How to correctly select a high-voltage disconnector

High-voltage disconnectors are important equipment in power systems, used to cut off circuits during equipment overhaul or line maintenance to ensure the safety of operators. Correctly selecting high-voltage disconnectors is essential to ensuring the reliability and safety of power systems. The following are key points to consider when selecting high-voltage disconnectors.

1. Clarify voltage level and rated current

The voltage level and rated current of high-voltage disconnectors are the basic parameters for selection. The voltage level determines the insulation level and scope of application of the disconnector, while the rated current reflects its maximum current carrying capacity during long-term operation. When selecting, the specifications of the disconnector should be determined based on the actual operating voltage and current requirements of the power system. For example, for a 12kV transmission line, a disconnector of the corresponding voltage level should be selected, and its rated current should be ensured to meet the maximum load current of the line.

2. Consider the operation mode and operation frequency

The operation modes of high-voltage disconnectors are mainly manual operation and electric operation. Manual operation is suitable for occasions with low operating frequency, such as equipment maintenance in substations; while electric operation is more suitable for occasions with high operating frequency or remote control, such as automated operation in smart grids. In addition, the operating frequency of the disconnector should also be considered, because frequent operation may affect the mechanical life of the disconnector. Therefore, when selecting, the operation mode should be determined according to the actual operating needs and operating frequency.

3. Pay attention to insulation performance and protection level

Insulation performance is an important indicator of high-voltage disconnectors and is directly related to the safe operation of equipment. When selecting, it should be ensured that the insulation level of the disconnector meets national standards or industry standards. At the same time, the protection level of the disconnector should also be considered, especially for disconnectors used outdoors, which need to have good dustproof, waterproof and moisture-proof performance. For example, disconnectors with IP54 protection level can effectively prevent dust and water from entering and are suitable for outdoor environments.

4. Choose a suitable structure

The structural forms of high-voltage disconnectors mainly include single-column, double-column and three-column types. Disconnectors of different structural forms differ in performance and application occasions. The single-column isolating switch has a simple structure and a small footprint, and is suitable for occasions with low voltage levels; the double-column isolating switch has good insulation performance and mechanical stability, and is suitable for occasions with medium and high voltage levels; the three-column isolating switch has a higher insulation level and stronger anti-pollution ability, and is suitable for occasions with high voltage and high pollution environments. When choosing, the appropriate structural form should be determined according to the actual application scenario and voltage level.

In short, the correct selection of high-voltage disconnectors requires comprehensive consideration of voltage level, operation mode, insulation performance, structural form, brand and cost-effectiveness. Only in this way can we ensure that disconnectors play an important role in the power system and ensure the safe operation of the power system.