16/5000 Diànqì jīchǔ zhīshì dǎbāo dài zǒu, chū xuézhě bì bèi Basic knowledge of electrical packaging away, beginners must have

Basic knowledge of electrical packaging away, beginners must have

1. Primary Circuit - The main electrical wiring from the generator to the electrical equipment via transformers and transmission and distribution lines, often referred to as primary circuits.

2. Secondary equipment - Secondary equipment is the work of a device monitoring and measurement, operation control and protection of auxiliary equipment, such as: instruments

, Relays, control cables, control and signaling equipment

3. Secondary circuit - secondary equipment connected in a certain order by the circuit, known as the secondary circuit or secondary circuit.

4. Low-voltage switch - is used to connect or disconnect 1000 volts AC and DC circuits below the switch electrical appliances. Different from the "safety regulations" in low pressure (right

Ground voltage below 250 volts).

5. Contactor - is used to remotely connect or disconnect the load current in the circuit of the low-voltage switch, is widely used in frequent start and control of the motor

Circuit.

6. Automatic air switch - Automatic air switch referred to as automatic switch, is the most complete low-voltage switch performance switch. It can not only cut off electricity

Road load current, and can disconnect the short-circuit current, commonly used in low-voltage high-power circuit as the main control electronics.

7. De-excitation switch - is a kind of DC single-pole air automatic switch dedicated to generator excitation circuit.

8. Isolation switch - is a switch with a visible fracture, there is no interrupter device. Can be used for on and off voltage without load lines, also allowed

Xu to connect or disconnect no-load lines, voltage transformers and limited capacity of the no-load transformer. The main use of the disconnector is when the electrical equipment

Prepared for inspection, used to isolate the power supply voltage.

9. High-voltage circuit breakers - 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,

System failure, the role of relay protection device to cut off the short-circuit current. It has a fairly complete arc structure and sufficient capacity to cut off

10. Arc suppression coil - is an adjustable inductor with a core, installed in the transformer or generator neutral point, when the single-phase ground

Barrier, from reducing the grounding current and arc suppression.

11. Reactor - Reactor is an inductive coil with small resistance. The coils are insulated from each other and the whole coil is insulated from the ground. Reactance

In series in the circuit to limit short-circuit current.

12. Eddy current phenomenon - such as the coil covered in a single piece of iron core, iron core can be seen as a number of closed wire composed of closed wire

The plane formed is perpendicular to the direction of the flux. Each closed wire can be regarded as a closed conductive loop. When the coil through the alternating current

, The flux passing through the closed wire changes continuously, and an induced electromotive force is generated in each wire and induces an induced current. In this way, whole

A core, the formation of a circle around the core axis of the induced current flow, as if the water in the same vortex. This is generated in the iron core

Induced current is called eddy current.

13. Eddy current loss - as the current flows through the resistor, the core of the eddy current to consume energy and the core fever, this energy loss is called vortex

Streaming loss.

14. Small current grounding system - neutral or ungrounded arc suppression coil grounding.

15. High-current grounding system - neutral grounding system.

16. Armature reaction - When there is no armature current, the main air gap magnetic field generated by the excitement current, when the armature current, the air gap will be the main magnetic field will

By the excitation current field and armature current magnetic field together formed. This effect of the armature current on the main magnetic field is called the armature reaction.

17. Induction motor - also known as induction motor, which is in accordance with the conductor cutting magnetic lines produce induced electromotive force, and current carrying conductor in the magnetic field by

To the role of permeability of these two principles of work. In order to keep relative motion between the magnetic field and the rotor conductor, the rotor speed is always less than than the rotation

Turn the magnetic field speed, so called asynchronous motor.

Synchronous speed - in the three-phase induction motor winding into the three-phase symmetrical current, then the motor in the air gap to produce a rotation

Magnetic field, according to the different number of motor poles, rotating magnetic field speed is also different, the number of poles slow speed. We called this rotating magnetic field speed

Synchronous speed.

Slip - synchronous speed n1 and the difference between the motor speed n (n1-n) is called the speed difference, speed difference and synchronous speed ratio is called slip

Rate, slip S is usually expressed as a percentage, that is, S = (n1-n) / n1╳100%

20. Star - delta for start - If the motor in normal operation, the stator winding connected to a triangle, the stator winding connected into a star at startup,

Start after the end of a triangle run, this start method is called star - delta transfer start. 21. Absorption ratio - Straightforward insulation test

The ratio of the resistance between 60 seconds and 15 seconds after the flow voltage.

21. Working Earth - In order to ensure safe and reliable operation of electrical equipment under normal or fault conditions, to prevent high voltage caused by equipment failure

, Must be grounded at a certain point in the power system, called working ground.

22. Protective grounding - In order to prevent electrical equipment damage caused by electrical shock accident, the electrical equipment under normal circumstances uncharged gold

Is a shell or frame connected with the earth, known as the protective ground.

23. Protection of zero - is the neutral point in the power supply system, the grounding point of the neutral point of the metal shell or frame connected to neutral

. This is also an important measure to protect personal safety.

24. Isolating switch - is a switch with a clearly visible break without an interrupter. Can be used for on and off voltage without load lines, also allowed

Xu to connect or disconnect no-load lines, voltage transformers and limited capacity of the no-load transformer. The main use of the disconnector is when the electrical equipment

Prepared for inspection, used to isolate the power supply voltage.

25. High-voltage circuit breakers - 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,

System failure, the role of relay protection device to cut off the short-circuit current. It has a fairly complete arc structure and sufficient capacity to cut off

.

26. Arc suppression coil - is a core adjustable inductor, installed in the transformer or generator of the neutral point, when the single-phase ground

Barrier, from reducing the grounding current and arc suppression.

27. Reactor - Reactor is a small resistance inductor coil, each coil turns insulated each other, the entire coil and the ground part of the insulation. Reactance

In series in the circuit to limit short-circuit current.

28. Eddy current phenomenon - such as the coil covered in a single piece of iron core, the iron core can be seen as many closed wire, closed wire

The plane formed is perpendicular to the direction of the flux. Each closed wire can be regarded as a closed conductive loop. When the coil through the alternating current

, The flux passing through the closed wire changes continuously, and an induced electromotive force is generated in each wire and induces an induced current. In this way, whole

A core, the formation of a circle around the core axis of the induced current flow, as if the water in the same vortex. This is generated in the iron core

Induced current is called eddy current.

29 eddy current loss - as the current flows through the resistor, the eddy current in the core to consume energy and make the core fever, this energy loss is called vortex

Streaming loss.

30. Small current grounding system - the neutral point is not grounded or arc suppression coil grounding.

31. Large current grounding system - the system of neutral grounding.

32. Armature reaction - When there is no armature current, the air gap main magnetic field is generated by the exciting current separately. When there is armature current, the air gap main magnetic field is

By the excitation current field and armature current magnetic field together formed. This effect of the armature current on the main magnetic field is called the armature reaction.

33. Electric Arc - A large collection of sparks creates an arc.

34. Phase Sequence - the order of magnitude of the sine of each phase through the same value. Any set of asymmetrical three-phase sinusoidal AC voltage or current phasors can be decomposed

Into three groups of symmetrical components: one is the positive sequence component, with the subscript "1" that the phase sequence and the original asymmetric sinusoidal phase sequence, that A-B-C

The phase of each phase difference of 120 °; a group of negative sequence components, with the subscript "2" that the phase sequence and the original asymmetric sinusoidal phase sequence on the contrary,

The order of A-C-B, the phase of each phase difference of 120 °; the other is the zero sequence component, with the subscript "0" that the same phase of the three phases. For example: two

Asymmetric phase operation will appear negative and zero sequence components.

35, the relay start-up current - can make the relay the minimum current value.

36, the current relay - Reactor access to the coil current to determine the size of its relay or relay is called the current relay.

37, the voltage relay - to respond to join the voltage level of the relay or not.

38, fast relay - generally refers to the relay action time less than 10 milliseconds relay.

39, quick break protection - without time limit, as long as the current reaches the setting value can be instantaneous protection.

40, differential protection - is the use of electrical equipment fault current changes to achieve the start of the protection.

41, zero sequence protection - reactive power system grounding fault zero sequence current and zero sequence voltage and electrical protection.

42, distance protection - the reaction point of failure to protect the installation of a distance protection device.

43, automatic reclosing - When the line fails, the circuit breaker trip, the device can be manually re-closing without manual operation.

Reclosing points single-phase and comprehensive reclosing.

44, integrated reclosing - its function is: single-phase single-phase fault jump, unsuccessful jump three-phase; phase fault jump three-phase, three-phase coincidence, unsuccessful jump

Three-phase.

45, acceleration after reclosing - reclosing on a permanent fault, the protection device once again without time-limited action to open the circuit breaker is not reclosing

, Called acceleration after reclosing.

46, the protection - to meet the system stability and equipment safety requirements, selectively quickly remove the protected equipment and protection of the entire line of failure.

47, backup protection - the main protection does not move or circuit breaker refused to move, to remove the fault protection

48, power factor - the ratio of active power P and apparent power S.

49, switching operation - when the electrical equipment from one state to another state, or change the system's operating mode, the need for a system

Column operation, we call this operation is the electrical equipment switching operation. Switching operation are:

(1) Transformer stop sending electricity

(2) power line stop sending electricity

(3) start of the generator, parallel and reconciliation column operation

(4) network of the ring and solution ring

(5) busbar wiring changes (that is, switching busbar operation)

(6) changes in the neutral point of grounding and arc suppression coil adjustment

(7) relay protection and automatic device changes in the state of use

(8) ground wire installation and removal

50, no-load loss - is the rated frequency of the sinusoidal AC rated voltage applied to a coil on the transformer (at the rated tap position)

While the remaining coils are open, the power drawn by the transformer is used to supply transformer core losses (eddy current and hysteresis losses)

51, no-load current - transformer no-load operation, the no-load current to establish the main flux, so the no-load current is the excitation current. Rated no-load

The current is applied to a coil at rated positive and weak AC rated voltage (at rated tap position) while the remaining coils are open

, Transformer current drawn three-phase arithmetic mean, expressed as a percentage of the rated current.

52, short-circuit loss - is the nominal frequency of rated current through a transformer coil, while the other coil short circuit, the transformer

The absorbed power, which is the loss of transformer winding resistance, ie copper loss (coil at rated tap point, temperature 70 ° C).

53, short circuit voltage - is when a coil connected to a short circuit, in order to generate rated current in the other coil of the rated frequency of the voltage (

At nominal tap position), expressed as a percentage of the rated voltage, which reflects the transformer impedance (resistance and leakage reactance) parameters, also known as the impedance voltage

(Temperature 70 ° C).