High-precision universal alternative and direct current measuring device

Abstract

A high-precision universal alternative and direct current measuring device comprises a casing, magnetic core windings and a circuit board, wherein the magnetic core windings and the circuit board are arranged in the casing. Magnetic cores of the magnetic core windings are made of soft magnetic materials of high magnetic conductivity and low residual magnetism, and two measuring heads of the same performance but different in winding directions are included, closure is complete, and no air gap exists; windings of the magnetic core windings are wound by high voltage resistant enameled wires, each magnetic core comprises the measuring head and a mutual inductive magnetic core, and all the magnetic cores are placed in a radome to play a strict magnetic shielding role; and the radome is of a multilayer structure and has both a magnetic field shielding function and an electric field shielding function, and thus, the current measuring precision can be improved. The measuring device includes a compensation winding which is used compensate a magnetic field generated by measured current at any time, so that only a magnetic field generated by exciting current but not other magnetic fields exists in the measuring heads, namely, a closed-loop magnetic flux gate principle is realized.

Description

technical field [0001] The invention relates to a current measuring device, in particular to a high-precision general AC and DC current measuring device. Background technique [0002] There are many ways to measure current. For non-contact current measuring devices, magnetic sensitive elements are usually used to measure the magnetic field generated by the current, and then calculate the magnitude of the current. For example, transformers are usually used to measure AC, and Hall principle is usually used to measure current when measuring DC. Among many current measurement schemes, the current measurement method based on the fluxgate principle is a very reliable and highly stable scheme. Because the fluxgate has high sensitivity, it is unmatched by other methods such as the Hall principle. At the same time, because the fluxgate is less affected by temperature, the current measurement device based on the fluxgate principle has good temperature characteristics and high sensiti...

AI Technical Summary

Problems solved by technology

Most of the fluxgate current measuring devices on the market are single measuring heads, with small measuring range and slow response time. They are generally used to measure DC current, but difficult to measure AC current, especially high-frequency AC current.

It is not advisable to simply increase the number of turns of the compensation coil to obtain large current measurement capabilities, because the inherent oscillation frequency of the measuring head will couple a large amount of interference components into the compensation coil, seriously affecting the output of the measurement device

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