30/10/2024
Learn the basic knowledge of electrical automation in one article
With the help of the upgrading and iteration of science and technology, electrical automation has completed automation control based on the advantages of modern technology, effectively changing the traditional mechanized production mode, so that it can realize the automation and efficiency of production through the control of electronic equipment. Automation is to use electricity to control electrical components to realize people's automation needs.
1. The primary circuit is the main electrical connection between the generator to the transformer, the transmission and distribution line and the electrical equipment, usually called the primary circuit.
2. Secondary equipment is an auxiliary equipment for monitoring, measuring, operating control and protecting the work of primary equipment, such as instruments, relays, control cables, control and signal equipment, etc.
3. The secondary circuit connected by secondary equipment in a certain order is called a secondary circuit or secondary circuit.
4. Low-voltage switch-used to open or close AC and DC circuits below 1000V. Different from the low voltage in the "Safety Regulations".
5. Contactors are low-voltage switches used to connect or disconnect load currents in circuits over long distances. Electrical Automation Training They are widely used for frequent starting and control of motors.
6. Automatic air switch, called automatic air switch, electrical automation data is the most perfect switch in low-voltage switch. It can not only cut off the load current of the circuit, but also cut off the short-circuit current. It is usually used as the main control device in low-voltage and high-power circuits.
7. Demagnetization switch is a DC single-pole air automatic switch specially used in generator excitation circuits.
8. Isolating switch-is a switch with obvious cracks without arc extinguishing device. It can be used to turn on and off voltage and no-load lines. It also allows the opening and closing of no-load lines, voltage transformers and no-load transformers with limited capacity. The main purpose of the isolating switch is to isolate the power supply voltage when repairing electrical equipment.
9. High-voltage circuit breaker, also called 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 short-circuit current through the relay protection device when the system fails. It has a fairly complete arc extinguishing structure and sufficient shunt capacity.
10. The arc extinguishing coil is an adjustable inductance coil with an iron core, which is installed at the neutral point of the transformer or generator. Electrical Automation Training When a single-phase ground fault occurs, the ground current and arc suppression can be reduced.
11. Reactor-The reactor is an inductor coil with very small resistance. Each turn of the coil is insulated from each other, and the entire coil is insulated from the grounded part. The reactor is connected in series to limit the short-circuit current in the circuit.
12. Eddy current loss-Like the current flowing through the resistor, the eddy current in the core consumes energy to heat the core. This energy loss is called eddy current loss.
13. Small current grounding system-the neutral point is not grounded or is not grounded through the arc suppression coil.
14. Large current grounding system-a system in which the neutral point is directly grounded.
15. Armature reaction-When there is no armature current, the main magnetic field in the air gap is generated only by the excitation current. When there is an armature current, the main magnetic field in the air gap is superimposed by the magnetic field of the excitation current and the magnetic field of the armature current. The effect of the armature current on the main magnetic field is called armature reaction.
16. Synchronous speed: When a three-phase symmetrical current is applied to the three-phase symmetrical winding of an asynchronous motor, a rotating magnetic field is generated in the air gap of the motor. Electrical Automation Training According to the different magnetic poles of the motor, the speed of the rotating magnetic field is different, and the speed of the magnetic pole is slow. We call the speed of this rotating magnetic field synchronous
17. Working grounding: In order to ensure the safe and reliable operation of electrical equipment in normal or faulty conditions and prevent high voltage caused by equipment failure, it is necessary to ground at a certain point in the power system, that is, working grounding.
18. Protective grounding: In order to prevent electric shock accidents caused by insulation damage of electrical equipment, electrical equipment is not energized under normal circumstances. 19. Protective zero connection-connect the metal casing or frame of the electrical equipment to the center line led out from the neutral point of the power supply neutral point grounding system. This is also an important measure to protect personal safety.
20. Isolating switch: The switch has a clear break and no arc extinguishing device. It can be used to switch voltage and no-load lines. It also allows switching no-load lines, voltage transformers and no-load transformers with limited capacity. The main function of the isolator is to isolate the power supply voltage when the electrical equipment is repaired.
21. High-voltage circuit breaker, also known as high-voltage switch. It can not only cut off or shut down the no-load current and load current in the high-voltage circuit, but also cut off the short-circuit current through the relay protection device when the system fails. It has a fairly complete arc extinguishing structure and sufficient current-breaking capacity.
22. The arc extinguishing coil is an iron core adjustable inductance coil installed on the neutral point of the transformer or generator. In the event of a single-phase grounding fault, it can reduce the grounding current and suppress the arc.
23. The reactor is an inductor coil with very small resistance. Each turn of the coil is insulated from each other, and the entire coil is insulated from the grounding part. The reactors are connected in series to limit the short-circuit current in the circuit.
24. The neutral point of the low-current grounding system is not grounded or is grounded with an arc extinguishing coil.
25. High-current grounding system-neutral point direct grounding system.
26. Armature reaction-when there is no armature current, the main magnetic field in the air gap is generated only by the excitation current. When armature current is present, the main magnetic field in the air gap is composed of the magnetic field of the excitation current and the magnetic field of the armature current. The effect of the armature current on the main magnetic field is called armature reaction. Electrical Automation Training
27. Arc: A large number of ignition sparks converge to form an arc.
28. Current relay-A relay that reacts to the current of the coil connected to the relay to determine whether the relay is working is called a current relay.
29. The action of the voltage relay is determined by the voltage applied to it.
30. Differential protection refers to the protection caused by current changes when an electrical device fails.
31. Zero-sequence protection is the protection of zero-sequence current, zero-sequence voltage, and zero-sequence quantity that are unique to ground faults in power systems.
32. Distance protection: A protection device that reflects the distance from the fault point to the protection device.
33. Automatic reclosing: When a line fails, the circuit breaker trips without manual operation, and the device automatically recloses. Recrystallization can be divided into single-phase recrystallization and comprehensive recrystallization.
34. Comprehensive reclosing - its function is: single-phase fault trips single phase, unsuccessful tripping of three phases; three-phase tripping fault, three-phase overlap, unsuccessful tripping of three phases.
35. Reclosing after accelerated reclosing is a permanent fault. Electrical automation training, the protection device trips again, without time limit, and does not reclose. It is called acceleration after reclosing.
36. Protection: In order to meet the requirements of system stability and equipment safety, all line faults protected by protected equipment and protection devices are selectively and quickly eliminated.
37. Backup protection: When the main protection device does not work or the circuit breaker does not work, the protection device used to eliminate the fault
38. Power factor: The ratio of active power P to apparent power S.
39. Switching operation: When the electrical equipment switches from one state to another, or changes the operation mode of the system, a series of operations need to be performed. We call this operation the switching operation of the electrical equipment.
40. No-load loss: The power received by the transformer when all other coils are open-circuited. The sinusoidal AC rated voltage of the rated frequency applied to the coil of the transformer is used to supply the core loss of the transformer.
41. No-load current: When the transformer is running at no-load, the main magnetic flux is determined by the no-load current, so the no-load current is the excitation current. The three-phase arithmetic mean current of the rated no-load current is the current of the transformer rated frequency when the positive and weak AC rated voltage are applied to one coil and the other coil is open-circuited, expressed as a percentage of the rated current.
42. Short-circuit loss is the power absorbed by the transformer when the rated current passes through one coil of the transformer at the rated frequency and the connection of the other coil is short-circuited.
Electrical automation is often used in equipment. It is a body composed of all components connected by wires to realize a set of functions. For example, the PLC control cabinet in the power distribution equipment uses the automation system to realize the intelligence and multi-function of the equipment.
