| Brand | ROCKWILL |
| Model NO. | 145kV HV Gas-Insulated Switchgear (GIS) |
| Rated voltage | 145kV |
| Rated normal current | 3150A |
| Series | ZF28 |
| Place of Origin | Zhejiang, China |
Product overview
ZF28-145 type GIS is composed of standard modules through same sized flanged joint, which can meet the demand for substation optimization design through the flexible combination between modules. It saves space and conforms to technical requests.
This product can be applied to power system, power generation, rail transportation, petrochemical, metallurgy, mining, building materials and other large industrial consumer.
Features and advantages of the product
Special arc extinguish chamber design with spring operation mechanism;
The structure is tight and the minimum interval width can reach 800mm;
Full three phase encapsulated；
Self-developed 3 position isolated grounding switch；
Completely self-research and development with high starting point and large investment;
Inspected to be qualified by KEMA High level of parameters, advanced structural design;
Insulation level is higher than IEC and GB standards;
Self-blast combined interrupter, 3-position disconnector and earthing switch, spring operating mechanism;
Double sealing ring structure;
Minimum area;Compact and standardized module design with minimum intervals width 800mm;
It is applied to cold, humid, salt fog, coastal, high altitude areas;
Spring operating mechanism base processed by Four Axis Milling CNC Machining Center imported from DMG, German;
Basin-type produced by vacuum epoxy casting Production line imported from Germany Hubers;
Technical Parameter
The core difference lies in the scenario adaptability brought by the "hybrid application of insulating media": ① Compared with fully gas-insulated GIS, HGIS connects via air-insulated busbars, reducing reliance on a fully enclosed gas environment. It has more advantages in scenarios where installation space is relatively sufficient but the volume of core components needs to be controlled; ② Compared with fully air-insulated AIS, the core functional modules of HGIS adopt gas insulation, resulting in a more compact structure. It is suitable for scenarios with limited floor space (such as urban substations and offshore platforms) and reduces the impact of the external environment on core components.
Insulation Principle:
In an electric field, the electrons in SF₆ gas molecules are slightly displaced from the nuclei. However, due to the stability of the SF₆ molecular structure, it is difficult for electrons to escape and form free electrons, resulting in high insulation resistance. In GIS (Gas-Insulated Switchgear) equipment, the insulation is achieved by precisely controlling the pressure, purity, and electric field distribution of the SF₆ gas. This ensures a uniform and stable insulating electric field between the high-voltage conductive parts and the grounded enclosure, as well as between different phase conductors.
Under normal operating voltage, the few free electrons in the gas gain energy from the electric field, but this energy is not sufficient to cause collision ionization of the gas molecules. This ensures the maintenance of the insulating properties.
Due to the excellent insulation performance, arc extinguishing performance and stability performance of SF6 gas, GIS equipment has the advantages of small footprint, strong arc extinguishing ability and high reliability, but the insulation ability of SF6 gas is greatly affected by the uniformity of the electric field, and it is easy to have insulation abnormalities when there are tips or foreign objects inside the GIS.
GIS equipment adopts a fully enclosed structure, which brings the advantages of internal components without environmental interference, long maintenance cycle, low maintenance workload, low electromagnetic interference, etc., while also having problems such as complex single overhaul work and relatively poor detection methods, and when the closed structure is eroded and damaged by the external environment, it will further bring a series of problems such as water ingress and air leakage.
