CN102590783A - Method for detecting error of indication of electric energy of high voltage energy meter and assessing qualification - Google Patents

Abstract

The invention discloses a method for inspecting the electric energy display value error of the high-voltage electric energy meter and a qualification assessment method which is convenient for operators to judge whether the electric energy measurement of the high-voltage electric energy meter is qualified, so as to improve the inspection accuracy. According to the actual parameters of the high-voltage electric energy meter to be inspected, a certain amount of electric energy is properly selected, and the output of the inspection device is controlled by the standard electric energy meter. When the output of the inspection device reaches this electric energy, the electric energy output by the inspection device automatically stops and automatically Read the accumulated electric energy of the inspected high-voltage electric energy meter, and use formula (1) to calculate the indication error of the accumulated electric energy of the inspected high-voltage electric energy meter: In the formula: γ _D ——The fixed systematic error % of the high-voltage electric energy meter inspection device, when no correction is required, γ _D = 0D _B ——The standard electric energy value output by the high-voltage electric energy meter inspection device, kWh or MWh; D _x —— The indicated energy value of the detected high-voltage electric energy meter, kWh or MWh. According to the expanded uncertainty U=ku _c , the indication error γ is qualified, so as to ensure the accuracy of the result judgment.

Description

A method for testing electric energy indication error of high-voltage electric energy meter and conformity assessment

technical field

The invention relates to a method for testing electric energy display value error of a high-voltage electric energy meter and a qualification assessment method, belonging to the technical field of measurement.

Background technique

The high-voltage electric energy meter represents the technical development direction of the high-voltage metering field of the distribution network in the future, and is a significant and transformative technical achievement. Compared with the traditional high-voltage metering system, the high-voltage electric energy meter reduces the resource consumption of copper, iron, and insulating materials, and the energy consumption is reduced by more than 80%. From the structure, it avoids the problems of easy power theft and ferromagnetic resonance at the low-voltage side. Typical energy saving and green technology achievements.

The electric energy meter is a legal measuring instrument, which is used to measure electric energy between electric power enterprises, power supply enterprises and users. According to the requirements of the national measurement regulations, measuring instruments must be inspected before they are put into operation to ensure safe operation and accurate measurement. The high-voltage electric energy meter is a new type of metering product. At present, there are no relevant regulations in the country to stipulate its inspection method.

Contents of the invention

The purpose of this method is to solve the problem of quantitative inspection and verification of the electric energy of the high-voltage electric energy meter, and provide a simple, intuitive and convenient method for the operator to judge whether the electric energy measurement of the high-voltage electric energy meter is qualified or not. , to improve the inspection efficiency of the high-voltage electric energy meter.

To achieve the above object, the present invention adopts the following technical solutions:

A method for testing the error of the electric energy indication value of a high-voltage electric energy meter and its conformity assessment. According to the actual parameters of the high-voltage electric energy meter to be inspected, a certain amount of electric energy value is appropriately selected, that is, the output of the inspection device is controlled according to the standard electric energy meter. When When the output of the inspection device reaches this electric energy, the electric energy output by the inspection device stops automatically, and the accumulated electric energy of the inspected high-voltage electric energy meter is automatically read, and the indication error of the accumulated electric energy of the inspected high-voltage electric energy meter is calculated by formula (1):

$\mathrm{<span\; class="notranslate">\; \&gamma;</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; Dx</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; D.</span>}}_{\mathrm{<span\; class="notranslate">\; B</span>}}}{{\mathrm{<span\; class="notranslate">\; D.</span>}}_{\mathrm{<span\; class="notranslate">\; B</span>}}}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; 100</span>}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&gamma;</span>}}_{\mathrm{<span\; class="notranslate">\; D.</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$

In the formula: γ _D ——the established systematic error % of the high-voltage electric energy meter inspection device, when no correction is required, γ _D = 0

D _B - the standard electric energy value output by the high-voltage electric energy meter inspection device, kWh or MWh;

D _x ——point energy indication value of the tested high-voltage electric energy meter, kWh or MWh.

(2)The reliability of the indication error obtained by this method and the consistency of the value transmission depend on the size of its uncertainty, and the sources of uncertainty in the inspection process mainly include: the uncertainty caused by the error of the high-voltage electric energy meter verification device The uncertainty component comes from the maximum allowable error of the standard device of the high-voltage electric energy meter; the uncertainty component caused by the rounding of the error of the inspected high-voltage electric energy meter; the uncertainty caused by the measurement repeatability of the inspected high-voltage electric energy meter and the standard device degree components, each uncertainty component is irrelevant, and the composite standard uncertainty is measured according to formula (2):

(2)

In the formula: c _i = 1, the sensitivity coefficient of the uncertainty component produced by the rounding off of the relative error data of the tested meter is 1;

u(x ₁ )——the uncertain component caused by the error of the high-voltage electric energy meter verification device;

u(x ₂ )——Uncertainty component caused by error rounding of the tested high-voltage electric energy meter;

u(x ₃ )——Uncertainty components caused by the measurement repeatability of the tested high-voltage electric energy meter and the standard device.

Take the inclusion factor k=2, so as to obtain the extended uncertainty U of formula (3) U=ku _c (3)

According to the expanded uncertainty U calculated by the formula (3), the indication error γ calculated by the public announcement (1) is qualified. When the indication error is qualified, the formula (4) should be satisfied.

|γ|+U≤MPEV (4)

Where: MPEV - the absolute value of the maximum allowable error

时，则|γ|≤MPEV即可判为合格。Among them, when

, then |γ|≤MPEV can be judged as qualified.

The effects of the method of the present invention are: 1. This high-voltage electric energy meter inspection device has realized the accuracy of indication value recorded by the high-voltage electric energy meter counter through the method of electric energy quantitative checking for the first time. 2. Through the analysis of the degree of certainty in the inspection process, the accuracy of the inspection results of the high-voltage electric energy meter is improved, and there is a good prospect for application and promotion.

Detailed ways

The present invention will be further described below in conjunction with embodiment.

The present invention uses inspection device configuration high-voltage standard voltage and current transformer, standard electric energy meter, adopts standard electric energy quantitative method test, promptly according to the actual parameter (Un=10kV, Imax=600A of the high-voltage electric energy meter of being checked, active energy pulse constant : 800imp/MWh, a three-wire three-phase high-voltage electric energy meter with an active energy meter accuracy of 0.5S), select 10MWh appropriately, and control the output of the inspection device by the standard electric energy meter. When the output of the device reaches 10MWh, the electric energy output by the device will automatically Stop, automatically read the accumulated electric energy (kWh or MWh) of the counter of the checked high-voltage electric energy meter, and use the formula (1) to calculate the indication error of the accumulated electric energy of the checked high-voltage electric energy meter counter:

$\mathrm{<span\; class="notranslate">\; \&gamma;</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; Dx</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; D.</span>}}_{\mathrm{<span\; class="notranslate">\; B</span>}}}{{\mathrm{<span\; class="notranslate">\; D.</span>}}_{\mathrm{<span\; class="notranslate">\; B</span>}}}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; 100</span>}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&gamma;</span>}}_{\mathrm{<span\; class="notranslate">\; D.</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$

条件下重复进行5次独立测量，分别得到各次的电能量示值误差，如下表所示。The tested high-voltage electric energy meter is at Un=10kV, Imax=600A,

Repeat 5 independent measurements under the same conditions, and obtain the error of the electric energy indication value of each time, as shown in the table below.

Indication error of electric energy measured 5 times Unit: %

Then the corresponding standard deviation estimated value S=0.007071%, the uncertainty component u(x ₃ )=0.002357% caused by the measurement repeatability of the tested high-voltage electric energy meter and the standard device

The uncertain component caused by the error of the high-voltage watt-hour meter verification device, the uncertainty component comes from the maximum allowable error of the standard device of the watt-hour meter, and the 0.1-level watt-hour meter verification device is used to verify the tested watt-hour meter, and any load with a phase of 1.0 The absolute value of the error of the lower device is considered not to exceed 0.1, that is, the half-width of the dispersion interval is 0.1, and this interval can be considered to obey the normal distribution (k=3).

Because of the uncertainty component caused by data rounding, the high-voltage electric energy meter under inspection is 0.5, and its rounding interval is 0.05%, that is, the quantization error introduced by rounding is 0.025%, and it obeys a uniform distribution in this interval

时各标准不确定度汇总表Thus it is obtained at Un=10kV, Imax=600A,

Summary table of standard uncertainties

Calculated combined standard uncertainty

时的最大允许误差绝对值MPEV＝0.5，故此时

而各次电能量示值误差的绝对值|γ|≤MPEV，故可认为该被检高压电能表的电能量示值误差合格。Take the inclusion factor k=2, so as to obtain the expanded uncertainty U=ku _c =0.0728%, and the high-voltage electric energy meter under inspection is in

The absolute value of the maximum allowable error MPEV=0.5, so at this time

And the absolute value |γ|≤MPEV of each electric energy indication error, so it can be considered that the electric energy indication error of the high-voltage electric energy meter under inspection is qualified.

Claims (2)

1. A method for checking the electric energy indication error of a high-voltage watt-hour meter and a method for conformity assessment, which is characterized in that, according to the actual parameters of the high-voltage watt-hour meter being tested, a certain amount of electric energy is appropriately selected, that is, the test device is controlled by a standard watt-hour meter When the output of the inspection device reaches the selected electric energy, the electric energy output by the inspection device will automatically stop, and the accumulated electric energy of the inspected high-voltage electric energy meter will be automatically read, and the accumulated electric energy of the inspected high-voltage electric energy meter will be calculated by formula (1). Energy indication error: $\mathrm{<span\; class="notranslate">\; \&gamma;</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; Dx</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; D.</span>}}_{\mathrm{<span\; class="notranslate">\; B</span>}}}{{\mathrm{<span\; class="notranslate">\; D.</span>}}_{\mathrm{<span\; class="notranslate">\; B</span>}}}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; 100</span>}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&gamma;</span>}}_{\mathrm{<span\; class="notranslate">\; D.</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$ In the formula: γ _D ——the established systematic error % of the high-voltage electric energy meter inspection device, when no correction is required, γ _D = 0 D _B - the standard electric energy value output by the high-voltage electric energy meter inspection device, kWh or MWh; D _x ——point energy indication value of the tested high-voltage electric energy meter, kWh or MWh. 2. inspection high-voltage watt-hour meter electric energy indication value error and conformity assessment method as claimed in claim 1, it is characterized in that, the reliability degree of the indication error obtained by calculation and the consistency of value transfer depend on its uncertainty The size of the uncertainty in the inspection process mainly includes: the uncertainty component caused by the error of the high-voltage electric energy meter verification device, the uncertainty component comes from the maximum allowable error of the high-voltage electric energy meter standard device; the tested high-voltage electric energy meter Uncertainty components generated by error rounding; Uncertainty components caused by the measurement repeatability of the tested high-voltage electric energy meter and the standard device, each uncertainty component is irrelevant, and the composite standard uncertainty is measured according to formula (2): $u_c=\sqrt{\mathrm{\&Sigma;}{c}_i^2{u}^2\left(x_i\right)}---\left(2\right)$ In the formula: c _i = 1, the sensitivity coefficient of the uncertainty component produced by the rounding off of the relative error data of the tested meter is 1; u(x ₁ )——the uncertain component caused by the error of the high-voltage electric energy meter verification device; u(x ₂ )——Uncertainty component caused by error rounding of the tested high-voltage electric energy meter; u(x ₃ )——the uncertainty component caused by the measurement repeatability of the tested high-voltage electric energy meter and the standard device; Take the inclusion factor k=2, so as to obtain the extended uncertainty U of formula (3) U=ku _c (3) According to the expanded uncertainty U calculated by the formula (3), the indication error γ calculated by the public announcement (1) is qualified. When the indication error is qualified, the formula (4) should be satisfied. |γ|+U≤MPEV (4) Where: MPEV - the absolute value of the maximum allowable error Among them, when , then |γ|≤MPEV is judged as qualified.