The working principle and main functions of a transformer short-circuit impedance tester

The working principle of the transformer short-circuit impedance tester is mainly based on the bridge principle. During the testing process, the transformer short-circuit impedance tester is connected to the transformer to be tested and a test signal is added to it. By utilizing the bridge balance condition, the short-circuit impedance value of the transformer under test can be detected. In the balanced state of the bridge, the influence of measuring components (including the leakage impedance of the transformer itself and the saturation characteristics of the iron core) on the test results can be eliminated or reduced through appropriate testing schemes. These influencing factors may lead to deviations in test results, therefore corresponding calibration and correction are required.

The transformer short-circuit impedance tester can also perform no-load short-circuit impedance testing. By comparing it with the nameplate value or factory value, defects such as winding displacement and deformation can be detected. These defects may be caused by factors such as severe fault currents during transportation, installation, and operation.

In general, the transformer short-circuit impedance tester uses a measurement method based on the bridge principle, combined with appropriate testing plans and calibration correction measures, to eliminate or reduce potential impacts during the testing process, thereby ensuring the accuracy and reliability of the test results.

The transformer short-circuit impedance tester is a commonly used testing instrument in power systems. Its main function is to measure the low voltage short-circuit impedance of transformers, and judge the performance status of transformers through measurement. The main functions of the transformer short-circuit impedance tester are as follows:

① Short circuit impedance measurement: used for low voltage short circuit impedance experiments of transformers, which can display measurement parameters such as voltage, current, active power, impedance value, impedance voltage percentage, reactance value, leakage inductance value, etc. on the same screen for three-phase or single-phase display.

② Measurement of no-load loss: The instrument displays three-phase voltage, three-phase current, and three-phase power. The instrument displays the distortion rate of the applied power waveform and calculates the percentage of no-load current and no-load loss of the transformer.

③ Load loss measurement: Display three-phase voltage, three-phase current, and three-phase power, automatically calculate the impedance voltage percentage of the transformer, and convert it to the load loss at rated temperature and rated current. The instrument has a frequency conversion function, which can accurately measure over a wide frequency range.

④ Split phase measurement: used to check for defects in the single-phase winding of three-phase transformers or when there is no three-phase power supply on site.

⑤ Harmonic analysis function: It can measure the content and total distortion rate of multiple harmonics, and display the original waveform and bar chart.

⑥ The instrument adopts a Chinese menu and Chinese prompts, and the operation is simple.

⑦ The instrument is equipped with a USB interface, which allows the data stored in the instrument to be imported into the USB drive at any time. During instrument testing, it can be directly stored in the USB drive.

In addition, the tester not only supports internal power testing, but also external voltage regulator power testing. The high measurement accuracy of the instrument depends on its phase-locked loop technology, which ensures the testing accuracy of the instrument by synchronously sampling AC signals. The measurement range of the short-circuit impedance tester can be extended, and the measurement range can be further expanded through external CT and PT.

In summary, the transformer short-circuit impedance tester plays an important role in the power system and is an important tool for ensuring the normal operation and performance evaluation of transformers.

ZC-204B Transformer short-circuit impedance tester has the internal adjustable power output and do not need the outside pressure regulator, only need to provide 220V power supply can be tested, especially suitable for the field of 110kV level and above the main transformer for low voltage short circuit impedance measurement.

Kvtester Electronics Technology Co.,Ltd. is a high-tech enterprise specializing in power testing, testing, research and development, production, and sales of testing equipment. It has been engaged in the electrical testing industry for many years, and its products are of high quality. We welcome customers to come and purchase. Service hotline: 0086-27-81778799, to learn more, visit the official website: www.kvtester.com