Product Details

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 have become increasingly stringent. However, oil-immersed test transformers are increasingly unable to meet the demands 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. Due to its excellent insulation properties, arc-extinguishing capability, and non-flammability, SF6 gas has been widely adopted as a new insulating medium.

After years of effort, 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 rating) and free from oil pollution. Thanks 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 use.

II. Structure:

1. The XEDQB series products feature entirely new design concepts, material selection, and manufacturing processes. Therefore, they are not only compact, lightweight, and aesthetically pleasing, but also meet all technical indicators required by 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 core, with QZ-type wire continuously wound directly on a specially made high-strength insulating cylinder to form a high-voltage tower coil. The outer shell is appropriately sized and filled with SF6 gas.

2. The difference between XEDQB (QZ) and XEDQB products lies in the clever integration of a high-voltage rectifier silicon stack inside the high-voltage bushing. By inserting or extracting a 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) and XEDQB products lies in the internal structure of the bushing.

Working Principle:

Power is input to an operation box equipped with overcurrent automatic trip and zero-position interlock to prevent sudden pressurization. The voltage is then regulated by an auto-transformer and fed to the primary winding of the YDQ test transformer. According to the principle of electromagnetic induction, a voltage amplitude proportional to the turns ratio between the secondary (high-voltage) winding and the primary winding is obtained - power frequency high voltage. This power frequency high voltage can be rectified by a high-voltage silicon stack and filtered by a stabilizing capacitor to produce DC high voltage, whose amplitude is twice the RMS value of the power frequency high voltage.

Main Technical Parameters of Test Transformer (Below 100/150)

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