Energy-saving knowledge of distribution system

1. Three-phase alternating current: An electric power system consisting of three alternating current circuits with the same frequency, equal potential amplitude, and a phase difference of 120° each, called three-phase alternating current.

2. Primary equipment: The equipment directly related to the production of electrical energy and transmission and distribution is called primary equipment. Including a variety of high voltage circuit breakers, disconnectors, busbars, power cables, voltage transformers, current transformers, reactors, arresters, arc suppression coils, shunt capacitors, and high voltage fuses.

3. Secondary equipment: Auxiliary equipment that monitors, measures, controls, and protects primary equipment. Such as all kinds of relays, signal devices, measuring instruments, recording equipment and recording wave telemetry, remote signaling devices and various control cables, small bus and so on.

4, high-voltage circuit breakers: also known as high-voltage switch, which can not only cut off or close the high voltage circuit no-load current and load current, and when the system fails, through the role of protective relays, cut off the overload current and short-circuit current . It has a fairly complete arc extinguishing structure and sufficient flow breaking capacity.

5. Load switch: The structure of the load switch is similar to the isolation switch except that a simple arc extinguishing device is installed. It also has an obvious disconnection point. It has a certain current-breaking capacity and can operate with load, but it cannot directly disconnect the short-circuit current. If necessary, it must rely on high-voltage fuses connected in series with it.

6、Air circuit breaker (automatic switch): It is a manual (or electric) closing, with the buckle to keep the closing position, and the trip mechanism acts on the tripping and has an arc extinguishing device. It is widely used in 500V. In the following AC and DC devices, when an overload, short circuit, voltage drop, or disappearance occurs in the circuit, the circuit can be automatically shut off.

7. Cable: A wire composed of a core wire (conductive part), an additional insulating layer, and a protective layer is called a cable.

8. Busbars: Electrical busbars are access devices for the collection and distribution of electrical energy. It determines the number of electrical distribution equipment and shows how to connect generators, transformers and lines, and how to connect with the system to complete transmission and distribution tasks. .

9, current transformer: also known as instrument converter, is a large current into a small current instrument.

10. Transformer: A stationary electrical device is a device used to convert a certain value of an AC voltage into another AC voltage of the same or different values.

11, high-voltage electroscope: used to check high voltage network transmission and distribution equipment, overhead lines, cables are charged tools.

12. Grounding line: It is an important tool to ensure the staff when unexpected voltage occurs on the equipment and lines that have been out of power. According to the ministerial regulations, the grounding wire must be made of a bare copper wire of 25mm2 or more.

13. Nameplate: It is used to warn people not to approach the equipment and the live parts, indicate the working place prepared for the staff, and remind to take safety measures, as well as to prohibit the traceboard of a certain equipment or a certain section of the line from being energized. Can be divided into warning class, allow class, prompt class, and forbidden.

14, Barrier: In order to prevent the staff from accidentally touching the live equipment and installing the equipment, there are two kinds of temporary barriers and permanent barriers.

15. Insulation rods: also known as gram rods, insulated rods, operating rods and so on. Insulating rod consists of three parts: work head, insulation rod and handle. It is used to close or open the high-voltage isolation switch, disassemble and disassemble the portable grounding wire, and to perform measurements and tests.

16, step voltage: If there is a potential difference between the two points on the ground at a horizontal distance of 0.8m, when the human body's two feet contact the two points, then the body will withstand the voltage, this voltage is called the step voltage. The largest step voltage occurs between the grounding body at a distance of 0.8 m from the ground of the grounding body.

17. Phase sequence: The sequence of phases is the order in which the instantaneous value of AC changes from a negative value to a positive value through zero.

18. Electric power network: The electric power network is a part of the electric power system. It is a unified network composed of various types of substations (stations) and various transmission and distribution lines of different voltage levels.

19. Power system: The power system is a part of the power system. It consists of power generators and power distribution devices, boost and buck substations, transmission and distribution lines, and consumer power equipment.

20, power system: Power plants, substations and users of electricity equipment, the phase and the power network and thermal power (or hydraulic) system connected together as a whole called the power system.