High-voltage electrical equipment in power systems (such as transformers, switchgear, cable joints, etc.) may experience partial discharge (PD) phenomena during long-term operation due to manufacturing defects, aging, moisture, and other reasons. Partial discharge not only reduces the insulation performance of equipment but can also lead to serious faults or even safety accidents. Therefore, regular detection and assessment of partial discharge conditions in power equipment are crucial for preventing power accidents. As an effective detection tool, the ultrasonic partial discharge inspection instrument plays an important role in the maintenance of power systems.
Working Principle
The working principle of the ultrasonic partial discharge inspection instrument is based on the ultrasonic signals generated during partial discharge. When partial discharge occurs inside power equipment, ultrasonic signals with frequencies higher than 20kHz are generated. These signals can propagate to the external environment through gaps, holes, and other openings on the equipment surface. The ultrasonic partial discharge inspection instrument captures these ultrasonic signals by placing ultrasonic sensors on the equipment casing or at joint surfaces, and analyzes them through signal processing technology to determine whether there is a partial discharge problem in the equipment.
Construction
The ultrasonic partial discharge inspection instrument typically includes the following main components:
Ultrasonic sensor: used to capture ultrasonic signals.
Signal processing unit: includes preamplifier, filter, signal processor, etc., used to amplify and process ultrasonic signals.
Display and control unit: includes display screen, keyboard or touch screen, used to display detection results and control instrument operation.
Power unit: usually designed as portable, equipped with rechargeable batteries.
Usage Method
Startup preparation: Check if the battery level is sufficient and ensure the sensor connection is correct.
Select detection mode: Choose the appropriate detection mode based on the detection object.
Connect sensor: Place the ultrasonic sensor at appropriate positions on the equipment under test, such as casing gaps, joints, etc.
Collect data: Start the instrument to begin data collection.
Data analysis: Observe signal strength, waveform, and other characteristics on the display screen.
Record results: Record abnormal readings and their locations.
Follow-up measures: If abnormalities are detected, further diagnosis or repair measures are required.
Precautions
Safe operation: Ensure compliance with all safety regulations before conducting tests.
Environmental factors: Conduct tests in a quiet environment as much as possible to reduce the impact of background noise.
Equipment check: Check battery level, date, time, and functionality before use.
Signal check: Ensure that a slight, uniform electrical noise is heard in the earphones, and the curve drawing area on the test interface shows the center line aligned with 0dB, with the average value 10dB lower.
Save results: Store after confirming correctness for later management and analysis.
Features
Non-invasive detection: No need to contact high-voltage components, reducing operational risk.
Anti-interference capability: Advanced digital signal processing technology can effectively suppress background noise.
High sensitivity: Can capture weak partial discharge signals.
Intuitive display: Directly displays signal waveforms on the screen, making it easy for intuitive judgment.
Easy operation: User-friendly interface, convenient for field operation.
Multi-functional integration: Supports multiple detection modes, suitable for different types of power equipment.
Application Fields
The ultrasonic partial discharge inspection instrument is widely used in multiple fields:
Power systems: Used for condition monitoring of high-voltage equipment such as transformers, switchgear, and cable joints.
Manufacturing: Used for quality control of electrical equipment during production processes.
Research institutions: Used for research and development of new materials and new technologies.
Conclusion
The ultrasonic partial discharge inspection instrument, as an important diagnostic tool, can help power engineers detect and solve potential problems in power equipment in a timely manner, thereby improving the reliability and safety of power systems. With technological development, such detection instruments will continue to play an important role in the maintenance of power systems.
