50kv/5kva Test Transformer:
I. Overview:
Test transformers are essential equipment for testing and preventive maintenance of power equipment. With the development of China's power industry, the requirements for test transformers are increasing, and
oil-immersed test transformers are increasingly unable to meet the requirements of field work in terms of size, weight, and performance.
With the advancement of basic scientific research in China and the application of new materials and processes, the new medium sulfur hexafluoride gas has been introduced into the field of power equipment applications. Due to its excellent insulation properties, arc extinguishing performance, and non-flammability, SF6 gas has been widely used as a new insulating medium.
After years of efforts, our factory has successfully developed a gas-filled lightweight test transformer. Compared with oil-immersed lightweight test transformers, it is 20%-60% lighter (depending on voltage and capacity level) and has no oil pollution. Due to the adoption of new production processes, the technical performance of the product has been significantly improved, making it particularly suitable for field work and frequent mobile working conditions.
II. Structure:
1. The XEDQB series products feature entirely new design concepts, material selection, and process flows. Therefore, they are not only small in size, light in weight, and aesthetically pleasing, but also all technical indicators meet the requirements of the <−98> standard. 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, with QZ type wires directly and continuously wound into a high-voltage tower coil on a specially made high-strength insulating cylinder. The shell is of appropriate dimensions and filled with SF6 gas.
2. The difference between XEDQB (QZ) products and XEDQB products lies in the clever installation of the high-voltage rectifier silicon stack inside the high-voltage bushing. 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 XEDQB (QZ) products and XEDQB products lies in the internal structure of the bushing.
Working Principle:
Power is input to the operation box, which has overcurrent automatic trip and zero-position interlock device to prevent sudden pressurization. The voltage is regulated by the auto-transformer and input to the primary winding of the YDQ test transformer. According to the principle of electromagnetic induction, the secondary (high-voltage) winding obtains a voltage amplitude equal to the turns ratio times the primary voltage - power frequency high voltage. This power frequency high voltage can be rectified by the high-voltage silicon stack and filtered by the voltage-stabilizing capacitor to obtain DC high voltage, whose amplitude is 2 times the effective value of the power frequency high voltage.
Main Technical Parameters of Test Transformer (100/150 and below)
50kv/5kva Test Transformer
|
Specification
|
Capacity
(kVA)
|
High Voltage Output
|
Low Voltage Output
|
Meter
|
Ratio
|
Temperature Rise ℃
|
|
Voltage (kV)
|
Current (mA)
|
Voltage (V)
|
Current (A)
|
Voltage (V)
|
High/Meter
|
30 minutes
|
|
1.5/50
|
1.5
|
50
|
30
|
200
|
7.5
|
100
|
500
|
10
|
|
3/50
|
3
|
50
|
60
|
200
|
15
|
100
|
500
|
10
|
|
5/50
|
5
|
50
|
100
|
200
|
25
|
100
|
500
|
10
|
|
10/50
|
10
|
50
|
200
|
200
|
50
|
100
|
500
|
10
|
|
20/50
|
20
|
50
|
400
|
380
|
53
|
100
|
500
|
10
|
|
30/50
|
30
|
50
|
600
|
380
|
79
|
100
|
500
|
10
|
|
50/50
|
50
|
50
|
1000
|
380
|
120
|
100
|
500
|
10
|
|
5/100
|
5
|
100
|
50
|
380
|
13
|
100
|
1000
|
10
|
|
10/100
|
10
|
100
|
100
|
200
|
50
|
100
|
1000
|
10
|
|
20/100
|
20
|
100
|
200
|
380
|
53
|
100
|
1000
|
10
|
|
30/100
|
30
|
100
|
300
|
380
|
79
|
100
|
1000
|
10
|
|
50/100
|
50
|
100
|
500
|
380
|
132
|
100
|
1000
|
10
|
|
100/100
|
100
|
100
|
1000
|
380
|
263
|
100
|
1000
|
10
|
|
20/150
|
20
|
150
|
130
|
380
|
53
|
150
|
1000
|
10
|
|
30/150
|
30
|
150
|
200
|
380
|
79
|
150
|
1000
|
10
|
|
50/150
|
50
|
150
|
330
|
380
|
132
|
150
|
1000
|
10
|
|
100/150
|
100
|
150
|
665
|
380
|
263
|
150
|
1000
|
10
|
