Inflatable Test Transformer

Test transformer is essential test equipment for power equipment detection and preventive tests. With the development of China's power industry, the voltage level requirements for test transformers are increasingly higher, while traditional oil-immersed test transformers are increasingly unable to meet on-site work requirements in terms of volume, weight, and performance.

Chinese Name

Inflatable Test Transformer

English Name

The inflatable test transformer

Nature

New insulating medium

Advantages

Small size, light weight, beautiful appearance

With the progress of basic scientific research in China and the application of new materials and new processes, the new medium sulfur hexafluoride gas has been pushed 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, leading to the creation of the inflatable test transformer.

After years of efforts, the inflatable lightweight test transformer has been successfully developed. Compared with traditional oil-immersed lightweight test transformers, this series of products is 20%-60% lighter in weight (depending on voltage and capacity level), and has no oil pollution. The voltage level of a single test transformer can reach 300KV. Due to the adoption of new production processes, the technical performance of the product has been greatly improved, making it particularly suitable for on-site work and frequent mobile working conditions.

Introduction

The high-voltage test transformer is produced based on the Ministry of Machinery and Electronics' "Test Transformer" standard, with extensive improvements over the original similar products. The AC/DC high-voltage test transformer is a new type of product produced based on the YD series test transformer, in accordance with the national standard "JB∕T 9641-1999" after improvements. This series of products features small size, light weight, compact structure, complete functions, strong universality, and convenient use. It is particularly suitable for insulation strength tests under power frequency or DC high voltage for various high-voltage electrical equipment, electrical components, and insulating materials in power systems, industrial and mining enterprises, and scientific research departments. It is an indispensable important equipment in high-voltage testing.

Structure

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 international high-standard requirements.

The YDQ series products use high-quality cold-rolled DQ-151 oriented silicon steel sheets stacked into a multi-stage cylindrical frame-shaped iron core, and use QZ type wires to continuously wind high-voltage tower-type coils directly on a specially made high-strength insulating cylinder. The shell is of suitable size and 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, and by inserting or extracting the short-circuit rod, the YDQ 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 and the structure of the high-voltage coil.

4. YDQW products are based on ordinary transformers, with improved technology and techniques, using different insulation structures, and the arc extinguishing capability of SF6 gas itself, so that under high voltage, the transformer has basically no partial discharge. Thus, when using this transformer as a high-voltage power source for partial discharge tests of electrical equipment, it can be combined with high-precision



Working Principle

Power is input into the operation box with overcurrent automatic trip and zero-position interlock device to prevent sudden pressurization, and the voltage is adjusted through the auto-transformer to input into the primary winding of the YDQ test transformer. According to the principle of electromagnetic induction, in the secondary (high-voltage) winding, a voltage amplitude equal to the ratio of turns between the secondary and primary windings can be obtained - power frequency high voltage. This power frequency high voltage can be rectified by a high-voltage silicon stack and filtered by a voltage-stabilizing capacitor to obtain DC high voltage, whose amplitude is twice the effective value of the power frequency high voltage.

 

Technical Parameters

>Voltage level: 10——600KV

>Capacity range: 1——600KVA

>No-load current: <7%

>Impedance voltage: <8%

>Partial discharge at rated voltage: <5PC



Model Meaning

Rated output voltage KV

Rated capacity KVA

JZ AC/DC, C cascade

Inflatable Q

Single phase D

Characteristics

1. Clean, no oil contamination, no maintenance required;

2. Not affected by harsh weather conditions, can be tested immediately after on-site handling without needing to rest;

3. Insulation strength is significantly higher than oil-immersed test transformers, with extremely low corona.