The advantages and basic principles of high and low voltage switchgear

As the name suggests, the high and low voltage switchgear is a device that connects high voltage or low voltage cables, like the high voltage cabinets used in general power supply bureaus and substations, and then step down to the low voltage cabinet through a transformer. So the product is actually a kind of electrical equipment. The process is that the outside line first enters the main control switch in the cabinet, then enters the sub-control switch, and finally each branch is set according to its needs. Such as instrumentation, automatic control, motor magnetic switch, various AC contactors, etc., and some also have high-voltage room and low-voltage room switch cabinets, and high-voltage busbars.

The advantages of high and low voltage switchgear:

1. Reasonable design: unitized design is carried out according to the characteristics of various switches, such as escape ports, drawings, etc., and combined into functional units.

2. Universal structure, flexible assembly: C-shaped profile meets the requirements of various structural forms, protection levels and surrounding conditions.

3. Standard modules: can be separately composed of protection, operation, conversion, control and other standard unit module structures.

4. Safety protection: The isolation between areas and the mutual isolation of the incoming and outgoing lines of functional units are used to effectively strengthen the safety and protection performance.

The basic principle of high and low voltage switchgear:

1. When a partial discharge occurs inside the high and low voltage switchgear, most of the electromagnetic waves generated by the discharge will be shielded by the metal shell of the switchgear, and a small part will generate a transient ground voltage through the joint of the metal box. By using the test probe to test the instantaneous potential change on the outer surface of the metal box, the degree of partial discharge inside the switchgear can be reflected. A number of test probes are arranged on the surface of the switchgear, and several interference signal acquisition probes are supplemented around to carry out continuous monitoring simultaneously. According to the time delay principle, it is possible to locate the local discharge source inside the switchgear.

2. The main parts of the high and low voltage switchgear include: vacuum circuit breakers, current transformers, on-site microcomputer protection devices, operating loop accessories, and various position auxiliary switches. Among these components, the circuit breaker and current transformer are installed inside the switch cabinet, while the microcomputer protection, accessories, and watt-hour meter are installed on the panel of the relay room, and the terminal block and various power air switches are installed inside the relay room. , The terminal block is connected to the circuit breaker mechanism through a control cable or a special socket