Urumqi Nantianya Electrical Complete-sets Equipment Co.,Ltd.
Add : 366 Tongbaishan Street, Economic and Technological Development Zone, Urumqi
Phone : 86-:13809951165
Service Phone :0991-4653766


Application of 10kV load switch cabinet in power distribution engineering

10kv distribution network directly faces the majority of electricity customers, and the load switch is the main equipment in the distribution network. Its quality is directly related to the safety and power quality of the 10kv power grid. This paper studies the many characteristics of the 10kv load switch cabinet. Can be familiar with its connection method and management method, correctly use 10kv load switch cabinet to ensure safe use of electricity.

1 10kv load switch cabinet main technology

The rated voltage, rated current and rated frequency, as well as the breaking current of the active load can be matched with other electrical equipment manufactured and used in China; the phase of the power load switch and the relative withstand voltage level, and the withstand voltage level between the fractures are consistent with The national standard meets the requirements of safe operation level; whether the dynamic and thermal stable current of the electric load switch can meet the maximum current and stability requirements of the current system of the power system; the equipment of the power load switch connecting the transformer unit and the function of the fuse blowing time Coordination, whether it can be adapted to the power system out-of-line relay protection setting; since the 10kv load switch cabinet breaks in the sf6 air box, several unit breaks can be installed in the same air box, and the 10kv bus line is also closed. Correspondingly, the probability of failure is reduced, and the function of clear demarcation, extension and safe power supply of the incoming and outgoing lines of the dividing chamber cable is satisfied.

2 system and power supply wiring method using load switch customer

Figure 1, 2, 3, 4 several 10kv power supply wiring form, they are mainly 10kv power cable line as the incoming line power supply, and use 10kv high-voltage side metering (technically small-capacity power customers use low-voltage metering) As the basis for calculating the electricity bill. The required power load is generally 1000kva, 10kv dual-channel power supply for the larger load power customer main wiring, as shown in Figure 1, 2; single-channel power supply and 10kv outlet power customers, as shown in Figure 3; 10kv single-channel power supply, the required power load is relatively small, and can also be used in the form of box-type power supply, as shown in Figure 4. The following is explained separately as shown in the figure.

The main wiring mode of the 10kv two-way cable incoming power supply is normally two-way power supply segmentation operation, which is operated by segmentation measurement. Once there is a problem with any of the incoming power supplies, the 10kv load switch on the power loss side can be pulled open and the contact switch can be closed to continue power supply. Figure 1, 2 is a schematic diagram of the main wiring of a typical 10kv dual-supply power supply. The number and capacity of the transformer can be adjusted according to the requirements of the technical specifications as needed. The actual operation proves that a set of load switches with two power supply line load switches connected to each other must be installed between the 10kv two-segment busbars to meet the requirements of 10kV power supply flexibility and safety reliability. According to the customer's operation and management level, and from the needs of operational safety and inspection and maintenance, Figure 2 adds an electric load switch to each busbar, mainly for the normal inspection of the measuring unit and the component repair work during the operation. Security service.

The customer's two 10kv power supply lines can be directly drawn from the two 10kv outlet circuit breakers of the substation, or from the exit of the two-component boundary room of the nearest power customer. The 10kv power load switch replaces the original circuit breaker, and saves the test and maintenance of relay protection, circuit breakers and other electrical equipment. It is simple, reliable and easy to master.

Figure 3 and Figure 4 are schematic diagrams of the main wiring of a 10kv single-channel power supply. The main difference between the two is not the number of transformers installed. The key is whether there is a 10kv outlet unit. Considering the operation management and specific operations after the power equipment is put into operation, generally speaking, the power load provided by the outlet unit of Figure 3 is often an extension of the same related customer. For example, a large living community or a building group, due to the need of power supply distance and power supply load, radiates power from the main substation of the power customer to the surrounding, using a power supply wiring method, otherwise there are some operational management, scheduling, and operation. In terms of coordination, it is not appropriate for power customers to use this type of wiring. Figure 4 shows a typical 10kv metering customer supply form, which is used in many box variants. The main wiring described above is only a schematic diagram, the purpose is to explain the object suitable for the use of power load switches. As for the selection and installation of components such as 10kv arresters, current transformers, voltage transformers, etc., it should be based on the power supply scheme of the power system. Design drawings are carried out.

Application of 3 10kv load switch cabinet in power distribution engineering

It adopts 10kv load switch and fast fuse with locking device, and it is used together with the isolated isolating knife. It has the qualification of electrical technical specification, small volume, simple maintenance and debugging, so that it needs to be equipped with single capacity (oil change 630kva and below, Power customers with transformers of 800kva and below) can be powered by a combination of load switch-fuse combination electrical switchgear and oil-to-converter (or box-type transformer) with full-sealed oil. Each transformer is used in multiple transformers. Each transformer is equipped with a load switch-fuse combination electrical switchgear. If the operating environment requires fire protection, or when economic conditions permit and the operating environment is suitable, dry-type transformers should be used for power supply.

Using 10kv load switch, several unit parts can be placed in one sf6 air box to form a switch box with closed bus bar and simple structure and small size. It better solves the problem of cable t-connection and extension, enabling each power customer to pass. The power load switch of the demarcation chamber is isolated and extended to realize the t connection of the 10kv power cable and the extension of the power supply connection. In addition, in order to ensure the power supply reliability of some power customers, the dual-loop power supply (ring network) power supply scheme can be considered in the case of a small increase in investment, thereby greatly improving the safety and reliability of the power supply. The wiring mode of the 10kv demarcation chamber power load switch can be determined according to the specific situation (generally, there are more 3 to 4 units installed in each boundary chamber), as shown in Figure 5.

From the wiring diagram in Figure 5, the 10kv busbar is closed. In fact, the building block type structure can be used to easily expand and increase the number of connections. At the same time, the operation and management system of the 10kv power load switch is established to ensure normal operation. The switching operation and mutual isolation are not affected, and the safe operation of the 10kv distribution network is better satisfied.

Of course, as the number of power cable power supply customers continues to increase, the number of demarcation chambers increases rapidly, increasing the workload of power system operation management and switching operations. Therefore, the currently operating 10kv load switch cabinet, under the premise of ensuring safe operation, how to research and improve from the operation mode, further meet and meet the requirements of operation management automation, facilitate the upgrading and upgrading of the distribution network in the future, better for safe operation. Service, there is still a lot of work that needs to be improved.

4 Conclusion

In summary, the 10 kV load switch cabinet has the advantages of safety and reliability, long electrical life, frequent operation, compact structure, small size, light weight, and basically no maintenance. The load switch can be used with the current limiting fuse. Good protection of small and medium capacity transformers. It is the main equipment used in power distribution engineering.


[1] Pan Yudong Wang Wei, development and application of 10kv switchgear [j] Science and Technology Information, 2008.23

Note: All formulas and charts in the article should be viewed in pdf format.

Previous:Talking about SF6 load switch and inflatable cabinet switchgear
Next:Electrical installation engineering knowledge