Partial Discharge Detection Device for Transformers
Introduction
The partial discharge detection device for transformers is an instrument specifically used to detect partial discharge phenomena in transformers (including voltage transformers and current transformers). Partial Discharge (PD) is a common fault symptom in power equipment, posing a threat to the long-term stable operation of transformers. By using the partial discharge detection device, potential insulation defects inside the transformer can be detected and diagnosed early, allowing for appropriate maintenance measures to be taken and extending the transformer's service life.
Working Principle
The working principle of the partial discharge detection device for transformers is based on capturing the electromagnetic wave signals generated by partial discharges inside the transformer. When partial discharge occurs inside the transformer, a pulse current is generated in the coupling capacitor Ck. The detection device captures these signals through built-in sensors (such as coupling capacitors, sensors, etc.), and amplifies them through a preamplifier and filter amplifier. The discharge pulses are displayed on the oscilloscope screen and simultaneously sent to a pulse peak meter (logarithmic meter) to display their peak values. The apparent discharge charge of the transformer is detected using the comparison method, where a certain amount of charge is injected into both ends of the transformer before the test, the amplification factor is adjusted to establish a scale, and then the partial discharge pulses received in the transformer under actual voltage are compared with the scale to obtain the apparent discharge charge of the transformer.
Technical Parameters
Capacitance range of testable products: 6pF~250μF.
Detection sensitivity and allowable current: Depending on the model and application, specific detection sensitivity and allowable current ranges may vary.
Elliptical scanning time base:
Frequency: 50Hz, 100Hz, 150Hz, 200Hz, 400Hz.
Rotation: in steps of 30 degrees, rotatable up to 120 degrees.
Working mode: Standard - Expanded - Linear.
Input voltage range for high-frequency time base ellipse: 13~275V.
Display unit: Uses a 100×80mm rectangular oscilloscope tube with brightness and focus adjustment functions.
Application Scenarios
Voltage transformers: Used to detect whether partial discharge phenomena exist inside voltage transformers.
Current transformers: Used to detect whether partial discharge phenomena exist inside current transformers.
Switchgear: Can detect transformers within switchgear, especially at circuit breaker ports, gas-filled cable boxes, voltage transformers, and busbar compartments.
Usage Steps
Preparation: Ensure the tester is correctly connected to the power supply and all sensors are ready.
Select detection mode: Choose the appropriate detection mode based on the type of equipment to be tested.
Set parameters: Set corresponding test parameters according to the equipment's characteristics, such as frequency range, sensitivity, etc.
Start detection: Start the tester and follow the instructions to perform partial discharge detection.
Data recording and analysis: Record detection data and use built-in software for analysis to evaluate the insulation status of the transformer.
Usage Precautions
Safe operation: Ensure compliance with all safety regulations, especially when operating in high-voltage environments.
Correct connection: Ensure all connections are correct to avoid measurement errors due to incorrect connections.
Avoid interference: Minimize external interference, especially during measurement, to ensure data accuracy.
Regular maintenance: Regularly maintain and calibrate the tester to maintain its optimal performance.
Conclusion
The partial discharge detection device for transformers is one of the indispensable tools in power system maintenance. It helps technicians accurately assess the insulation status of transformers and prevent failures caused by poor insulation. With technological advancements, future partial discharge detection devices for transformers will become more intelligent and portable, providing stronger technical support for power system maintenance work.
I hope this article provides you with a comprehensive understanding of the partial discharge detection device for transformers. If you have any specific questions or need further information, please feel free to let me know.
