CN108594155B - Supersaturation characteristic parameter measurement system and method for current transformer of electric energy meter - Google Patents
Supersaturation characteristic parameter measurement system and method for current transformer of electric energy meter Download PDFInfo
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- 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
Abstract
The invention discloses a supersaturation characteristic parameter measurement system and method of a current transformer of an electric energy meter, comprising a critical saturation current measurement unit and a supersaturation characteristic processing unit, wherein the critical saturation current measurement unit comprises a current source, an adjustable resistor and a critical saturation current measurement circuit, the current source is respectively connected with a signal input end and the adjustable resistor of the critical saturation current measurement circuit through the measured current transformer, the current source is also directly connected with the critical saturation current measurement circuit, the adjustable resistor is also connected with an adjusting output end of the critical saturation current measurement circuit, and the saturation characteristic processing unit comprises an MCU processor, a display screen and an RS232 communication circuit. According to the invention, the critical saturation current of the current transformer under the nominal secondary load is measured, the saturation characteristic parameter of the current transformer of the electric energy meter is calculated, and the current transformer is displayed and outputted in a communication way, so that the current transformer is the basis for the design of the electric energy meter for resisting short-time overcurrent impact, and has a good application prospect.
Description
Technical Field
The invention relates to a supersaturation characteristic parameter measurement system and method for a current transformer of an electric energy meter, and belongs to the technical field of electronic measurement.
Background
The electric energy meter is used as high-precision metering equipment, short-time overcurrent impact which is more than 20 times of nominal maximum current is required to be born in field operation, the design of short-time overcurrent impact resistance is related to the metering reliability of the electric energy meter, and various alternative current transformers are required to be obtained in the design of the electric energy meter under different load conditions, and secondary output parameters of the current transformers are required to be obtained when the short-time overcurrent impact is generated.
At present, the common processing mode is to verify the short-time overcurrent resistance of the electric energy meter through an overcurrent experiment, and the disadvantage is that after the design is verified, if the design parameters are changed, repeated testing is needed, and the time and the labor are wasted; moreover, the test needs a short-time overcurrent which can accurately output more than 20 times of the nominal maximum current, the output current is large, the secondary device of the current transformer has the risk of burning and cracking, the measuring difficulty is high, and the safety is low; finally, since the primary current and the secondary current are not linear in the short-time overcurrent, the maximum bearable current intensity of the electric energy meter sampling circuit needs to be found through repeated tests in derating design, which is very inconvenient.
How to overcome the problems is to test the short-time overcurrent impact resistance of the electric energy meter, and the problem needs to be solved currently.
Disclosure of Invention
The invention aims to overcome the problems in the prior art that the short-time overcurrent resistance of the electric energy meter is verified through an overcurrent experiment. According to the system and the method for measuring the supersaturation characteristic parameters of the current transformer of the electric energy meter, the critical saturation current of the current transformer under the nominal secondary load is measured, the saturation characteristic parameters of the current transformer of the electric energy meter are calculated according to the supersaturation characteristics of the current transformer of the electric energy meter, and the short-time overcurrent impact resistance performance test of the electric energy meter is completed through display and communication output.
In order to achieve the above purpose, the technical scheme adopted by the invention is as follows:
the supersaturation characteristic parameter measurement system of the current transformer of the electric energy meter comprises a critical saturation current measurement unit and a supersaturation characteristic processing unit,
the critical saturated current measuring unit comprises a current source, an adjustable resistor and a critical saturated current measuring circuit, wherein the current source is respectively connected with a signal input end and the adjustable resistor of the critical saturated current measuring circuit through a measured current transformer, the current source is also directly connected with the critical saturated current measuring circuit, the adjustable resistor is also connected with an adjusting output end of the critical saturated current measuring circuit, an interface end of the critical saturated current measuring unit is connected with an interface end of the supersaturation characteristic processing unit,
the saturation characteristic processing unit comprises an MCU processor, a display screen and an RS232 communication circuit, wherein the MCU processor is used as an interface end of the saturation characteristic processing unit and is connected with an interface end of the critical saturation current measuring unit, the MCU processor is also respectively connected with the display screen and the RS232 communication circuit, and the RS232 communication circuit is connected with the test terminal.
According to the supersaturation characteristic parameter measurement system for the current transformer of the electric energy meter, the current source is a current source for outputting low-noise power frequency sine wave current signals.
According to the supersaturation characteristic parameter measurement system for the current transformer of the electric energy meter, the critical saturation current measurement circuit is an AD sampling circuit, a 24-bit AD sampling chip is arranged in the critical saturation current measurement circuit, and the model of the 24-bit AD sampling chip is an ADS1210 sampling chip.
According to the supersaturation characteristic parameter measurement system for the current transformer of the electric energy meter, the critical saturation current measurement unit and the supersaturation characteristic processing unit are connected through the SPI communication bus.
According to the supersaturation characteristic parameter measurement system for the current transformer of the electric energy meter, the resistance value of the adjustable resistor is adjustable, the nominal resistor is formed, and the adjustable resistor ranges from 5 ohms to 1 Kohm.
The measuring method of the supersaturation characteristic parameter measuring system of the current transformer of the electric energy meter comprises the following steps,
step (A), a test starting command and test parameters are sent through a test terminal, and a supersaturation characteristic processing unit controls a critical saturation current measuring unit to start current transformer supersaturation characteristic parameter measurement according to the received starting command and test parameters;
step (B), the resistance value of the adjustable resistor is adjusted to a set value, a nominal resistor is formed, a current source is started, the current source outputs current to a tested current transformer, the current source output current increases linearly from zero along with time, and the current source output current increases gradually to a maximum output value;
step (C), the supersaturation characteristic processing circuit continuously tests to obtain a zero crossing point of a secondary current signal output by the tested current transformer, and judges whether saturation occurs in the zero crossing point; if saturation occurs, recording the peak value of the secondary current signal, stopping the current output of the current source, and executing the step (D); if the peak value of the current signal is smaller than or equal to the peak value of the previous period and saturation does not occur, stopping the current output of the current source, increasing the set value of the adjustable resistor, and executing the step (B); if the current signal peak value is larger than the peak value of the previous period and saturation does not occur, executing the step (C);
the MCU processor receives a current signal when the current source stops outputting current and is positioned at saturation, and calculates to obtain saturation characteristic parameters of the current transformer of the electric energy meter according to the supersaturation characteristic of the current transformer of the electric energy meter;
and (E) displaying the saturation characteristic parameters of the current transformer of the electric energy meter obtained through calculation through a display screen, and transmitting the saturation characteristic parameters to a test terminal.
According to the measuring method of the supersaturation characteristic parameter measuring system of the current transformer of the electric energy meter, the step (C) is to judge whether the zero crossing point is saturated or not, wherein the judgment is realized by detecting whether the waveform of a current signal crosses zero in advance or not according to the fact that when the magnetic core of the current transformer is saturated, the output current of the current transformer is reduced to zero, and if so, the current transformer is saturated.
The measuring method of the supersaturation characteristic parameter measuring system of the current transformer of the electric energy meter comprises the step (D) of approximating the pure resistance characteristic of the secondary load according to the supersaturation characteristic of the current transformer of the electric energy meter.
The measuring method of the supersaturation characteristic parameter measuring system of the current transformer of the electric energy meter comprises the following steps of (D) calculating to obtain the saturation characteristic parameter of the current transformer of the electric energy meter,
(D1) Because the secondary load of the current transformer of the electric energy meter is approximately pure resistance, the secondary current is in direct proportion to the induced electromotive force, and the magnetic flux phi of the current transformer is the integral of the secondary current, as shown in the following formula:
φ＝(1/N 2 )∫e 2 dt＝(R/N 2 )∫I 2 dt
wherein N is 2 Is of secondary turns, e 2 Is induced electromotive force, R is secondary impedance,I 2 Is the secondary current;
(D2) When the phase is fixedly integrated from 0 degrees to 180 degrees, the obtained magnetic flux of the current transformer is saturated magnetic flux phi max, and the current transformer is in a critical saturated state, wherein the magnetic flux is represented by the following formula:
wherein, the time between zero crossing points of the output of the primary current and the secondary current is shortened when the current source increases the primary current, the primary current is critical saturated current and the effective value is I 1pumn Peak value I of corresponding secondary current 2pun ；
(D3) Because the saturation magnetic flux phi max of the current transformer is not variable, the secondary impedance R and I are under critical saturation 2pun Inversely proportional, when the secondary impedance is adjusted from R to Rde, the corresponding secondary current peak I under critical saturation 2pu The following formula is shown:
I 2pu ＝R/R de *I 2pun
(D4) The short-time overcurrent effective value to be met by the electric energy meter is I 1maxm Peak value is I 1max Based on the characteristic that the saturation magnetic flux is not variable, the phase x at saturation is obtained as shown in the following formula:
；
wherein x is the phase at saturation, representing when the primary current is I 1max The magnetic core is saturated when the phase is x or 180+x, and the secondary current output is zero;
(D5) And calculating the effective value, the peak value, the effective value in the unsaturated period and the unsaturated time of the secondary current according to the phase x in the saturated state, wherein the effective value, the peak value, the effective value in the unsaturated period and the unsaturated time are shown in the following formula:
peak value I of secondary current 2m Is that
I 2m ＝I 1max /N 2 sinx；
Effective value I of secondary current 2 Is that
；
Effective value I of secondary current in unsaturated period 2 ' as
；
The unsaturated time t of the secondary current is
t＝ω/x。
The beneficial effects of the invention are as follows: according to the system and the method for measuring the supersaturation characteristic parameters of the current transformer of the electric energy meter, the critical saturation current of the current transformer under the nominal secondary load is measured, the saturation characteristic parameters of the current transformer of the electric energy meter are calculated according to the supersaturation characteristics of the current transformer of the electric energy meter, and the saturation characteristic parameters are displayed and output in a communication mode and are the basis of the design of the electric energy meter for resisting short-time overcurrent impact, so that the test of the short-time overcurrent impact resistance of the electric energy meter is realized, the test is convenient, the cost is low, the safety performance is high, and the application prospect is good.
Drawings
FIG. 1 is a system block diagram of a system for measuring supersaturation characteristic parameters of a current transformer of an electric energy meter according to the present invention;
FIG. 2 is a flow chart of a method for measuring supersaturation characteristic parameters of a current transformer of an electric energy meter according to the present invention;
fig. 3 is a schematic diagram of the current transformer of the present invention with its output current dropping to zero at saturation.
Detailed Description
The invention will be further described with reference to the drawings. The following examples are only for more clearly illustrating the technical aspects of the present invention, and are not intended to limit the scope of the present invention.
As shown in fig. 1, the supersaturation characteristic parameter measurement system of the current transformer of the electric energy meter comprises a critical saturation current measurement unit and a supersaturation characteristic processing unit,
the critical saturated current measuring unit comprises a current source, an adjustable resistor and a critical saturated current measuring circuit, wherein the current source is respectively connected with a signal input end and the adjustable resistor of the critical saturated current measuring circuit through a measured current transformer, the current source is also directly connected with the critical saturated current measuring circuit, the adjustable resistor is also connected with an adjusting output end of the critical saturated current measuring circuit, an interface end of the critical saturated current measuring unit is connected with an interface end of the supersaturation characteristic processing unit,
the saturation characteristic processing unit comprises an MCU processor, a display screen and an RS232 communication circuit, wherein the MCU processor is used as an interface end of the saturation characteristic processing unit and is connected with an interface end of the critical saturation current measuring unit, the MCU processor is also respectively connected with the display screen and the RS232 communication circuit, and the RS232 communication circuit is connected with the test terminal.
Preferably, the current source is a current source outputting a low-noise power frequency sine wave current signal, the low-noise power frequency sine wave current signal starts to be output after the current source receives the starting signal, the output current signal gradually increases along with time, and the output current signal drops to zero after receiving the stopping signal.
Preferably, the critical saturation current measuring circuit is an AD sampling circuit, a 24-bit AD sampling chip is built in, the model of the 24-bit AD sampling chip is an ADS1210 sampling chip, and the 24-bit AD sampling chip is used for measuring voltage signals at two ends of the adjustable resistor and converting the voltage signals into a current value of a secondary output of the measured current transformer. And detecting the zero crossing point interval time of the measurement signal, and when the interval time between the zero crossing points of the detection signal is shortened, considering that the saturation phenomenon occurs in the current transformer to be measured, recording the peak value of the signal to be measured and outputting the peak value.
Preferably, the critical saturation current measuring unit and the supersaturation characteristic processing unit are connected through an SPI communication bus, so that the communication speed is high and the reliability is high.
Preferably, the resistance value of the adjustable resistor is adjustable, the nominal resistor is formed, and the adjustable resistor ranges from 5 ohms to 1 Kohm.
According to the supersaturation characteristic parameter measurement system of the current transformer of the electric energy meter, the supersaturation characteristic parameter measurement method of the current transformer of the electric energy meter, as shown in figure 2, comprises the following steps,
step (A), a test starting command and test parameters are sent through a test terminal, and a supersaturation characteristic processing unit controls a critical saturation current measuring unit to start current transformer supersaturation characteristic parameter measurement according to the received starting command and test parameters;
step (B), the resistance value of the adjustable resistor is adjusted to a set value to form a nominal resistor, a current source is started, the current source outputs current to a tested current transformer, the current source output current increases linearly from zero along with time, and the current source output current increases gradually to a maximum output value;
step (C), the supersaturation characteristic processing circuit continuously tests to obtain a zero crossing point of a secondary current signal output by the tested current transformer, and judges whether saturation occurs in the zero crossing point; if saturation occurs, recording the peak value of the secondary current signal, stopping the current output of the current source, and executing the step (D); if the peak value of the current signal is smaller than or equal to the peak value of the previous period and saturation does not occur, stopping the current output of the current source, increasing the set value of the adjustable resistor, and executing the step (B); if the current signal peak value is larger than the peak value of the previous period and saturation does not occur, executing the step (C);
the judgment of whether the zero crossing point is saturated is realized according to the fact that when the magnetic core of the current transformer is saturated, the output current of the current transformer is reduced to zero, as shown in fig. 3, the reduction process is rapid and the time is extremely short, whether the waveform of a current signal crosses zero in advance is detected, and if the waveform crosses zero in advance, the current transformer is saturated;
step (D), the MCU processor receives a current signal when the current source stops outputting current and is positioned at saturation, and calculates and obtains a saturation characteristic parameter of the current transformer of the electric energy meter according to the supersaturation characteristic of the current transformer of the electric energy meter, wherein the supersaturation characteristic of the current transformer of the electric energy meter is the characteristic of approximate pure resistance of a secondary load, and the saturation characteristic parameter of the current transformer of the electric energy meter is obtained by calculation,
(D1) Because the secondary load of the current transformer of the electric energy meter is approximately pure resistance, the secondary current is in direct proportion to the induced electromotive force, and the magnetic flux phi of the current transformer is the integral of the secondary current, as shown in the following formula:
φ＝(1/N 2 )∫e 2 dt＝(R/N 2 )∫I 2 dt
wherein N is 2 Is of secondary turns, e 2 Is induced electromotive force, R is secondary impedance, I 2 Is the secondary current;
(D2) When the phase is fixedly integrated from 0 degrees to 180 degrees, the obtained magnetic flux of the current transformer is saturated magnetic flux phi max, and the current transformer is in a critical saturated state, wherein the magnetic flux is represented by the following formula:
wherein, the time between zero crossing points of the output of the primary current and the secondary current is shortened when the current source increases the primary current, the primary current is critical saturated current and the effective value is I 1pumn Peak value I of corresponding secondary current 2pun ；
(D3) Because the saturation magnetic flux phi max of the current transformer is not variable, the secondary impedance R and I are under critical saturation 2pun Inversely proportional, when the secondary impedance is adjusted from R to R de Corresponding secondary current peak value I under critical saturation 2pu The following formula is shown:
I 2pu ＝R/R de *I2 pun
(D4) The short-time overcurrent effective value to be met by the electric energy meter is I 1maxm Peak value is I 1max Based on the characteristic that the saturation magnetic flux is not variable, the phase x at saturation is obtained as shown in the following formula:
；
wherein x is the phase at saturation, representing when the primary current is I 1max The magnetic core is saturated when the phase is x or 180+x, and the secondary current output is zero;
(D5) And calculating the effective value, the peak value, the effective value in the unsaturated period and the unsaturated time of the secondary current according to the phase x in the saturated state, wherein the effective value, the peak value, the effective value in the unsaturated period and the unsaturated time are shown in the following formula:
peak value I of secondary current 2m Is that
I 2m ＝I 1max /N 2 sinx；
Effective value I of secondary current 2 Is that
；
Effective value I of secondary current in unsaturated period 2 ' as
；
The unsaturated time t of the secondary current is
t＝ω/x；
And (E) displaying the saturation characteristic parameters of the current transformer of the electric energy meter obtained through calculation through a display screen, and transmitting the saturation characteristic parameters to a test terminal.
In summary, according to the system and the method for measuring the supersaturation characteristic parameters of the current transformer of the electric energy meter, the critical saturation current of the current transformer under the nominal secondary load is measured, the saturation characteristic parameters of the current transformer of the electric energy meter are calculated according to the supersaturation characteristics of the current transformer of the electric energy meter, and the saturation characteristic parameters are displayed and output in a communication mode, so that the system and the method are the basis for the design of the electric energy meter for resisting short-time overcurrent impact, and therefore the system and the method for measuring the supersaturation characteristic parameters of the current transformer of the electric energy meter are used for testing the short-time overcurrent impact resistance of the electric energy meter.
The foregoing has outlined and described the basic principles, features, and advantages of the present invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, and that the above embodiments and descriptions are merely illustrative of the principles of the present invention, and various changes and modifications may be made without departing from the spirit and scope of the invention, which is defined in the appended claims. The scope of the invention is defined by the appended claims and equivalents thereof.
Claims (8)
1. The utility model provides an electric energy meter current transformer supersaturation characteristic parameter measurement system which characterized in that: comprises a critical saturation current measuring unit and a supersaturation characteristic processing unit,
the critical saturated current measuring unit comprises a current source, an adjustable resistor and a critical saturated current measuring circuit, wherein the current source is respectively connected with a signal input end and the adjustable resistor of the critical saturated current measuring circuit through a measured current transformer, the current source is also directly connected with the critical saturated current measuring circuit, the adjustable resistor is also connected with an adjusting output end of the critical saturated current measuring circuit, the critical saturated current measuring unit is used as an interface end of the critical saturated current measuring unit and is connected with an interface end of the supersaturation characteristic processing unit,
the saturation characteristic processing unit comprises an MCU processor, a display screen and an RS232 communication circuit, wherein the MCU processor is used as an interface end of the saturation characteristic processing unit and is connected with an interface end of the critical saturation current measuring unit, the MCU processor is also respectively connected with the display screen and the RS232 communication circuit, and the RS232 communication circuit is connected with the test terminal;
(B) The resistance value of the adjustable resistor is adjusted to a set value to form a nominal resistor, a current source is started, the current source outputs current to a tested current transformer, and the current source output current increases linearly from zero to the maximum output value gradually over time;
(C) The supersaturation characteristic processing circuit continuously tests to obtain a zero crossing point of a secondary current signal output by the tested current transformer, and judges whether saturation occurs in the zero crossing point; if saturation occurs, recording the peak value of the secondary current signal, stopping the current output of the current source, and executing the step (D):
the MCU processor receives a current signal when the current source stops outputting current and is positioned at saturation, and calculates and obtains saturation characteristic parameters of the current transformer of the electric energy meter according to the supersaturation characteristic of the current transformer of the electric energy meter;
wherein, the step (D) is used for calculating the saturation characteristic parameter of the current transformer of the electric energy meter, and comprises the following steps,
(D1) Because the secondary load of the current transformer of the electric energy meter is approximately pure resistance, the secondary current is in direct proportion to the induced electromotive force, and the magnetic flux phi of the current transformer is the integral of the secondary current, as shown in the following formula:
Φ＝(1/N 2 )∫e 2 dt＝(R/N 2 )∫I 2 dt
wherein N is 2 Is of secondary turns, e 2 Is induced electromotive force, R is secondary impedance, I 2 Is the secondary current;
(D2) When the phase is fixed and integrated from 0 to 180 degrees, the obtained magnetic flux of the current transformer is saturated magnetic flux phi max The current transformer is in a critical saturation state, and the following formula is shown:
wherein, the time between zero crossing points of the output of the primary current and the secondary current is shortened when the current source increases the primary current, the primary current is critical saturated current and the effective value is I 1pumn Peak value I of corresponding secondary current 2pun ；
(D3) Due to the saturation flux phi of the current transformer max Invariable, critical saturated, secondary impedances R and I 2pun Inversely proportional, when the secondary impedance is adjusted from R to R de Corresponding secondary current peak value I under critical saturation 2pu The following formula is shown:
I 2pu ＝R/R de *I 2pun
(D4) The short-time overcurrent effective value to be met by the electric energy meter is I 1maxm Peak value is I 1max Based on the characteristic that the saturation magnetic flux is not variable, the phase x at saturation is obtained as shown in the following formula:
；
wherein x is the phase at saturation, representing when the primary current is I 1max The magnetic core is saturated when the phase is x or 180+x, and the secondary current output is zero;
(D5) And calculating the effective value, the peak value, the effective value in the unsaturated period and the unsaturated time of the secondary current according to the phase x in the saturated state, wherein the effective value, the peak value, the effective value in the unsaturated period and the unsaturated time are shown in the following formula:
peak value I of secondary current 2m Is that
I 2m ＝I 1max /N 2 sinx；
Effective value I of secondary current 2 Is that
；
Effective value I of secondary current in unsaturated period 2 ' as
；
The unsaturated time t of the secondary current is
t＝x/ω。
2. The system for measuring supersaturation characteristic parameters of a current transformer of an electric energy meter according to claim 1, wherein: the current source is a current source for outputting a low-noise power frequency sine wave current signal.
3. The system for measuring supersaturation characteristic parameters of a current transformer of an electric energy meter according to claim 1, wherein: the critical saturation current measuring circuit is an AD sampling circuit, a 24-bit AD sampling chip is arranged in the critical saturation current measuring circuit, and the model of the 24-bit AD sampling chip is an ADS1210 sampling chip.
4. The system for measuring supersaturation characteristic parameters of a current transformer of an electric energy meter according to claim 1, wherein: the critical saturation current measuring unit and the supersaturation characteristic processing unit are connected through an SPI communication bus.
5. The system for measuring supersaturation characteristic parameters of a current transformer of an electric energy meter according to claim 1, wherein: the resistance of the adjustable resistor is adjustable to form a nominal resistor, and the adjustable resistor ranges from 5 ohms to 1 Kohm.
6. A measuring method based on the supersaturation characteristic parameter measuring system of the current transformer of the electric energy meter according to any one of claims 1 to 5, which is characterized in that: comprises the steps of,
step (A), a test starting command and test parameters are sent through a test terminal, and a supersaturation characteristic processing unit controls a critical saturation current measuring unit to start current transformer supersaturation characteristic parameter measurement according to the received starting command and test parameters;
step (B), the resistance value of the adjustable resistor is adjusted to a set value, a nominal resistor is formed, a current source is started, the current source outputs current to a tested current transformer, the current source output current increases linearly from zero along with time, and the current source output current increases gradually to a maximum output value;
step (C), the supersaturation characteristic processing circuit continuously tests to obtain a zero crossing point of a secondary current signal output by the tested current transformer, and judges whether saturation occurs in the zero crossing point; if saturation occurs, recording the peak value of the secondary current signal, stopping the current output of the current source, and executing the step (D); if the peak value of the current signal is smaller than or equal to the peak value of the previous period and saturation does not occur, stopping the current output of the current source, increasing the set value of the adjustable resistor, and executing the step (B); if the current signal peak value is larger than the peak value of the previous period and saturation does not occur, executing the step (C);
the MCU processor receives a current signal when the current source stops outputting current and is positioned at saturation, and calculates to obtain saturation characteristic parameters of the current transformer of the electric energy meter according to the supersaturation characteristic of the current transformer of the electric energy meter;
and (E) displaying the saturation characteristic parameters of the current transformer of the electric energy meter obtained through calculation through a display screen, and transmitting the saturation characteristic parameters to a test terminal.
7. The method for measuring the supersaturation characteristic parameter of the current transformer of the electric energy meter according to claim 6, wherein the method comprises the following steps: and (C) judging whether the zero crossing point is saturated or not according to the fact that when the magnetic core of the current transformer is saturated, the output current of the current transformer is reduced to zero, whether the waveform of a current signal is crossed in advance or not is detected, and if the waveform of the current signal is crossed in advance, the current transformer is saturated.
8. The method for measuring the supersaturation characteristic parameter of the current transformer of the electric energy meter according to claim 6, wherein the method comprises the following steps: and (D) approximating the pure resistance characteristic of the secondary load according to the supersaturation characteristic of the current transformer of the electric energy meter.
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Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2645465A1 (en) * | 1975-10-10 | 1977-04-21 | Gen Electric | PROCEDURE AND ARRANGEMENT FOR DETERMINING THE APPEARANCE OF MAGNETIC SATURATION IN A TRANSFORMER CORE |
| US4456875A (en) * | 1981-07-07 | 1984-06-26 | Hydro-Quebec | Demagnetization circuit for current transformers |
| CN102809678A (en) * | 2012-08-03 | 2012-12-05 | 江苏林洋电子股份有限公司 | Device for improving current sampling linear range and electric energy measuring accuracy of electric energy meter |
| JP2013096848A (en) * | 2011-11-01 | 2013-05-20 | Hirose Electric Co Ltd | Current sensor |
| CN103176147A (en) * | 2013-03-13 | 2013-06-26 | 江苏省电力公司电力科学研究院 | Current transformer remanence measurement system and method |
| CN104122524A (en) * | 2014-07-31 | 2014-10-29 | 国家电网公司 | Method and system for lowering measuring error of current transformer |
| CN104251948A (en) * | 2014-10-22 | 2014-12-31 | 华自科技股份有限公司 | Test device and test method suitable for differential protection detection of CT (current transformer) saturation |
| KR20160116832A (en) * | 2015-03-31 | 2016-10-10 | 명지대학교 산학협력단 | Current transformer saturation detection method and apparatus |
| CN106842099A (en) * | 2017-04-10 | 2017-06-13 | 国家电网公司 | A kind of CT saturation recognition methods and device |
| CN106873461A (en) * | 2017-03-02 | 2017-06-20 | 国家电网公司 | A kind of control method of remanence of current transformer degaussing gear |
| CN107340489A (en) * | 2017-07-05 | 2017-11-10 | 广东电网有限责任公司电力科学研究院 | A kind of CT saturation detection method and device |
| CN208110026U (en) * | 2018-04-28 | 2018-11-16 | 国网江苏省电力有限公司电力科学研究院 | A kind of electrical energy meter electricity current transformer supersaturation characterisitic parameter measuring system |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9829512B2 (en) * | 2013-10-21 | 2017-11-28 | Guildline Instruments Limited | Methods and systems relating to AC current measurements |
-
2018
- 2018-04-28 CN CN201810396782.3A patent/CN108594155B/en active Active
Patent Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2645465A1 (en) * | 1975-10-10 | 1977-04-21 | Gen Electric | PROCEDURE AND ARRANGEMENT FOR DETERMINING THE APPEARANCE OF MAGNETIC SATURATION IN A TRANSFORMER CORE |
| US4456875A (en) * | 1981-07-07 | 1984-06-26 | Hydro-Quebec | Demagnetization circuit for current transformers |
| JP2013096848A (en) * | 2011-11-01 | 2013-05-20 | Hirose Electric Co Ltd | Current sensor |
| CN102809678A (en) * | 2012-08-03 | 2012-12-05 | 江苏林洋电子股份有限公司 | Device for improving current sampling linear range and electric energy measuring accuracy of electric energy meter |
| CN103176147A (en) * | 2013-03-13 | 2013-06-26 | 江苏省电力公司电力科学研究院 | Current transformer remanence measurement system and method |
| CN104122524A (en) * | 2014-07-31 | 2014-10-29 | 国家电网公司 | Method and system for lowering measuring error of current transformer |
| CN104251948A (en) * | 2014-10-22 | 2014-12-31 | 华自科技股份有限公司 | Test device and test method suitable for differential protection detection of CT (current transformer) saturation |
| KR20160116832A (en) * | 2015-03-31 | 2016-10-10 | 명지대학교 산학협력단 | Current transformer saturation detection method and apparatus |
| CN106873461A (en) * | 2017-03-02 | 2017-06-20 | 国家电网公司 | A kind of control method of remanence of current transformer degaussing gear |
| CN106842099A (en) * | 2017-04-10 | 2017-06-13 | 国家电网公司 | A kind of CT saturation recognition methods and device |
| CN107340489A (en) * | 2017-07-05 | 2017-11-10 | 广东电网有限责任公司电力科学研究院 | A kind of CT saturation detection method and device |
| CN208110026U (en) * | 2018-04-28 | 2018-11-16 | 国网江苏省电力有限公司电力科学研究院 | A kind of electrical energy meter electricity current transformer supersaturation characterisitic parameter measuring system |
Non-Patent Citations (2)
| Title |
|---|
| Detection of Saturation of Core of Current Transformer Using Combined Feature of Hilbert Transform and Stockwell Transform 等.Operating characteristics of the Permanent-Magnet-Biased Saturation Based Fault Current Limiter.《2008 International Conference on High Voltage Engineering and Application》.2009,全文. * |
| 陆泉森 等 .电流互感器大电流饱和测试技术与实现方法研究.《 中国设备工程》.2017,全文. * |
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