CN-121978609-A - Extreme temperature range precision compensation method based on direct current electric energy meter

CN121978609ACN 121978609 ACN121978609 ACN 121978609ACN-121978609-A

Abstract

The invention provides an extreme temperature domain precision compensation method based on a direct current electric energy meter, which comprises the following steps of obtaining cyclic experimental data of a sample direct current electric energy meter in a full temperature domain, and constructing a zero bias temperature model and a gain temperature model as a preliminary error compensation model through a least square method; and (3) independently correcting the direct current electric energy meter to be measured according to individual differences, collecting temperature data of the direct current electric energy meter in real time, and implementing dynamic real-time compensation. The invention adopts an automatic compensation method, and can effectively inhibit the interference of the thermal hysteresis effect on the metering performance through a dynamic feedback regulation mechanism.

Inventors

WANG YANXU
LIU YINHU
SONG XIAOHUI
CHEN MIN
LI YUANYUAN
WANG WEICHEN

Assignees

江苏林洋能源股份有限公司

Dates

Publication Date: 20260505
Application Date: 20251208

Claims (9)

1. The method for compensating the precision under the extreme temperature range based on the direct current electric energy meter is characterized by comprising the following steps of: s1, acquiring cyclic experimental data of a sample direct current electric energy meter in a full temperature range, and constructing a zero bias temperature model and a gain temperature model by a least square method to serve as a preliminary error compensation model; s2, aiming at individual differences, independently correcting the direct current electric energy meter to be detected, constructing a Bayesian linear regression model by using compensation values of a plurality of preset reference temperatures, and introducing coefficients of a preliminary error compensation model as prior information; The first-order and second-order temperature coefficients of zero offset and gain are iteratively optimized through a Markov chain Monte Carlo sampling algorithm MCMC, and a full-temperature-domain continuous compensation curve of the direct-current electric energy meter to be measured is generated and stored; S3, acquiring temperature data of the direct current electric energy meter in real time, and implementing dynamic real-time compensation, wherein when the temperature changes to the current temperature T, a zero offset value V 0(ref) , a zero offset temperature coefficient K 0 and a zero offset second-order temperature coefficient K 02 at a reference temperature T ref are acquired according to a full-temperature-domain continuous compensation curve of the direct current electric energy meter to be tested, which is generated in the S2, and then the zero offset value V 0(comp) after temperature compensation is; V 0(comp) ＝V 0(ref) +K 0 ×(T-T ref )+K 02 ×(T-T ref ) 2 When the temperature changes to the current temperature T, obtaining a gain value G (ref) , a gain temperature coefficient K G and a second-order temperature coefficient K G2 at a reference temperature T ref according to an error compensation model, wherein the gain value G (comp) after temperature compensation is as follows: G (comp) ＝G (ref) ×[1+K G ×(T-T ref )+K G2 ×(T-T ref ) 2 ] Based on the temperature compensated zero offset value V 0(comp) and the gain value G (comp) , the original measured value V meas(raw) is compensated to obtain a final compensated voltage measured value V meas(comp) :
2. the method for compensating accuracy in an extreme temperature range based on a direct current electric energy meter according to claim 1, wherein S1 comprises: S11, simulating an extreme temperature region continuous temperature change environment through a high-low temperature circulation experiment box, selecting a plurality of sample direct current electric energy meters to develop a plurality of groups of circulation experiments, wherein each group of circulation experiments comprises a complete flow of low temperature, normal temperature, high temperature and normal temperature; s12, setting a plurality of uniform temperature points in a circulation experiment, repeatedly measuring after each temperature point is constant, and synchronously recording zero offset data and gain original data of voltage and current, wherein the zero offset data is a deviation value of an output signal during zero input, and the gain original data is a ratio of the output signal to an input standard signal; S13, acquiring zero bias compensation values and gain attenuation compensation values of all temperature points based on the zero bias data and the gain original data, and performing curve fitting by adopting a least square method to respectively construct a zero bias temperature model and a gain temperature model as a primary error compensation model.
3. The method for compensating the precision under the extreme temperature range based on the direct current electric energy meter according to claim 2 is characterized in that the temperature range of the high-low temperature circulation experiment box is-40-85 ℃ in the 500 groups of circulation experiments in S1.
4. The method for compensating accuracy in an extreme temperature range based on a direct current electric energy meter according to claim 2, wherein in S1, a zero bias temperature model V 0(T) and a gain temperature model G (T) are respectively: V 0(T) ＝V 0(nor) +K 0_nor ×(T-T nor )+K 02_nor ×(T-T nor ) 2 G (T) ＝G (nor) ×[1+K G_nor ×(T-T nor )+K G2_nor ×(T-T nor ) 2 ] wherein, T is the actual working temperature of the equipment, and the unit is the temperature; T nor , reference temperature (normal temperature, usually set to 25 ℃) is a reference temperature point for calibration and coefficient fitting; V 0(T) zero offset output when the actual working temperature is T, wherein the unit is V or A; V 0(nor) zero offset reference at reference temperature T nor , the unit is V or A; K 0_nor general zero bias first order temperature coefficient, with the unit of V/° C or A/° C, describing the linear drift rate of zero bias temperature relative to V 0(nor) offset; K 02_nor a general zero bias second order temperature coefficient, the unit is V/° C or A/° C, describing the secondary nonlinear drift degree of zero bias voltage with the offset of temperature relative to V 0(nor) ; G (T) , the gain coefficient when the actual working temperature is T, the unit is the amplification factor/°C, and the gain coefficient is the actual gain value at the temperature G (nor) ; G (nor) , gain reference value at reference temperature T nor , wherein the unit is amplification factor; K 0_nor a general gain first-order temperature coefficient, wherein the unit is the amplification factor/° C, and the linear change proportion of the gain relative to G (nor) along with offset is described; k 02_nor A general gain second-order temperature coefficient, the unit is the amplification factor/° C, describes the secondary nonlinear change proportion of the gain relative to the G (nor) with temperature offset.
5. The method for compensating the precision under the extreme temperature range based on the direct current electric energy meter according to claim 1, wherein in S2, The preset reference temperature points comprise-40 ℃, 25 ℃, 60 ℃ and 85 ℃ which respectively correspond to a low temperature limit, a normal temperature standard, a medium-high Wen Jiedian and a high temperature limit; based on four reference temperature points, segmenting the temperature range of the direct current electric energy meter to be measured, and acquiring first-order and second-order temperature coefficients of zero offset and gain corresponding to each segment of temperature range.
6. The method for compensating accuracy under extreme temperature range based on direct current electric energy meter according to claim 1, wherein in step S2, a markov chain monte carlo sampling algorithm is adopted to perform iterative optimization on a bayesian linear regression model, a combustion period sample is discarded after iteration, a zero bias temperature coefficient and a gain temperature coefficient are determined according to a calculated average value of remaining samples, the zero bias temperature coefficient and the gain temperature coefficient comprise a first-order coefficient and a second-order coefficient, and a full temperature range continuous compensation curve is generated.
7. The method for compensating the precision under the extreme temperature range based on the direct current electric energy meter according to claim 1, wherein the method is characterized in that temperature data are collected in real time to generate a dynamic compensation track, and a prompt is given when an error exceeds a threshold value.
8. An extreme temperature range accuracy compensation system based on a direct current electric energy meter, characterized in that the system is configured to perform the compensation method according to any one of claims 1-8.
9. A computer readable storage medium, on which a computer program is stored, characterized in that the compensation method according to any one of claims 1-8 is implemented when said program is executed.

Description

Extreme temperature range precision compensation method based on direct current electric energy meter Technical Field The invention belongs to the technical field of precision control of direct current metering equipment, and particularly relates to a precision compensation method under an extreme temperature range based on a direct current electric energy meter. Background The direct current electric energy meter is a core metering device in the fields of new energy power generation, industrial measurement and control, rail traffic and the like, the measurement accuracy of the direct current electric energy meter is directly related to fairness of energy trade settlement and accuracy of industrial process parameter control, and the direct current electric energy meter is an important technical link for guaranteeing safe and stable operation of related electric systems. Specifically, in photovoltaic power stations, wind power plants and matched energy storage systems, a direct current electric energy meter needs to operate in an outdoor environment with a great day-and-night temperature difference, in industrial workshops equipped with high-precision manufacturing equipment, a current monitoring instrument always faces continuous high-temperature tests, and in outdoor power supply systems of rail transit (particularly lines operating in high-cold or high-heat areas), direct current metering equipment also needs to cope with extreme weather conditions. However, under such extreme temperature conditions of-40 ℃ to 85 ℃, the metering accuracy of a direct current electric energy meter faces serious challenges. The temperature range covers the extremely cold freezing and thawing environment to the high-temperature damp-heat environment, so that the performance of core components in the direct current meter can be obviously changed. The temperature drift coefficient of the temperature sensitive element such as the precise resistor and the operational amplifier fluctuates in a nonlinear way along with the temperature, so that obvious deviation is generated between the nominal parameter and the actual working parameter of the element, further the current sampling signal is distorted, finally a non-negligible error is generated between the measured value and the actual current value, and the error amplitude is obviously aggravated along with the expansion of the temperature range. Currently, compensation methods commonly adopted in the industry depend on hardware compensation circuits with fixed parameters, and the methods can realize limited-precision error correction only in a conventional temperature range of 25-60 ℃. When the temperature ranges of-40 ℃ to 85 ℃ and the corresponding application scenes are faced, the traditional compensation effect is obviously reduced, and the actual requirements of the current high-precision metering cannot be met. Therefore, development of a targeted technical solution is needed to break through this key technical bottleneck. Disclosure of Invention Aiming at the problems, the invention provides a metering precision optimization scheme of a direct current meter in an extreme temperature range, which can ensure that the metering precision of the direct current meter in the extreme temperature range of-40-85 ℃ is stably controlled within +/-0.5%. The technical scheme of the invention is as follows: The invention provides an extreme temperature range precision compensation method based on a direct current electric energy meter, which comprises the following steps: s1, acquiring cyclic experimental data of a sample direct current electric energy meter in a full temperature range, and constructing a zero bias temperature model and a gain temperature model by a least square method to serve as a preliminary error compensation model; s2, aiming at individual differences, independently correcting the direct current electric energy meter to be detected, constructing a Bayesian linear regression model by using compensation values of a plurality of preset reference temperatures, and introducing coefficients of a preliminary error compensation model as prior information; The first-order and second-order temperature coefficients of zero offset and gain are iteratively optimized through a Markov chain Monte Carlo sampling algorithm MCMC, and a full-temperature-domain continuous compensation curve of the direct-current electric energy meter to be measured is generated and stored; S3, acquiring temperature data of the direct current electric energy meter in real time, and implementing dynamic real-time compensation, wherein when the temperature changes to the current temperature T, a zero offset value V 0(ref), a zero offset temperature coefficient K 0 and a zero offset second-order temperature coefficient K 02 at a reference temperature T ref are acquired according to a full-temperature-domain continuous compensation curve of the direct current electric energy meter to be tested, which is gene