Self-calibration harmonic current transformer based on gapped iron core coil

The invention discloses a self-calibration harmonic current transformer based on a gapped iron core coil. The transformer can output digital quantity and voltage simulation quantity which are linearly proportional to primary current containing harmonics, and can achieve the purposes of measurement and protection. The self-calibration harmonic current transformer comprises a gapped iron core, a primary coil, a measurement secondary coil, a protection secondary coil, a calibration coil, a monitoring secondary coil, an annular shielding box with a slotted inner ring, a first resistor, a second resistor, a third resistor, a sampling resistor, a first operational amplifier, a second operational amplifier, a third operational amplifier, a fourth operational amplifier, a first bidirectional voltage regulator tube, a second bidirectional voltage regulator tube, a third bidirectional voltage regulator tube, a fourth bidirectional voltage regulator tube, a signal conditioning circuit, an analog-to-digital converter, a microprocessor, a digital-to-analog conversion circuit, a calibration current drive circuit, a communication interface, and a first integral summation circuit and a second integral summation circuit which use a lossy integrator.