HuaTianLogo

Power detection technology / Power detection

Detection Technology

Working principle of high voltage test transformer

time:2021/9/18   source:华天电力  reading:243 time

The iron core of the oil-immersed high-voltage test transformer is a single-phase core type, which is made of high-quality cold-rolled oriented silicon steel sheets, and the fastening method uses steel as a clamp. The high-voltage coil is a cylindrical multi-layer tower type, wound by high-quality polyester enameled wire and high-voltage insulation material. The low-voltage coil is outside, and the instrument coil is an independent winding, generally 100V. The shell is octagonal, and test transformers above 10KVA are equipped with movable iron wheels. It has the characteristics of light weight, small size, convenient movement and superior performance.


Hipot Test Set.png


The working principle of oil-immersed high voltage test transformer


1. Test transformer with taps:


In order to satisfy the contradiction between a transformer with a higher voltage and a lower voltage and a lower current and a higher current, the high-voltage winding is divided into two windings, one is the winding with the larger current, the other is the winding with the smaller current, and then Two windings are connected in series and lead out separately, schematic diagram of the principle


2. Cascade test transformer:


In order to obtain a higher voltage test transformer, a cascade method can also be used to obtain a higher voltage. The relationship between the capacity and voltage of the three transformers satisfies: P1=2P2=3P3, U(total)=1U+2U+3U.


3. AC, AC and DC test transformers:


Input the industrial frequency power supply into the operation box (or console), adjust the voltage through the auto-voltage regulator and input it to the primary winding of the test transformer. According to the principle of electromagnetic induction, power frequency high voltage can be obtained in the secondary (high voltage) winding. After the power frequency high voltage is rectified and filtered by the high voltage silicon stack, the DC high voltage can be obtained, and its amplitude is 1.4 times the effective value of the power frequency high voltage. It's just that the short-circuit bar should be drawn out when using DC, and the short-circuit bar should be inserted when using AC.


Copyright description: all articles, pictures, video and other materials on this site belong to wuhan huatian power automation co., LTD. For use, please contact us; Permission to reprint articles, pictures, video and other materials please quote "from: huatian power".