The function and principle of ring main unit

2024-11-06 10:46:59 格雷诺（厦门）开关有限公司

Air-insulated ring main unit is generally called semi-insulated ring main unit; gas-insulated ring main unit is generally called fully-insulated ring main unit. The difference is that
1. After gas-filled insulation, the phase-to-phase distance is only 1/3 of that of the air-insulated cabinet, and the size of the switch cabinet is greatly reduced.
2. Insulation medium of fully-insulated ring main unit: SF6, N2 and other gases or their composite gases are used as insulation medium, with strong insulation performance.
3. Electrical clearance: The insulation performance of insulating gas is much stronger than that of air, and the electrical clearance of fully-insulated cabinet is much smaller than that of semi-insulated cabinet.
4. Equipment size: Due to the small electrical clearance, the size of fully-insulated cabinet is much smaller than that of semi-insulated cabinet of the same voltage level, and the floor space is small.
5. Altitude influence: The main circuit components of fully-insulated ring main unit are built in the gas-filled compartment, the pressure is constant, and it is not affected by altitude, which is particularly suitable for high altitude areas. The insulation performance of semi-insulated ring network cabinet is directly affected by altitude.

The standard product air-insulated ring network cabinet is generally called semi-insulated ring network cabinet; gas-insulated ring network cabinet is generally called fully-insulated ring network cabinet. The difference is that

1. After gas-filled insulation, the phase-to-phase distance is only 1/3 of that of the air-insulated cabinet, and the size of the switch cabinet is greatly reduced.

2. Insulation medium of fully-insulated ring network cabinet: SF6, N2 and other gases or their composite gases are used as insulation medium, with strong insulation performance.

3. Electrical clearance: The insulation performance of insulating gas is much stronger than that of air, and the electrical clearance of fully-insulated cabinet is much smaller than that of semi-insulated cabinet

4. Equipment size: Due to the small electrical clearance, the size of fully-insulated cabinet is much smaller than that of semi-insulated cabinet of the same voltage level, and the footprint is small.

5. Altitude influence: The main circuit components of the fully-insulated ring network cabinet are built in the gas-filled compartment, the pressure is constant, and it is not affected by altitude, which is particularly suitable for high-altitude areas. The insulation performance of semi-insulated ring network cabinet is directly affected by altitude. Standard products are used below 1000m, and special design is required for higher altitudes. 6. Pollution influence: Pollution cannot affect the gas-filled compartment of the fully insulated ring network cabinet, which is suitable for polluted areas. Semi-insulated ring network cabinet is directly affected by pollution, and special design is required for particularly harsh conditions. Siemens fully insulated ring network cabinet model is 8DH10/8Dj20; semi-insulated is simosec. Air-insulated ring network cabinet is generally called semi-insulated ring network cabinet; gas-insulated ring network cabinet is generally called fully insulated ring network cabinet. The difference is that 1. After gas-filled insulation, the phase-to-phase distance is only 1/3 of that of the air-insulated cabinet, and the size of the switch cabinet is greatly reduced. 2. Insulation medium of fully insulated ring network cabinet: SF6, N2 and other gases or their composite gases are used as insulation medium, with strong insulation performance. 3. Electrical clearance: The insulation performance of insulating gas is much stronger than that of air, and the electrical clearance of fully insulated cabinets is much smaller than that of semi-insulated cabinets.
4. Equipment size: Due to the small electrical clearance, the size of fully insulated cabinets is much smaller than that of semi-insulated cabinets of the same voltage level, and the floor space is small.
5. Altitude influence: The main circuit components of fully insulated ring network cabinets are built into the gas-filled compartments, the pressure is constant, and they are not affected by the altitude, which is particularly suitable for high altitude areas. The insulation performance of semi-insulated ring network cabinets is directly affected by the altitude.
Standard products are used below 1000m, and special designs are required for higher altitudes.
6. Pollution influence: Pollution cannot affect the gas-filled compartments of fully insulated ring network cabinets, which are suitable for polluted areas. Semi-insulated ring network cabinets are directly affected by pollution, and special designs are required for particularly harsh conditions.
Air-insulated ring network cabinets are generally called semi-insulated ring network cabinets; gas-insulated ring network cabinets are generally called fully insulated ring network cabinets. The difference is that
1. After gas-filled insulation, the phase-to-phase distance is only 1/3 of that of air-insulated cabinets, and the size of the switch cabinet is greatly reduced.
2. Insulation medium of fully insulated ring network cabinet: SF6, N2 and other gases or their composite gases are used as insulation medium, with strong insulation performance.
3. Electrical clearance: The insulation performance of insulating gas is much stronger than that of air, and the electrical clearance of fully insulated cabinet is much smaller than that of semi-insulated cabinet
4. Equipment size: Due to the small electrical clearance, the size of fully insulated cabinet is much smaller than that of semi-insulated cabinet of the same voltage level, and the footprint is small.
5. Altitude influence: The main circuit components of fully insulated ring network cabinet are built into the gas-filled compartment, the pressure is constant, and it is not affected by altitude, which is particularly suitable for high altitude areas. The insulation performance of semi-insulated ring network cabinet is directly affected by altitude
, standard products are used below 1000m, and higher altitudes require special design
6. Pollution influence: Pollution cannot affect the gas-filled compartment of fully insulated ring network cabinet, which is suitable for polluted areas. Semi-insulated ring network cabinet is directly affected by pollution
, and special design is required for particularly harsh conditions.
Air-insulated ring main unit is generally called semi-insulated ring main unit; gas-insulated ring main unit is generally called fully-insulated ring main unit
The difference is
1. After gas-filled insulation, the phase-to-phase distance is only 1/3 of that of the air-insulated cabinet, and the size of the switch cabinet is greatly reduced.
2. Insulation medium of fully-insulated ring main unit: SF6, N2 and other gases or their composite gases are used as insulation medium, with strong insulation performance.
3. Electrical clearance: The insulation performance of insulating gas is much stronger than that of air, and the electrical clearance of fully-insulated cabinet is much smaller than that of semi-insulated cabinet
4. Equipment size: Due to the small electrical clearance, the size of fully-insulated cabinet is much smaller than that of semi-insulated cabinet of the same voltage level, and the footprint is small.
In order to improve the reliability of power supply and enable users to obtain power from two directions, the power supply network is usually connected in a ring. This power supply method is referred to as ring network power supply. In AC 10KV distribution systems such as industrial and mining enterprises, residential areas, ports and high-rise buildings, due to the small load capacity, the high-voltage circuit is usually controlled by load switches or vacuum contactors and is equipped with high-voltage fuse protection. The system usually adopts ring network power supply, and the high-voltage switch cabinet used is generally called ring network cabinet.
Ring network refers to a ring distribution network, that is, the power supply trunk forms a closed ring, the power supply supplies power to this ring trunk, and then distributes power to the outside through high-voltage switches from the trunk. The advantage is that each distribution branch can get power from both its left trunk and its right trunk. When the left trunk fails, it continues to get power from the right trunk, and when the right trunk fails, it continues to get power from the left trunk. In this way, although the total power supply is single-circuit power supply, each distribution branch gets the benefits similar to dual-circuit power supply, thereby improving the reliability of power supply.The so-called "ring network cabinet" means that each distribution branch is equipped with a switch cabinet (outgoing switch cabinet), and the busbar of this switch cabinet is also part of the ring trunk. That is to say, the ring trunk is composed of the busbars of each outgoing cabinet connected together. Each outgoing cabinet is called a "ring network cabinet". In fact, if you take out a ring network cabinet alone, you can't see the meaning of "ring network".The rated current of these ring network cabinets is not large, so the high-voltage switch of the ring network cabinet generally does not use a complex circuit breaker but a simple high-voltage load switch with a high-voltage fuse. In other words, the high-voltage switch in the ring network cabinet is generally a load switch. The ring network cabinet uses a load switch to operate the normal current and a fuse to cut off the short-circuit current. The combination of the two replaces the circuit breaker. Of course, this can only be limited to a certain capacity.Such a switch cabinet can also be used in a non-ring network structure distribution system. Therefore, with the widespread application of this switch cabinet, the "ring network cabinet" has jumped out of the scope of ring network distribution and generally refers to a high-voltage switch cabinet with a load switch as the main switch.
The ring network cabinet has not appeared for a long time, but it has been widely used in recent years. This is mainly because the buildings of newly developed industrial enterprises and institutions are mostly medium and small in capacity from the perspective of power supply and distribution. Their distribution transformers generally do not exceed 1250KVA, long-term stable power supply, and high-voltage switches are not frequently operated. For this type of user, the performance of the ring main unit is not perfect, but it is sufficient and competent. With large-scale urban construction, a large number of large high-rise buildings have sprung up, and the substation is often located downstairs. According to fire protection requirements, the substation equipment must be "oil-free". According to the reasonable use of the construction area, the substation equipment should be "miniaturized", so the ring main unit or vacuum circuit breaker, dry transformer, dry transformer entered the building. The ring main unit has a simple structure, reliable and safe operation, small maintenance, and low operating costs. Compared with the switch cabinet equipped with circuit breakers, it has outstanding advantages. The ring main unit requires the load switch to have higher performance and smaller size, and a new type of load switch came into being, which in turn led to the technological progress of the ring main unit. Today's ring main unit not only has excellent performance but also has serialization, which further expands the scope of use of the ring main unit.