Optimisation SF6 handling procedures during on-site testing and commissioning for GIS

Gas Compartment Design and Optimization

Pre-filled SF6 Gas Compartments

Gas compartments are pre-filled with sulfur hexafluoride (SF6) at a pressure slightly above atmospheric pressure for transportation. This ensures that the equipment remains stable during transit and reduces the workload required for on-site installation.

Optimization to Minimize SF6 Usage

Gas compartments are optimized to use the minimum amount of SF6 necessary for a given functionality. Since the lowest achievable SF6 recovery pressure is defined, the mass of SF6 released into the atmosphere is directly proportional to the size of the gas compartment. Through this optimization, the usage of SF6 can be minimized, thereby reducing environmental impact.

Use of Cable Plugs for Connecting High-Voltage Cables

Cable plugs are used to connect high-voltage cables, eliminating the need for complete SF6 recovery or opening the gas compartment when connecting the cables to the GIS. The cable compartment includes a socket, and the cables are simply plugged in. This method simplifies the connection process while maintaining the system's seal and safety.

Utilizing Power Voltage Transformers (VT) for High-Voltage Testing

During high-voltage testing, power voltage transformers (VT) can energize from the low-voltage side, thus avoiding the need to handle SF6 to connect the high-voltage source for testing. After the high-voltage test, the power VT can continue to function as a standard instrument transformer. This approach not only enhances testing efficiency but also reduces the need for SF6 handling.

Use of Bushing Connections for High-Voltage Testing

Bushing connections can be used to connect the high-voltage source for testing without the need to handle SF6. However, this method may introduce some limitations related to on-site partial discharge tests. Despite these limitations, it still provides a convenient and environmentally friendly way to perform high-voltage tests.