RU94032785A - Device determining dissipation factor of dielectric - Google Patents

Abstract

FIELD: electric measuring technology; can be used to measure dissipation factor of solid insulation materials, liquid dielectrics, for example, transformer oil. SUBSTANCE: device includes high-voltage transformer with additional tap on high-voltage winding, tested capacitor, resistor, circuit measuring phase difference indication unit, source of sinusoidal signal made in the form of generator of stable frequency. Circuit measuring phase difference has two inputs, one being connected to common connection point of tested capacitor and resistor, the other one, to additional tap of high-voltage winding of transformer, its output is connected to indication unit which measures dissipation factor of dielectric by formula tgδ = tg(π/2-α-γ), where δ is dielectric loss angle of tested capacitor; a is angle between voltage across high-voltage winding of transformer and drop of voltage across resistor; g is angle between voltage across high-voltage winding of transformer and drop of voltage across tested capacitor. Angle g is assumed to be constant depending on value of resistor, voltage across output of high-voltage winding of transformer which are constant values for given particular device. EFFECT: enhanced authenticity of measurement of dissipation factor of dielectric.

Claims (1)

The invention relates to electrical engineering and can be used to measure the dielectric loss tangent of solid insulating materials, liquid dielectrics, for example transformer oil. The device contains a high-voltage transformer with an additional output on a high-voltage winding, a test capacitor, a resistor, a phase difference measurement circuit, an indication unit, a sinusoidal signal source made in the form of a stable frequency generator, and the phase-matching signal circuit has two inputs, one of which is connected to the common point of connection of the tested capacitor and resistor, the other to the additional output of the high-voltage winding of the transformer, and the output is connected to the display unit, which measures dielectric loss tangent by the formula specified in the description. The angle between the voltage on the high-voltage winding of the transformer and the voltage drop across the tested capacitor is taken as a constant angle, depending on the value of the resistor, the voltage at the output of the high-voltage winding of the transformer, which are constant values for this particular device.