Author: Noyafa–Cable Locator Suppliers
Electrical knowledge These electrical knowledge, electric power people must know electrical knowledge 1. Active power——In the process of transmission and transmission of alternating current electric energy, the part of the energy used to convert it into electromagnetic form is called active work. 2. Reactive power——In the process of AC power transmission and transmission, the part of the energy used for the exchange of electromagnetic fields in the circuit is called reactive power. 3. Power system——The whole composed of generators, power distribution devices, step-up and step-down substations, power lines and power users is called a power system.
Neutral point displacement: In a three-phase circuit, when the three-phase load of the power supply voltage is symmetrical, if the three-phase load is also symmetrical, the voltage of the neutral point is zero regardless of whether there is a neutral point. However, if the three-phase load is asymmetric, and there is no neutral line or the neutral line impedance is large, then a voltage will appear at the neutral point, which is called the neutral point displacement phenomenon. 4. Operating overvoltage——The transient voltage increase caused by the opening and closing operation of the circuit breaker and the short circuit or ground fault is called operating overvoltage.
5. Resonant overvoltage——Due to the operation of the circuit breaker, the power grid circuit is divided or the components with iron cores tend to be saturated, resulting in the inductive and capacitive reactance of a certain circuit meeting the resonance conditions, which may cause the voltage to rise due to resonance, which is called resonance overvoltage. 6. Electrical main wiring——It mainly refers to the electric power transmission circuit designed to meet the predetermined power transmission mode and operation requirements in power plants, substations, and power systems, indicating the interconnection between high-voltage electrical equipment. 7. Double bus connection——It has two sets of busbars: working busbars and spare busbars.
Each circuit is connected to two sets of busbars through a circuit breaker and two sets of isolating switches, respectively, and the busbars are connected through a busbar connecting circuit breaker (referred to as a busbar connection), which is called double busbar connection. 8. One and a half circuit breaker wiring——Every two components (outgoing line or power supply) use three circuit breakers to form a series connection to two sets of busbars, which is called one and a half circuit breaker wiring, also known as 3/2 wiring. 9. Factory electricity——During the start-up, operation, decommissioning and maintenance of the power plant, there are a large number of mechanical equipment driven by electric motors to ensure the normal operation of the main equipment of the unit and auxiliary equipment such as coal transportation, coal crushing, ash removal, dust removal and water treatment. run.
These motors, as well as the whole plant's operation, operation, test, maintenance, lighting and other electrical equipment are all plant loads, and the total power consumption is collectively referred to as plant electricity. 10. Factory electricity consumption rate——The percentage of the power consumption of the power plant in the total power generation of the power plant is called the power consumption rate of the power plant. Plant electricity consumption rate is one of the main economic indicators of power plant operation.
11. Regular load——Motors that are used frequently and continuously every day. 12. Infrequent load——Loads used only during maintenance, accidents or start-up and shutdown of the furnace. 13. Continuous load——The load is continuously operated for more than 2h each time.
14. Short-term load——Only run the load for 10-120min each time. 15. Intermittent load——Repeated and periodic work, each cycle does not exceed the load of 10min. 16. Self-starting of the motor——Motors in normal operation in factory systems,“When the power supply bus voltage suddenly disappears or decreases significantly, if a short period of time (usually 0.5—1.5s) Before its speed drops a lot or before it stops, the factory bus voltage returns to normal (such as power failure removal or automatic backup power supply), the motor will accelerate by itself and return to normal operation, this process is called. Self-starting of the motor.
17. Loss of magnetism——The sudden partial or complete loss of excitation of a synchronous generator is called loss of excitation. 18. Excitation control system——The entire system consisting of the excitation regulator, the excitation power unit and the generator itself is called the excitation control system. 19. Self-shunt static excitation system——Use a transformer connected to the generator outlet.
(called the excitation transformer) as the excitation power supply, which is supplied to the generator excitation after being rectified by silicon. Because the excitation transformer is connected in parallel with the generator outlet, this excitation method is called the self-shunt excitation method. The excitation transformer and the rectifier are all static components, so it is also called the self-shunt excitation static excitation system. 20. Transformer——It is a sensor for secondary equipment such as measuring instruments, relay protection and automatic devices in the power system to obtain electrical primary circuit information.
The role of the transformer is to convert high voltage and large current into low voltage and small current in proportion. 21. Sulfur hexafluoride circuit breaker——The circuit breaker that uses SFe gas with excellent arc extinguishing performance and insulation performance as the arc extinguishing medium is called SF 6 circuit breaker. It has the characteristics of strong breaking capacity and small size, but the structure is more complicated, the metal consumption is large, and the price is more expensive.
22. Vacuum circuit breaker——A circuit breaker that uses the high dielectric strength of vacuum to extinguish the arc is called a vacuum circuit breaker. This kind of circuit breaker has the characteristics of fast arc extinguishing speed, non-oxidizing contact material, long life and small size. 23. Work grounding——It is the grounding required to ensure the normal operation of the power system.
For example, the neutral point of the transformer in the neutral point direct grounding system is grounded, and its function is to stabilize the potential of the power grid to the ground, thereby reducing the insulation to the ground. 24. Lightning protection grounding——It is the grounding set for the needs of lightning protection. For example, the grounding of lightning rods (wires) and arresters is to make the lightning current smoothly lead to the ground, so as to reduce the lightning overvoltage, so it is also called overvoltage protection grounding.
25. Protective grounding——Also known as safety grounding, it is a grounding set for personal safety, that is, the casing (including the cable sheath) of the electrical equipment must be grounded to prevent the casing from being charged and endangering personal safety. 26. Instrument control grounding——The thermal control system, data acquisition system, computer monitoring system, transistor or microcomputer type relay protection system and remote communication system of the power plant are used to stabilize the potential and prevent interference. Instrument control grounding is also known as electronic system grounding.
27. Grounding resistance——It refers to the resistance encountered when the current enters the earth through the grounding body and spreads around. 28. Voltage——When a unit positive charge is shifted from a high potential to a low potential, the work done by the electric field force on it is called voltage. 29. Current——It is a physical phenomenon in which a large number of charges move in a regular direction under the action of the electric field force.
30. Resistance——When the current passes through the conductor, it will be resisted, because the free electrons are constantly colliding with the atoms and molecules in the conductor during the movement, so that the free electrons are subject to a certain resistance. The resistance of a conductor to current flow is called resistance. These electrical knowledge, electric power people must know electrical knowledge Shenzhen Noyafa Electronic Technology Co., Ltd.
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