A current sampling circuit

Abstract

A current sampling circuit, the fifth resistor and the sixth resistor are connected to the first sampling line and the second sampling line connected by the manganin shunt, so that the current will not flow in the direction of the first resistor and the second resistor, thereby affecting the electric energy The meter measures normally; the fifth resistor and the sixth resistor are added, so that the current flows from the fifth resistor and the sixth resistor to the input terminal of the power transformer, which can effectively prevent the smart meter from running quickly or not; and the measurement error is in Under the basic current and voltage, it can meet the accuracy requirements of national standards, and at the same time, it can accurately measure the electric energy consumed by users, reducing various economic disputes and energy measurement losses.

Description

technical field [0001] The invention relates to the technical field of electric energy measurement, in particular to a current sampling circuit. Background technique [0002] The smart meter is the smart terminal of the smart grid. It is no longer an electric energy meter in the traditional sense. In addition to the basic power consumption measurement function of the traditional electric energy meter, the smart meter also has two-way multiple functions in order to adapt to the use of smart grid and new energy. Intelligent functions such as rate metering function, user-end control function, two-way data communication function of multiple data transmission modes, and anti-theft function. [0003] The primary condition for the accuracy of electric energy measurement of smart meters is the accuracy of sampling, and the current internal sampling of smart meters basically adopts the method of manganese copper for current sampling, which can not only sample the AC component but als...

AI Technical Summary

Problems solved by technology

[0003] The primary condition for the accuracy of electric energy measurement of smart meters is the accuracy of sampling, and the current internal sampling of smart meters basically adopts the method of manganese copper for current sampling, which can not only sample the AC component but also the DC component to ensure normal measurement; However, the live wire on the manganese copper is used as the ground wire of the smart meter. When the live wire on the manganese copper is disconnected and not connected, the smart meter will not be able to measure accurately, and the error value will even reach 99.9%, which cannot meet the current state grid products. Level 2 Accuracy requirements of the table

[0004] Since the smart meter is a metering product, inaccurate metering is a major quality problem. Once it happens, it will cause economic disputes, and serious lawsuits. There is no good solution to this kind of problem, which has been plagued by the industry. Enterprises and State Grid Corporation of China

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