Dielectric loss tester, the better the insulation performance, the instrument through precise vector operations
The dielectric loss tester (often abbreviated as "loss tester") is a core detection instrument used in the power system to evaluate the insulation status of high-voltage electrical equipment. It accurately determines whether the insulation of equipment is damp, aged, deteriorated, or has other defects by measuring the dielectric loss factor (tanδ or tgδ) and capacitance (Cx) of the insulating material.
Currently, mainstream loss testers have eliminated the traditional bulky high-voltage bridges (such as the QS1 Schering bridge) and generally adopt variable frequency anti-interference and fully digital technology, featuring high automation, strong anti-interference capability, and precise measurement.
The following is a detailed introduction to the core principles, functions, and technical characteristics of such instruments:
⚡ Core Testing Principle
Under the action of AC voltage, an ideal insulating material only produces pure capacitive current (current leads voltage by 90°). However, due to the presence of conductance and polarization losses in actual insulating materials, the angle by which the current leads the voltage will be less than 90°. This difference angle δ is the dielectric loss angle.
tanδ (loss value): The smaller this value, the lower the energy loss of the insulating material and the better the insulation performance. The instrument directly obtains the tanδ value and capacitance value of the test object through precise vector operations.
Variable frequency anti-interference technology: This is the soul of modern loss testers. In the field, there is usually strong 50Hz power frequency electromagnetic interference. The instrument outputs test frequencies different from the power frequency (such as 45Hz/55Hz or 55Hz/65Hz and other heterodyne signals) to perfectly avoid field interference, fundamentally solving the problem of accurate measurement in strong electric field environments.
