Method and device for measuring dielectric loss angle

Abstract

The invention provides a method and a device for measuring a dielectric loss angle. The method comprises the following steps of: acquiring a voltage signal V0 on a sample, and a voltage signal Vx obtained by converting a current signal which flows through the sample; sampling the voltage signal V0 and the voltage signal Vx obtained by converting the current signal for finite times; averaging the sampled signals by using a plesiochronous algorithm to obtain an averaged waveform of the voltage signal V0 and the voltage signal Vx; performing fourier transform on the averaged waveform of the voltage signal V0 and the voltage signal Vx to obtain a cosine component coefficient arl and a sine component coefficient brl of the first harmonic of the averaged waveform of the voltage signal V0, and a cosine component coefficient axl and a sine component coefficient bxl of the first harmonic of the averaged waveform of the voltage signal Vx; and calculating a tangent value tan(delta) of the dielectric loss angle.

Description

technical field [0001] The invention belongs to the field of material property analysis, and in particular relates to a method for measuring a dielectric loss angle of a dielectric material and a corresponding measuring device. Background technique [0002] The dielectric loss angle is the complementary angle between the current vector and the voltage vector flowing in the dielectric under an alternating electric field, usually denoted as δ. The dielectric loss angle is an important index reflecting the insulation performance of high-voltage electrical equipment. Changes in the dielectric loss angle can reflect insulation defects such as moisture, deterioration, deterioration, or gas discharge in the insulation. [0003] Usually, in the process of measuring the dielectric loss angle, the sine value tanδ of the dielectric loss angle is directly measured, and the dielectric loss is directly represented by it. The traditional methods of measuring the dielectric loss angle mai...

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Problems solved by technology

Generally speaking, at a frequency as low as 0.1Hz, there is no loss reference that can be used as a lossless component. The component that was originally regarded as a lossless component at 50Hz is no longer considered as a lossless component at 0.1Hz. It is a lossless standard capacitor. Therefore, the original bridge method using a standard capacitor as a bridge arm will fail, so the bridge method is not suitable for the measurement of the dielectric loss angle at 0.1Hz ultra-low frequency.

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