An error compensation method for maintaining accurate and stable internal clock accuracy of an electric energy meter

Abstract

The present invention relates to the field of power technologies, and particularly to an error compensation method for maintaining accurate and stable clock accuracy inside an electricity meter; the method includes the following steps: S1. Set up a programmable constant temperature and humidity test chamber, and simultaneously prepare multiple electricity meters of the same model; S2. Conduct high and low temperature cyclic shock; S3. After completing the high and low temperature cyclic shock, place the meters at normal temperature for at least 7 days; S4. Set k + 3 temperature value points, respectively adjust the temperature of the programmable constant temperature and humidity test chamber to the k + 3 temperature value points, and record the clock error and temperature ADC value of each electricity meter at different temperature value points; S5. Construct a clock error-temperature curve; S6. Configure the clock error-temperature curve into the metering controller of the electricity meter to calculate the real-time clock error of the electricity meter; the present invention considers the problem of maintaining accurate clock of the electricity meter after frequent hot and cold alternation.

Description

Technical Field

[0001] The present invention relates to the field of power technology, and particularly to an error compensation method for maintaining accurate and stable internal clock accuracy of an electric energy meter. Background Art

[0002] An electric energy meter is a key device in the field of electric power metering and management, with a series of diverse and crucial functions, deeply embedded in all aspects of the operation of modern power systems and the electricity consumption life of users; the internal clock of the controller in the electric energy meter, as a key component of the electric energy meter, is the basis for time-of-use electricity price billing and the guarantee of long-term billing accuracy, and plays a crucial role in aspects such as load monitoring and prediction assistance, power grid fault monitoring and time tracing, and multi-meter data synchronization.

[0003] However, a DC electric energy meter for accurately measuring large currents is installed in the compact internal circuit system of a charging pile. When the system is in the large-current load charging mode, a large-current impact surges into the shunt of the electric energy meter. The shunt is generally made of manganin material and has good conductivity. However, due to its own resistance, under the long-term and high-intensity impact of large currents, its temperature soars rapidly. Because there are many metal devices and various precision electronic components in the electric energy meter, the overall electric energy meter is in a high-temperature state; however, as the load decreases, the temperature of the electric energy meter gradually decreases and basically remains consistent with the room temperature. Such frequent thermal and cold shocks may cause the internal clock of the electric energy meter controller to fail the re-inspection clock error after a period of time after calibration, and even have a certain impact on the lifespan. Therefore, how to calibrate the internal clock of the electric energy meter according to temperature shocks to ensure the normal operation of other modules of the system is a key problem to be solved.

[0004] Chinese Patent CN117289587A discloses a calibration system and method for real-time clock calibration of an electricity consumption management device. The electricity consumption management device includes a concentrator and an electric energy meter in an electricity consumption information system. The controller in the system is respectively connected to a high and low temperature chamber, a plurality of first temperature sensors, at least one daily timing calibrator, an ambient temperature regulating device, at least one second temperature sensor, and a first multiplexing device. Through the control of the controller, a stable calibration ambient temperature and environment temperature can be provided for the electricity consumption management device and the daily timing calibrator, effectively ensuring the reliability of the calibration process and providing an environmental guarantee for high-precision calibration of the real-time clock of the electricity consumption management device; by ensuring the stability of the calibration ambient temperature, reliable real-time data can be provided for obtaining the compensation curve for time-domain segmented interpolation compensation of the electricity consumption management device, and thus, while effectively improving the calibration efficiency of the electricity consumption management device, the accuracy of the compensation curve for time-domain segmented interpolation compensation can be greatly improved. However, in the actual use process, the electric energy meter may be used alternately in hot and cold conditions, and the above method does not cover the compensation in this case.

[0005] Therefore, there is an urgent need to provide an error compensation method that can maintain the accuracy and stability of the internal clock of the electric energy meter. Compared with the existing technology, the compensation problem of the electric energy meter clock under the condition of alternating hot and cold is considered. Summary of the Invention

[0006] The present invention solves the technical problems existing in the prior art, and provides an error compensation method for maintaining the accuracy and stability of the internal clock of the electric energy meter.

[0007] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0008] An error compensation method for maintaining the accuracy and stability of the internal clock of the electric energy meter includes the following steps:

[0009] S1. Build a programmable constant temperature and humidity test chamber, and at the same time prepare multiple electric energy meters of the same model. Each electric energy meter is connected to a clock tester;

[0010] S2. Put all the electric energy meters into the programmable constant temperature and humidity test chamber for high and low temperature cyclic shock;

[0011] S3. After completing the high and low temperature cyclic shock, place it at normal temperature for at least 7 days;

[0012] S4. For the electric energy meters after completing step S3, within the working temperature range of the electric energy meters, set multiple temperature value points, control the programmable constant temperature and humidity test chamber, adjust the temperature to each temperature value point respectively, and place it for the same time at each temperature value point state, and record the clock error and temperature ADC value of each electric energy meter at different temperature value points;

[0013] S5. According to the clock error and temperature ADC value of each electric energy meter at different temperature value points, construct a clock error temperature curve;

[0014] S6. Configure the clock error temperature curve into the metering controller of the electric energy meter. The metering controller calculates the clock error of the electric energy meter according to the current temperature ADC value in the electric energy meter and the clock error temperature curve, and writes the clock error into the clock error compensation register in the metering control.

[0015] Further, the specific method for constructing the clock error temperature curve in step S5 is: according to the clock error and temperature ADC value of each electric energy meter at different temperature value points, construct a cubic compensation curve fitting between the clock error and the temperature ADC value to obtain the clock error temperature curve.

[0016] Furthermore, the expression of the clock error temperature curve is as follows:

[0017] ;

[0018] In the above formula, represents the clock error, represents the cubic coefficient, represents the ADC value of the current temperature of the electricity meter, represents the quadratic coefficient, represents the linear coefficient, represents the zero-order coefficient.

[0019] Furthermore, it further includes step S7. In step S7, the temperature of the programmable thermostatic and humidistatic test chamber is controlled to normal temperature, and all the electricity meters are placed for at least 48 hours, and then the clock error of each electricity meter after being placed at normal temperature is recorded, so as to adjust the parameter d in the clock error temperature curve, upload the adjusted parameter d to the metering controller, and adjust the clock error temperature curve.

[0020] Furthermore, the specific method for adjusting the parameter d in the clock error temperature curve in each electricity meter is: record the clock error of the electricity meter in step S7 as e, and then calculate the parameter d in the adjusted clock error temperature curve according to the following formula:

[0021] ;

[0022] In the above formula, represents the parameter d in the adjusted clock error temperature curve.

[0023] Further, the specific method for the high and low temperature cyclic shock in step S2 is: set four shock temperatures, and the four shock temperatures are 25 、70 、-25 、70 , and conduct shocks at these four shock temperatures of 25 、70 、-25 、70 in sequence. At each shock temperature, shock for at least 3 hours and cycle at least 3 rounds.

[0024] Furthermore, in step S2, use a clock tester to record the clock error of each electricity meter at each shock temperature during the high and low temperature cyclic shock. In step S3, according to the clock error at each shock temperature, calculate the clock stability coefficient of each electricity meter, set a stability coefficient threshold. When the clock stability coefficients of all the electricity meters are less than or equal to the stability coefficient threshold, then proceed to step S4. Otherwise, repeat steps S2 - S3.

[0025] Furthermore, the calculation method for the clock stability coefficient of each electricity meter is: take the clock errors at 25 in the last high and low temperature cyclic shock and the last 70 After the impact, the clock error is subtracted and the absolute value is taken. This absolute value is the clock stability coefficient calculated by the watt-hour meter.

[0026] Further, in step S1, the watt-hour meter outputs a second pulse signal to the clock tester through the pulse signal line to connect the watt-hour meter and the clock tester.

[0027] Further, the multiple temperature value points set in step S4 include the highest temperature value, the lowest temperature value, the normal temperature value within the operating temperature range of the watt-hour meter, and any other k temperature value points.

[0028] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0029] (1) The present invention accurately calibrates the clock of the watt-hour meter: By analyzing and applying the test verification data of the internal clock high and low temperature performance of a large number of watt-hour meter control chips, it is possible to more accurately calibrate the clock of the watt-hour meter based on the characteristics of the clock under different temperature environments and under cold and heat alternation, effectively reducing the timing error caused by temperature influence, and improving the accuracy and reliability of the overall timing of the watt-hour meter.

[0030] (2) The present invention optimizes the temperature compensation mechanism: The constructed temperature compensation model fully considers various factors such as the production equipment parameters and the clock error data of the watt-hour meter, and can perform intelligent corresponding compensation on the clock of the watt-hour meter according to different temperature conditions; under actual high and low temperature impacts, the clock of the watt-hour meter can operate stably and accurately.

[0031] (3) The present invention reduces the occurrence of abnormal problems: Considering the characteristics of abnormal problems and the life cycle, the calibration method and the temperature compensation model help to predict in advance various clock-related abnormal situations that may occur under high and low temperature working conditions; by timely calibration and reasonable compensation, the probability of abnormal problems such as the clock running too fast, too slow, or even stopping due to temperature factors is reduced, ensuring the long-term stable normal operation of the watt-hour meter, and reducing subsequent problems such as inaccurate metering caused by clock abnormalities after the watt-hour meter is actually installed on site.

[0032] (4) The present invention extends the service life of the watt-hour meter: From the perspective of the life cycle, due to accurate calibration and effective temperature compensation, the internal clock of the watt-hour meter can operate in a relatively suitable and stable state, avoiding the problem of accelerated decline in clock performance caused by long-term exposure to high and low temperature adverse working conditions.

[0033] (5) The present invention improves production efficiency and quality control: In the production process, based on the calibration method under high and low temperature shock and the temperature compensation model of curve fitting, the manufacturer can better perform targeted clock calibration and quality control on the product based on equipment parameters, etc.; in the production process, timely discover and solve related problems such as clock frequency deviation that may occur due to temperature influence, thereby improving the overall production efficiency and product quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a flow chart of the present invention.

[0035] Figure 2 It is a schematic diagram of the change of the clock error of the electric energy meter of the present invention during different times of high and low temperature shocks. DETAILED DESCRIPTION

[0036] The technical solution of the present invention will be clearly described below in conjunction with the accompanying drawings. Obviously, the described embodiments are not all embodiments of the present invention, and all other embodiments obtained by ordinary technicians in the field without making creative work are within the protection scope of the present invention.

[0037] like Figure 1 As shown, the present invention provides an error compensation method for maintaining the accuracy and stability of the internal clock of an electric energy meter, comprising the following steps:

[0038] S1. Build a high-precision programmable constant temperature and humidity test chamber. The programmable constant temperature and humidity test chamber is equipped with a temperature control device that can quickly increase or decrease the temperature. The preferred model of the programmable constant temperature and humidity test chamber is the GDJS-408D Aoke Environmental Test High and Low Temperature Alternating Humidity Test Chamber. The temperature control device controls the temperature fluctuation with an accuracy of ; At the same time, prepare multiple electric energy meters to be processed. The models of the prepared electric energy meters are the same, the initial status is normal, and there are no obvious faults; and select the clock tester as the reference clock source. The model of the clock tester is selected as HPU-1012. The electric energy meter outputs a second pulse signal (1Hz square wave signal) to the clock tester through the pulse signal line to achieve connectivity between the electric energy meter and the clock tester, and accurately monitor the operation of the electric energy meter clock in real time.

[0039] S2. After the electric energy meter is powered on, the program is burned into the electric energy meter, and the operation program of the MCU control chip inside the electric energy meter is recorded into the electric energy meter to make the electric energy meter work and run normally. All the electric energy meters are placed in a programmable constant temperature and humidity test box for high and low temperature cycle shock. The high and low temperature cycle shock is specifically: set four shock temperatures, the four shock temperatures are 25 , 70 , -25 , 70 , in order at 25 、70 、 - 25 、70 Perform impacts at these four impact temperatures, with each impact temperature lasting at least 3 hours and cycling at least 3 rounds; in this step, use a clock tester to record the clock errors of each watt-hour meter at each impact temperature during the high and low temperature cycling impact process.

[0040] S3. After completing the high and low temperature cycling impact, place it at room temperature (25 ) for 7 days or more, draw a graph based on the recorded clock errors at each impact temperature, as shown in Figure 2 . After each thermal shock (high and low temperature cycling impact), the clock error at each temperature will change, and according to Figure 2 , it can be concluded that after multiple thermal shocks, the clock of the watt-hour meter can tend to be stable, with less impact on the accuracy of the subsequent clock calibration work.

[0041] In step S3, it also includes calculating the clock stability coefficient of each watt-hour meter based on the clock error at each impact temperature, judging the clock stability coefficient, setting a stability coefficient threshold. When the clock stability coefficients of all watt-hour meters are less than or equal to the stability coefficient threshold, proceed to step S4; otherwise, repeat steps S2 - S3; the calculation method of the clock stability coefficient is: take the difference between the clock errors after the last high and low temperature cycling impact at 25 and the last 70 impact, and take the absolute value. The absolute value is the calculated clock stability coefficient of the corresponding watt-hour meter; the stability coefficient threshold is greater than 0 and less than or equal to 0.1, and the stability coefficient threshold is preferably 0.1.

[0042] S4. Within the operating temperature range of the watt-hour meter, set the highest temperature value, the lowest temperature value, the room temperature value, and any other k point temperature values, a total of k + 3 temperature value points. Control the programmable thermostatic and humidistatic test chamber and adjust it to these k + 3 temperature value points respectively. Stablely place it for 2 hours at each temperature value point state. During the placement period at each temperature value point, through the data acquisition system connected to the watt-hour meter, real-time monitor the operating state of the internal clock of the watt-hour meter, and record the clock errors and temperature ADC values of each watt-hour meter at different temperature value points.

[0043] S5. According to the clock errors and temperature ADC values of each watt-hour meter at different temperature value points, construct a cubic compensation curve fitting between the clock error and the temperature ADC value to obtain the clock error temperature curve, and the expression is as follows:

[0044] ;

[0045] In the above formula, represents the clock error, represents the cubic coefficient, represents the ADC value of the current temperature of the electricity meter, represents the quadratic coefficient, represents the linear coefficient, represents the zero-order coefficient.

[0046] S6. Configure the clock error temperature curve constructed in step S5 into the metering controller of the electricity meter. According to the real-time temperature at which the electricity meter is located, convert the real-time temperature into the ADC value of the current temperature of the electricity meter. The metering controller calculates the real-time clock error of the electricity meter based on the current temperature ADC value in the electricity meter and the clock error temperature curve, and writes the clock error into the clock error compensation register in the metering control to perform clock error calibration.

[0047] S7. Control the temperature of the programmable constant temperature and humidity test chamber to normal temperature. Place all the electricity meters in the programmable constant temperature and humidity test chamber for 48 hours. After 48 hours, record the clock errors of all the electricity meters after being placed at normal temperature. According to the recorded clock errors of all the electricity meters, adjust the parameter d in the clock error temperature curve, upload the adjusted parameter d to the metering controller, and adjust the clock error temperature curve; ensure that the clock errors of the electricity meters are accurately compensated in each temperature range, and recheck the clock parameters to check whether there is a "rebound" error due to sudden temperature changes.

[0048] The specific method for adjusting the parameter d in the clock error temperature curve of each electricity meter according to the recorded clock errors of all the electricity meters is as follows: Denote the clock error of the electricity meter after being placed at normal temperature recorded in step S7 as e, and then calculate the parameter d in the adjusted clock error temperature curve according to the following formula:

[0049] ;

[0050] In the above formula, represents the parameter d in the adjusted clock error temperature curve.

[0051] As Figure 2 shown, the error after trimming at normal temperature is close to 0. After 70 high temperatures and returning to normal temperature, the moderate error offset is the largest. The error will recover some after being placed at normal temperature overnight, and then recover some again after low temperature, and then the normal temperature error will become larger again after high temperature. The error as a whole presents a "wave" - shaped curve. After multiple high - low temperature cycle impacts, the clock error will gradually decrease.

[0052] Embodiment

[0053] In this embodiment, 12 electric energy meters are specifically selected, and the steps S1 - S3 are carried out in sequence for three high - low temperature cycle shocks. During the high - low temperature cycle shock, the errors at each shock temperature are shown in Table 1:

[0054] Table 1

[0055]

[0056] According to the results in Table 1, the clock stability coefficients of each electric energy meter are calculated. It can be obtained that except for the electric energy meter No. 44, the absolute values of the clock stability coefficients of the other electric energy meters are between 0 and 0.1. Therefore, the steps S4 - S7 are carried out for these 11 electric energy meters. Among them, the k + 3 temperature value points, their corresponding ADC values, and clock errors are shown in Table 2:

[0057] Table 2

[0058]

[0059] According to the data in Table 2, the obtained clock error - temperature curve has the following expression:

[0060] .

[0061] Therefore, the corresponding a is and b is and c is and d is .

[0062] In the present invention, the clock of the electricity meter is accurately calibrated. Through the analysis and application of a large amount of test verification data on the high and low temperature performance of the internal clock of the electricity meter control chip, it is possible to more accurately calibrate the clock of the electricity meter based on the characteristics shown by the clock in different temperature environments and under alternating hot and cold conditions, effectively reducing the timing error caused by temperature effects and improving the accuracy and reliability of the overall timing of the electricity meter. The temperature compensation mechanism is optimized. The constructed temperature compensation model fully considers various factors such as the parameters of the produced equipment and the clock error data of the electricity meter, and can perform intelligent corresponding compensation for the clock of the electricity meter according to different temperature conditions, enabling the clock of the electricity meter to operate stably and accurately under actual high and low temperature impacts. The occurrence of abnormal problems is reduced. Considering the characteristics of abnormal problems and the life cycle, the calibration method and the temperature compensation model help to predict in advance various clock-related abnormal situations that may occur under high and low temperature working conditions. By timely calibration and reasonable compensation, the probability of abnormal problems such as the clock running too fast, too slow, or even stopping due to temperature factors is reduced, ensuring the long-term stable normal operation of the electricity meter and reducing subsequent problems such as inaccurate metering caused by clock abnormalities after the electricity meter is actually installed on site. The service life of the electricity meter is extended. From the perspective of the life cycle, due to accurate calibration and effective temperature compensation, the internal clock of the electricity meter can operate in a relatively suitable and stable state, avoiding the problem of accelerated decline in clock performance caused by long-term exposure to high and low temperature adverse working conditions. The production efficiency and quality control are improved. In the production link, based on the calibration method under high and low temperature impacts and the temperature compensation model of curve fitting, the manufacturer can better calibrate the clock and control the quality of the product according to the equipment parameters, etc. Timely discover and solve related problems such as clock frequency deviation that may occur due to temperature effects during the production process, improving the overall production efficiency and the quality of the product when it leaves the factory.

[0063] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, rather than a limitation on the protection scope of the present invention. Any simple modification or equivalent replacement of the technical solution of the present invention by those of ordinary skill in the art does not depart from the essence and scope of the technical solution of the present invention.

Claims

1. An error compensation method for maintaining accurate and stable internal clock accuracy of an electric energy meter, characterized in that It includes the following steps: S1. Set up a programmable constant temperature and humidity test chamber, and prepare multiple watt-hour meters of the same model at the same time. Each watt-hour meter is connected to a clock tester; S2. Place all the electricity meters in a programmable thermostatic and humidistatic test chamber for high and low temperature cyclic shock. During the high and low temperature cyclic shock, set four shock temperatures, which are 25 , 70 , -25 , 70 . Use a clock tester to record the clock errors of each electricity meter at each shock temperature during the high and low temperature cyclic shock; S3. After completing the high and low temperature cycle shock, place it at room temperature for at least 7 days. Calculate the clock stability coefficient of each electricity meter according to the clock error at each shock temperature, and set the stability coefficient threshold. When the clock stability coefficients of all electricity meters are less than or equal to the stability coefficient threshold, proceed to step S4; otherwise, repeat steps S2 - S3. The calculation method for the clock stability coefficient of each electricity meter is as follows: Take the absolute value of the difference between the clock error after the last high and low temperature cycle shock at 25 and the clock error after the last shock at 70 . The absolute value is the calculated clock stability coefficient of this electricity meter; S4. For the watt-hour meters after completing step S3, within the operating temperature range of the watt-hour meters, set multiple temperature value points, control the programmable constant temperature and humidity test chamber, adjust the temperature to each temperature value point respectively, place for the same time at each temperature value point state, and record the clock error and temperature ADC value of each watt-hour meter at different temperature value points; S5. Construct a clock error-temperature curve according to the clock error and temperature ADC value of each watt-hour meter at different temperature value points; S6. Configure the clock error-temperature curve into the metering controller of the watt-hour meter. The metering controller calculates the clock error of the watt-hour meter according to the current temperature ADC value in the watt-hour meter and the clock error-temperature curve, and writes the clock error into the clock error compensation register in the metering control; 2. A method for error compensation to maintain accurate and stable internal clock accuracy of an electric energy meter according to claim 1, characterized in that, The specific method for constructing the clock error-temperature curve in step S5 is: according to the clock error and temperature ADC value of each watt-hour meter at different temperature value points, construct a cubic compensation curve fitting between the clock error and the temperature ADC value to obtain the clock error-temperature curve; 3. A method for error compensation to maintain accurate and stable internal clock accuracy of an electric energy meter according to claim 2, characterized in that, The expression of the clock error-temperature curve is as follows: ； In the above formula, represents the clock error, represents the cubic coefficient, represents the current ADC value of the electricity meter temperature, represents the quadratic coefficient, represents the linear coefficient, represents the zero - order coefficient.

4. An error compensation method for maintaining the accuracy and stability of the internal clock of an electric energy meter according to claim 3, characterized in that, It also includes step S7. In step S7, control the temperature of the programmable constant temperature and humidity test chamber to normal temperature, place all the watt-hour meters for at least 48 hours, then record the clock error of each watt-hour meter after being placed at normal temperature, thereby adjusting the parameter d in the clock error-temperature curve, uploading the adjusted parameter d to the metering controller, and adjusting the clock error-temperature curve; 5. A method for error compensation to maintain accurate and stable internal clock accuracy of an electric energy meter according to claim 4, characterized in that, The specific method for adjusting the parameter d in the clock error-temperature curve in each watt-hour meter is: record the clock error of the watt-hour meter in step S7 as e, and then calculate the parameter d in the adjusted clock error-temperature curve according to the following formula; ； In the above formula, represents the parameter d in the adjusted clock error temperature curve.

6. A method for error compensation to maintain accurate and stable internal clock accuracy of an electric energy meter according to claim 1, characterized in that The specific method of high and low temperature cyclic shock in step S2 is as follows: successively perform shocks at the four shock temperatures of 25 , 70 , -25 , 70 For each shock temperature, shock for at least 3 hours and cycle at least 3 rounds.

7. A method for error compensation to maintain accurate and stable internal clock accuracy of an electric energy meter according to claim 1, characterized in that, In step S1, the watt-hour meter outputs a second pulse signal to the clock tester through a pulse signal line to realize the connection between the watt-hour meter and the clock tester; 8. A method for error compensation to maintain accurate and stable internal clock accuracy of an electric energy meter according to claim 1, characterized in that, The multiple temperature value points set in step S4 include the highest temperature value, the lowest temperature value, the normal temperature value within the operating temperature range of the watt-hour meter, and any other k point temperature values.

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