Method for dynamically adjusting current channel gain of wide-range electric energy meter

Abstract

The invention relates to a method for dynamically adjusting the current channel gain of a wide-range electric energy meter. The method comprises the following steps of: (1) partitioning an entire measuring range into a plurality of measuring ranges on an MCU (Microprogrammed Control Unit) module of the electric energy meter, wherein an overlap region exists between every two adjacent measuring ranges, and every measuring range corresponds to a gain value; and (2) making the MCU module of the electric energy meter receive a signal from an ADC (Analog to Digital Converter) module to compute the input value of a signal input end and adjust the gain value of a programmable gain amplifier according to a measuring range at which the input value is positioned, wherein the gain value of the programmable gain amplifier is not adjusted by the MCU module of the electric energy meter when the input value is in the overlap region. According to the method, dynamic gain can be performed on an input current signal to meet the requirements of a high-magnification and high-accuracy electric energy meter, and repeated jitter of gain switching can be prevented simultaneously.

Description

【Technical field】 [0001] The invention relates to a control method for measuring instruments and meters, in particular to a method for dynamically adjusting current channel gain of a wide-range electric energy meter. 【Background technique】 [0002] With the promotion of the country's strong smart grid, the measurement accuracy and dynamic range requirements of the smart meter are continuously improved by various power consumption units and power companies. The chip and the energy meter MCU module, the operational amplifier is equipped with a current signal input terminal, because the operational amplifier is set with a fixed magnification to amplify the input current signal, although this can guarantee the measurement accuracy of the small current point to a certain extent, but the overall Therefore, the dynamic range of the meter is limited and cannot meet the market demand for high-magnification meters; or an ADC conversion chip with a higher sampling number is selected, b...

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Problems solved by technology

[0002] With the promotion of the country's strong smart grid, the measurement accuracy and dynamic range requirements of the smart meter are continuously improved by various power consumption units and power companies. The chip and the energy meter MCU module, the operational amplifier is equipped with a current signal input terminal, because the operational amplifier is set with a fixed magnification to amplify the input current signal, although this can guarantee the measurement accuracy of the small current point to a certain extent, but the overall Therefore, the dynamic range of the meter is limited and cannot meet the market demand for high-magnification meters; or an ADC conversion chip with a higher sampling number is selected, but the price of this type of chip is very expensive, which is several times the price of a general ADC conversion chip, so it cannot be used. generally adopted

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