How is the leakage alleviation and monitoring of SF6 circuit breakers carried out?

The following content will be divided into three parts: the hazards of leakage, measures to mitigate leakage, and monitoring technologies for leakage.

The Hazards of SF6 Leakage

1) Equipment safety risks:

Reduced insulation performance: A decrease in SF6 pressure directly leads to a decline in the insulation strength of circuit breakers, which may cause breakdown under overvoltage and trigger serious accidents.

2) Insufficient breaking capacity: Insufficient SF6 gas pressure in the arc extinguishing chamber will fail to effectively quench the arc, possibly resulting in the failure of the circuit breaker when interrupting fault currents, and even explosion.

3) Economic cost: SF6 gas is expensive, and frequent gas replenishment incurs significant maintenance costs.

Leakage mitigation measures

The core of the mitigation measures lies in "preventing trouble before it happens", and controlling throughout the entire life cycle from design, manufacturing, installation, operation to decommissioning.

Replacing flange connections with welded structures: For components that do not need to be disassembled, welding should be used as much as possible to eliminate leakage points fundamentally.

Reducing the number of sealing points: Through integrated design, the number of flanges and joints in the circuit breaker is reduced.

Gas treatment system: Equipped with self-sealing inflation valves and sampling valves, which can automatically seal after the pipeline is unplugged to prevent leakage caused by operational errors.

Summary and Best Practices

An integrated strategy for the leakage management of SF6 circuit breakers is:

1. First choice:

prevention - Purchase high-quality, low-leakage design equipment and install it in accordance with standards.

2. Regular monitoring:

Rely on density relays for safety protection, and regularly inspect pressure gauges and data.

3. Precise leak detection:

When pressure anomalies are detected or regular surveys are needed, use infrared imaging leak detectors for efficient and accurate leak point location.

4. Quantitative assessment:

Establish a gas management ledger and calculate the leakage rate annually or semi-annually to ensure compliance with environmental protection standards.

5. Full life cycle responsibility:

From charging, operation to decommissioning and recycling, ensure "zero emissions" of SF6 gas.

With increasingly strict environmental regulations and the advancement of the "dual carbon" goals, the control of SF6 leakage has become an indispensable and highly demanding aspect of power grid operation and maintenance. In the future, the development and application of "SF6-free" circuit breakers using environmentally friendly alternative gases (such as g³ and AirPlus) will be the ultimate solution. However, during the transitional period, the meticulous management of the existing large number of SF6 equipment is of critical importance.

LW25-126 outdoor high voltage porcelain SF6 circuit breaker

LW25-126 outdoor high voltage porcelain SF6 circuit breaker is an outdoor, three-phase AC 50Hz high voltage electrical equipment. It is primarily used to protect transmission and distribution lines and can also be used as a tie breaker. This circuit breaker features a three-phase mounted on one frame, with no provision for single-phase operation.

LW25-126 Outdoor High Voltage Porcelain Column SF6 Circuit Breaker