What about the basic information about the base station battery? Please see the article breakdown below

 

1 base station power supply

1.1 Structure of base station system

1.2

 

 

1.2 Composition of communication power

 

2 Mains

2.1 Mains classification

According to the power supply conditions, line introduction methods and operating status of the area where the communication bureau (station) is located, the city power is divided into four categories, and the division conditions should meet the following requirements:

  1. The first-class mains power supply is to introduce one power supply from two stable and reliable independent power sources. The two power sources should not have power outages for maintenance at the same time, the average number of monthly power outages should not be greater than one, and the average time for each failure should not be greater than 0.5 h. The two power supply lines should be equipped with a backup mains power automatic input device.
  2. The planned maintenance of power outages for Class II municipal power supply lines is allowed. The average number of monthly power outages should be no more than 3.5, and the average failure time should not be greater than 6 hours.
  3. For the three types of mains power supply, one power supply line is introduced from one power supply. The power supply lines are long and there are many users. The average number of monthly power outages should be no more than 4.5, and the average failure time should not be more than 8 hours.
  4. The power supply of the four types of city power shall meet the requirements of one of the following conditions:

1) One power supply line is introduced from one power supply, and power is often interrupted day and night. There is no guarantee for power supply, which can not meet the requirements of three types of power supply.

2) There are seasonal power outages or no utility power available.

2.2 Mains power introduction

There are four ways to introduce foreign utility power:

1) The newly-built machine room is provided with a special transformer, which is led to the base station dedicated transformer through a 10KV high voltage, and is responsible for the power supply of the base station equipment after the voltage is reduced by the transformer.

2) There is no special transformer in the newly-built machine room. One 380V (or 220V) is led from the remote public transformer to the base station, which is responsible for the power supply of the base station equipment.

3) The base station with a dedicated transformer in the rented private house is led from the output branch of the low-voltage power distribution system of the rented private house to the base station.

4) The base station of the leased private house without a special transformer is led from the total AC distribution box of the rented private house to the base station.

  • The voltage level of the newly introduced base station power from the base station can be comprehensively determined according to the local power supply conditions, power capacity, and requirements of the power supply department.
  • New base stations should be introduced with mains power that is better than three or three types (average monthly mains failure ≤ 4.5 times and average duration of each failure ≤ 8h) as the main AC power source. Introduced capacity of foreign utility should be considered according to long-term load

3 AC distribution box

Role: The entrance of the base station power supply, which provides power for the entire base station.

Output: AC equipment power supply and DC input of the switching power supply in the entire computer room

3.1 Technical requirements for AC distribution boxes

  1. The base station should be equipped with a mains / oil engine switch and a mobile oil engine emergency interface. The mobile oil engine emergency interface is configured as a standard plug type (matching the AC incoming voltage system).
  2. The AC power distribution box should have a built-in surge protector (SPD), and its flow capacity should be selected in accordance with the relevant requirements of the "Code for Design of Communication Bureaus (Stations) Lightning and Grounding Engineering" (GB 50689). Pluggable lightning protection modules are strictly forbidden to use as parallel SPDs of the order of 80kA, 120kA.
  3. The AC power distribution box should be equipped with a multi-circuit AC metering smart meter device to measure the AC power of the AC input and output branches in the AC power distribution box.

3.2 AC distribution box configuration

Item

AC power consumption

Remark

Communication equipment load

10.0KW

A system is considered at a peak of 2KW, and an average of 1.5KW is considered, and three transmission equipment’s are considered at a total of 1KW

Battery charging power

8.1KW

Normally in the state of floating charge, consider 1500AHLiFePO4

Air conditioning

2.0KW

Normally 1KW power consumption

Lighting and other

0.5KW

 

Total

20.6KW

 

 

Item

Foreign utility power introduction capacity

AC drop cable diameter

AC distribution box input circuit breaker capacity

Self-built transformer capacity

1

8KW

3*25mm2

220V/63A

 

2

15KW

4*25mm2

380V/63A

20KVA

3

20KW

4*25mm2

380V/63A

30KVA

4

25KW

4*25mm2

380V/63A

50KVA

5

30KW,35KW,40KW,45KW

4*35mm2

380V/100A

50KVA

6

60KW

4*70mm2

380V/160A

80KVA

 

4 switching power supply

50A per module, fully equipped with 600A, can meet the total DC load of the base station

Classification: 150A, 200A, 250A, 300A ... just the number of modules

Early 24V switching power supply, 24V / 48V integrated switching power supply

Switching power supply equipment capacity configuration

Switching power supply = DC load of base station equipment + battery charging current

The number of rectifier modules is configured in n + 1 redundancy mode, where: n = (DC load of base station equipment + battery charging current) / The capacity of a single rectifier module is configured in this period, rounded to an integer.

Power off branch once, 50A (or 32A) × 18 (DC circuit breaker), 16A × 6 (DC circuit breaker), mainly connected to wireless devices,

Secondary power-off branch, 32A × 6 (DC air circuit breaker), 16A × 6 (DC air circuit breaker), mainly connected to transmission equipment.

5 Battery

The battery is generally combined with the battery iron frame: single-layer, double-layer, multi-layer; vertical, horizontal

5.1 Battery requirements

  1. The capacity of the battery pack should be determined comprehensively taking into account factors such as customer demand, utility power reliability, operation and maintenance capabilities, machine room area, and machine room load bearing.
  2. In principle, the base station is equipped with a set of lead-acid battery packs; or according to the actual environment of the base station and the required capacity, the batteries are divided into two groups for configuration.
  3. The battery packs from different manufacturers, different models, different capacities, and different periods (the difference in delivery date is more than one year) are strictly forbidden to use in parallel.
  4. After environmental and economic evaluations, it is indeed possible to save air-conditioning electricity consumption. Ordinary lead-acid batteries can be used in conjunction with the battery incubator solution or high-temperature lead-acid battery technology solution.
  5. The technical solution of the integrated lithium iron phosphate battery pack can be used in scenarios with small space, lack of air conditioning devices, and certain restrictions on load bearing. It is recommended that the battery pack capacity not exceed 200Ah.

5.2 Battery configuration

Configure according to the recent load of the base station.

Configuration based on the city's power situation in the area needs to consider the power outage, the travel time of mobile oil engines from the maintenance center to the base station, the waiting time when there are insufficient maintenance personnel or there are many power outages in the base station.

For VIP base stations and base stations with remote geographical locations and inconvenient emergency power generation, battery backup time can be appropriately increased.

among them:

K-Safety factor 1.25

I-Recent load current

T-discharge hours (h)

t-Minimum ambient temperature (5 ℃)

η-discharge capacity coefficient

Discharge hours

2

3

6

10

η

0.61

0.75

0.88

1

 

α-Battery temperature coefficient 0.006

6 Base station power grounding system

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 7 Lightning protection for base station power
 

 

 

 

 

 

 

 

8 Power cord calculation and selection

8.1 Power cables for base stations

8.2 DC Power Line Section Selection

 

Fixed distribution of voltage drop at different operating voltages

 

24

-48

-60

+130

Total pressure drop

Voltage

 

Total pressure drop

Voltage

 

Total pressure drop

Voltage

 

Total pressure drop

Voltage

 

Battery-DC Distribution Panel

1.8

0.3

1.4

0.2

1.6

0.2

2

0.4

DC Power Distribution Panel

0.5

0.4

0.5

0.5

DC Power Distribution Panel-Power Shelf

0.4

0.4

0.4

0.4

Power shelf

0.2

0.2

0.2

0.2

Power Shelf-Communication Equipment

0.4

0.2

0.3

0.5

 

case analysis

Example: The local telephone -48V power supply in a certain bureau, the maximum load current in the long-term busy is 500A, the distance from the battery to the DC power distribution screen is 6m, and the distance from the DC power distribution screen to the city telephone room power distribution screen is 15m. What type of feeder?

Solution: ① Find the cross section of the battery to the DC distribution screen

Because copper wire is generally used from battery to DC power distribution screen, rT = 57, and it can be obtained by checking the table. This wire allows voltage drop ΔU = 0.2V, so

Select 4 RVVZ 1X300 (mm2) copper core flame-retardant PVC insulated sheathed flexible cables (two positive and two negative).

This type of copper core wire has a safe current carrying capacity of 744A, which fully meets the actual load current requirements.

② Find the wire cross section of the DC power distribution screen to the power distribution screen of the local telephone room.

It can be known from the table that this voltage drop ΔU = 0.6V, so:

Choose RVVZ 1X240 (mm2) copper core flame-retardant PVC insulated sheathed flexible cables 4 (two positive and two negative), choose RVVZ 1X120 (mm2) copper core flame-retardant PVC insulated sheathed flexible cables 1 ( Protected area).

This type of copper core wire has a safe current carrying capacity of 628A, which fully meets the actual load current requirements.

8.3 AC Power Line Section Selection

The selection of AC low voltage power lines is based on the safe current carrying method of the wires (various insulated wires, according to the type of insulation and the laying method, the maximum current allowed for long-term passage is called the safe current carrying capacity).

The current of each wire from the distribution transformer to the AC distribution screen can be calculated by the following formula

The current of each wire from the generator to the AC power distribution screen can be calculated by the following formula

 

The current from the AC power distribution screen to the lead of the switching power supply rectifier can be calculated by the following formula

AC low voltage power line selection

The current from the AC power distribution screen to the input wire of the UPS device can be calculated by the following formula

 

The current on the input lead from the UPS to the AC power distribution screen can be calculated by the following formula

The current from the UPD distribution screen to the load equipment wire can be calculated by the following formula

When the load is three-phase

When the load is single phase

case analysis

Example: A new -48V switching power supply rectifier module rack is newly installed in a certain bureau. The switching power rectifier module rack is configured with 1000A in the long term. What specification type feeder should be selected from the AC power distribution screen to the switching power rectifier module rack?

Choose one RVVZ 5X50 (mm2) copper core flame-retardant PVC insulated sheathed flexible cable (1 core for A, B, and C three phases, 1 core for neutral, 1 core for protective ground).

This type of copper core wire has a safe current carrying capacity of 155A, which fully meets the actual load current requirements.

AC Power Line Section Selection-Ampacity

Allowable ampacity when laying PVC insulated cable in air

 

Cable allows continuous ampacity

Insulation type

Sticky impregnated paper, no drip paper

PVC

Jacket

With steel armor sheath

No steel armor sheath

Max core operating temperature(℃)

80

70

Number of cores

Single core

Two core

Three or four core

Single core

Two core

Three or four core

Core cross section(mm2)

2.5

 

 

 

 

18

15

4

 

30

26

 

24

21

6

 

40

35

 

31

27

10

 

52

44

 

44

38

16

 

69

59

 

60

52

25

116

93

79

95

79

69

35

142

111

98

115

95

82

50

174

138

116

147

121

104

70

218

174

151

179

147

129

95

267

214

182

221

181

155

120

312

245

214

257

211

181

150

356

280

250

294

242

211

185

414

 

285

340

 

146

240

495

 

338

410

 

294

300

570

 

383

478

 

328

Ambient temperature

 

 

 

 

 

 

 

Note:

  1. The values ​​in the table are for aluminum core cables; the allowable continuous ampacity value for copper core cables can be multiplied by 1.29.

   2. Single core is only suitable for DC.

If you want to know more information, you can click this link.

https://www.ctechibattery.com

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