Protective Rogowski coil current transformer based on combined integral

Abstract

The invention relates to the technical field of electric power measurement, and especially to a protective Rogowski coil current transformer based on the combined integral. The protective Rogowski coil current transformer based on the combined integral includes a current wire, a Rogowski coil, a first conditioning circuit, a second conditioning circuit, a first converting circuit, a second converting circuit and a digital processor. The first conditioning circuit and the first converting circuit are connected in series to form a digital integral circuit. The second conditioning circuit and the second converting circuit are connected in series to form a hardware analog integral circuit. The digital integral circuit and the hardware analog integral circuit are connected in parallel and are connected to two ends of an output lead of the Rogowski coil. The digital integral circuit is connected to the digital processor. The hardware analog integral circuit is connected to the digital processor. The protective Rogowski coil current transformer based on the combined integral has good measurement accuracy during a steady-state current, well meets the error requirements during a steady-state primary rated current, has good transient characteristics during a transient current, and restores a primary measured current without distortion.

Description

technical field [0001] The invention relates to the technical field of power measurement, in particular to a Rogowski coil current transformer for protection based on combination integral. Background technique [0002] At present, my country's power grid is developing in the direction of intelligence, digitization, and networking, and new digital requirements are put forward for the collection of backbone power grid and substation current. Due to the shortcomings of traditional electromagnetic current transformers, such as large volume, high cost, easy saturation of iron core, complex insulation structure, and the inability to directly connect the secondary analog output to the computer, it has been unable to meet the requirements of safe, stable and efficient development of the power system. . The electronic current transformer sensor based on Rogowski coils uses non-magnetic materials, small size, no saturation, large dynamic range, wide frequency band, digital secondary ...

AI Technical Summary

Problems solved by technology

[0007] In order to solve the problem that the current Rogowski coil current transformer for protection uses a single integrator, the measurement accuracy of the steady-state primary rated current is not high, the transient characteristics of the fault current are poor, and the primary measured current cannot be restored without distortion. The invention provides a combined integration technique, which has high measurement accuracy in steady state current and good transient characteristics in transient current, and can restore the measured current without distortion

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