Electric energy meter with wide range and adaptive adjusting method of current channel thereof

Abstract

The invention discloses a wide-range electric energy meter and its current channel adaptive adjustment method, wherein the electric energy meter includes a group of first sampling transformers CT for measuring small current signals ₁ , a set of second sampling transformers CT for measuring large current signals ₂ , an electronic switch MUX, a metering chip and an MCU microcontroller; the signal input end of the metering chip is connected to the first sampling transformer CT respectively through the electronic switch MUX ₁ and the second sampling transformer CT ₂ connection; the MCU single-chip computer communicates with the metering chip through the SPI bus with DMA transfer function; the MCU single-chip computer is connected with the electronic switch MUX through the I/O port, and is used to control the switching of the electronic switch MUX. The invention is a multi-range measurement, and the current within the full range of 1 (100) A, especially the measurement point below 5% of the basic current, can also be accurately measured.

Description

technical field [0001] The invention relates to a wide-range electric energy meter and a method for self-adapting the current channel. Background technique [0002] At present, since 2009, with the large-scale development of smart grid construction in my country, the demand for electric energy meters on the low-voltage side is gradually increasing, and the general electric energy meter specifications are determined according to 6 to 12 times the calibrated current, resulting in many Electric energy meters with various current specifications, such as 1.5 (6) A, 1 (10) A, 5 (60) A, 10 (100) A and other specifications. Due to the large number of current specifications, it is inevitable to bring a large amount of redundant workload to power users in meter inspection, distribution, installation and maintenance, and it also brings convenience to malicious electricity theft. At the same time, in order to match the design and production of electric energy meters with various current...

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Problems solved by technology

However, if you choose a smaller pulse constant in the selection of the pulse constant, it will be too slow in the verification of small currents and will bring workload to the verification; if you choose a larger pulse constant, the pulse width will not reach the power grid when the current is high. Each pulse width required by the company should be 80ms±15ms

[0007] 2) If two sets of sampling transformers or one set of sampling transformers and one set of sampling manganese copper are used, although the above problems can be solved, the selection of the sampling switching point is generally to select the reading current for judgment and then switch, which cannot To meet the rapid load changes, there is a measurement blind area that may lead to inaccurate measurement

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