What Is an Online Monitoring System for Switchgear? A Detailed Explanation of Temperature and Partial Discharge Monitoring

• Why is online monitoring necessary for switchgear?: Switchgear is one of the most common types of main equipment in substations. Overheating of internal contacts, aging insulation, and partial discharge are the primary causes of switchgear failures. Online monitoring can detect anomalies inside the switchgear around the clock without interrupting power supply, thereby eliminating faults before they escalate.
• Two Key Monitoring Dimensions: Temperature Monitoring—Detects temperature rises at critical electrical connection points such as contacts and busbar joints; Partial Discharge Monitoring—Detects partial discharge signals from insulating components within the switchgear. These two complementary approaches cover the most common failure modes in switchgear.
• Non-invasive installation: The sensors are installed inside the cabinet but do not come into contact with high-voltage live parts; equipment modifications need only be completed during scheduled power-outage maintenance windows and will not affect normal operations.

1. The Synergy Between Temperature Monitoring and Partial Discharge Monitoring

Abnormal temperatures and partial discharge activity in switchgear often go hand in hand—increased contact resistance leads to localized overheating, which accelerates insulation aging; insulation aging triggers partial discharge, which further erodes the insulation… creating a vicious cycle. Temperature monitoring and partial discharge monitoring address this cycle from two distinct physical perspectives: temperature monitoring detects the "thermal" symptoms, while partial discharge monitoring identifies the "electrical" root cause.

Temperature monitoring methods include: wireless temperature sensors (strapped to contact arms), fiber-optic temperature measurement (probes embedded in contact or busbar joint surfaces), and infrared temperature measurement windows (non-contact temperature measurement through infrared windows). The technical approaches for partial discharge monitoring include: transient earth voltage (TEV) detection, ultrasonic detection, and ultra-high frequency (UHF) detection.

2. Comparison of Temperature Monitoring Solutions

3. Frequently Asked Questions FAQ

3.1 Q:Switchgear monitoringrespond in singingTransformer monitoringIs it the same system?

A: While the monitored objects and sensors differ, the backend system can be unified. Data from switchgear monitoring and transformer monitoring can be integrated into the same comprehensive monitoring platform, allowing the operational status of all station equipment to be viewed on a single interface.

3.2 Q: Can monitoring equipment be retrofitted to switchgear that is already in service?

A: Yes. Wireless temperature sensors can be installed during power outages for maintenance, and TEV and ultrasonic partial discharge sensors can be mounted on the exterior of the cabinet walls. The scope of the retrofit work is not extensive.

3.3 Q: Does every switchgear cabinet need to be equipped with monitoring?

Answer: Installation should be prioritized on critical feeder panels, bus tie panels, and feeder-in panels. For a large number of feeder-out panels, installation can be carried out in batches based on their importance.

Disclaimer: The content of this document is provided solely for technical exchange and reference purposes and does not constitute any form of purchase commitment or contractual offer.

Need an online monitoring solution for switchgear? Please contact Innotongda for configuration recommendations. Service Hotline: 13959168359 (same number on WeChat).