CN112946549A - Method for correcting direct current component in alternating current system - Google Patents
Method for correcting direct current component in alternating current system Download PDFInfo
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
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Abstract
The invention discloses a method for correcting direct current component in an alternating current system, which comprises the following steps: step S1, after the ammeter calibration is completed, under the no-load condition of the table body, the signal acquisition device measures a group of DC offset correction values; and step S2, in the normal metering stage of the electric meter, the signal acquisition device remeasures a group of DC offset correction values, and step S3 calculates the external input direct current value according to the formula T. In step S1, after the meter calibration is completed, the platform body does not output current, and the metering chip is ensured to be in an EMM mode at present; the following steps are carried out: step S11, turn off the high pass of NVM 1; step S12, configuring the waveform buffer as a 128-point synchronous sampling mode: step S13, starting the automatic DC offset correction function; in step S14, after t1 seconds, the DCOS _ Ix register value is read and saved in the EEPROM, which is recorded as DCOS _ Iref. Through DCoffset function, test direct current to through the compensation coefficient, realize exchanging the high accuracy measurement of error.
Description
Technical Field
The invention relates to the technical field of power detection, in particular to a method for correcting a direct current component in an alternating current system.
Background
With the rapid development of the smart grid technology, the power load structure in the power grid is greatly changed, and the nonlinear loads are increasing day by day, for example, a large number of applications of various frequency conversion devices, half-bridge or full-bridge rectification equipment, electric arc furnaces, rolling mills and electric railways, and these nonlinear loads generate a large number of non-sinusoidal waves to be injected into the power grid, which causes the voltage and current waveforms of the power system to be distorted, and causes various damages to various electrical equipment devices such as generators, relay protection devices, communication equipment and automatic control devices, and further affects the metering accuracy.
The direct current magnetic bias or the direct current interference in the alternating current generally exists in various application systems of a power transmission network and terminals thereof, the direct current interference not only exists in an alternating current power grid and a power generation inverter system, but also has the same problem of direct current component interference in a plurality of high-power systems, particularly in the fields of variable frequency control, switching power amplifiers, uninterruptible power supplies, alternating current stabilized power supplies and the like, and therefore how to detect the direct current voltage and current and correct the direct current voltage and current in an appropriate mode is the technical key of magnetic bias suppression.
Disclosure of Invention
The invention aims to solve the problem of difficult detection and correction of direct current components in an alternating current system, and provides a method for correcting the direct current components in the alternating current system.
In order to achieve the above technical object, a technical solution provided by the present invention is a method for correcting a dc component in an ac system, comprising the steps of:
step S1, after the ammeter calibration is completed, under the no-load condition of the table body, the signal acquisition device measures a group of DC offset correction values;
step S2, in the normal metering phase of the electric meter, the signal acquisition device re-measures a set of DC offset correction values,
and step S3, calculating the external input direct current value according to the formula T.
In step S1, after the meter calibration is completed, the platform body does not output current, and the metering chip is ensured to be in an EMM mode at present; the following steps are carried out:
step S11, turn off the high pass of NVM 1; configuring HPFOFF (bit1 bit) of NVM1_ CFG (0x80) to be 1;
step S12, configuring the waveform buffer as a 128-point synchronous sampling mode: bit7:6 of WSAVECON (0x63) is configured to be 0x 2;
step S13, starting the automatic DC offset correction function; AUTODC _ EN (0x91) is configured to be 0x 0095; that is, NVM1_ DC _ DIS (bit7) is 1, i.e., the DC offset auto-correction result does not affect the metrology channel parameter calculation;
ix _ DC _ EN (Bit0/Bit2/Bit4) is 1, i.e., IA/IB/IC automatic offset correction is enabled.
In step S14, after t1 is 2.56 seconds, the register value of DCOS _ Ix (0x1d/0x1e/0x1f) is read and stored in the EEPROM as DCOS _ Ief.
In step S2, in the normal metering phase of the electric meter, the electric meter is currently in the EMM mode:
step S21, turn off the high pass of NVM 1;
step S22, configuring the waveform buffer as a 128-point synchronous sampling mode:
step S23, starting the automatic DC offset correction function;
in step S24, after t2 is 2.56 seconds, the DCOS _ Ix register value is read and saved in the EEPROM as DCOS _ Ix, where t1 is equal to t 2.
The formula T is calculated as follows:
IA1＝(DCOS_Ix-DCOS_Iref)*0.512*(2^12)*KI2/(1+Gain)；
wherein, IA1Inputting a direct current value for the outside; KI2The current register value is multiplied by the conversion coefficient to obtain the actual current value; the AC conversion coefficient is obtained by calculation in a meter calibration link; gain is a normalized value of channel Gain.
Gain is calculated from the channel Gain register value and, if RegGain > (2^15),
then Gain ═ i (RegGain-2^16)/(2^ 15); otherwise, Gain is RegGain/(2^ 15).
The derivation of equation T is as follows:
according to the definition of the effective value of the current, respectively passing a direct current and an alternating current through resistors with the same resistance value, and if the heat generated by the two currents passing through the resistors in the same time is the same, the current value of the direct current is the current value of the alternating current;
according to the current effective value definition, the metering chip loads alternating current and direct current with the same effective value under the condition that channel gain correction is not carried out, and the measured values of the current effective value register are the same;
the definition is as follows:
IA2is the effective value of the alternating current,
IA1the effective value of direct current; the effective value of the direct current is an external input direct current value;
KI2the current register value is multiplied by the conversion coefficient to obtain the actual current value; the coefficient can be obtained by calculation in a meter calibration link;
KI1the direct current conversion coefficient is the conversion coefficient of a direct current effective value and a current register value;
applying an alternating current and a direct current of the same effective value, IA1＝IA2，
And due to IA2＝KI2*REGIA2，IA1＝KI1*REGIA1；
KI2*REGIA2＝IA1＝KI1*REGIA1，
When the channel gain correction value is 0, REGIA2＝REGIA1，KI2＝KI1；
When the channel gain correction value is not 0, as can be seen from the gain correction relationship,
REGIA2/(1+Gain)＝REGIA1，KI1＝KI2/(1+Gain)；
therefore, the conversion method between the dc offset correction value and the dc effective value is as follows:
IA1＝(DCOS_Ix-DCOS_Iref)*0.512*(2^12)*KI1；
＝(DCOS_Ix-DCOS_Iref)*0.512*(2^12)*KI2/(1+Gain)；
wherein the content of the first and second substances,
DCOS _ Ix is a correction value obtained under the condition that the direct current offset automatic correction function is enabled under the normal metering operation of the electric meter;
DCOS _ Iref is a correction value enabling the dc offset automatic correction function under no load, i.e., when no dc signal is applied.
The invention has the beneficial effects that: according to the invention, through the metering chip, after the DC offset is automatically corrected in an EMM mode, the principle of the amplitude of the direct current signal can be reversely deduced according to the correction value, and the measured direct current signal comprises channel noise and an externally input direct current signal. The channel noise can be obtained by correcting the DC offset under the current no-load condition; namely, the externally input direct current semaphore can be obtained by subtracting channel noise from the measured direct current signal, namely the externally input direct current semaphore, and the high-precision measurement of the alternating current error can be realized.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments, it should be understood that the specific embodiment described herein is only a preferred embodiment of the present invention, and is only used for explaining the present invention, and does not limit the scope of the present invention, and all other embodiments obtained by a person of ordinary skill in the art without making creative efforts shall fall within the scope of the present invention.
Example (b): a method of correcting a dc component in an ac system, comprising the steps of:
step S1, after the ammeter calibration is completed, under the no-load condition of the table body, the signal acquisition device measures a group of DC offset correction values;
in step S1, after the meter calibration is completed, the platform body does not output current, and the metering chip is ensured to be in an EMM mode at present; the following steps are carried out:
step S11, turn off the high pass of NVM 1; configuring HPFOFF (bit1 bit) of NVM1_ CFG (0x80) to be 1;
step S12, configuring the waveform buffer as a 128-point synchronous sampling mode: bit7:6 of WSAVECON (0x63) is configured to be 0x 2;
step S13, starting the automatic DC offset correction function; AUTODC _ EN (0x91) is configured to be 0x 0095; that is, NVM1_ DC _ DIS (bit7) is 1, i.e., the DC offset auto-correction result does not affect the metrology channel parameter calculation;
ix _ DC _ EN (Bit0/Bit2/Bit4) is 1, i.e. IA/IB/IC automatic offset correction is started;
in step S14, after t1 is 2.56 seconds, the register value of DCOS _ Ix (0x1d/0x1e/0x1f) is read and stored in the EEPROM as DCOS _ Ief.
Step S2, in the normal metering stage of the electric meter, the signal acquisition device re-measures a set of DC offset correction values, and in the normal metering stage of the electric meter, the electric meter is currently in the EMM mode:
step S21, turn off the high pass of NVM 1;
step S22, configuring the waveform buffer as a 128-point synchronous sampling mode:
step S23, starting the automatic DC offset correction function;
in step S24, after t2 is 2.56 seconds, the DCOS _ Ix register value is read and saved in the EEPROM as DCOS _ Ix, where t1 is equal to t 2.
And step S3, calculating the external input direct current value according to the formula T.
The formula T is calculated as follows:
IA1＝(DCOS_Ix-DCOS_Iref)*0.512*(2^12)*KI2/(1+Gain)；
wherein, IA1Inputting a direct current value for the outside; KI2The current register value is multiplied by the conversion coefficient to obtain the actual current value; the AC conversion coefficient is obtained by calculation in a meter calibration link; gain is a normalized value of channel Gain.
Gain is calculated from the channel Gain register value and, if RegGain > (2^15),
then Gain ═ i (RegGain-2^16)/(2^ 15); otherwise, Gain is RegGain/(2^ 15).
The derivation of equation T is as follows:
according to the definition of the effective value of the current, respectively passing a direct current and an alternating current through resistors with the same resistance value, and if the heat generated by the two currents passing through the resistors in the same time is the same, the current value of the direct current is the current value of the alternating current;
according to the current effective value definition, the metering chip loads alternating current and direct current with the same effective value under the condition that channel gain correction is not carried out, and the measured values of the current effective value register are the same;
the definition is as follows:
IA2is the effective value of the alternating current,
IA1the effective value of direct current;
KI2the current register value is multiplied by the conversion coefficient to obtain the actual current value; the coefficient can be obtained by calculation in a meter calibration link;
KI1the direct current conversion coefficient is the conversion coefficient of a direct current effective value and a current register value;
applying an alternating current and a direct current of the same effective value, IA1＝IA2，
And due to IA2＝KI2*REGIA2，IA1＝KI1*REGIA1；
KI2*REGIA2＝IA1＝KI1*REGIA1，
When the channel gain correction value is 0, REGIA2＝REGIA1，KI2＝KI1；
When the channel gain correction value is not 0, as can be seen from the gain correction relationship,
REGIA2/(1+Gain)＝REGIA1，KI1＝KI2/(1+Gain)；
therefore, the conversion method between the dc offset correction value and the dc effective value is as follows:
KI1＝(DCOS_Ix-DCOS_Iref)*0.512*(2^12)*KI1；
＝(DCOS_Ix-DCOS_Iref)*0.512*(2^12)*KI2/(1+Gain)；
wherein the content of the first and second substances,
DCOS _ Ix is a correction value obtained under the condition that the direct current offset automatic correction function is enabled under the normal metering operation of the electric meter;
DCOS _ Iref is a correction value enabling the dc offset automatic correction function under no load, i.e., when no dc signal is applied.
The above-mentioned embodiments are preferred embodiments of the method for correcting dc component in ac system according to the present invention, and the scope of the present invention is not limited thereto, and all equivalent changes in shape and structure according to the present invention are within the protection scope of the present invention.
Claims (6)
1. A method of correcting a dc component in an ac system, comprising:
the method comprises the following steps:
step S1, after the ammeter calibration is completed, under the no-load condition of the table body, the signal acquisition device measures a group of DC offset correction values;
step S2, in the normal metering phase of the electric meter, the signal acquisition device re-measures a set of DC offset correction values,
and step S3, calculating the external input direct current value according to the formula T.
2. The method according to claim 1, wherein the method further comprises:
in step S1, after the meter calibration is completed, the platform body does not output current, and the metering chip is ensured to be in an EMM mode at present; the following steps are carried out:
step S11, turn off the high pass of NVM 1;
step S12, configuring the waveform buffer as a 128-point synchronous sampling mode:
step S13, starting the automatic DC offset correction function;
in step S14, after t1 seconds, the DCOS _ Ix register value is read and saved in EEPROM,
denoted DCOS _ Iref.
3. A method of correcting a dc component in an ac system according to claim 1 or 2, wherein:
in step S2, in the normal metering phase of the electric meter, the electric meter is currently in the EMM mode:
step S21, turn off the high pass of NVM 1;
step S22, configuring the waveform buffer as a 128-point synchronous sampling mode:
step S23, starting the automatic DC offset correction function;
after step S24 and t2, the DCOS _ Ix register value is read and saved in the EEPROM, which is denoted as DCOS _ Ix, where t1 is equal to t 2.
4. The method according to claim 1, wherein the method further comprises:
the formula T is calculated as follows:
IA1＝(DCOS_Ix-DCOS_Iref)*0.512*(2^12)*KI2/(1+Gain)；
wherein, IA1Inputting a direct current value for the outside; KI2The current register value is multiplied by the conversion coefficient to obtain the actual current value; the AC conversion coefficient is obtained by calculation in a meter calibration link; gain is a normalized value of channel Gain.
5. The method according to claim 4, wherein the method further comprises:
gain is calculated from the channel Gain register value and, if RegGain > (2^15),
then Gain ═ i (RegGain-2^16)/(2^ 15); otherwise, Gain is RegGain/(2^ 15).
6. The method for correcting a direct current component in an alternating current system according to claim 1 or 4, wherein:
the derivation of equation T is as follows:
according to the definition of the effective value of the current, respectively passing a direct current and an alternating current through resistors with the same resistance value, and if the heat generated by the two currents passing through the resistors in the same time is the same, the current value of the direct current is the current value of the alternating current;
according to the current effective value definition, the metering chip loads alternating current and direct current with the same effective value under the condition that channel gain correction is not carried out, and the measured values of the current effective value register are the same;
the definition is as follows:
IA2is the effective value of the alternating current,
IA1the effective value of direct current; the effective value of the direct current is an external input direct current value;
KI2the current register value is multiplied by the conversion coefficient to obtain the actual current value; the coefficient can be obtained by calculation in a meter calibration link;
KI1the direct current conversion coefficient is the conversion coefficient of a direct current effective value and a current register value;
applying an alternating current and a direct current of the same effective value, IA1＝IA2，
And due to IA2＝KI2*REGIA2，IA1＝KI1*REGIA1；
KI2*REGIA2＝IA1＝KI1*REGIA1，
When the channel gain correction value is 0, REGIA2＝REGIA1，KI2＝KI1；
When the channel gain correction value is not 0, as can be seen from the gain correction relationship,
REGIA2/(1+Gain)＝REGIA1，KI1＝KI2/(1+Gain)；
therefore, the conversion method between the dc offset correction value and the dc effective value is as follows:
IA1＝(DCOS_Ix-DCOS_Iref)*0.512*(2^12)*KI1；
＝(DCOS_Ix-DCOS_Iref)*0.512*(2^12)*KI2/(1+Gain)；
wherein the content of the first and second substances,
DCOS _ Ix is a correction value obtained under the condition that the direct current offset automatic correction function is enabled under the normal metering operation of the electric meter;
DCOS _ Iref is a correction value enabling the dc offset automatic correction function under no load, i.e., when no dc signal is applied.
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Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000295305A (en) * | 1999-03-11 | 2000-10-20 | Intersil Corp | Successive approximate correction for dc offset on filter buffer base band path of wireless data receiver |
| JP2001078494A (en) * | 1999-09-06 | 2001-03-23 | Yaskawa Electric Corp | Method of correcting dc offset of ac motor driver |
| CN1881788A (en) * | 2005-06-15 | 2006-12-20 | 恩益禧电子股份有限公司 | Variable gain amplifier circuit and DC offset correction method and radio receiving device |
| CN101937017A (en) * | 2010-08-10 | 2011-01-05 | 珠海中慧微电子有限公司 | Dynamic direct-current removing method for intelligent electric meter during alternating-current sampling |
| CN102435810A (en) * | 2011-09-14 | 2012-05-02 | 北京国基科技股份有限公司 | Method and device for detecting direct-current component in alternating current |
| CN102707821A (en) * | 2011-03-28 | 2012-10-03 | 深圳市汇顶科技有限公司 | Method and system for de-noising touch detection device |
| CN104811404A (en) * | 2015-04-14 | 2015-07-29 | 华南理工大学 | DC deviation correcting method and device |
| CN106452139A (en) * | 2016-10-31 | 2017-02-22 | 上海新时达电气股份有限公司 | Circuit for testing DC component in AC voltage and device for eliminating DC component |
| CN107767722A (en) * | 2017-11-14 | 2018-03-06 | 国网浙江省电力公司培训中心 | A kind of multifunctional digital electric energy metering Training Simulation System |
| CN209182489U (en) * | 2018-11-16 | 2019-07-30 | 怀化建南机器厂有限公司 | A kind of direct current energy meter current channel conditioning circuit |
| CN209690401U (en) * | 2019-01-11 | 2019-11-26 | 西安铁路职业技术学院 | A kind of alternating voltage DC component detection circuit |
| CN112098712A (en) * | 2020-07-28 | 2020-12-18 | 宁波三星医疗电气股份有限公司 | Electricity larceny prevention method |
Patent Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000295305A (en) * | 1999-03-11 | 2000-10-20 | Intersil Corp | Successive approximate correction for dc offset on filter buffer base band path of wireless data receiver |
| JP2001078494A (en) * | 1999-09-06 | 2001-03-23 | Yaskawa Electric Corp | Method of correcting dc offset of ac motor driver |
| CN1881788A (en) * | 2005-06-15 | 2006-12-20 | 恩益禧电子股份有限公司 | Variable gain amplifier circuit and DC offset correction method and radio receiving device |
| CN101937017A (en) * | 2010-08-10 | 2011-01-05 | 珠海中慧微电子有限公司 | Dynamic direct-current removing method for intelligent electric meter during alternating-current sampling |
| CN102707821A (en) * | 2011-03-28 | 2012-10-03 | 深圳市汇顶科技有限公司 | Method and system for de-noising touch detection device |
| CN102435810A (en) * | 2011-09-14 | 2012-05-02 | 北京国基科技股份有限公司 | Method and device for detecting direct-current component in alternating current |
| CN104811404A (en) * | 2015-04-14 | 2015-07-29 | 华南理工大学 | DC deviation correcting method and device |
| CN106452139A (en) * | 2016-10-31 | 2017-02-22 | 上海新时达电气股份有限公司 | Circuit for testing DC component in AC voltage and device for eliminating DC component |
| CN107767722A (en) * | 2017-11-14 | 2018-03-06 | 国网浙江省电力公司培训中心 | A kind of multifunctional digital electric energy metering Training Simulation System |
| CN209182489U (en) * | 2018-11-16 | 2019-07-30 | 怀化建南机器厂有限公司 | A kind of direct current energy meter current channel conditioning circuit |
| CN209690401U (en) * | 2019-01-11 | 2019-11-26 | 西安铁路职业技术学院 | A kind of alternating voltage DC component detection circuit |
| CN112098712A (en) * | 2020-07-28 | 2020-12-18 | 宁波三星医疗电气股份有限公司 | Electricity larceny prevention method |
Non-Patent Citations (1)
| Title |
|---|
| 刘建等: "直流磁场和静电对智能电表的影响仿真分析", 电测与仪表, vol. 51, no. 16, pages 88 - 93 * |
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