DGA Monitoring Enhances Transformer Reliability at Guoneng Shenwan Chizhou Power Generation Co., Ltd.

Background and Regulatory Imperative

Transformers are vital components in power plants, and their insulation oil condition serves as a critical indicator of internal health. The State Energy Investment Group's 2022 directive, "Notice on Issuing the List of Special Anti-Accident Measures for the Electric Power Industry of State Energy Group 2022," explicitly mandates the installation of reliable online oil chromatographic monitoring devices on 220kV main transformers. This requirement stems from the need to:

• Continuously monitor key fault gases (e.g., hydrogen, methane, ethylene, acetylene)
• Enable early detection of incipient faults (e.g., partial discharge, thermal degradation, arcing)
• Prevent catastrophic failures and unplanned outages

Recognizing this imperative, Guoneng Shenwan Chizhou proactively assessed its assets and identified the absence of online oil quality monitoring systems on its main and starting transformers—a significant gap given their operational lifespan of approximately 19 years.

Technical Specifications of Assets

| Asset Type | Manufacturer | Model | Rated Capacity | Connection Group | DCS System | |-------------------|----------------------------------|-------------------|----------------|------------------|--------------------| | #1 & #2 Main Transformers | Baoding Tianwei Baobian Electric | SFP-370000/220 | 370 MVA | YNd11 | Shanghai Xinhua XCD800 | | #01 HV Start/Standby Transformer | Xi'an XD Transformer Co., Ltd. | Not specified | Not specified | Not specified | Shanghai Xinhua XCD800 |

The Solution: HZ-DGA-900 Online DGA System

To address the regulatory requirement and operational need for real-time monitoring, Guoneng Shenwan Chizhou selected the HZ-DGA-900 Online DGA Monitoring System. This system offers:

Advanced Performance and High Sensitivity

• Multi-Gas Detection: Accurately measures critical fault gases (H₂, CH₄, C₂H₂, C₂H₄, C₂H₆, CO, CO₂) at ppm levels.
• Thermal Cycling Technology: Enhances gas extraction efficiency and measurement stability.
• Robust Calibration: Ensures long-term accuracy with minimal drift, reducing maintenance frequency.

Seamless SCADA Integration

A key success factor was the system’s effortless integration into the existing Shanghai Xinhua XCD800 Distributed Control System (DCS). This integration enables:

• Real-time data visualization on plant control screens
• Automated alarm generation for abnormal gas concentrations
• Historical trend analysis for predictive diagnostics
• Centralized data storage and reporting

Project Implementation

A total of 33 HZ-DGA-900 units were deployed across the #1 and #2 main transformers and the #01 high-voltage starting/standby transformer. The implementation process included:

1. Site Assessment: Customized sensor placement based on transformer design.
2. Non-Invasive Installation: Minimized operational disruption.
3. System Commissioning: Rigorous field acceptance testing confirmed measurement accuracy and communication reliability.
4. Operator Training: Ensured effective utilization of the monitoring data.

Operational Benefits

The deployment of the HZ-DGA-900 system has transformed transformer maintenance at Guoneng Shenwan Chizhou from reactive to predictive:

• Early Fault Detection: Identification of abnormal gas trends before failures escalate.
• Reduced Downtime: Prevention of unplanned outages through timely interventions.
• Extended Asset Lifespan: Optimized maintenance scheduling based on actual condition.
• Regulatory Compliance: Full adherence to State Energy Group’s 2022 safety directives.

Conclusion

For aging critical assets like transformers, real-time DGA monitoring is no longer optional—it is a necessity for safety, reliability, and regulatory compliance. The HZ-DGA-900 system’s proven performance at Guoneng Shenwan Chizhou Power Generation Co., Ltd. demonstrates its capability to deliver:

• High-precision gas analysis
• **Seamless project underscores our commitment to providing cutting-edge solutions that empower power generation facilities to safeguard their infrastructure and operational continuity.