Dielectric response of power transformers and the negative dissipation factor

摘要: SUMMARY This paper presents the appropriate measurement circuit and interpretation scheme of dielectric response oil-paper insulated Power Transformers. The traditional three terminal technique (voltage source, current input, guard wire) occasionally leads to appearance a negative dissipation factor. An equivalent diagram along with practical measurements was used investigate reasons for this problem. These are resistance, capacitances tank, instrument impedance inductance windings. Particularly resistance as well instruments input should be low. is conducted across wide frequency range in order discriminate between influences oil, interfacial polarization (transformer construction geometry) water content. By novel combination time domain measurement, very fast data can accomplished. fully detailed conjunction examples power transformers, illustrate impacts connection on accuracy moisture determination.