A method to improve the precision of built-in real-time clock of energy meter mcu

Abstract

The invention discloses a method for improving the precision of a built-in real-time clock of an electric energy meter MCU. Based on the practical crystal oscillator frequency, fine compensation can be achieved. An electric energy meter comprises the MCU, a crystal oscillator and a power management unit. The method for improving the precision of the built-in real-time clock of the electric energy meter MCU includes the following steps of compensation amount calculation and clock calibration. Compensation amount calculation is performed according to the following processes that firstly, frequency deviations of the practical crystal oscillator under different temperatures are measured; secondly, a temperature-frequency deviation curve sketch is drawn, and the turn temperature T0 is found out; thirdly, the measured frequency deviations of the two sides of T0 undergo curve fitting, and a corresponding buckling constant is obtained; fourthly, a temperature-frequency deviation function table is formed according to a function of the third process, the frequency deviation value of the current temperature can be obtained through the temperature-frequency deviation function table according to the practical environmental temperature, and the frequency deviation value serves as the compensation amount for calibrating the clock under the practical environmental temperature. According to the method for improving the precision of the built-in real-time clock of the electric energy meter MCU, an accurate compensation value can be obtained according to errors of the practical crystal oscillator, and therefore the precision of the clock is improved.

Description

technical field

[0001] The invention relates to a method for improving the precision of a real-time clock (RTC) built into an MCU of an electric energy meter. Background technique

[0002] As a metering product for electric energy metering and electricity bill settlement, smart energy meters are required to have stable and accurate metering performance, so as to ensure that the interests of both electricity consumers and power suppliers are not damaged. At present, smart energy meters generally have time-sharing and multi-rate energy meters, and the requirements for time accuracy are getting higher and higher, and the problem of daily timing errors is also more prominent. In the rectification notice issued by the supplier, both Article 2 "Components Link" and Article 11 "Design and Manufacturing Process Link" focused on the problem of daily timekeeping error out-of-tolerance, requiring key rectification. According to the technical specifications of the smart energy meter of...

Examples

Embodiment Construction

[0032] The present invention as Figure 1-4 As shown: the electric energy meter includes an MCU, a crystal oscillator and a power management unit, and the power management unit is connected to a battery and a regulated power supply through a power supply circuit;

[0033] It includes the following steps: calculating the compensation amount and correcting the clock;

[0034] The calculation of the compensation amount is carried out according to the following process:

[0035] 1) Measure the frequency deviation of the actual crystal oscillator at different temperatures;

[0036] 2) Draw a sketch of the temperature-frequency deviation curve and find out the turning temperature T 0 ;

[0037] 3), respectively for T 0 The frequency deviation measured on both sides is used for curve fitting to obtain the corresponding curvature constant.

[0038] 3.1), when T0 When , the curvature constant K of the temperature and frequency offset function is fitted according to the measured va...

technical field

[0001] The invention relates to a method for improving the precision of a real-time clock (RTC) built into an MCU of an electric energy meter. Background technique

[0002] As a metering product for electric energy metering and electricity bill settlement, smart energy meters are required to have stable and accurate metering performance, so as to ensure that the interests of both electricity consumers and power suppliers are not damaged. At present, smart energy meters generally have time-sharing and multi-rate energy meters, and the requirements for time accuracy are getting higher and higher, and the problem of daily timing errors is also more prominent. In the rectification notice issued by the supplier, both Article 2 "Components Link" and Article 11 "Design and Manufacturing Process Link" focused on the problem of daily timekeeping error out-of-tolerance, requiring key rectification. According to the technical specifications of the smart energy meter of...

Examples

Embodiment Construction

[0032] The present invention as Figure 1-4 As shown: the electric energy meter includes an MCU, a crystal oscillator and a power management unit, and the power management unit is connected to a battery and a regulated power supply through a power supply circuit;

[0033] It includes the following steps: calculating the compensation amount and correcting the clock;

[0034] The calculation of the compensation amount is carried out according to the following process:

[0035] 1) Measure the frequency deviation of the actual crystal oscillator at different temperatures;

[0036] 2) Draw a sketch of the temperature-frequency deviation curve and find out the turning temperature T 0 ;

[0037] 3), respectively for T 0 The frequency deviation measured on both sides is used for curve fitting to obtain the corresponding curvature constant.

[0038] 3.1), when T0 When , the curvature constant K of the temperature and frequency offset function is fitted according to the measured va...

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