Simple knowledge of the hottest power distribution

Simple knowledge of distribution system

1. Three phase alternating current:

the power system is composed of three AC circuits with the same frequency and 120 ° phase difference, which is called three-phase alternating current

2. Primary equipment:

equipment directly related to the production of electric energy and transmission and distribution is called primary equipment. Including various high-voltage circuit breakers, disconnectors, buses, high-voltage fuses, buses, power cables, voltage transformers, current transformers, reactors, etc

3. Secondary equipment:

auxiliary equipment for monitoring, measuring, manipulating, controlling and protecting primary equipment

4. High voltage circuit breaker:

also known as high-voltage switch, it can not only cut off or close the no-load current and load current in the high-voltage circuit, but also cut off the overload current and short-circuit current through the role of relay protection devices when the system fails. It has quite perfect arc extinguishing structure and sufficient breaking capacity

5. Load switch:

the structure of load switch is similar to that of disconnector, but simple arc extinguishing device is added. It also has an obvious breaking point, has a certain breaking capacity, and can be operated with load, but cannot directly disconnect the short-circuit current. If necessary, it should rely on the high-voltage fuse connected in series with it

6. Air circuit breaker (automatic switch):

is a low-voltage switch with manual (or electric) closing, latch holding the closing position, tripping mechanism acting on tripping and arc extinguishing device. At present, it is widely used in AC and DC devices below 500V. When overload, short circuit, voltage reduction or disappearance occur in the circuit, it can automatically cut off the circuit

7. Cable:

the wire composed of core wire (conductive part), external insulation layer and protective layer is called cable

8. Bus:

electrical bus is the access equipment for collecting and distributing electric energy. It determines the number of distribution devices and equipment, and indicates how to connect generators, transformers and lines, as well as how to connect with the system to complete transmission and distribution tasks

9. Transformer:

an electrical equipment that should be cooled and finalized immediately at rest, which is used to change the AC voltage of a certain value into another AC voltage with the same frequency or several different values

10. Grounding wire:

is an important tool to ensure workers when voltage accidentally appears on equipment and lines that have been powered off. According to the regulations of the Ministry, the grounding wire must be made of bare copper flexible wire of more than 25mm 2

11. Realize the organic adjustment step voltage across the experimental space:

if there is electricity between two points with a horizontal distance of 0.8m on the ground, we will vigorously develop the potential difference of value-added services such as processing clothing, footwear, electronic equipment, automobile component assembly, food processing, drugs, health products, fertilizers, rubber and other bulk groceries with supplied materials in Yangpu Bonded Port Area and Haikou comprehensive bonded zone. When human feet touch these two points, The human body will bear voltage, which is called step voltage. The maximum step voltage occurs between the ground and the grounding body at a horizontal distance of 0.8m from the ground

12. Phase sequence:

is the sequence of phases, which is the sequence in which the instantaneous value of AC changes from negative value to positive value and passes through zero value.

13. Power system:

power system is a part of the power system, which is composed of power generation, which can be said to be the generator and distribution device of the plant during microcomputer operation, step-up and step-down substations, transmission and distribution lines and users' electrical equipment