Online Monitoring of Oil-Immersed Transformers: Ensuring Safety and Reliability in Subway Systems-INNO

At FJINNO, we understand that oil-immersed transformers are critical components of power systems, and their reliable operation is paramount, especially in demanding environments like subway systems. We're committed to providing advanced transformer monitoring solutions, and this article highlights the importance of online monitoring, particularly fiber optic temperature sensing, to enhance safety and prevent costly downtime. FJINNO's expertise in fluorescence-based fiber optic temperature sensors offers a superior approach to traditional methods.

This article explores the crucial role of online monitoring for oil-immersed transformers in subway systems, focusing on the advantages of FJINNO's fiber optic temperature sensor technology. We'll delve into the various monitoring techniques, the importance of temperature monitoring, and a real-world case study demonstrating the benefits.

The Importance of Oil-Immersed Transformers in Subway Systems

Subway systems rely on oil-immersed transformers to provide stable power for train operation. The high-frequency operation and large power demands of these systems place significant stress on transformers. A transformer failure can lead to service interruptions, delays, and potentially hazardous situations. Therefore, real-time condition monitoring and assessment of transformer health are essential for ensuring the safe and efficient operation of subway systems.

Online Monitoring Techniques for Smart Oil-Immersed Transformers

Comprehensive transformer monitoring requires a multi-faceted approach, utilizing various online monitoring techniques:

Temperature Monitoring: Utilizing sensors, such as FJINNO's fluorescence fiber optic temperature sensors, to continuously monitor the temperature of transformer oil and windings, detecting potential overheating.
Dissolved Gas Analysis (DGA): Employing gas chromatography to analyze the concentration of dissolved gases in transformer oil, indicating internal faults like arcing or partial discharge.
Oil Quality Analysis: Regularly testing the dielectric strength, acidity, and impurity content of transformer oil to assess its degradation.
Current and Voltage Monitoring: Continuously monitoring the input and output currents and voltages of the transformer to identify abnormal fluctuations.
Partial Discharge (PD) Detection: Using online PD monitoring equipment to detect internal insulation degradation, preventing catastrophic failures.

The Critical Role of Temperature Monitoring

When the load on a transformer increases, changes in voltage and current are the first indicators. Voltage and current monitoring are fundamental. However, as the load increases, so does the transformer's temperature. Therefore, in addition to voltage and current, temperature monitoring is crucial. Other monitoring methods, like DGA and PD detection, often show changes accompanied by temperature variations. While voltage and current changes are rapid, temperature changes follow closely, reflecting the transformer's operating state under load.

Due to the size of transformers, especially large-capacity units, increased load leads to higher current flow through the windings, intensifying magnetic induction and causing temperature rise. This temperature change directly reflects the winding's operating condition. Transformers are filled with oil for cooling and insulation. The windings can be thought of as a "heater" within the large volume of oil. The time it takes for the oil to heat up depends on the transformer's design and oil capacity.

Directly monitoring transformer winding temperature has long been a challenge. Traditional methods, like thermal imagers or platinum resistance temperature detectors (RTDs), are ineffective because they cannot penetrate the oil and enclosure, or they compromise insulation and pose electrical hazards. Fiber optic temperature sensors, particularly FJINNO's fluorescence fiber optic technology, have revolutionized this aspect of transformer monitoring. FJINNO's sensors offer:

Intrinsic Safety: Fiber optics are non-conductive, eliminating electrical risks.
Electromagnetic Interference (EMI) Immunity: Optical signals are unaffected by EMI, making them ideal for the high-EMI environment within a transformer.
High Temperature Resistance: Fluorescence fiber optic sensors can withstand the high temperatures found in transformer windings.
Compact Size: The small size of fiber optic sensors allows for easy installation directly on the windings.
High Accuracy: FJINNO's fiber optic temperature sensors provide precise and reliable temperature readings.

Case Study: Application in a Subway Project

A subway project in Suzhou, China, implemented a fiber optic temperature monitoring system to ensure the reliable operation of its oil-immersed transformers. This system provides real-time monitoring, enabling early detection and resolution of potential issues. This reduces the risk of equipment failure, extends transformer lifespan, minimizes unplanned downtime, and significantly improves the overall efficiency of the subway system.

Benefits of Online Monitoring

Early Warning: Detects potential transformer faults before they escalate.
Accurate Diagnosis: Identifies the type and location of faults, guiding maintenance efforts.
Reduced Maintenance Costs: Minimizes unnecessary inspections and repairs.
Enhanced Safety: Ensures transformer operation within safe limits, preventing accidents.
Optimized Operation: Provides data for improved management and optimization of the subway power system.
Predictive Maintenance: Enables proactive maintenance scheduling based on real-time condition data.

FAQ: Fiber Optic Temperature Sensing

1. What are the advantages of fiber optic temperature sensors over traditional temperature sensors?

Fiber optic temperature sensors offer several key advantages:

EMI Immunity: They are not affected by electromagnetic interference, making them ideal for high-voltage environments like transformers.
Electrical Isolation: They are non-conductive, eliminating the risk of electrical shorts or sparks.
Small Size and Flexibility: They can be easily installed in tight spaces, such as directly on transformer windings.
High Accuracy and Stability: They provide precise and reliable temperature measurements over long periods.
Remote Sensing Capability: They can transmit temperature data over long distances without signal degradation.
Chemical Resistance: Suitable for harsh environments.

2. How does a fluorescence-based fiber optic temperature sensor work?

Fluorescence-based fiber optic temperature sensors utilize a special material (phosphor) at the tip of the optical fiber. When light is shone on this material, it emits light (fluoresces) with a decay time that is directly proportional to the temperature. By measuring the decay time, the sensor accurately determines the temperature.

3. Are fiber optic temperature sensors suitable for high-temperature applications?

Yes, many fiber optic temperature sensors, including FJINNO's, are designed for high-temperature applications. The specific temperature range depends on the materials used in the sensor construction. FJINNO offers sensors capable of operating in very high-temperature environments.

4. Can fiber optic temperature sensors be used in explosive environments?

Yes, fiber optic temperature sensors are intrinsically safe and do not pose a spark hazard, making them suitable for use in potentially explosive environments.

5. What is the typical lifespan of a fiber optic temperature sensor?

Fiber optic temperature sensors are known for their long lifespan and stability. With proper installation and care, they can provide reliable measurements for many years, often exceeding the lifespan of the equipment they are monitoring.

6. How are fiber optic temperature sensors installed?

Installation methods vary depending on the application. For transformer winding monitoring, the sensors are typically attached directly to the windings during the manufacturing process or retrofitted using specialized techniques. FJINNO provides detailed installation guidelines and support.

In conclusion, FJINNO is a global leader in fiber optic temperature sensing technology. Our commitment to innovation, customization, and customer support makes us the ideal partner for ensuring the safe and reliable operation of critical assets like oil-immersed transformers. Choose FJINNO for superior transformer monitoring solutions.

Fiber optic temperature sensor, Intelligent monitoring system, Distributed fiber optic manufacturer in China