Online Partial Discharge Testers Are Used for Real-Time Monitoring of High-Voltage Electrical Equipment Such as Transformers, GIS, and Cable Connections
The online partial discharge tester is a critical device for real-time monitoring of the internal insulation condition of high-voltage electrical equipment (such as transformers, GIS, cables, and switchgear). By capturing the weak partial discharge signals generated during equipment operation, it enables early detection of insulation defects and prevents sudden failures. Based on the latest industry developments and technology trends from 2025-2026, here is an in-depth analysis of online partial discharge testers: 1. Core Functions and Working Principle Detection Targets: Primarily detects partial discharge caused by internal insulation gaps, impurities, or surface contamination. Technical Principles: UHF Method: Currently the mainstream technology for GIS and transformer online monitoring. Uses built-in or external sensors to receive electromagnetic wave signals in the 300MHz-3GHz band, featuring strong anti-interference capability and high positioning accuracy. Acoustic Emission (AE) Method: Uses piezoelectric sensors to receive acoustic signals generated by discharge, commonly used for surface discharge detection in switchgear and cable terminations, suitable for close-range positioning. Transient Earth Voltage (TEV) Method: Primarily used for medium-voltage switchgear, detecting transient earth voltage signals on metal cabinet surfaces. High-Frequency Current Transformer (HFCT) Method: Uses clamp sensors placed on cable ground wires to detect high-frequency current pulses, widely applied in cable online monitoring. Intelligent Upgrade (2026 Trend): Modern instruments are no longer merely "data collectors" but integrate AI intelligent diagnostic algorithms. The system can automatically filter background noise, identify discharge types (such as floating potential, tip discharge, surface discharge), and generate trend prediction reports, achieving a shift from "passive alarm" to "active early warning." 2. 2025-2026 Industry Leading Manufacturers and Technology Landscape Based on the latest industry evaluations and market feedback, manufacturers are primarily divided into international giants and domestic leading enterprises: International Renowned Brands Hitachi Energy (formerly ABB Power Grids): Advantages: Pioneer of UHF technology and standards-setting participant. Their systems offer extremely high stability and global application cases in large GIS and transformer monitoring. Applicable Scenarios: EHV/UHV substations and large hub stations. Domestic Leading Brands (Main Force in Domestic Substitution) With the acceleration of China smart grid construction, domestic equipment has become highly competitive in sensitivity, anti-interference, and cost-effectiveness, with some indicators even surpassing imported products. Wuhan UHV Power Technology Co., Ltd. & Wuhan Huatian Electric Power Automation Co., Ltd.: Features: Ranked at the forefront in 2025 industry rankings. Known for "high signal-to-noise ratio identification" and "multi-band fusion" technology, trusted by State Grid and large energy groups. Rich product lines in both portable and online types with fast after-sales response. Tianjin Anyuan Technology Development Co., Ltd.: Features: Focused on electrical equipment insulation monitoring, with multiple core patents (such as large motor PD detection systems and VHF monitoring devices for variable frequency systems). Outstanding performance in the petrochemical industry with high explosion-proof requirements and large rotating motor monitoring. Jiangsu Fenggong Electric Technology Co., Ltd.: Features: A leader in GIS partial discharge online monitoring, providing "precise sensing + long-term reliability" full-scenario solutions, particularly outstanding in long-term sensor stability.
