What is a switchgear？low voltage switchgear and high voltage switchgear What's the difference?

A switch cabinet is an electrical equipment in which the external wires first enter the main control switch inside the cabinet, and then enter the sub control switch. Each branch is set according to its needs. Such as instruments, self-control, motor magnetic switches, various AC contactors, etc. Some also have high voltage and low voltage room switchgear, high voltage busbars, such as power plants, etc. Some also have low cycle load shedding to protect the main equipment.

The main function of a outdoor switchgear is to open, close, control, and protect electrical equipment during the process of power generation, transmission, distribution, and energy conversion in the power system. The components inside the switchgear mainly include circuit breakers, isolating switches, load switches, operating mechanisms, transformers, and various protective devices. There are many classification methods for switchgear, such as the installation of circuit breakers, which can be divided into movable switchgear and fixed switchgear; According to the different cabinet structures, it can be divided into open type switchgear, metal enclosed switchgear, and metal enclosed armored switchgear; According to different voltage levels, it can be divided into high-voltage switchgear, medium voltage switchgear, and low-voltage switchgear. Mainly suitable for various occasions such as power plants, substations, petrochemicals, metallurgical steel rolling, light industry textiles, factories and mines, residential areas, high-rise buildings, etc.

1. Incoming cabinet

Also known as a power receiving cabinet, it is a device used to receive electrical energy from the power grid (from the incoming line to the busbar), usually equipped with circuit breakers CT、PT、 Isolation knives and other components.

2. Outgoing cabinet

Also known as a feeder cabinet or distribution cabinet, it is a device used to distribute electrical energy (from the busbar to each outgoing line), usually equipped with circuit breakers CT、PT、 Isolation knives, etc.

3. Busbar connection cabinet

Also known as a busbar disconnect cabinet, it is a device used to connect two sections of busbars (from busbar to busbar). It is commonly used in single busbar segmented and double busbar systems to meet the requirements of different operating modes and ensure selective load shedding in case of faults.

4. PT cabinet

Also known as voltage transformer cabinet, it is usually directly installed on the busbar to detect the busbar voltage and achieve protection functions. Internally equipped with PT, isolation knife, fuse, lightning arrester, etc.

5. Isolation cabinet

Used to isolate two sections of busbars or to isolate power receiving equipment from power supply equipment, it can provide a visible endpoint for operators to facilitate maintenance and repair operations. Due to the fact that the isolation cabinet does not have the ability to break or connect load currents, the handcart of the isolation cabinet cannot be pushed or pulled when the circuit breaker it is matched with is closed. In general, circuit breaker auxiliary contacts are interlocked with isolated handcarts to prevent misoperation.

6. Measuring cabinet

It is divided into high voltage and low voltage metering, generally equipped with isolation switches, fuses CT、PT、 Active and reactive energy meters, relays, and primary auxiliary secondary equipment such as load monitoring devices.

7 SVG

Static reactive power generator, also known as high-voltage dynamic reactive power compensation device, or static synchronous compensator. It is the best solution in the field of reactive power control.

8. Inflatable switchgear includes circuit breakers, isolating switches, grounding switches CT、PT、 The busbar and other enclosed components are combined inside a metal shell, and then gas with good insulation and arc extinguishing properties is used as phase to phase and ground insulation measures.

9. The 10 kV switchgear is divided into central cabinet and ring main cabinet. The full name of the central cabinet is metal armored central movable switchgear, which belongs to high-voltage distribution equipment with a maximum working voltage of 3.6, 7.2, and 12 kV. It is an indoor complete set of distribution equipment for three-phase AC 50HZ single busbar segmented system or double busbar segmented system.

Ring main unit. It is an electrical equipment with high-voltage switchgear installed in metal or non-metal insulated cabinets or made into assembled interval ring network power supply units. The core part adopts load switches and fuses, and has the advantages of simple structure, small size, low price, improved power supply parameters and performance, and power supply safety.

10. Box transformation. Box type substation is a high-voltage switchgear suitable for mines, factories, oil and gas fields, and wind power stations, replacing the original civil power distribution room.