFor sampling the corresponding frequency, fΔFor frequency deviation, M is the number of harmonics, M is the total number of harmonics, AmFor each of the amplitudes of the harmonics,
for each harmonic phase, TNS＝1/fNSFor the sampling time, at [ T ]0,T0+nTNS]Equal interval sampling nN +1 times, T0For the sampling start, N is the period, and N is the sampling point for each period.
5. The apparatus of claim 1, wherein the error calculation module calculates the error of the electronic transformer to be tested according to the sampled measured electrical energy data subjected to the asynchronous measurement processing and the sampled reference electrical energy data subjected to the asynchronous measurement processing, and includes:
wherein A ismThe ratio difference of the electronic transformer to be detected is obtained;
the angular difference of the electronic transformer to be detected is obtained;
data is sampled for measured electrical energy that is subject to an unsynchronized measurement process,
and sampling data for the reference electric energy subjected to asynchronous measurement processing.
6. An electronic transformer error measurement method, characterized in that the method comprises:
when the upper computer sends a test instruction, sending a pulse per second signal to a merging unit and a data acquisition module of the electronic transformer to be tested;
receiving a network message data frame sent by a merging unit of the electronic transformer to be tested after receiving the pulse per second signal, and analyzing the network message data frame to obtain tested electrical energy sampling data of the electronic transformer to be tested;
acquiring electric energy data of a standard electronic transformer after receiving the pulse per second signal to acquire reference electric energy sampling data;
and respectively carrying out asynchronous measurement processing on the measured electrical energy sampling data and the reference electrical energy sampling data, and calculating the error of the electronic transformer to be measured according to the measured electrical energy sampling data subjected to asynchronous measurement processing and the reference electrical energy sampling data subjected to asynchronous measurement processing.
7. The method of claim 6, further comprising:
the method comprises the steps of obtaining a CPU time stamp when an upper computer sends a test instruction, comparing the CPU time stamp with the time when an online monitoring module obtains tested electrical energy sampling data and the time when a data acquisition module obtains reference electrical energy sampling data after obtaining the tested electrical energy sampling data and the reference electrical energy sampling data, and filtering redundant electrical energy sampling data generated due to different hardware time sequences in the tested electrical energy sampling data and the reference electrical energy sampling data according to a comparison result to ensure synchronization of data.
8. The method of claim 6, wherein the error calculation module further comprises:
when the electronic transformer to be tested is of a Rockwell coil structure, before asynchronous measurement processing is carried out on the sampled data of the tested electrical energy, Hilbert phase shift conversion processing is carried out on the sampled data of the tested electrical energy.
9. The method of claim 6, wherein the method performs asynchronous measurement processing on the measured electrical energy sample data and the reference electrical energy sample data respectively by using the following method, comprising:
for input signals
Performing first iterative computation by adopting a complex rectangle product to obtain a first iterative result:
the method for performing iteration for a preset number of times according to the first iteration result to acquire data subjected to asynchronous processing comprises the following steps:
wherein the content of the first and second substances,
the data is obtained after the nth iteration of the periodic signal corresponding to the tested electrical energy sampling data and is subjected to asynchronous measurement processing;
obtaining data which is obtained after the nth iteration of the periodic signal corresponding to the reference electric energy sampling data and is subjected to asynchronous measurement processing; etai nA weighting factor for the nth iteration; i is a serial number and is started as i0And i ═ i0,…,i0+N；f＝fNS+fΔF is the power frequency, fNSFor sampling the corresponding frequency, fΔFor frequency deviation, M is the number of harmonics, M is the total number of harmonics, AmFor each of the amplitudes of the harmonics,
for each harmonic phase, TNS＝1/fNSFor the sampling time, at [ T ]0,T0+nTNS]Equal interval sampling nN +1 times, T0For the sampling start, N is the period, and N is the sampling point for each period.
10. The method according to claim 6, wherein the calculating the error of the electronic transformer under test according to the measured electric energy sampling data subjected to the asynchronous measurement processing and the reference electric energy sampling data subjected to the asynchronous measurement processing comprises:
wherein A ismThe ratio difference of the electronic transformer to be detected is obtained;
the angular difference of the electronic transformer to be detected is obtained;
data is sampled for measured electrical energy that is subject to an unsynchronized measurement process,
and sampling data for the reference electric energy subjected to asynchronous measurement processing.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010870712.4A CN112068061A (en) | 2020-08-26 | 2020-08-26 | Electronic transformer error measuring device and method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010870712.4A CN112068061A (en) | 2020-08-26 | 2020-08-26 | Electronic transformer error measuring device and method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN112068061A true CN112068061A (en) | 2020-12-11 |
Family
ID=73660213
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010870712.4A Pending CN112068061A (en) | 2020-08-26 | 2020-08-26 | Electronic transformer error measuring device and method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112068061A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114002639A (en) * | 2021-10-19 | 2022-02-01 | 华中科技大学 | Relative error self-monitoring system and method of electric signal acquisition circuit |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102928803A (en) * | 2012-10-18 | 2013-02-13 | 中国电力科学研究院 | Electronic transformer checking device based on synchronization pulse output power supply |
| CN103278791A (en) * | 2013-05-10 | 2013-09-04 | 国家电网公司 | Electronic transformer amplitude and phase error checking system with networked detection function |
| CN103760468A (en) * | 2014-02-18 | 2014-04-30 | 国家电网公司 | Double-circuit line non-synchronous sampling double-end fault distance detection method based on jacobian matrix |
| CN104076319A (en) * | 2014-05-04 | 2014-10-01 | 贵州电力试验研究院 | Online error analysis system of digitized electric energy metering device |
| CN106383330A (en) * | 2016-10-08 | 2017-02-08 | 清华大学 | Digital electric energy metering algorithm test platform |
| CN108051850A (en) * | 2017-12-07 | 2018-05-18 | 合肥国为电子有限公司 | A kind of untethered memory-type seismic detector collecting method |
| CN108132455A (en) * | 2017-12-19 | 2018-06-08 | 国网重庆市电力公司电力科学研究院 | Global error check system based on combining unit |
| CN110958071A (en) * | 2019-10-30 | 2020-04-03 | 中国电力科学研究院有限公司 | Electronic transformer clock error self-calibration system and method based on 4G module |
| CN111562537A (en) * | 2020-04-21 | 2020-08-21 | 北京化工大学 | Synchronous measurement method for dynamic errors of electric energy meter |
-
2020
- 2020-08-26 CN CN202010870712.4A patent/CN112068061A/en active Pending
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102928803A (en) * | 2012-10-18 | 2013-02-13 | 中国电力科学研究院 | Electronic transformer checking device based on synchronization pulse output power supply |
| CN103278791A (en) * | 2013-05-10 | 2013-09-04 | 国家电网公司 | Electronic transformer amplitude and phase error checking system with networked detection function |
| CN103760468A (en) * | 2014-02-18 | 2014-04-30 | 国家电网公司 | Double-circuit line non-synchronous sampling double-end fault distance detection method based on jacobian matrix |
| CN104076319A (en) * | 2014-05-04 | 2014-10-01 | 贵州电力试验研究院 | Online error analysis system of digitized electric energy metering device |
| CN106383330A (en) * | 2016-10-08 | 2017-02-08 | 清华大学 | Digital electric energy metering algorithm test platform |
| CN108051850A (en) * | 2017-12-07 | 2018-05-18 | 合肥国为电子有限公司 | A kind of untethered memory-type seismic detector collecting method |
| CN108132455A (en) * | 2017-12-19 | 2018-06-08 | 国网重庆市电力公司电力科学研究院 | Global error check system based on combining unit |
| CN110958071A (en) * | 2019-10-30 | 2020-04-03 | 中国电力科学研究院有限公司 | Electronic transformer clock error self-calibration system and method based on 4G module |
| CN111562537A (en) * | 2020-04-21 | 2020-08-21 | 北京化工大学 | Synchronous measurement method for dynamic errors of electric energy meter |
Non-Patent Citations (2)
| Title |
|---|
| 刘彬等: "基于Rogowski线圈的电子式电流互感器复合误差计算方法", 《高电压技术》 * |
| 毛安澜等: "适用高寒地区电子式互感器校准系统的研究与实现", 《高压电器》 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114002639A (en) * | 2021-10-19 | 2022-02-01 | 华中科技大学 | Relative error self-monitoring system and method of electric signal acquisition circuit |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102012494B (en) | Transformer calibrator and calibration method thereof | |
| CN101807795B (en) | Method for forming electric energy metering simulation system and device thereof | |
| Liu et al. | The evaluation of phasor measurement units and their dynamic behavior analysis | |
| CN102928803B (en) | Electronic transformer checking device based on synchronization pulse output power supply | |
| CN108845281B (en) | Online comparison detection method for power quality monitoring device | |
| CN110967658B (en) | Analog input merging unit calibrator tracing method based on digital differential method | |
| CN112731242A (en) | Calibration method of on-site calibrator of online power quality monitoring device | |
| CN202939299U (en) | Electronic transformer calibration device based on synchronous pulse output power supply | |
| CN113625215B (en) | Voltage transformer abnormity calibration method and device based on sectional test | |
| CN114252695A (en) | Integral calibration method and system for electric energy metering device | |
| CN112068061A (en) | Electronic transformer error measuring device and method | |
| Castello et al. | Measurement of synchrophasors with stand alone merging units: A preliminary study | |
| CN114200381A (en) | System and method for detecting reliability of intelligent electric meter | |
| CN210347905U (en) | System for be used for carrying out whole system of examining to direct current transformer check gauge | |
| CN204287355U (en) | The specified time-delay detection system of Intelligent substation merging unit | |
| CN109856583B (en) | Measuring device and method for transmission delay of electronic current transformer | |
| CN110703180A (en) | Multi-mode intelligent substation simulation system and method | |
| CN106932746B (en) | Electronic current transformer performance test system and method | |
| Cheng et al. | System for calibrating analogue merging units in absence of synchronization signals | |
| CN112213541B (en) | Time keeping method applied to transient recording type fault indicator | |
| CN115078803A (en) | Distributed radio parameter sampling system and method | |
| Guo et al. | Research on online detection method of power quality monitoring device and system design | |
| CN103616580B (en) | Merge cells data conversion angular difference method of testing | |
| KR101777038B1 (en) | Protection relay device | |
| CN113884966A (en) | Alternating current-direct current sensor broadband calibrator and performance detection calibration method thereof |
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 | ||
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20201211 |