Better to Know to the SF6 fully Gas filled Ring Main Unit

1. Main Features of SF6 Gas Insulated Switchgear:

Gas insulated switchgear  adopts SF6 as the main insulation medium on 10kv to 35kv ring main unit. In the construction of urbanization, the SF6 full gas filled ring main unit has the signification benefits on compact and modular design. It widely adopts on urban power grid, rail transit, new energy industry, and industrial enterprises.

1.1 The Modular Design of SF6 Gas Insulated Switchgear

The sf6 ring main unit  mainly has C (cable switch panel), V(vacuum circuit breaker panel), D(direct cable connection panel), De(direct cable connection with earthing panel), F(switch-fuse disconnection panel), and M(metering panel).

In actual cases, C and V unit offers the control and protection to inputting and outputting cable power line. Besides the function of load operation, the V unit has more function on cutting off short circuit current and load current. The M unit equips metering CT, and PT, and energy meter. Normally, it has 800mm width which is same as a KYN28-12 . D and De unit is used for raising the cable height from the ground to the top of the sf6 ring main unit. In addition, the F unit also used in inputting and outputting protection, but terminal users prefer to adopts V unit instead of F unit, since the controlling gear is more complex.

1.2 The Compact Design of SF6 Gas Insulated Switchgear

Normally, the dimension of a C or V unit is W*H*D=371*1800*750 (mm), however, a input or output panel of a KYN28-12 is W*H*D=800*2300*1500(mm). It has no doubt that the sf6 ring main unit has more competitive on logistics and land costs. Moreover, a sf6 gas insulated switchgear has a lower material costs than a KYN28-12 as the compact designing.

2.  Structural S cheme  of a sf6 Gas Insulated Switchgear

   In a gas insulated switchgear, it mainly has SF6 gas tank, main switch and breaker, busbar system, controlling gear and secondary control and protection system.

   The sf6 gas tank adopts 201 or 304 stainless steel, of which the annual leakage rate is lower than 0.1%, which is designed as fully sealed and insulated. It ensures maintenance-free service for more than 30 years.

   It is similar as a air insulated switchgear  that the main switch and breaker in a input and output panel is earthing switch, disconnect switch, load switch breaker and vacuum circuit breaker for control and protection of power systems.

   In one common sf6 tank, it could integrate 7 modular units at the most of a 10 kv power grid system. Otherwise, a connection cable and cable plug is necessary for extensions. However, in one common tank, modular units is connected by the copper busbar.

   The secondary control and protection system has the function to monitoring the value voltage and current to protect sf6 ring main unit from system failure. Meanwhile, it also support automation, remote control, data acquisition, and access to SCADA system. In addition, the sf6 ring main unit also provide auxiliary power supply to ensure normal operation of control and signal transmission.

2.1  SF6 Gas Insulated S witchgear S tructure D iagram :

2.2 Outside Dimensions  of a SF6 Ring Main Unit：

2.3 Standard S olution and E xtension M odules ：

3.Parameter of SF6 Gas Insulated Switchgear