A brief overview of the operating principle of handheld partial discharge detectors!

发布时间：2022-01-22

A handheld partial discharge (PD) analyzer, also known as a handheld partial discharge detector or partial discharge tester, is primarily used for measuring and diagnosing partial discharge activity in power equipment, including power transformers, GIS equipment, high-voltage switchgear, ring main units, and other transformer‑related devices.

The principle of a handheld partial discharge (PD) analyzer is to measure the magnitude of partial discharges by detecting UHF surface waves and ultrasonic signals. It employs multi-sensor intelligent external sensors to capture high-frequency ultrasonic signals, analyzing both the radiation emitted by partial discharges and the resulting UHF and ultrasonic signals. By integrating specialized algorithms with advanced signal-processing techniques, this portable PD device can accurately and efficiently diagnose internal partial discharges in electrical equipment and pinpoint their specific locations.

　　I. Scope of Application for Handheld Partial Discharge Detectors

　　Handheld partial discharge (PD) detectors are widely used in critical sectors such as power generation, grid operations, the petrochemical industry, railway electrification systems, and aerospace. These key industries shoulder significant responsibilities for China’s economic development and serve as drivers of technological progress; ensuring their stable growth is therefore of paramount importance. Partial discharge monitoring is a crucial indicator of insulation condition in electrical equipment, significantly contributing to its long-term reliable operation. The deployment of handheld PD instruments enables technical personnel to promptly identify potential faults within equipment, address issues at an early stage, and safeguard the healthy performance of electrical assets.

　　II. Detection Principle of Handheld Partial Discharge Detectors

　　When partial discharge occurs in electrical equipment, it is accompanied by physical phenomena such as ultrasonic waves, heat, light, and electromagnetic fields. Among these, ultrasonic waves propagate outward from the source in a square‑wave pattern. A handheld partial‑discharge locator detects the ultrasonic signals generated to determine the magnitude and precise location of the partial discharge, and, combined with real‑time display of waveforms and data, enables rapid diagnosis of the discharge condition. This handheld device integrates both transient earth‑fault voltage and ultrasonic detection methods.

III. Product Features of the Handheld Partial Discharge Tester

　　1. Ultrasonic and TEV waveforms, along with the three warning thresholds—yellow, green, and red—are displayed on the same interface.

　　2. Use transient earth voltage (TEV) and ultrasonic methods to detect the magnitude of partial discharge, expressed in dBmV.

　　3. In ultrasonic mode, listen to partial discharge signals in real time through headphones.

　　4. The display shows waveforms in real time, automatically extracts meaningful waveforms, and saves test data automatically, facilitating the retrieval and analysis of test records.

　　5. High signal amplification and high sensitivity; a signal reception range of 15 meters and strong anti-interference capability.

　　6. Moderately intense red laser aiming, focused beam, precise positioning

　　7. Equipped with a color LCD panel, it delivers more intuitive display, offers user-friendly human–machine interaction, and is easy to operate and carry.

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