When selecting a test transformer, the following factors should be taken into account:

发布时间：2022-05-30

Test transformers are characterized by their compact size, light weight, robust construction, comprehensive functionality, high versatility, and ease of use. They are particularly well suited for power systems, industrial and mining enterprises, research institutions, and other organizations that conduct insulation‑strength tests on various high‑voltage electrical equipment, components, and insulating materials under power‑frequency or DC high voltage. As such, they are indispensable and essential equipment in high‑voltage testing. When selecting a test transformer, the following factors should be taken into account:

Voltage: Based on the test specimen, one should first consider the voltage rating of the test transformer. The selection criterion is that the high-voltage side’s rated voltage of the test transformer must exceed the test voltage of the specimen. In addition, it is necessary to ensure that the low-voltage side voltage of the test transformer is compatible with the on-site testing conditions. According to regulations, the voltage classes for test transformers in China include 5, 10, 25, 35, 50, 100, 150, and 300 kV.

Current: The rated output current of the test transformer should exceed the current required by the device under test. The current magnitude can be estimated based on the capacitance. Capacity: The capacity of the test transformer can be determined from its rated current, rated voltage, and the formula P = UnIn. According to regulations, the standard capacity ratings for test transformers in China are 3, 5, 10, 25, 50, 100, 150, and 200 kVA. For example: In terms of voltage rating, a distribution transformer has a voltage rating of 10 kV and a capacity of 1000 kVA, while the test specimen is rated at 10 kV. Therefore, a test transformer rated at 50 kV and 5 kVA would be selected. This choice satisfies the requirements for the factory‑acceptance test of the 10 kV, 1000 kVA distribution transformer—whose factory test voltage is 35 kV and AC test voltage is 30 kV—as well as the testing of 10 kV insulators, high‑voltage switchgear, and the DC withstand test of 10 kV cables.

Working Principle of the Transformer Volt-Ampere Characteristic Tester

How should a transformer volt-ampere characteristic tester be used?

Working Principle of the Transformer Volt-Ampere Characteristic Tester

How should a transformer volt-ampere characteristic tester be used?