Partial discharge refers to a localized, repetitive discharge phenomenon that occurs in the insulation medium of high-voltage equipment. Although the energy of such discharge is relatively small, it can gradually damage the insulation material over time, leading to equipment failure. Therefore, regular partial discharge testing is crucial to ensure the stable operation of the power system. As a traditional detection method, the simulated partial discharge tester still holds an important position in the field of partial discharge detection.
Working Principle
The working principle of the simulated partial discharge tester is based on the detection of electromagnetic field changes generated during the partial discharge process. When partial discharge occurs, it is accompanied by the emission of electromagnetic waves. These signals are captured by specific sensors, then processed through amplification, filtering, and other preprocessing steps, and finally displayed as partial discharge waveforms on an oscilloscope. Operators can judge the type and severity of partial discharge based on the characteristics of the waveform.
Main Features
High detection sensitivity: Capable of capturing very weak partial discharge signals.
Wide applicability: Suitable for testing various high-voltage equipment, including transformers, cables, GIS, etc.
High signal-to-noise ratio: Uses advanced signal processing technology to effectively reduce background noise interference.
Intuitive display: Usually equipped with a large-screen oscilloscope tube or LCD display, making test waveforms clearly visible.
Large dynamic range: The amplification system is well-designed to handle signals of different amplitudes.
Multiple frequency band combinations: Provides a variety of frequency band options to meet different types of partial discharge detection needs.
Auxiliary zero-marking system: Facilitates accurate signal positioning for operators.
Usage Steps
Preparation: Check that the instrument is intact and ensure good contact between the sensor and the equipment under test.
Connection: Correctly connect the test circuit according to the instruction manual.
Calibration: Use a calibration pulse generator to calibrate the instrument to ensure it is in optimal working condition.
Data acquisition: Start the instrument and begin collecting data.
Waveform observation: Observe the partial discharge waveform characteristics on the oscilloscope.
Data analysis: Judge the partial discharge condition based on waveform shape, amplitude, and other characteristics.
Record results: Record test data, including waveform diagrams, discharge counts, etc.
Precautions
Safety first: Before testing, ensure that operators understand and comply with all safety regulations.
Environmental conditions: Conduct tests in a clean, dry, and interference-free environment as much as possible.
Instrument maintenance: Regularly maintain and service the instrument to ensure it remains in good working condition.
Professional training: Operators should receive professional training to ensure they can correctly interpret test results.
Application Cases
Transformer partial discharge detection: During routine maintenance of transformers, use a simulated partial discharge tester to check for signs of partial discharge, thereby assessing the insulation condition of the transformer.
Cable joint detection: By conducting partial discharge tests on cable joints, potential quality issues at the joints can be detected in a timely manner.
GIS equipment maintenance: The simulated partial discharge tester can be used for daily maintenance of GIS equipment, helping maintenance personnel determine whether there are partial discharge issues inside the equipment.
Conclusion
The simulated partial discharge tester, with its high sensitivity, wide applicability, and intuitive operation interface, has become one of the important tools for partial discharge detection in the power industry. With technological advancements, this type of instrument will continue to play a key role in the preventive maintenance of power equipment.
