Product Details

Product Structure:

1. Its design concept, material selection, and manufacturing process are all new. Therefore, it is not only small in size, light in weight, and beautiful in appearance, but also all technical indicators meet the requirements of the <<JB3570－９８>> standard.

It uses high-quality cold-rolled DQ－151 oriented silicon steel sheets stacked into a multi-stage cylindrical frame-shaped iron core. On a specially made high-strength insulating cylinder, QZ-type wires are used to directly and continuously wind the high-voltage tower-type coil. The shell is of suitable dimensions and filled with SF6 gas inside.

2. The difference between 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, it can be switched between power frequency high-voltage AC output or high-voltage DC output.

3. The difference between products lies in the internal structure of the bushing.

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 the high-voltage silicon stack and filtered by capacitors 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 extracted, and when using AC, the short-circuit rod should be inserted.

2. Test transformer with taps:

In order to simultaneously satisfy the contradiction between higher voltage with smaller current and lower voltage with larger current, the high-voltage winding is divided into two windings: one with larger current and the other with smaller current. Then the two windings are connected in series and led out separately, as shown in the schematic diagram.

3. Cascade test transformer:

Standards and Applicable Scope:

JB/T9641－1999.    《Test Transformer Standard》
GB1094.1－1996.    《Power Transformers Part 1 General》
GB1094.2－1996.    《Power Transformers Part 2 Temperature Rise》
GB1094.2－1996.    《Power Transformers Part 3 Insulation Levels and Insulation Tests》
GB1094.2－1996.    《Power Transformers Part 5》
GB311.1－1997      《Insulation and Coordination of High Voltage Transmission and Transformation Equipment》
GB/T16927.1－1997  《High Voltage Test Techniques Part 1 General Test Requirements》
GB/T16927.1－1997  《High Voltage Test Techniques Part 2 Measuring Systems》
GB/7345－1987      《Partial Discharge Measurement》
GB2536－1990.      《Transformer Oil》
GB7252－1987.      《Guide to the Analysis and Judgment of Dissolved Gases in Transformer Oil》
GB7328－1987.      《Measurement of Sound Level of Transformers and Reactors》
JB8749－1998..      《General Technical Conditions for Voltage Regulators》
JB/T8169           《Coupling Capacitors and Capacitor Voltage Dividers》
JB/T563-1999       《Technical Conditions for Ordering Coupling Capacitors and Capacitors》
DL/T848.3          《General Technical Conditions for High Voltage Test Devices》

Parameters:

◆ Input Current: 0 ～ 25A◆ Power Supply Voltage: AC220V ±10%,50Hz±1 Hz

◆ Meter Voltage: 0 ～ 100V (Other ranges can be customized)

◆ Output Voltage: 0 ～ 250V

◆ Output Current: 0 ～ 20A

◆ Voltage Measurement Accuracy: 0.5 %FS ±3 digits

◆ Current Measurement Accuracy: 0.5 %FS ±3 digits

◆ Timing Length: 0 ～ 9999 S (Special modes can work for long periods)

◆ Operating Environment: Ambient temperature 0～50 ℃ Relative humidity ≤85 RH