System Architecture of Switchgear Online Monitoring
The Switchgear Online Monitoring System is designed to provide real-time monitoring of partial discharge (PD) signals and environmental parameters (temperature and humidity) during the operation of medium- and high-voltage switchgear.
The system integrates multiple intelligent sensors, including:
- Smart 3-in-1 Sensor (Transient Earth Voltage (TEV), Ultrasonic (AA), and Temperature & Humidity monitoring)
- Smart UHF Sensor (Ultra High Frequency sensor for partial discharge detection)
- Smart Spatial UHF Sensor (space electromagnetic radiation detection)
These sensors continuously capture PD signals and environmental data. When abnormal insulation conditions or discharge activity occurs inside the switchgear cabinet, the collected data is wirelessly transmitted via LoRa to the access node for analysis. After intelligent data processing, results are uploaded to the backend monitoring platform through 4G wireless or wired Ethernet for comprehensive diagnosis.
Through advanced partial discharge detection and insulation fault warning, the system provides early alerts, helping operators maintain the safe and reliable operation of switchgear.
Compared with traditional monitoring solutions, this system features:
- Battery-powered smart sensors (no external power required)
- High stability and anti-interference capability
- Easy installation and near zero maintenance
This makes it ideal for long-term online switchgear condition monitoring.
Surface Discharge Characteristics of Switchgear
Main Monitoring Devices
HMJ1010-WAT Smart 3-in-1 Partial Discharge Sensor
| Project Name | Technical Parameters |
| TEV | |
| Frequency Range | 1–100 MHz |
| Measurement Range | 0–70 dB |
| AA | |
| Resonant Frequency | 40 kHz |
| Measurement Range | -10–75 dB |
| Temperature & Humidity | |
| Temperature Measurement Range | -40–125 ℃ |
| Humidity Measurement Range | 0–100 %RH |
| Communication Protocol | Wireless: LoRa |
| Wired: RS485 | |
| Power Supply | Wireless: Built-in lithium battery |
| Wired: DC 24V DC Power Supply | |
| Operating Temperature | -40–+85 ℃ |
| Operating Humidity | 5–95 %RH |
HMK1010-WG Smart UHF Partial Discharge Sensor
| Parameter | Specification |
| Frequency Range | 300 – 1500MHz |
| Measurement Range | -80 to -10dBm |
| Average Equivalent Height | ≥10mm |
| Sensitivity | ≤6.5V/m |
| Dynamic Range | ≥40dB |
| Communication Protocol | Wireless: LoRa / Wired: RS485 |
| Power Supply | Wireless: Built-in lithium battery / Wired: DC24V |
| Operating Temperature | -40 to +85℃ |
| Operating Humidity | 5% – 95% RH |
HMJ1010-WGK Smart Spatial UHF Partial Discharge Sensor
| Item | Specification |
| Frequency Range | 300–1500 MHz |
| Measurement Range | -80 to -10 dBm |
| Average Equivalent Height | ≥10 mm |
| Sensitivity | ≤6.5 V/m |
| Dynamic Range | ≥40 dB |
| Communication Protocol | Wireless: LoRaWired: RS485 |
| Power Supply | Wireless: Built-in lithium batteryWired: DC 24V |
| Operating Temperature | -40°C to +85°C |
| Operating Humidity | 5%–95% RH |
Field Deployment
The Switchgear Online Monitoring Solution can be flexibly deployed in substations, ring main units (RMU), and power distribution rooms. By integrating TEV detection, ultrasonic monitoring, and UHF sensing technologies, the system ensures accurate fault location, real-time condition monitoring, and predictive maintenance.
This solution helps power utilities and industrial users reduce downtime, prevent equipment failure, and improve the overall reliability of the power grid.
