40.5KV 1600A Outdoor high-voltage SF6 tank circuit breaker

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Definition:

The LW30 series Outdoor high-voltage SF6 tank circuit breaker is a specialized electrical switching device designed to interrupt high-voltage electrical circuits during fault conditions or for routine switching operations. It utilizes sulfur hexafluoride (SF6) gas as the arc-quenching and insulating medium contained within a sealed tank. This type of circuit breaker is specifically engineered for outdoor installations in electrical substations and power distribution networks.

Product Features:

1. High dielectric strength: The SF6 gas, with its exceptional insulation properties, allows for a compact design, instilling confidence in the circuit breaker's performance.

2. Superior arc-quenching capability: SF6 efficiently extinguishes electrical arcs, enabling fast circuit interruption.

3. Environmentally sealed: The gas is securely contained in a hermetically sealed tank, providing robust protection to internal components against environmental factors, ensuring peace of mind for the operators.

4. Long service life: The arc-quenching properties of SF6 gas result in minimal wear on contacts, ensuring a long service life and reliability.

5. Low maintenance requirements: Sealed design reduces the need for frequent inspections and maintenance.

6. High reliability: Consistent performance under various environmental conditions.

7. Compact size: Smaller footprint compared to air-insulated circuit breakers of similar ratings.

8. Silent operation: SF6 gas reduces operating noise compared to air blast circuit breakers.

9. Fast operating speed: Quick response to fault conditions, minimizing damage to connected equipment.

10. High short-circuit breaking capacity: Capable of interrupting large fault currents safely.

Working Principle:

The SF6 tank circuit breaker operates on the principle of arc interruption in a controlled SF6 gas environment. When a fault occurs or during intentional switching, the breaker contacts separate, creating an arc between them. The SF6 gas, under pressure, flows through specially designed nozzles around the arc. As the gas flows, it cools and de-ionizes the arc plasma, rapidly extinguishing the arc at a current zero crossing. The excellent dielectric properties of SF6 prevent arc re-ignition, effectively interrupting the circuit.

The breaker utilizes a stored energy mechanism, typically spring-operated, to provide the necessary force for rapid contact separation and closure. This mechanism can be charged electrically or manually, ensuring operation even in the absence of auxiliary power.

Working Conditions:

Outdoor high-voltage SF6 tank circuit breakers are designed to operate under various environmental conditions:

1. Ambient temperature range: Typically -40°C to +50°C

2. Altitude: Up to 1000m above sea level (with derating factors for higher altitudes)

3. Humidity: Up to 95% relative humidity

4. Pollution levels: Suitable for various pollution levels, from light to heavy industrial environments

5. Wind speed: Capable of withstanding high wind speeds, often up to 34 m/s

6. Seismic conditions: Designed to operate in seismically active areas, with specific ratings available

7. Ice accretion: Able to function with ice buildup, typically up to 20mm thickness

Main Technical Parameters:

1. Rated voltage: Typically ranging from 72.5 kV to 800 kV

2. Rated current: From 1250 A to 6300 A, depending on the model

3. Rated short-circuit breaking current: Up to 63 kA

4. Rated short-time withstand current: Up to 63 kA for 3 seconds

5. Rated peak withstand current: Up to 170 kA

6. First-pole-to-clear factor: 1.3 or 1.5, depending on the system configuration

7. Rated operating sequence: O-0.3s-CO-3min-CO (Open-Close-Open cycle)

8. Rated SF6 gas pressure: Typically 0.5-0.7 MPa at 20°C

9. Mechanical endurance: 10,000 operations without maintenance

10. Electrical endurance: Typically 100 full short-circuit interruptions at rated capacity

Structure:

The outdoor high-voltage SF6 tank circuit breaker consists of several key components:

1. Interrupter unit: Houses the main contacts and arc-quenching nozzles within the SF6 gas-filled tank.

2. Support structure: Insulating columns that support the interrupter unit and provide electrical isolation from the ground.

3. Operating mechanism: Spring-operated or hydraulic system for contact actuation.

4. Control cabinet: Houses control, monitoring, and auxiliary equipment.

5. Gas monitoring system: Monitors SF6 gas pressure and density.

6. Bushings: Provide electrical connection and insulation between the interrupter and external conductors.

7. Grading capacitors: Ensure uniform voltage distribution across interrupter breaks in series (for higher voltage ratings).

8. Tanks: Sealed containers holding the SF6 gas, typically made of corrosion-resistant materials.

9. Gas handling system: Allows for gas filling, evacuation, and reclamation.

10. Current transformers: These are often integrated into the bushings for measurement and protection purposes. They play a crucial role in the interruption process by providing accurate current readings, which are used to trigger the breaker's operation and ensure safe interruption of high short-circuit currents.

Product Advantages:

1. High reliability and long service life due to minimal contact wear.

2. Compact design allows for space-saving substation layouts.

3. Excellent performance in harsh environmental conditions.

4. Low maintenance requirements reduce operational costs.

5. Fast interruption times enhance system stability and equipment protection.

6. The high dielectric strength of SF6 allows for higher voltage ratings in compact designs.

7. Environmentally sealed design protects internal components from contamination.

8. Silent operation reduces noise pollution in residential areas.

9. Capability to interrupt high short-circuit currents safely.

10. Flexibility in installation due to modular design and lightweight construction.

Application Range:

Outdoor high-voltage SF6 tank circuit breakers find applications in various parts of the electrical power system:

1. Transmission substations: Protection and switching of high-voltage transmission lines.

2. Distribution substations: Sectionalizing and protection of distribution networks.

3. Power generation plants: Generator protection and synchronization.

4. Industrial facilities: Protection of large motors, transformers, and distribution systems.

5. Renewable energy integration: Grid connection and protection for wind farms and solar plants.

6. Railway electrification: Traction power supply systems.

7. HVDC converter stations: AC side protection and switching.

8. Capacitor and reactor banks: Switching and protection of reactive power compensation devices.

9. Bus sectionalizing: Isolation and reconfiguration of substation bus systems.

10. Transformer protection: Primary side isolation and fault current interruption for large power transformers.

Installation:

The installation of outdoor high-voltage SF6 tank circuit breakers requires careful planning and execution:

1. Site preparation: Ensure a level foundation capable of supporting the breaker's weight and withstanding operational forces.

2. Assembly: Many breakers are shipped partially disassembled to facilitate transportation. On-site assembly may be required, following manufacturer guidelines.

3. Mounting: Secure the support structure to the foundation using appropriate anchoring methods.

4. Gas handling: Fill the interrupter tanks with SF6 gas to the specified pressure, following proper gas handling procedures to prevent environmental release.

5. Electrical connections: Install high-voltage bushings and connect to the substation bus or overhead lines. Ensure proper torque on all electrical connections.

6. Control wiring: Connect the control and auxiliary circuits to the substation control system, including trip and close circuits, position indicators, and monitoring systems.

7. Functional testing: Perform mechanical operation tests, timing tests, and insulation resistance measurements before energization.

8. Commissioning: Conduct full functional tests, including protection system coordination, before putting the breaker into service.

9. Environmental considerations: Implement appropriate measures for SF6 gas management, including leak detection and recovery systems.

10. Safety measures: Install proper grounding, safety interlocks, and warning signs as required by safety regulations.

11. Documentation: Maintain detailed records of installation procedures, test results, and as-built drawings for future reference and maintenance.

Conclusion

In conclusion, outdoor high-voltage SF6 tank circuit breakers are:Critical components in modern power systems.Offering high performance.Reliability.Efficiency in a compact package.Their ability to safely interrupt high fault currents while withstanding harsh environmental conditions makes them indispensable in ensuring the stability and safety of electrical networks worldwide.