Error compensation method for keeping accuracy and stability of internal clock precision of electric energy meter

Abstract

The invention relates to the technical field of electric power, in particular to an error compensation method for keeping accurate and stable clock precision in an electric energy meter. Comprising the following steps: S1, building a programmable constant-temperature and constant-humidity test box, and preparing a plurality of electric energy meters with the same model at the same time; s2, performing high and low temperature cycle impact; s3, after the high and low temperature cycle impact is completed, placing for at least 7 days in a normal temperature state; s4, setting k + 3 temperature value point positions, respectively adjusting the temperature of the programmable constant temperature and humidity test box to the k + 3 temperature value point positions, and recording clock errors and temperature ADC values of each electric energy meter at different temperature value point positions; s5, constructing a clock error temperature curve; s6, configuring the clock error temperature curve into a metering controller of the electric energy meter, and calculating a real-time clock error of the electric energy meter; the problem of keeping the clock of the electric energy meter accurate after frequent cooling and heating alternation of the electric energy meter is considered.

Description

Technical Field

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

[0002] The electric energy meter is a key device in the field of electricity measurement and management. It has a series of diverse and vital functions and is deeply embedded in all aspects of modern power system operation and users' electricity consumption life. 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. It plays a vital role in load monitoring and forecasting assistance, power grid fault monitoring and time tracing, and multi-meter data synchronization.

[0003] However, the DC energy meter used to accurately measure large currents is installed in the compact internal circuit system of the charging pile. When the system is in high-current load charging mode, a large current surges into the energy meter shunt. The shunt is generally made of manganese copper material and has good conductivity, but due to its own resistance, under the long-term and high-intensity impact of large current, its temperature rises sharply. Because there are many metal devices in the energy meter and various types of sophisticated electronic components are complicated, the energy meter is at a high temperature as a whole; however, as the load decreases, the temperature of the energy meter gradually decreases and basically remains consistent with the room temperature. This frequent hot and cold shock may cause the internal clock of the energy meter controller to fail the re-check clock error after a period of time after calibration, and even have a certain impact on the life. Therefore, how to calibrate the internal clock of the energy meter according to the temperature shock so that other modules of the system can operate normally is a key problem that needs to be solved.

[0004] Chinese patent CN117289587A discloses a calibration system and method for real-time clock calibration of power management equipment. The power management equipment includes a concentrator and an electric energy meter in an electric power information system. The controller in the system is respectively connected to a high and low temperature box, multiple first temperature sensors, at least one daily time calibrator, an ambient temperature adjustment device, at least one second temperature sensor and a first multi-way selection device. Through the control of the controller, a stable calibration environment temperature and ambient temperature can be provided for the power management equipment and the daily time calibrator, effectively ensuring the reliability of the calibration process and providing environmental protection for high-precision calibration of the real-time clock of the power management equipment; by ensuring the stability of the calibration environment temperature, reliable real-time data can be provided for obtaining the compensation curve for time-domain segmented interpolation compensation of the power management equipment, thereby effectively improving the calibration efficiency of the power management equipment and greatly improving the accuracy of the compensation curve for time-domain segmented interpolation compensation. However, in actual use, the electric energy meter may be used alternately between hot and cold, and the compensation in this case is not involved in the above method.

[0005] Therefore, there is an urgent need to provide an error compensation method that maintains 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 alternating hot and cold conditions 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 an internal clock of an electric energy meter.

[0007] To achieve the above purpose, the technical solution adopted by the present invention is as follows: An error compensation method for maintaining the accuracy and stability of an internal clock of an electric energy meter comprises the following steps: S1. Build a programmable constant temperature and humidity test chamber and prepare multiple electric energy meters of the same model. Each electric energy meter is connected to the clock tester. S2. Place all the electric energy meters in a programmable constant temperature and humidity test chamber and subject them to high and low temperature cycle shock; S3. After completing the high and low temperature cycle shock, place it at room temperature for at least 7 days; S4. For the electric energy meter after completing step S3, multiple temperature value points are set within the working temperature range of the electric energy meter, and the programmable constant temperature and humidity test chamber is controlled to adjust the temperature to each temperature value point respectively, and each temperature value point is placed for the same time, and the clock error and temperature ADC value of each electric energy meter at different temperature value points are recorded; S5. construct a clock error temperature curve according to the clock error and temperature ADC value of each electric energy meter at different temperature value points; S6. The clock error temperature curve is configured in 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.

[0008] Furthermore, 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, a cubic compensation curve fitting between the clock error and the temperature ADC value is constructed to obtain the clock error temperature curve.

[0009] Furthermore, the expression of the clock error temperature curve is as follows: ; In the above formula, represents the clock error, represents the cubic coefficient, Indicates the current ADC value of the electric energy meter temperature. represents the quadratic coefficient, represents the first-order coefficient, Represents the zero-order coefficient.

[0010] Furthermore, step S7 is also included. In step S7, the temperature of the programmable constant temperature and humidity test chamber is controlled to normal temperature, all the electric energy meters are placed for at least 48 hours, and then the clock error of each electric energy meter after being placed at normal temperature is recorded, so as to adjust the parameter d in the clock error temperature curve, and the adjusted parameter d is uploaded to the metering controller to adjust the clock error temperature curve.

[0011] Furthermore, the specific method for adjusting the parameter d in the clock error temperature curve in each electric energy meter is: the clock error of the electric energy meter recorded in step S7 is recorded as e, and then the parameter d in the adjusted clock error temperature curve is calculated according to the following formula: ; In the above formula, Denotes parameter d in the adjusted clock error temperature curve.

[0012] Furthermore, the specific method of high and low temperature cycle shock in step S2 is: setting four shock temperatures, the four shock temperatures are 25 , 70 , -25 , 70 , in order at 25 , 70 , -25 , 70 The impact was carried out at these four impact temperatures, with each impact temperature lasting at least 3 hours and repeated for at least 3 rounds.

[0013] Furthermore, in step S2, a clock tester is used to record the clock error of each electric energy meter at each impact temperature during the high and low temperature cycle impact process. In step S3, the clock stability coefficient of each electric energy meter is calculated based on the clock error at each impact temperature, and a stability coefficient threshold is set. When the clock stability coefficients of all electric energy meters are less than or equal to the stability coefficient threshold, step S4 is performed, otherwise steps S2-S3 are repeated.

[0014] Furthermore, the calculation method of the clock stability coefficient of each electric energy meter is as follows: And the last 70 The clock error after the impact is subtracted and its absolute value is taken, and the absolute value is the clock stability coefficient calculated by the electric energy meter.

[0015] Furthermore, in step S1, the electric energy meter outputs a second pulse signal to the clock tester through the pulse signal line, thereby achieving connectivity between the electric energy meter and the clock tester.

[0016] Furthermore, the multiple temperature value points set in step S4 include the highest temperature value, the lowest temperature value, the normal temperature value and any other k temperature value points within the operating temperature range of the electric energy meter.

[0017] Compared with the prior art, the present invention has the following beneficial effects: (1) The present invention accurately calibrates the clock of an electric energy meter: by analyzing and applying a large amount of high and low temperature performance test verification data of the internal clock of the electric energy meter control chip, the electric energy meter clock can be calibrated more accurately based on the characteristics of the clock under different temperature environments and alternating hot and cold conditions, effectively reducing the timing error caused by temperature influence and improving the accuracy and reliability of the overall timing of the electric energy meter.

[0018] (2) The present invention optimizes the temperature compensation mechanism: the constructed temperature compensation model fully considers various factors such as production equipment parameters and electric energy meter clock error data, and can perform intelligent compensation for the electric energy meter clock according to different temperature conditions; it allows the electric energy meter clock to operate stably and accurately under actual high and low temperature shocks.

[0019] (3) The present invention reduces the occurrence of abnormal problems: Taking into account the characteristics of abnormal problems and the life cycle, the calibration method and temperature compensation model help to predict in advance various clock-related abnormal situations that may occur under high and low temperature conditions; through timely calibration and reasonable compensation, the probability of abnormal problems caused by temperature factors, such as the clock running too fast, too slow, or even stopping, is reduced, ensuring the long-term stable and normal operation of the electric energy meter, and reducing subsequent problems such as inaccurate measurement caused by clock abnormalities after the electric energy meter is actually installed on site.

[0020] (4) The present invention extends the service life of the electric energy meter: From the perspective of the life cycle, due to precise calibration and effective temperature compensation, the internal clock of the electric energy meter can operate in a relatively suitable and stable state, avoiding the problem of accelerated clock performance degradation caused by long-term exposure to high and low temperature adverse working conditions.

[0021] (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

[0022] Figure 1 It is a flow chart of the present invention.

[0023] Figure 2It 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

[0024] 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.

[0025] 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: 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.

[0026] 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 The shocks are carried out at these four shock temperatures, with each shock temperature being subjected to at least 3 hours of shock and at least 3 cycles. In this step, a clock tester is used to record the clock error of each electric energy meter at each shock temperature during the high and low temperature cycle shock process.

[0027] S3, after completing the high and low temperature cycle shock, normal temperature (25 ) for 7 days or more, and plot the clock error at each shock temperature recorded, such as Figure 2As shown in the figure, after each thermal shock (high and low temperature cycle shock), the error of the clock at each temperature will change, and according to Figure 2 It can be concluded that the clock of the electric energy meter can become stable only after multiple hot and cold shocks, which has little impact on the accuracy of the subsequent clock calibration work.

[0028] In step S3, the clock stability coefficient of each electric energy meter is calculated according to the clock error at each shock temperature, and the clock stability coefficient is judged and a stability coefficient threshold is set. When the clock stability coefficients of all electric energy meters are less than or equal to the stability coefficient threshold, step S4 is performed, otherwise, step S2-step S3 are performed again; the calculation method of the clock stability coefficient is: the clock stability coefficient of the last high and low temperature cycle shock for 25 And the last 70 The clock error after the impact is subtracted and the absolute value is taken. The absolute value is the clock stability coefficient calculated by the corresponding electric energy 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.

[0029] S4. Within the working temperature range of the electric energy meter, set the highest temperature value, the lowest temperature value, the normal temperature value and any other k temperature points, a total of k+3 temperature points, control the programmable constant temperature and humidity test chamber, adjust to these k+3 temperature points respectively, and place it stably at each temperature point for 2 hours. During the placement at each temperature point, monitor the operating status of the internal clock of the electric energy meter in real time through the data acquisition system connected to the electric energy meter, and record the clock error and temperature ADC value of each electric energy meter at different temperature points.

[0030] S5. According to the clock error and temperature ADC value of each electric energy meter at different temperature value points, a cubic compensation curve fitting between the clock error and the temperature ADC value is constructed to obtain a clock error temperature curve, which is expressed as follows: ; In the above formula, represents the clock error, represents the cubic coefficient, Indicates the current ADC value of the electric energy meter temperature. represents the quadratic coefficient, represents the first-order coefficient, Represents the zero-order coefficient.

[0031] S6. Configure the clock error temperature curve constructed in step S5 into the metering controller of the electric energy meter. According to the real-time temperature of the electric energy meter, convert the real-time temperature into the current electric energy meter temperature ADC value. The metering controller calculates the real-time 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 to calibrate the clock error.

[0032] S7. Control the temperature of the programmable constant temperature and humidity test chamber to room temperature, place all the electric energy meters in the programmable constant temperature and humidity test chamber for 48 hours, and after 48 hours, record the clock errors of all the electric energy meters after being placed at room temperature, and adjust the parameter d in the clock error temperature curve according to the recorded clock errors of all the electric energy meters. Upload the adjusted parameter d to the metering controller and adjust the clock error temperature curve; ensure that the clock error of the electric energy meter is accurately compensated in each temperature range, and re-check the clock parameters to check whether there is a "rebound" error due to a sudden temperature change.

[0033] The specific method of adjusting the parameter d in the clock error temperature curve in each electric energy meter according to the clock errors of all the electric energy meters recorded is as follows: the clock error of the electric energy meter after being placed at normal temperature recorded in step S7 is recorded as e, and then the parameter d in the adjusted clock error temperature curve is calculated according to the following formula: ; In the above formula, Denotes parameter d in the adjusted clock error temperature curve.

[0034] like Figure 2 As shown in the figure, the error after normal temperature adjustment is close to 0. The moderate error offset is the largest after high temperature and recovery to normal temperature. The error will recover a little after being placed at normal temperature overnight. After passing through low temperature, the normal temperature error will recover a little again. After passing through high temperature again, the normal temperature error of the clock will become larger. The overall error presents a "wave" curve. After multiple high and low temperature cycle shocks, the clock error will gradually decrease.

[0035] Example In this embodiment, 12 electric energy meters are specifically selected, and steps S1-S3 are performed in sequence to perform three high and low temperature cycle shocks. During the high and low temperature cycle shock process, the error at each shock temperature is shown in Table 1: Table 1

[0036] According to the results in Table 1, the clock stability coefficient of each electric energy meter is calculated. It can be found that except for the electric energy meter No. 44, the absolute values ​​of the clock stability coefficients of the remaining electric energy meters are between 0 and 0.1; therefore, the steps S4-S7 are performed on the 11 electric energy meters, where the k+3 temperature value points, their corresponding ADC values, and clock errors are shown in Table 2: Table 2

[0037] According to the data in Table 2, the obtained clock error temperature curve is expressed as follows: .

[0038] Therefore, the corresponding a is , b is , c is d is .

[0039] In the present invention, the clock of the electric energy meter is accurately calibrated: by analyzing and applying the high and low temperature performance test verification data of the internal clock of a large number of electric energy meter control chips, the clock of the electric energy meter can be calibrated more accurately according to the characteristics of the clock under different temperature environments and alternating hot and cold conditions, effectively reducing the timing error caused by temperature influence, and improving the accuracy and reliability of the overall timing of the electric energy meter. Optimize the temperature compensation mechanism: The constructed temperature compensation model fully considers various factors such as the production equipment parameters and the error data of the electric energy meter clock, and can intelligently compensate the clock of the electric energy meter according to different temperature conditions; under the actual high and low temperature impact, the electric energy meter clock can run stably and accurately. Reduce the occurrence of abnormal problems: considering the characteristics of abnormal problems and the life cycle, the calibration method and temperature compensation model help to predict in advance various abnormal situations related to the clock that may occur under high and low temperature conditions; through timely calibration and reasonable compensation, the probability of abnormal problems such as the clock running too fast, too slow, or even stopping caused by temperature factors is reduced, ensuring the long-term stable normal operation of the electric energy meter, and reducing the subsequent problems such as inaccurate measurement caused by abnormal clocks after the electric energy meter is actually installed on site. Extend the service life of the energy meter: From the perspective of the life cycle, due to precise calibration and effective temperature compensation, the internal clock of the energy meter can operate in a relatively suitable and stable state, avoiding the problem of accelerated clock performance degradation caused by long-term exposure to high and low temperature conditions. Improve production efficiency and quality control: In the production process, based on the calibration method under high and low temperature shocks and the temperature compensation model of curve fitting, manufacturers can better perform targeted clock calibration and quality control on products based on equipment parameters, etc.; in the production process, timely discover and solve related problems such as clock frequency offset that may occur due to temperature, and improve overall production efficiency and product quality.

[0040] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, rather than to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions of the technical solution of the present invention by ordinary technicians in this field do not deviate from the essence and scope of the technical solution of the present invention.

Claims

1. An error compensation method for maintaining the accuracy and stability of the internal clock of an electric energy meter, characterized in that: The following steps are involved: S1. Build a programmable constant temperature and humidity test chamber and prepare multiple electric energy meters of the same model. Each electric energy meter is connected to the clock tester. S2. Place all the electric energy meters in a programmable constant temperature and humidity test chamber and subject them to high and low temperature cycle shock; S3. After completing the high and low temperature cycle shock, place it at room temperature for at least 7 days; S4. For the electric energy meter after completing step S3, multiple temperature value points are set within the working temperature range of the electric energy meter, and the programmable constant temperature and humidity test chamber is controlled to adjust the temperature to each temperature value point respectively, and each temperature value point is placed for the same time, and the clock error and temperature ADC value of each electric energy meter at different temperature value points are recorded; S5. construct a clock error temperature curve according to the clock error and temperature ADC value of each electric energy meter at different temperature value points; S6. The clock error temperature curve is configured in 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.

2. The error compensation method for maintaining the accuracy and stability of the internal clock of an electric energy meter according to claim 1, characterized in that: The specific method of 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, a cubic compensation curve fitting between the clock error and the temperature ADC value is constructed to obtain the clock error temperature curve.

3. The error compensation method for maintaining the accuracy and stability of the internal clock 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, Indicates the current ADC value of the electric energy meter temperature. represents the quadratic coefficient, represents the first-order coefficient, Represents the zero-order coefficient.

4. The error compensation method for maintaining the accuracy and stability of the internal clock of an electric energy meter according to claim 3 is characterized in that: It also includes step S7, in which the temperature of the programmable constant temperature and humidity test box is controlled to normal temperature, all the electric energy meters are placed at least 48 hours, and then the clock error of each electric energy 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.

5. The error compensation method for maintaining the accuracy and stability of the internal clock of the electric energy meter according to claim 4 is characterized in that: The specific method for adjusting the parameter d in the clock error temperature curve in each electric energy meter is as follows: the clock error of the electric energy meter recorded in step S7 is recorded as e, and then the parameter d in the adjusted clock error temperature curve is calculated according to the following formula: ； In the above formula, Denotes parameter d in the adjusted clock error temperature curve.

6. The error compensation method for maintaining the accuracy and stability of the internal clock of an electric energy meter according to claim 1, characterized in that: The specific method of high and low temperature cycle shock in step S2 is: set four shock temperatures, the four shock temperatures are 25 , 70 , -25 , 70 , in order at 25 , 70 , -25 , 70 The impact was carried out at these four impact temperatures, with each impact temperature lasting at least 3 hours and repeated for at least 3 rounds.

7. The error compensation method for maintaining the accuracy and stability of the internal clock of an electric energy meter according to claim 6, characterized in that: In step S2, a clock tester is used to record the clock error of each electric energy meter at each impact temperature during the high and low temperature cycle impact process. In step S3, the clock stability coefficient of each electric energy meter is calculated based on the clock error at each impact temperature, and a stability coefficient threshold is set. When the clock stability coefficients of all electric energy meters are less than or equal to the stability coefficient threshold, step S4 is performed, otherwise steps S2-S3 are repeated.

8. The error compensation method for maintaining the accuracy and stability of the internal clock of an electric energy meter according to claim 7, characterized in that: The calculation method of the clock stability coefficient of each electric energy meter is as follows: And the last 70 The clock error after the impact is subtracted and its absolute value is taken, and the absolute value is the clock stability coefficient calculated by the electric energy meter.

9. The error compensation method for maintaining the accuracy and stability of the internal clock of an electric energy meter according to claim 1, characterized in that: In step S1, the electric energy meter outputs a second pulse signal to the clock tester through the pulse signal line, thereby achieving connectivity between the electric energy meter and the clock tester.

10. The error compensation method for maintaining the accuracy and stability of the internal clock 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, and any other k temperature value points within the working temperature range of the electric energy meter.

Images