Hello, could you please teach me how to design a 6KV substation?

6kv substation design Therefore, the dw10-4000/2 automatic switch is selected. The main data are as follows

Model number

Rated current (a)

Rated current of overcurrent release (a)

Instantaneous Setting current of overcurrent release (a)

Limit breaking current ka DC 440v

t≤0.013

AC 380vcosф≥0.4 period component effective value< /p>

dw10—4000/2

4000

2500

2500—3750-7500

30

40

b: Breaking capacity verification

ibr≥is(up3;)iim

Where.ibr—breaking current of the device

　is(up3;)—effective value of periodic component of three-phase short-circuit current in maximum operating mode

　iim---effective value of impact short-circuit

　ibr=40 ≥is(up3;)=40

Therefore, it meets the requirements.

Because this switch has the ability to limit current breaking. Therefore, the dynamic and thermal stability is not checked

c: Selection of low-voltage busbar

Since the low-voltage side of the transformer is 0.4kv and the rated capacity is 1250kva, the busbar specification is lmy--- -3(120x10) 50x6

d: Selection of low-voltage power distribution panel

Since it is a low-voltage power distribution device and the ggd3-01 AC low-voltage power distribution cabinet is selected according to the usage conditions. References are as follows:

Model number

Rated insulation voltage

Working frequency

Working voltage

Working current

p>

Short circuit breaking capacity

Ultimate breaking capacity

ggd3-01

660v

50r/2

380v

2500a

50ka

105ka

3: Selection of high-voltage electrical equipment

High voltage Selection of switch cabinet models

Since 6kv high-voltage power distribution devices generally use complete sets of high-voltage switch cabinets with five-proof functions

According to the installation location and use environment, each electrical component is placed in the high-voltage switch cabinet Due to different installation methods and economical requirements, gg-1a(f) type high-voltage switch cabinet is selected (the selection and verification are the same as those for low voltage and are not listed here) . Since it meets the requirements of each component, it is not listed in full. Its technical indicators are as follows:

Model number

Stable voltage

Rated current

< p> Operation method

Busbar system

Overall dimensions

gg—1a(f)---073

6kv

1000a

Manual

Single busbar

Width x depth x height 1218x1215x3100

Chapter 9 Substation Relay protection

6kv systems are all small ground current systems, so usually only protection devices to prevent phase short circuits and selective high-voltage leakage protection devices to prevent single-phase grounding are installed

1. Phase-to-phase short circuit protection

Installation principles for protection:

a Use two-phase wiring, and the protection devices of the entire system are installed on the two phases of the same phase

b Generally, two-stage current protection devices are installed. The first stage has no time-limited current speed stage protection as auxiliary protection, and the second stage has time-limited current speed stage protection as main protection.

c The first section of current quick-break protection should have selective action, and its installation condition is to meet the requirements of the minimum protection range.

d. For cable lines, when the quick-breaking protection does not meet the protection range requirements, time-limited current quick-breaking protection can be installed.

e. For substation applications that have strict requirements for busbar residual voltage, no The time-limited current quick-break protection removes various faults that cause the busbar residual voltage to be lower than the rated voltage of 60, and the protection device can operate indiscriminately

f. In order to speed up the removal of short circuits for important user cable lines with large loads and a total length of less than 1km The longitudinal differential current protection device can be used for faults

g Non-important users with small loads can be protected by fuses

h The protection adopts remote backup mode

2 Setting calculation of current quick-break protection

(1) Operating current of relay

iop.k=kk*kkx*ica/ki*kre

In the formula iop.k-The operating current a of the relay

kk-Reliability coefficient, 1.2 for electromagnetic and transistor relays, 1.4 for inductive relays

kkx-Wiring coefficient of the protection device

p>

ki-current transformer ratio

kre-return coefficient

ica-maximum long-term operating current of the line

iop.k=kk *kkx*ica/ki*kre=1.2*1*203.8*5/250=5.8a

(2) The sensitivity of the protection device meets the requirements of the following formula

kr=iup2; min/iop.kki≥1.5

where kr-sensitivity coefficient of the protection device

iup2;min-minimum two-phase short-circuit current a at the end of the protected line

kr=iup2;min/iop.kki=4500*5/5.8*250=15.5≥1.5

Therefore, the load requirement of the protection device. Look up table 7-1. Select the dl-34 type current relay overcurrent protection. The action time limit is determined by the following formula

tp=tep δt

Where tp-the action time of the protection device setting s'

tep - the setting time of end adjacent element protection s

δt

-time limit stage

Since the protection device is located At the end, an instantaneous protection device should be installed, and its action time limit

tp=tep δt=0 0.5=0.5s

Check Table 7-2 and select ds-122 type time relay.

Chapter 10 Electrical Systems Used in Substations

1. Operating Power Supply of Substations

Operating power supplies include DC and AC, except for some In addition to the AC operating power supply used in small substations, general substations use DC operating power supply

The DC operating power supply includes silicon rectified DC power supply and battery DC power supply. According to the actual situation and usage requirements of the mine, 6kv power supply Cadmium-nickel storage battery used for electricity. Moreover, the battery has two sets of rectifier devices for charging and floating charging. The bzgn-i-//200 type is selected for table lookup.

2. Electricity used by the substation

Since there are two main transformers in the substation, the load used by the substation is not large, and there is a battery backup system, so we choose A transformer. Select the S7-30/10 transformer according to the load size of the substation (the values ??are the same as before, so they will not be calculated again)

Chapter 11 Central signaling device of the substation

1: Design principles of central signaling devices

(1) When the substation is under centralized control, there should be indication signals for the tripping and closing positions of the controlled circuit breakers in the control room

(2) A manned substation should be equipped with a central accident signal and a central warning signal device that can restore the audio signal in the control room or duty room

(3) The central accident signal device should be installed when the circuit breaker trips. hour. In addition to sending out sound signals in a timely manner, there should also be lights or other indication signals on the control panel or power distribution device indicating that the circuit has tripped in an accident

(4) The central warning signal device will, when the circuit fails, In addition to sending out sound signals in time, there should also be indicators (lights or signal relays) showing the nature, location and scope of the fault.

(5) There should be a difference between central accident signals and warning signals. Generally, accident signals are used Buzzer; warning signal is sounded by an electric bell.

(6) After the central signal sends out the sound, it should be able to return to the sound manually or automatically, and the indication of the nature, location and scope of the fault should be maintained until the protection action situation is recorded (light plate signal) and the fault is eliminated. To (flash signal)

(7) The display devices of each signal should be appropriately centralized to facilitate monitoring by on-duty personnel

(8) The central accident and warning signals of the substation should generally be It can act repeatedly. For example, the main wiring of the substation is relatively simple, and the central emergency signal does not need to act repeatedly.

(9) Components controlled locally on the power distribution device should be sent separately according to bus segments and groups

(10) Accident signals and warning signals

(11) The integrity test of the central accident and warning signaling device and its optical signboard should be able to be carried out.

The signaling device should have a reliable power supply, and the power supply fuses of important signaling devices should be monitored.

In short, the signaling device is required to be simple, reliable, and eye-catching. It should be able to accurately reflect the operating status of the monitored electrical equipment and be able to check the integrity of the signaling device at any time as needed. When an abnormality occurs in the monitored equipment

(12), the signaling device can automatically send out sound and light signals. After the signal is sent, it should be possible to determine the nature, location and scope of the fault, and the light signal should be maintained until the protection action situation is recorded and the fault is eliminated. The audio signal should be able to be reset manually or automatically as needed.

2 Design of central signal device

When designing the central signal, the current wiring method is generally selected, and there is no need to design it yourself. The two commonly used wiring methods are: wiring for accident signals that do not repeat actions, wiring for warning signals that repeat actions; wiring for accidents and warning signals that repeat actions instantaneously; wiring for repeated actions for accidents and delayed and repeated actions for warning signals, according to design principles and The actual situation of this substation chooses the wiring method of repeated action of accident signals and repeated actions of warning signals.

Chapter 12 Internal and external layout of the substation

1. General requirements for substation layout

Transformers are generally floor-standing and installed on steel bars. General requirements for the layout of substations in the first section of the hybrid section

General requirements for the layout of substations:

1. The equipment layout should be compact and reasonable to facilitate the operation, inspection, transportation and maintenance of the equipment. and experiments, but also consider development possibilities.

2. The location of each room is reasonably arranged. The location of the power distribution room should be convenient for the entry and exit of lines; the low-voltage power distribution room should be as close as possible to the transformer room; the capacitor room should be as adjacent as possible to the high-voltage power distribution room; the location of the control room, duty room and auxiliary room should be convenient for staff work and management.

3. Make full use of natural lighting and natural ventilation. The transformer room and capacitor room should be kept away from western exposure, and the control room should be kept away from the south.

4. The floors of the power distribution room, control room, duty room, etc. should generally be 150mm~300mm higher than the outdoor level. The substation attached to the workshop can be level with the workshop floor. The ground elevation of the transformer room depends on needs

5. A manned substation should have a separate control room or duty room, and be equipped with other auxiliary rooms and living facilities

2 . Minimum electrical spacing requirements:

The minimum electrical spacing (safety clearance) of outdoor power distribution devices should not be less than the values ??listed in Table 10-1.

Symbol

Scope of application

Rated voltage/kv

3—10

35

63

a1

Between the live part and the grounded part

200

400

650

Between the upward extension line of the mesh barrier 2.5m away from the ground and the live part above the barrier

a2

Between the live parts of different phases

p>

200

400

6500

Between the live parts of the leads on both sides of the break of the circuit breaker and isolating switch

b1

When the equipment is transported, between the outer corridor and the unobstructed live part

950

1150

1400

Between the unobstructed live parts of the intersection that are subject to power outages for maintenance at different times

Between the grid-shaped barrier and the insulator and the live parts

b2

Mesh Between shielding and live parts

300

500

750

c

Unshielded bare conductor to Between the ground

2700

2900

3100

Between the unobstructed bare conductor and the top of the building or structure

d

Between parallel unobstructed live parts that are not subject to power outage and maintenance at the same time

2200

2400

2600

p>

Between the live parts and the edges of buildings and structures

2. The electrical spacing between power distribution devices in the house should not be less than 1-2 billion.

Symbol

Scope of application

Rated voltage/kv

∧500

500～1000

a1

Between the live part and the grounded part

15(30)

15(30)

a2< /p>

Between charged parts of different phases

15(30)

15(30)

b1

Between the live part and the fence

100

100

b2

Between the live part and the mesh barrier

< p> 100

100

b3

Between the live part and the non-porous fence

50

50

c

Between bare conductor without fence and ground (floor)

2200

2200

d1

Horizontal clear distance between unbarred bare conductors and opposite walls of the passage

1500

2000

d2

Horizontal clear distance between bare conductors without fences on the opposite side of the passage

1000

1500

1. The width of the corridor of the power distribution device should not be less than Table 10- Values ??in 3

Arrangement method

Back maintenance corridor

Front operation corridor

General value

Recommended Value

General value

Recommended value

When there is a power distribution device on one side

When there are power distribution devices on both sides

< p> 800

800

1000

1000

1300

1800

1800

2500

2. When the installation length of the low-voltage power distribution device does not exceed 6m, one exit is allowed in the maintenance corridor behind the screen; when the length is 6~15m, two exits are allowed. One outlet should be provided at each end. When the length exceeds 15m, in addition to one outlet at each end, an outlet should be added in the middle so that the distance between the two outlets does not exceed 15m. The width of the outlet should not be less than 0.8m. When the clear width of the maintenance corridor behind the screen exceeds 3m, it is not subject to the above requirements.

3. The blocking height of low-voltage power distribution devices in the house should not be lower than 1.7m for mesh blocking and 1.2m for fences. 1.7m without holes.

4. When the unblocked bare conductor is arranged above the corridor and the height above the ground is less than the c value in table (10-2), blocking protection should be set up, and the blocking height should not be less than 1.9m.

3. Low-voltage distribution room

1. Low-voltage distribution devices are generally located in a separate low-voltage distribution room. For manned substations, the low-voltage distribution room is allowed Merge with the duty room. At this time, the distance between the front of the low-voltage power distribution device and the wall should not be less than 3m.

2. For factories or workshops that adopt centralized control (such as coal preparation plants, etc.), they are allowed to merge with the control room. This The distance between the low-voltage distribution panel group and the control panel group shall not be less than 0.8m if arranged in a single row.

2. Low-voltage power distribution panels are generally arranged away from the wall, and the width of the maintenance corridor behind the panel and the front operation corridor

See Table (10-3). When there are channels at both ends of the screen, there should be protective plates on the sides of the screen, and the distance between the two sides of the screen should not be less than 0.8m from the wall. There should be a 200mm gap when one side is against the wall.

4. When the number of screens is 3 or less, single-sided power distribution screens can also be installed against the wall. At this time, there should be a gap of 25mm between the back of the screen and the wall, and 25mm between the sides of the screen. There should be a 200mm gap in the wall.

5. When the length of the power distribution room is more than 8m, two doors should be installed and arranged at both ends as much as possible. When only one door is provided, this door should not lead to the high-voltage distribution room.

6. When the same low-voltage power distribution room is used to supply electricity to a class of loads, fire partitions or fireproof partitions are installed at the busbar sections. The cables supplying a class of loads should not pass through the same Cable trench.

7. The height of the low-voltage distribution room should be considered comprehensively with the transformer room. Generally, the following dimensions can be referred to: when adjacent to the elevated floor transformer room, the height is 4~4.5m; when adjacent to the raised floor transformer room, the height is 4~4.5m; When the power distribution room is adjacent to each other, the height is 3.5~4m; when the power distribution room is for cable entry, the height is 3m.

8. When the power distribution room uses overhead cable entry, the incoming power distribution screen should be in line with the transformer room On the same center line as the cable entry hole in the partition wall.

4. Transformer

1. The layout and main dimensions of the transformer room are related to the inlet and outlet methods and the equipment used.

The layout of the transformer room has two types: raised floor and non-raised floor. Whether the floor is raised or not depends on the ventilation method and ventilation area of ??the transformer room. When the area of ??the inlet and outlet windows of the transformer room is not When the ventilation conditions are met, the floor of the transformer room should be raised. Generally, "wind out" affects the height of the transformer room, and "air in" affects the floor of the transformer room. When the floor is not raised, the height of the transformer room is generally 3.5m~4.8m; when the floor is raised, the wind inlet tunnel is below the floor, and the raised height of the floor is generally 0.8m. , 1.0m and 1.2m, the height of the transformer room is generally increased by 4.8m~5.7m accordingly

Based on concrete foundation.

Between adjacent oil-immersed transformers outside the house, when the oil volume exceeds 2500kg, the fire separation distance shall not be less than 5m for 35kv; and shall not be less than 6m for 63kv; otherwise, a fire partition wall should be installed. The height of the fire partition wall should not be lower than the top of the transformer oil pillow, and the length should be 0.5m longer than each side of the oil storage pool.

When the oil volume of the transformer is more than 1000kg, an oil storage tank that can accommodate 100 oil volumes or an oil storage pool or oil retaining wall that can accommodate 20 oil volumes should be set below it. When there is no 20-meter oil storage tank or oil retaining wall, facilities should be provided to drain the oil to a safe place and should not cause pollution hazards. The area of ??the oil storage tank is calculated based on the outer contour of the equipment plus 1m. A pebble layer with a thickness of 250mm is generally laid in the oil storage tank (the pebble diameter should be 50mm~80mm). In order to prevent rainwater from flowing into the oil storage tank, the height of the four walls of the oil storage tank should be 100mm higher than the ground. And plaster the surface with cement.

For other oil-filled equipment arranged outside the house, when the oil volume of a single tank reaches more than 1000kg, an oil storage tank should also be set up according to the above requirements.

The layout position of the transformer should not only meet the safety clearance and fire protection distance, but also consider shortening the lead length on each side of the transformer as much as possible. For this reason, the position of the transformer should be arranged on the same center line as possible with the incoming line structure and the incoming line switch cabinet in the 6(10)kv power distribution room.

Chapter 13 Lightning Protection and Grounding of Substations

1. Lightning Protection of Substations

Lightning Protection Oil of Substations Protect against direct lightning strike overvoltage and induced intrusion wave overvoltage from the line, as well as induced and counterattack overvoltage generated when lightning strikes on the lightning rod.

(1) Protection from direct lightning strikes

The method of protecting substations from direct lightning strikes is to install lightning rods and place the equipment and buildings that need protection within the protection range.

When lightning strikes a lightning rod, the voltage drop generated by the lightning current on the lightning rod discharges toward the protected object. This phenomenon is called counterattack. A certain distance should be maintained between an independent lightning rod and the object to be protected.

In order to avoid counterattack, the distance between the lightning rod and the protected equipment shall not be less than 5m, and the distance between the lightning rod ground electrode and the protected ground electrode shall not be less than 3m, and the impact grounding resistance of the lightning rod shall not be greater than 10ω.

(2) Protection from lightning intrusion waves

The substation uses valve-type arresters installed on each bus section to protect against overvoltage caused by lightning intrusion waves.

Since the arrester has a certain effective protection distance, the electrical installation distance between the arrester and the protected equipment cannot be too far, otherwise the overvoltage value generated on the protected equipment will be very large and it will not be able to protect the equipment. purpose. The most important equipment in the substation is the transformer. Its price is high and the insulation level is low. In order to effectively protect the transformer, it is best to connect the arrester directly in parallel with the transformer. But in fact, there are other switching devices between the transformer and the busbar, so they have to be separated by a certain distance. Therefore, in order for the arrester to effectively play its role, the requirements in Table (11-1) should be met when installing the arrester.

Voltage level

kv

Set the range of the lightning protection line

Distance to the transformer

To other electrical appliances Distance

Number of transformer incoming circuits

One

Two

Three

Four

35

Incoming line section

Whole line

25

55

35

80

40

95

45

105

Calculated based on the distance to the transformer increased by 35

63

Incoming line section

Whole line

40

80

65< /p>

110

75

130

85

145

110

Whole line

90

135

155

175

2: Defense of entry and exit lines Lightning protection

(1): Lightning protection for 3~10kv distribution lines

When lightning strikes on the 3~10kv distribution lines of the substation, the lightning intrusion wave will travel along the distribution lines Intrusion into substations poses a threat to distribution devices and transformer insulation. Therefore, valve-type arresters should be installed on each busbar and each overhead line, as shown in Figure (11-3). For overhead lines with cable sections, the lightning arrester should be installed at the connection between the cable and the overhead line, and its grounding end should be connected to the metal sheath of the cable. If there is a reactor on the distribution line, a set of valve-type arresters should be installed between the reactor and the cable head to prevent damage to the cable insulation when the voltage at the reactor end rises.

(2): Lightning protection of distribution network

1. The 3kv~10kv distribution transformer connected to the overhead line should be protected by a valve-type arrester on its 3kv~10kv side. And install it as close to the transformer as possible, and its ground wire should be connected to the neutral point on the low-voltage side of the transformer (or in a power grid where the neutral point is not grounded, the neutral point penetrates the ground terminal of the fuse) and the metal shell.

2. For distribution transformers with 3kv~10kv, y, yn0 and y, y connections in multiple minefields, in addition to installing arresters on the high-voltage side, it is recommended to install a set of 220v arresters on the low-voltage side. 440v varistor or breakdown fuse to prevent reverse transformation wave and low-voltage side lightning intrusion wave from breaking down the high-voltage side insulation. Distribution transformers with low-voltage neutral points that are not grounded should be equipped with breakdown fuses at the neutral point.

3.3kv~10kv pole-mounted circuit breakers and load switches should be protected by valve-type arresters or air gaps. Pole-mounted circuit breakers, load switches or isolating switches that are often operated with circuit breakers and are energized should be equipped with lightning arresters or protective gaps on the live side. The grounding wire should be connected to the metal shell of the pole-mounted circuit breaker, etc., and the grounding resistance should not exceed 10ω.

a) 3kv~10kv overhead distribution lines are not equipped with lightning protection wires.

b) In order to improve the insulation level of 3kv~10kv reinforced concrete pole distribution lines, porcelain cross arms or insulators with a higher voltage can be used.

c) The insulator pins of low-voltage overhead lines connected to household lines should be grounded, and the grounding resistance should not exceed 30ω. For iron cross-arm reinforced concrete pole lines with soil resistivity of 200ω·m and below, the iron feet of the insulator should be connected to the grounding device at the entrance, and no additional grounding device should be installed.

In densely populated public places, such as theaters and teachers' connection lines, as well as the connection lines led by wooden poles or wooden cross arms, the iron feet of the insulators should be grounded, and special insulators should be installed.

Grounding device, except for reinforced concrete poles whose natural grounding resistance does not exceed 30ω.

In areas where the annual average thunderstorm days do not exceed 30 days, in areas where low-voltage lines are shielded by buildings, etc., and in places where the distance between the household line and the low-voltage grounding point is not more than 50m, the insulator legs of the household line are not required. Ground.

d) In areas with many mines or sections prone to lightning strikes, electricity meters directly connected to overhead lines should be equipped with lightning protection devices.

3: Substation grounding system

(1) Scope of protective grounding

1. Parts that should be grounded:

( 1) Bases and shells of motors, transformers, electrical appliances, and portable electrical appliances;

(2) Electrical equipment transmission devices;

(3) Secondary windings of transformers, Except where otherwise provided for in relay protection;

(4) The frame of the power distribution panel and control panel;

(5) The metal and reinforced concrete structure of the outdoor power distribution device and Metal fences and metal doors close to live parts;

(6) AC and DC power cable junction boxes, metal shells of terminal boxes, technical sheaths of cables, threaded steel pipes, etc.;

(7) The outer sheath of the armored control cable and 1 to 2 shielded core wires of the unarmored cable.

2. Parts that do not need to be grounded:

(1) In dry rooms with poor conductive floors such as wood and asphalt, the rated voltage is AC 380v and below, current 440v and below The shell of electrical equipment (except when people may touch grounded objects at the same time);

(2) In dry places, the rated voltage is AC 127v and below, DC 110v and The following electrical equipment shells (except for places with explosion risks);

(3) The shells of instruments, relays and other low-voltage electrical appliances installed on power distribution panels, control panels and power distribution devices, as well as local When the insulation is damaged, the metal base of the insulator, etc., which will not cause dangerous voltage on the support;

(4) Equipment installed on a grounded metal frame (to ensure good contact), such as bushings, etc. (with (Except places with explosion hazards);

(5) Brackets in battery rooms with rated voltages of 220v and below.

4. Scope of working grounding

(1)) Neutral points of transformers, generators, and capacitor banks. In the neutral point insulation system of the transformer, the fuse is broken down Grounding;

(2) Current transformer, lightning rod, lightning protection wire, lightning protection net, protection gap, etc.

Chapter 14: Electrical Lighting Design

1 Principles and Requirements of Electrical Lighting Design

(1) Whether the lighting design is reasonable or not not only affects the safety of the staff Vision is healthy, and it will also affect the safety production of industrial and mining enterprises and the economy of lighting. To this end, lighting design should follow the following principles:

(2) There should be appropriate illumination on the working surface. It not only ensures the lighting requirements for work and visual health, but also ensures the economy of lighting.

(3) Ensure uniformity of lighting, limit glare, and strive for visual comfort. The brightness distribution in the working environment should be uniform, not only to ensure uniform lighting on the working surface, but also to ensure that the brightness difference between the working surface and the surrounding environment (walls, ceilings, floors, etc.) is not too large.

(4 Ensure the stability of lighting and avoid the stroboscopic effect. The luminous flux of lighting should be stable, prevent the swing of the electric light source, try to eliminate the stroboscopic effect of the electric light source or choose an electric light source with a low stroboscopic effect.

(5) The color rendering of electric light sources is better. In places where color rendering is required, electric light sources with a high color rendering index or a mixture of multiple light sources should be used.

( 6) The lighting device must be technologically advanced, safe and reliable, and easy to maintain and repair.

(7) The lighting device should be selected to be as beautiful as possible and harmonious with the surrounding environment and buildings.

2. Selection of electric light source types

When selecting the type of electric light source, the general principles for selecting electric light sources are as follows:

(1) Try to choose electric light sources with high luminous efficiency and long service life to ensure economical lighting.

(2) In places with rotating machinery, electric lights without stroboscopic light should be selected. Light source.

(3) In places with high color rendering requirements, electric light sources with high color rendering index should be selected.

(4) In places with large voltage fluctuations, electric light sources should be selected. The luminous flux is less affected by voltage changes.

3. Fluorescent lamps are used for lighting in the substation according to the actual situation.

4. Illumination calculation.

(1) Calculation of unit capacity

p.σ=pa=16*50=2400w

(2) Number of lamps required

n=eava/kukφ30*150/0.85*0.8*90=74

(3) The layout of the lamps is determined according to the length and width of the room and the working location;

5. Arrangement of lighting equipment

There are several types of lighting distribution boxes: suspended and embedded. During layout, they can be hung on the wall or embedded in the wall according to the different forms of the distribution box. The center of the distribution box and transformer box is 1.5m away from the ground. If the lighting is not controlled in the distribution box, the installation height of the distribution box can be increased by more than 2m. Lighting line conductors generally use rubber insulated cables

Summary of Chapter 15

After this period of practical operation, I have a deeper understanding and mastery of the previous theoretical knowledge. I have also enriched my knowledge in all aspects, laid a good foundation for future work, and paved the way for further enriching my knowledge and quality in the future. Through this period of internship, I have also improved my abilities and qualities in all aspects. However, I also discovered my own shortcomings during the internship, such as weak and unreliable knowledge, narrow knowledge, not broad enough, and poor practical ability. In short, this period of internship was of great help to me. , due to the limitations of my own ability, I still hope that all teachers will criticize and correct the shortcomings in the design, and please take care of me. I also ask all teachers to provide more opinions.

Main references

1. "Coal Mine Safety Regulations"

2. "Coal Mine Electrician's Manual"

3. "Design Guidance Book"

4. "Power Supply for Industrial and Mining Enterprises"

5. "Setting Rules for Mine Low-voltage Power Grid Short-Circuit Protection Devices"

6. "Electrical Product Samples and Products Table of Contents

7. Other information