Views: 0 Author: Site Editor Publish Time: 2023-11-27 Origin: Site
What are the advantages of SF6 load switch?
Compared with the traditional medium voltage load switch operated in air and the characteristics operated in SF6 gas environment, the application advantage of SF6 (sulfur hexafluoride) load switch in medium and high voltage electrical equipment is significant.
Performance comparison between SF6 switch and medium voltage air switch:
• The table below shows some of the main features of the load switches that affect the application or required space. Of course, the table data of the air load switch is a general product, and the specific performance data of the air load switch produced by many different manufacturers may be very different.
• The air switch sizes shown are suitable for the most common (15 kV 600 A) switches, while the 27 kV switches are of much larger sizes. Despite the typical data used by the air switch, the table is considered valid for the overall understanding.
SF6 switch
Medium pressure air switch
SF6 switch | Medium pressure air switch | |
Mechanical life | 5000 Times | ANSI C37.22 Standard requires 500 times @15kV |
Electrical life | 630A 100 times | ANSI C37.22 The standard requires 30 times @15kV |
Environment | Welded stainless steel switch housing, sealed for life, isolated from contaminants | Switch in air, exposure to pollutants, corrosive effects, dust, dirt |
Size | Very small for the 27.6kV 600A 356X203X229mm | 15kV 600A711X635X660mm |
Isolation can be seen | Yes | Yes |
Functionality | To introduce the fault off (off capability) grounding of the feeder | The ground switch is not integrated |
Mode of operation | Manual spring operation, electric operation, electric spring energy storage operation | Manual spring operation, electric spring energy storage operation |
Institutional strength | • Very small, small exercise quality | • Very large, with great exercise quality |
Maintenance | Very low: | High: |
| 1.Switch housing is sealed for life 2.No-contact inspection or replacement | 1.The switch is operating in the air | |
Else | SF6 Leak, gas treatment | No need to deal with |
Which one is better, SF6 switch or medium voltage air switch?
It shows that the advantages and disadvantages between SF6 load switch and air insulated load switch are compared. It is obvious that the load switch sealed in SF6 has obvious advantages and excellent performance.
Based on the data in the Table, the following observations can be made:
• Durability: The durability of the SF6-type load switch is significantly higher than the air switch that only meets the durability requirements of ANSI C37.22.
• Environment: Type SF6 switch is isolated from the atmosphere, so the switch performance will not decrease in harsh environment.
• Size: the SF6-type switch (no operator) is more than 90% smaller than the basic air switch, thus greatly reducing the installation space of the entire switchgear.
• Maintenance: The maintenance required for the switch itself is basically not required.
• This comparison shows the superiority of SF6 load breaker switch compared with traditional load breaker air switch.
• Price: SF6 load switch price is higher, but the long-term use is safe and reliable, maintenance free, service life is longer, for the need for frequent operation, reliable protection of power distribution applications, the cost performance is higher.
How can environmentally friendly gas load switches replace SF6?
• Environmental protection gas load switch, can be said to be a kind of vacuum load switch, through the vacuum load switch and isolation series, or vacuum load switch + separate three station switch to form a whole, to achieve SF6 replacement.
• Schneider SM AirSeT adopts parallel vacuum arc extinguishing technology, in the traditional bag upper pouring arc chamber, 3 station switch open through the arc chamber to extinguish the arc, AirSeT compressed air from air, need not worry about the greenhouse effect, good insulation performance, gas non-toxic, no need to worry about gas leakage of equipment operations personnel safety hazard.12kV, 1250A 31.5kA, 600mm wide, 1050mm deep, 2220mm deep, inflation pressure of 0.14 Mpa.
• UniSec AirPlus HBC Using the traditional 3 station switch + vacuum arc design, pouring inside the epoxy resin shell, before 3 station switch fracture using SF6 insulation, ABB new insulation gas AirPlus, insulation strength similar to SF6, AirPlus is a breakthrough of environmental protection hybrid gas, 3M company C5 and air hybrid gas, than SF6 gas global warming potential value reduced 99.99%. UniSec AirPlus HBC Rated voltage is 24kV 1250A 25kA, 500mm wide, 1070mm deep, 2000mm, deep air inflation pressure of 0.14 Mpa.
• SF6 As a greenhouse gas, will inevitably be replaced by environmental protection gas, but how to develop good insulation performance, and have the opening function of the alternative gas, is the key, vacuum arc extinguishing load switch + disconnecting switch can not be said to be a complete replacement of SF6 load switch, can only be said to be a solution. To achieve the same performance of the SF6 load switch in the above table, only the environmental protection gas replaces the SF6 gas switch, can be said to be the real environmental protection gas load switch.
