What causes switchgear partial discharge?
Switchgears contain numerous devices and components, with small insulation distances. Internal high-voltage equipment includes circuit breakers, busbars, and cable connectors. During operation, these devices are affected by electrical, thermal, mechanical, and environmental factors, leading to degradation of the insulation material. Manufacturing and installation defects, such as burrs on metal surfaces and poor contact at terminals, can cause partial discharge within the switchgear, damaging electrical equipment and affecting grid stability.
What is partial discharge monitoring system for switchgear?
Partial discharge is random and complex, requiring a high sampling rate for equipment monitoring. The industrial-grade microprocessor built into the partial discharge sensor can simultaneously process complex partial discharge signals and filter out interference signals. Through background data analysis, the insulation status is assessed, and the specific location of defects is determined, providing strong support for accident prevention.
The online partial discharge monitoring system for switchgear integrates three functions: ultrasonic partial discharge monitoring, transient ground voltage partial discharge monitoring, and ultra-high frequency partial discharge monitoring, improving the accuracy of monitoring results. The collected data is analyzed in real time. When partial discharge is detected, the online monitoring system immediately issues an alarm and displays the location of the partial discharge on the screen, assisting electricians in pinpointing and repairing the problem and eliminating safety hazards.
Components of the switchgear online PD monitoring system
Partial Discharge Sensor: Collects partial discharge data from high-voltage equipment, monitoring the insulation condition of the equipment in real time. The partial discharge data is transmitted wirelessly and uploaded in real time to the partial discharge data acquisition host.
Partial Discharge Data Acquisition: Centrally manages the data from the partial discharge sensors, analyzing the partial discharge data from each sensor in real time. The collected data is uploaded to the HMI or enterprise data platform via RS485, LoRa, or 4G wireless communication.
Communication Module: Generally refers to serial port servers and communication management devices, which upload equipment data to the network for remote management.
Online Partial Discharge Monitoring System: Primarily used to process partial discharge data, which can be viewed directly on the HMI.
Advantages of the online Partial Discharge Monitoring System for switchgear
Wireless Transmission: No additional wiring is required, maintaining the original performance and structure of the electrical equipment and improving safety.
Stable and Reliable System: The switchgear partial-discharge monitoring equipment is compact, and each device has a unique address, ensuring stable data transmission.
Excellent Anti-interference Capability: Utilizing advanced antenna-gating technology, combined with multiple noise-reduction methods such as pulse identification and characteristic-spectrum analysis, minimizes interference and significantly improves the signal-to-noise ratio.
Flexible Networking Method: The modular networking design allows one monitoring host to connect up to 128 wireless partial discharge sensors, adapting to various complex network environments.
Convenient Data Sharing: Seamless integration with the upper-level system allows any computer on the network to query data, improving data access convenience.
Efficient and Smooth Communication: Using the 470MHz~510MHz wireless transmission frequency band simplifies pairing and networking processes, ensuring efficient and stable communication.
Integration of Multiple Detection Technologies: Combining multiple detection technologies, such as UHE, AE, and TEV, accurately captures the time-domain characteristics of ultra-high-frequency signals, improving monitoring accuracy.
Local Area Network Distributed Monitoring: A local area network distributed monitoring system is built to achieve synchronous data acquisition from all sensors, ensuring real-time performance, and accurately locating defect positions by comparing signals between sensors.
Installation of PD monitoring system for switchgear
Partial discharge monitoring points are arranged at each switchgear enclosure location, and the partial discharge sensors are installed using magnetic adsorption. Clip-on partial discharge sensors are installed on the internal cables. Multiple monitoring points are arranged to improve the accuracy of the monitoring results and facilitate maintenance. The partial discharge acquisition host is installed via a rail system and can be installed inside the LCU panel or on the ceiling rail. One partial discharge acquisition host can connect to multiple sensors and transmit data wirelessly via LoRa to the partial discharge HMI.