HF-W-703 Switchgear Partial Discharge Monitoring

Overview of Switchgear Partial Discharge Monitoring

High-voltage switchgears are widely applied in distribution networks, and their safe operation plays a decisive role in power supply reliability. During production, transportation, installation and service, affected by manufacturing processes, installation methods as well as electrical, thermal, mechanical and environmental factors, the insulating medium inside switchgears will degrade continuously.

Switchgear Partial Discharge Monitoring can identify tiny equipment defects and analyze the degradation process of insulating medium during operation, enabling early warning of hidden risks in switchgears. This helps avoid massive losses caused by power supply failures and large-scale blackouts across the power grid.

Online Partial Discharge Monitoring System for Switchgears

System Introduction

This system serves for safety monitoring, early warning and protection of high-voltage switchgears. Co-developed with North China Electric Power University based on abundant field experience and professional theories, it is a high-performance digital online PD monitoring system integrating advanced sensors, signal processing, database and discharge identification algorithms.

It can identify typical partial discharge types and accurately locate faulty switchgears. Terminals acquire and preprocess on-site sensing data and upload them to the server. The server analyzes data against a multi-model expert database, outputs 2D and 3D trend graphs, and triggers alarms with discharge strength, position and time recorded for fault tracking.

With B/S framework, it supports data inquiry on PCs. Optional Web publishing function allows mobile and tablet access to alerts, facilitating intelligent and condition-based maintenance of switchgears.

 System Composition

The system mainly consists of high-performance sensors, partial discharge monitoring terminals and a comprehensive partial discharge analysis server.

• High-performance Sensors: Transient Earth Voltage (TEV) sensors and Acoustic Emission (AE) ultrasonic sensors.
• Monitoring Terminals: Collect data from sensors, conduct preliminary analysis and processing, and transmit data to the comprehensive analysis server via network.
• Comprehensive Analysis Server: Receives real-time data uploaded by on-site terminals, supports mass data storage and real-time monitoring display. It also performs discharge condition evaluation, multi-level early warning based on discharge severity, unified equipment management and partial discharge alarm notification through data mining and signal identification technologies.

3. Technical Features

1. Ultra-wideband signal acquisition covering a frequency range from 20 kHz to 1.5 GHz.
2. Adopts multiple analytical algorithms and professional partial discharge detection technologies to accurately identify partial discharge activities and filter out on-site interference signals.
3. Professional partial discharge analysis supports multiple digital signal processing technologies including Pulse Sequence Analysis (PSA), Frequency Domain Spectrum Analysis (FDS), Wavelet Analysis (WA) and Time-Frequency Map (TF Map) to extract authentic and valid partial discharge information. Based on Phase Resolved Partial Discharge (PRPD) patterns, the partial discharge pattern recognition algorithm implements Multivariate Statistical Distribution (MSD) to classify typical discharge types such as internal discharge, corona discharge and floating potential discharge.
4. Precise fault localization to pinpoint the specific switchgear with partial discharge.
5. Fully digital design with excellent electromagnetic compatibility and anti-interference capability to guarantee the accuracy of monitoring data.
6. Diversified alarm modes: when partial discharge magnitude exceeds the threshold, the system actively sends alarm signals to superior management equipment via Ethernet, analyzes detailed discharge information and displays results in both 2D and 3D forms.
7. Convenient equipment management: multiple on-site monitoring terminals can run independently with separate data recording, supporting local on-site display as well as data upload to the server for centralized viewing.
8. Optional Web information publishing function enables users to check switchgear discharge waveforms, spectrum analysis and alarm information anytime and anywhere via dedicated client software or web browsers on data acquisition terminals, PCs and smartphones.

Technical Specification Table

Project Cases