Hyosung offers a wide variety of SF6 Gas Insulated Switchgear ranging with rated voltages from 72.5kV to 800kV and rated short-circuit breaking current up to 63kA.
- Circuit Breaker
- Hyosung’s circuit breaker uses superior arc quenching performance and the insulation characteristics of the SF6 gas and adopts the puffer-type, which has a simple operation principle and structure. With the double trip coil, it guarantees reliable circuit breaking and its few parts allow for simple maintenance.
- Disconnecting Switch
- Disconnecting switch is a device used to segment the charge current section partitioned by the circuit breaker. It is operated by an electric motor; however, it can be manually operated for maintenance tests. In addition, the user can check the switch status since the switch status display is connected to the control shaft in the control box.
- Earthing Switches
- The earthing switch is classified into two types according to its role.
① Device earthing: manually and electrically controlled for maintenance
② Line earthing: controlled at high-speed. It has an input capacity even when the line is energized. For preventing any unforeseen accidents, it is interlocked with associated circuit breaker and disconnecting switches.
- Most busbars up to 362kV use three-phase batch tank for reducing the number of parts and installation period. The conductors are automatically connected via the tulip contactor when the housing of the busbars is assembled. The expansion or shrinkage of conductors due to temperature changes can be compensated.
- Current Transformers
- Current transformer protects the system by sensing any abnormal current in the line and measuring the usual conductive current. Insulation by high-voltage is not required since this is in the enclosure grounded at both ends of the circuit breaker and isolated by the first conductor and SF6 gas.
- Voltage Transformer
- Voltage transformer is a small-sized transformer using high-reliable gas insulated winding. It monitors the voltage of the line or the busbar. Voltage transformer is classified into two types: Metering Out Fit (MOF) and general meters.
- Lightning Arrester
- The lightning arrester protects the power utilities from overvoltage due to lightnings or surges and prevents the utilities from breakdowns and blackouts. It uses Zine-Oxide Lightning Arrestor (ZLA) which removes the series gap using Zinc Oxide element.
- The interface is classified into three types:
① Gas-to-Oil Bushing: when the interface is directly connected to the transformer, the bushing separates the gas and insulation oil. The bellows compensates the tolerance and minimizes vibration.
② Gas to Air Bushing: when the interface is directly connected to the feeder, the bushing filled with the SF6 gas is used.
③ Cable Sealing End: when the interface is directly connected to power cable
- Breaking Performance Analysis
- Low current breaking performance: analyze changes in SF6 gas density cause by arc heat generated between the poles of the circuit breaker by the charge current of transmission line.
- High current breaking performance: analyze changes in SF6 gas density by the high arc heat which is generated when the circuit breaker blocks the abnormal current. For maximizing the breaking performance, phoenics and fluent, the arc analysis tools, are used for analyzing the SF6 gas density and flow
Three-Dimensional Electric Field Analysis
- Because high voltage is applied in the SF6 GIS, a very precise electric field analysis is needed. Therefore, Hyosung uses a three-diemensional analysis program to design a product that analyzes the electric field distribution of all parts of the GIS including the busbar and insulating materials.
Mechanical Performance Analysis
- To maximize the optimum mechanical performance of the conductor, enclosure, and controller of the GIS, values (mass, shape, stress, transformation, etc) of all parts of the GIS are precisely analyzed using the structure analysis programs and three-dimensional design.
Three-Dimensional Design & Assembly
- Solid Edge, the latest three-dimensional design tool, is used for basic GIS design to assembling parts in order to minimize any possible design errors. It is also used to model the final installation so that the installation site is optimized by the assembled parts.
Seismic & Vibration
- To verify the seismic and vibration at the design stage, the latest seismic and vibration analysis tools, which consider all loads resulting from gravity (both the vertical load and the wind load), have been used for ensuring overall structural safety.