Current transformer capable of broadband wide-width measurement and magnetic interference resistance

Abstract

The invention discloses a current transformer capable of broadband wide-width measurement and magnetic interference resistance, and belongs to the technical field of transformers. A signal conditioning circuit comprises an induction circuit, a differential amplification circuit and a power amplification circuit; a Hall chip of the induction circuit is fixed in an air gap formed in the magnetic core; the output end of the power amplification circuit is connected with one end of a secondary coil; the other end of the secondary coil is connected in series with a first sampling resistor Rm1 and then is grounded; the point where the first sampling resistor Rm1 is grounded serves as a negative signal output end M1-; the point where the first sampling resistor Rm1 is connected with the secondarycoil serves as a positive signal output end M1+; the signal conditioning circuit further comprises a constant voltage source circuit; and the output end of the constant voltage source circuit is connected with the Hall chip. Under the condition that there is external magnetic interference in a broadband and wide-width range, the current can be still measured in high precision, DC and harmonic components in the current can be accurately measured, and measurement is not influenced by a power factor.

Description

technical field [0001] The invention belongs to the technical field of transformers, and relates to a current transformer, in particular to a current transformer with wide-band, wide-width measurement and anti-magnetic interference capabilities. Background technique [0002] my country refers to the standard structure of IEC / TC13 and the international proposal of OIML R46 electric energy meter to formulate the corresponding electric energy measurement and load control standard system. Higher requirements are put forward for current transformers for electric energy meters: wide dynamic range, high reliability, high sensitivity, high temperature stability, etc., while traditional electromagnetic current transformers have complex secondary coil winding process and winding Copper wire has disadvantages such as large temperature error, large size, non-linearity, easy saturation, small dynamic range, and susceptibility to external magnetic field interference, which can no longer mee...

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Problems solved by technology

[0002] my country refers to the standard structure of IEC / TC13 and the international proposal of OIML R46 electric energy meter to formulate the corresponding electric energy measurement and load control standard system. Higher requirements are put forward for current transformers for electric energy meters: wide dynamic range, high reliability, high sensitivity, high temperature stability, etc., while traditional electromagnetic current transformers have complex secondary coil winding process and winding Copper wire has disadvantages such as large temperature error, large size, non-linearity, easy saturation, small dynamic range, and susceptibility to external magnetic field interference, which can no longer meet the needs of industry development.

Especially in the new standard system, when the power factor is equal to 0.5L, the DC and even harmonics of the electric energy meter - the half-wave rectification waveform test stipulates the requirements, and the traditional electromagnetic current transformer can no longer meet the standard requirements.

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