Online GIS PD monitoring system according to IEC61850 protocol

Partial Discharge (PD) Detection in GIS

Both UHF (Ultra-High Frequency) and ultrasonic methods are effective for detecting partial discharges (PD) in Gas-Insulated Switchgear (GIS), each with distinct advantages:

• UHF Method: Detects PD pulses via high-frequency electromagnetic waves generated by PD activity within GIS.

• Ultrasonic Method: Identifies ultrasonic waves produced by bubble shocks caused by PD.

Key Monitoring Data

The main data monitored by a GIS PD monitoring system includes:

• UHF PD signals

• Ultrasonic PD signals

• Transformer voltage signals

The online monitoring system collects these signals and generates alarm information based on the GIS’s operational status.

System Composition

A GIS PD monitoring system comprises three core components:

• Sensors: Capture PD-related signals.

• UHF PD sensors detect electromagnetic signals.

• Ultrasonic sensors measure acoustic signals.

• Data Preprocessing System: Conditions and prepares signals for analysis.

• PD Monitoring IED (Intelligent Electronic Device): Processes, stores, and displays data at the bay level.

Signal Flow and Communication

• Process Level: UHF and ultrasonic sensors acquire electrical and acoustic signals, which are conditioned and transmitted to the PD monitoring IED.

• Bay Level: The IED stores, displays, and processes data. Specific communication service mapping (per IEC 61850) defines network transmission standards for sampled values between the process and bay levels.

• Station Level: Data is reported from the bay level to the station level via predefined communication services for centralized monitoring.

System Structure

The figure illustrates the architecture of a GIS PD monitoring system compliant with IEC 61850 standards.