Magnetic modulation current sensor and fabrication method thereof

Abstract

The invention provides a magnetic modulation current sensor. The magnetic modulation current sensor comprises a first magnetic core, a second magnetic core, a third magnetic core, a first coil, a second coil, an auxiliary coil, a primary coil, a secondary coil, an excitation signal generation unit and a current compensation unit, wherein the first coil and the second coil are respectively wound around the first magnetic core and the second magnetic core, the auxiliary coil is wound around the third magnetic core or the whole magnetic core, the primary coil and the secondary coil are wound around the whole magnetic core, the excitation signal generation unit is connected with input ends of the first coil and the second coil, an input end of the current compensation unit is connected with the second coil and the auxiliary coil, an output end of the current compensation unit is connected with the secondary coil, equivalent single-turns inductance of the first magnetic core and the secondmagnetic core is consistent, and the equivalent single-turns inductance of the third magnetic core is larger than those of the first magnetic core and the second magnetic core. The magnetic modulationcurrent sensor is a transformer model according to a modulation signal, the equivalent filtering inductance value of the secondary winding is improved by allowing the equivalent single-turns inductance of the third magnetic core to be larger than those of the first magnetic core and the second magnetic core, the filtering effect of excitation noise is improved, and thus, the modulation noise of the current sensor is prevented.

Description

technical field [0001] The invention relates to a current sensor and a manufacturing method thereof, in particular to a magnetic modulation current sensor and a manufacturing method thereof. Background technique [0002] High-precision AC-DC current sensor (DCCT) is widely used in many fields such as accelerators, medical treatment, scientific research, and measurement due to its high measurement accuracy, wide frequency bandwidth, and electrical isolation, and has broad application prospects. Accurate detection and control of DC current in DC transmission system, frequency conversion speed control device, UPS power supply, inverter welding machine, electrolytic plating, CNC machine tool, microcomputer monitoring system, accelerator operation, power grid monitoring system and in various fields that require isolation and detection of current , is the fundamental guarantee for the safe and reliable operation of the equipment and the first problem to be solved. [0003] Magnet...

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Problems solved by technology

However, the selected magnetic core with the same magnetic characteristics will still produce asymmetrical magnetic fields of the two excitation cores when the detection circuit passes the measured current, resulting in modulation noise

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