Condition-Based Maintenance & Fault Diagnosis for Power Equipment: Strategies and Technologies

The operational status of power equipment directly impacts the power supply quality of utility companies. Routine maintenance of power equipment can reduce the risk of failures; however, existing challenges in condition-based maintenance (CBM) still lead to significant consumption of human and material resources. By implementing CBM, utilities can gain real-time insights into equipment conditions, enabling immediate detection and repair of faults. This significantly improves power supply reliability and the overall health of power lines, providing a solid foundation for utility development.

1. The Role of Condition-Based Maintenance (CBM) for Power Equipment

1.1 Enhancing Distribution Network Reliability
Building and operating a distribution network requires not only rational structural design and economic efficiency, but also high reliability and advanced technology. Only by ensuring balanced progress across all these areas can a robust distribution network be established to meet growing electricity demands. Effectively improving distribution network reliability requires strategic implementation of substation equipment condition monitoring. CBM is one of the most effective approaches. By combining CBM with modern technologies, equipment faults can be detected and addressed promptly, preventing safety incidents and minimizing economic losses.

1.2 Promoting Standardized and Refined Management in Power Utilities
To achieve standardized and refined management, power utilities must move away from traditional, coarse management models. Clear, quantifiable standards and advanced scientific management principles must be implemented across all management processes. CBM effectively standardizes detailed management, enabling greater returns with lower investment and driving further development of power enterprises.

2. Common Faults in Electrical Equipment within Power Systems

2.1 Mechanical Failures
Mechanical failures primarily stem from inadequate maintenance. When maintenance personnel fail to conduct regular servicing, mechanical components operate continuously for extended periods, leading to wear, fatigue, and other abnormalities, potentially culminating in severe mechanical failure. Research indicates that motors in such equipment often operate independently, making fault diagnosis difficult and delaying timely detection and resolution. In such cases, maintenance personnel require not only extensive experience but also advanced diagnostic instruments to locate and address fault points.

2.2 Insulation Failures
Insulation failure is the most common fault during electrical equipment operation. High-voltage electrical units operating for long durations are susceptible to external factors such as high voltage and strong electric fields, compromising the safe operation of surface insulation and causing problems to arise. If undetected during inspection, these issues can worsen and escalate into major equipment failures. Studies show insulation failures frequently occur in components like transformers and current transformers. Primary causes include inherent design limitations, poor sealing, and external environmental erosion or corrosion of wiring. Additionally, compromised sealing of external materials can also lead to insulation failure.

2.3 Overheating Faults
Electrical equipment inherently generates and transfers heat during operation. Abnormalities in this process—such as short circuits—can cause a rapid surge in current and heat, potentially leading to sudden temperature spikes. This can severely damage components and disrupt equipment operation. Temperature anomalies in circuit components are relatively easy to detect during patrols, so maintenance personnel must promptly address them when discovered.

3. Research on Condition-Based Maintenance Technologies for Power Equipment

3.1 Adoption of Advanced Maintenance Technologies
CBM should follow the principle: "Repair what needs repair, and ensure repairs are done correctly." During implementation, new technologies should be integrated with legacy systems to enhance the modernization of power systems. As technology advances, maintenance techniques must keep pace. Common CBM technologies include condition monitoring, condition prediction, and condition assessment. First, equipment status is monitored using parameters. Then, prediction methods—such as time series analysis or artificial neural networks—are applied based on equipment type. Finally, assessment of inspection results provides reliable status reports to support the CBM process.

3.2 Application in Substations
Substations are fundamental infrastructure in power systems, responsible for power transmission and distribution. Traditional substation maintenance relies on relay protection devices. When an anomaly is detected, staff must travel to the site for inspection and repair, resulting in low efficiency. With the advancement of automation, integrating CBM with automation technologies has significantly improved maintenance efficiency. Remote monitoring enables staff to view operational parameters via computer, collect and analyze regional power usage data, identify anomalies, and predict potential faults based on historical data—enabling targeted, efficient maintenance and ensuring stable substation operation. Power systems are complex; a single component failure can trigger cascading failures. Therefore, CBM for disconnect switches is essential. These switches can fail due to overheating, which can be detected by monitoring surface temperature and addressed immediately. Although some utilities have deployed software and hardware for CBM, they still use traditional management methods, limiting the effectiveness of new technologies. Therefore, improving the competence of managers and technical staff is crucial to fully leverage CBM. As a novel technology, CBM requires continuous learning by personnel to ensure its full potential is realized.

3.3 Building a CBM Evaluation System
Routine maintenance in utilities typically involves inspecting transformers, power lines, circuit breakers, etc. While maintenance records are kept for reference during handovers, a formal evaluation system is often lacking. To improve maintenance effectiveness, a comprehensive CBM evaluation system should be established. Data collected during maintenance should be recorded and compiled into detailed status reports, forming a robust evaluation framework. This provides valuable historical data for future maintenance planning and decision-making.

Conclusion
Today’s society is information-driven and intelligent. Industries across the board are integrating automation and smart technologies. Given the extensive power grid infrastructure and expanding service areas in China, CBM is fundamental to maintaining power system stability. Therefore, utilities must strengthen maintenance practices to ensure grid reliability and operational stability.