YD Oil-immersed High Voltage Test Transformer
This series of products features a single-phase core type iron core, laminated with high-quality cold-rolled grain-oriented silicon steel sheets, and fastened with steel as clamping pieces. The high-voltage coil is a cylindrical multi-layer tower type, wound with high-quality polyester enameled wire and insulation materials with high withstand voltage. The low-voltage coil is on the 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, easy movement, and superior performance.
Collapse Working Principle
1. AC, AC/DC test transformer:
Input the power frequency power supply into the operation box (or operation console), and adjust the voltage through the auto-transformer to input to the primary winding of the test transformer. According to the principle of electromagnetic induction, power frequency high voltage can be obtained on the secondary (high voltage) winding. This power frequency high voltage can be rectified by high-voltage silicon stack and filtered by capacitor to obtain DC high voltage, whose amplitude is 1.4 times the effective value of the power frequency high voltage. However, when using DC, the short-circuit rod should be pulled out, and when using AC, the short-circuit rod should be inserted.
2. Test transformer with taps:
In order to simultaneously resolve the contradiction between higher voltage and lower current, and lower voltage and higher current, the high-voltage winding is divided into two windings: one with larger current and the other with smaller current. The two windings are then connected in series and led out separately. Schematic diagram of the principle.
3. Cascade test transformer:
To obtain a test transformer with higher voltage, a cascade method can also be used to achieve higher voltage. Figure 2 shows the principle wiring diagram of a three-stage cascade test transformer. The capacity and voltage relationship of the three transformers satisfy: P1=2P2=3P3, U(total)=1U+2U+3U.
Collapse Main Technical Indicators
>Rated capacity: 1~300KVA
>Rated output voltage of single unit:
(AC) 50, 100, 150, 200, 300KV
(DC) 70, 140, 210, 280KV
>Rated input voltage: 200V, 400V
>Transformation ratio: 500/1, 1000/1, 1500/1, 2000/1, 3000/1
>Transformation ratio error: ≤±1.5%
>Impedance voltage: <10%
Collapse Edit this section YDQ Gas-type Test Transformer
Collapse Overview
Collapse Gas-type Test Transformer
With the development of China's power industry, the voltage level requirements for test transformers are getting higher and higher, while traditional oil-immersed test transformers are increasingly unable to meet the requirements of on-site work in terms of size and weight. Gas-type test transformers reduce size and weight, making it more convenient for customers to carry to the site for testing
With the progress of basic scientific research in China, the application of new materials and new processes has pushed the new medium sulfur hexafluoride gas into the application field of power equipment. Due to the excellent insulation performance, arc extinguishing performance, and non-flammability of sulfur hexafluoride gas, it has been widely used as a new insulating medium.
1. The design concept, material selection, and process flow of the YDQ series products are all new. Therefore, they not only have small size, light weight, and beautiful appearance, but also all technical indicators meet the requirements of the <<JB3570-98>> standard.
YDQ series products use high-quality cold-rolled DQ-151 oriented silicon steel sheets laminated into a multi-stage cylindrical frame-shaped iron core, and use QZ type wire to continuously wind the high-voltage tower coil directly on a specially made high-strength insulating cylinder. The shell is of suitable shape and size, filled with SF6 gas inside.
2. The difference between YDQ(JZ) products and YDQ products is that the high-voltage rectifier silicon stack is cleverly installed inside the high-voltage bushing. By inserting or pulling out the short-circuit rod, it can be switched between power frequency high-voltage AC output and high-voltage DC output.
3. The difference between YDQ(C) products and YDQ products lies in the internal structure of the bushing.
Main Features
>The product is small in size and light in weight (40%-65% lighter than oil-immersed test transformers of the same level).
>Clean, no oil stains, no maintenance required.
>Unaffected by harsh climate and environment, can be tested immediately after on-site handling without waiting.
>Insulation strength is significantly higher than oil-immersed test transformers, with minimal corona.
