Main technical requirements of high voltage switchgear

According to the installation position of the high-voltage switchgear, it can be divided into two types: outdoor type and indoor type. Most power distribution equipment of 10KV and below adopts internal type. According to the installation method of high voltage switch cabinet, it can be divided into fixed type and trolley type. The structure is divided into two types: open type and closed type. It can be seen that the high-voltage switchgear is a complete set of power distribution equipment provided by the complete set of manufacturers.

Various high-voltage electrical appliances, measuring instruments, protective electrical appliances and control switches can be installed in this enclosed or semi-enclosed cabinet. Usually one (or two) switchgear forms a unit loop, that is, a compartment. When in use, you can select a high-voltage switch cabinet suitable for various circuit intervals according to the designed main circuit diagram, and then you can form the entire high-voltage power distribution equipment.

The advantages of high-voltage switchgear are compact structure, small footprint, convenient maintenance, and suitable for mass production. At present, various indoor high-voltage electrical appliances and 35KV and below are installed on high-voltage switch cabinets. The current-carrying conductors of electrical appliances in the cabinet and between these devices and the metal enclosure are insulated from each other. Most insulating materials consist of air or dry insulating materials.

The main technical requirements of high voltage switchgear are as follows:

1. The cabinet structure has sufficient mechanical strength to prevent secondary components from malfunctioning due to the operation of the main components.

2. The casing structure has measures to prevent the spread of accidents, and the secondary side equipment can be inspected and repaired safely, and there is no power failure on the primary side.

3. The high-voltage switchgear is equipped with mechanical or electrical safety interlocking devices to ensure operation in accordance with the prescribed procedures. If the disconnect switch cannot be operated after the circuit breaker is closed, the disconnect switch can be opened and closed after the circuit breaker is opened.

4. The distance between the electrical equipment of the primary circuit in the cabinet and the bus bar and other live conductors should meet the specified requirements.

5. The electrical equipment installed in the high voltage switch cabinet meets the following requirements:

(1) The installation conditions meet the technical requirements of the electrical or equipment itself.

(2) Under normal working conditions, free gas, electric arc and sparks in electrical equipment will not endanger personal safety.

(3) Various electrical appliances and equipment installed in or in the cabinet can be easily removed and replaced individually.

6. The installation method of the circuit breaker and operating mechanism can ensure that the opening and closing speed and contact stroke of the high voltage switch cabinet are not excessively affected by the connecting rod.