Single-channel partial discharge tester is an instrument specifically used to detect partial discharge phenomena in power equipment. This type of tester is typically used in laboratories and on-site testing to monitor and evaluate the insulation status of electrical equipment. Below is an overview of an article about the single-channel partial discharge tester.
Single-channel partial discharge tester
Partial Discharge (PD) is a discharge phenomenon that occurs in local areas of insulation materials in high-voltage electrical equipment when the electric field strength reaches a certain level. This phenomenon may be an early indicator of insulation material defects, so effective monitoring of it is crucial for predicting and preventing electrical equipment failures. The single-channel partial discharge tester is a tool specifically designed to detect and quantify partial discharges, suitable for the maintenance and testing of various electrical equipment.
Working Principle
The working principle of the single-channel partial discharge tester is based on the physical phenomena and changes in electrical signals that occur during partial discharge. The most common detection method is the pulse current method, which uses special sensors to capture the pulse current signals generated by partial discharges. These signals are then amplified, filtered, and analyzed by corresponding electronic devices.
Main Features
Strong anti-interference capability: Utilizes digital filtering technology to effectively eliminate on-site interference, enabling partial discharge measurement in strong interference environments.
High sensitivity: Can detect weak partial discharge signals.
High accuracy: Provides accurate and reliable data, helping to accurately assess insulation conditions.
Easy operation: Features an intuitive user interface and simple operating procedures.
Key Components
Preamplifier: Used to capture and amplify weak discharge signals transmitted from high-voltage equipment.
Filter: Selects signals within a specific frequency range to exclude interference.
Main amplifier: Further amplifies the signal to a detectable level.
Display unit: Displays graphical and numerical information of discharge pulses.
Detection Method
Startup preparation: Adjust the time base mode to "Ellipse".
Calibration: Correctly connect the calibration pulse generator and enable calibration.
After calibration: Disconnect the calibration connection line and remove the calibration pulse generator.
Power connection: Connect to the high-voltage test circuit power supply, turn on the zero mark switch, and slowly increase the test voltage.
Observation: Two zero mark pulses appear on the display ellipse, with a phase difference of 180 degrees. Rotate the "Ellipse Rotation" to a position convenient for observing the discharge location.
Partial discharge inception voltage: Continuously increase the voltage, noting the continuous discharge that appears. When the discharge amount exceeds the specified low value, the voltage at that time is the partial discharge inception voltage.
Discharge amount measurement: At the set voltage, when observing discharge pulse signals, adjust the amplifier switch so that the discharge pulse height is between 0.2-2 cm. The discharge amount is then the reading on the digital meter multiplied or divided by 10.
Application Fields
Power systems: Used for partial discharge detection in equipment such as substations, transmission lines, and cables.
Manufacturing industry: Used for quality control during production, such as factory inspection of transformers, motors, and other products.
Research institutions: Used to study the insulation performance and aging characteristics of high-voltage electrical equipment.
Technical Specifications
Detection channels: Single-channel design, suitable for detection of a single signal source.
Basic error of apparent charge q measurement: Includes linearity error, asymmetry error of positive and negative pulse response, range switching error test, low repetition rate pulse response error, and other items.
Maintenance and Care
Regular calibration: Calibrate the instrument according to the manufacturer's recommended intervals to ensure the accuracy of detection results.
Cleaning and maintenance: Regularly clean the instrument surface, especially the sensor parts, to avoid dust affecting detection accuracy.
Storage conditions: Store in a dry, ventilated place, avoiding high temperature and humid environments.
Conclusion
As a professional detection tool, the single-channel partial discharge tester plays an important role in power system maintenance and fault prevention. By accurately detecting partial discharge phenomena, it helps engineers identify potential problems in a timely manner, take measures to prevent equipment failures, and thus ensure the stable operation of the power system.
References
Yangzhou Darui Electric: Product introduction of single-channel partial discharge tester.
China Chemical Instrument Network: Detection methods and principles of single-channel partial discharge tester.
Sohu: Explanation of the principle of partial discharge tester by Engineer Lu from Zhongshi Holding Technology Research Institute.
Renren Library: Document on technical specifications of partial discharge tester.
