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慈溪1500KVA 13.8 0.38KV Mine Dry-Type Transformer

Dry-type transformers are widely used in local lighting, high-rise buildings, airports, wharf CNC machinery and equipment and other places. Simply put, dry-type transformers refer to transformers whose cores and windings are not immersed in insulating oil.

产品描述

Overview:

Dry-type transformers are widely used in local lighting, high-rise buildings, airports, wharf CNC machinery and equipment and other places. Simply put, dry-type transformers refer to transformers whose cores and windings are not immersed in insulating oil. Cooling methods are divided into natural air cooling (AN) and forced air cooling (AF). In natural air cooling, the transformer can operate continuously for a long time under the rated capacity. When forced air cooling, the output capacity of the transformer can be increased by 50%. It is suitable for intermittent overload operation or emergency accident overload operation; due to the large increase in load loss and impedance voltage during overload, it is in a non-economic operation state, so it should not be kept in continuous overload operation for a long time.

 

Structure type

It is mainly composed of an iron core composed of silicon steel sheets and a coil made of epoxy resin. An insulating tube is placed between the high and low voltage coils to increase electrical insulation, and the line is supported and constrained by spacers.

The fasteners that overlap the ring and its parts all have anti-loosening performance.

Construction performance:

(1) Solid insulation encapsulated winding

(2) Unencapsulated winding

Winding: Of the two windings, the higher voltage is the high-voltage winding, and the lower one is the low-voltage winding.

From the relative position of the high and low voltage windings, high voltage can be divided into concentric and overlapping types.

Concentric windings are simple and convenient to manufacture, so this structure is adopted.

Overlap type, mainly used for special transformers.

Structural characteristics of dry-type transformers

Because dry-type transformers have the advantages of strong short-circuit resistance, small maintenance workload, high operating efficiency, small size, and low noise, they are often used in places with high performance requirements such as fire prevention and explosion protection.

1. It is safe, fireproof, pollution-free, and can be directly operated in the load center;

2. Adopting domestic advanced technology, high mechanical strength, strong short-circuit resistance, small partial discharge, good thermal stability, high reliability and long service life;

3. Low loss, low noise, obvious energy saving effect, rabbit maintenance;

4. Good heat dissipation performance, strong overload capacity, and capacity operation can be increased when forced air cooling;

5. Good moisture-proof performance, adapt to high humidity and other harsh environments;

6. Dry-type transformers can be equipped with a complete temperature detection and protection system. Using intelligent signal temperature control system, it can automatically detect and circulate display the respective operating temperatures of the three-phase windings, can automatically start and stop the fan, and have functions such as alarms and trips;

7. Small size, light weight, less space and low installation cost.

1 Parameter

Model

S-1500 /13.8

Serial Nos.

2021

2001

Capacity

    150  kVA

Rated Frequency

50 Hz

Rate V

13800  /  230  V

Rated Current

6.28/376.5A

Insul. Class

LI 95 AC 35/AC5

Connection mode

Dyn11

Insul. Oil

25 Transformer purposed oil

Conditions

Outdoor

Phase

3

Cooling way

ONAN

Codes of P.

1TY.710.5277

2 Earth V.

Tapping stage

High Voltage V

Other Tapping V

Lower V

5

13800

13800±2×2.5 %

230

3 Insulation performance 

Resistance

Once to ground

Secondary to ground

Time of the secondary and ground

МΩ

2500

2500

2500

4 Voltage ratio &connection group label verification

High voltage winding HV

Low winding LV

Measurement deviation %

Connection group

Tapping stage

Voltage kV

Voltage kV

AB/ab

BC/bc

CA/ca

Verification

1

14.49

0.23

0.08

0.02

0.05

Dyn11

2

14.145

0.08

0.05

0.04

3

13.8

0.06

0.03

0.02

4

13.455

0.06

0.06

0.01

5

13.11

0.07

0.09

0.07

5 Wire-wound resistor

Winding Group

Position

Real test values

Max. Unbalance Rate %

AB (Ω)

BC (Ω)

CA (Ω)

High Voltage                            HV

1

12.94

12.98

12.96

0.33

2

12.63

12.67

12.65

3

12.32

12.36

12.34

4

12.01

12.05

12.03

5

11.71

11.74 

11.72

Low Voltage      LV

Line resistance

ab (mΩ)

bc (mΩ)

ca (mΩ)

1.13

6.094

6.101

6.163

Phase resistance

oa (mΩ)

ob (mΩ)

oc (mΩ)

2.12

3.047

3.053

3.112

6  Applied voltage withstand test.

Pressurized area

Voltage Testing kV

Test time S

Conclusion

High voltage to ground, low voltage

35

60

PASS

Low voltage to ground, high voltage

5

60

7  Induced Overvoltage Withstand Test

Applied voltage kV

Induced voltage kV

Induction

Frequency

Test time 

Conclusion

    LV

HV

Multiple

Hz

 S

PASS

0.46

27.6

2

150

40

8  No load loss and no load current test

Averaged voltage

Effective voltage

No-load Current  %

No-load Loss kW

kV

kV

0.23

0.23

0.66

0.245

9  Short circuit impedance and load loss measurement

Winding Group

Tapping place

Applied Current A

Short circuit impedance  %

No-load Loss kW

Total Loss kW

  HV-LV

3

6.28

4.02

1.915

2.16

10 Transformer oil test

Density ≤ 0.895㎏/dm³                       

Kinematical Viscosity 50°C≤11.6

Flash Point ≥140°C

 Insulating Oil Dielectric Loss ≤0.005

Acid Value ≤0.01mgKOH/g

Ash  -  %

Withstand voltage 45KV/2.5mm

Oil number Domestic 25# type

11 Sealing test

The product can endure 20  Kpa pressure for 12 hours without leakage.

Conclusion

This type of power transformer has passed the test and its performance meets with the National Standards GB/T 1094.1 ~ 2-2013, GB/T 1094.3-2003, GB/T 1094.5-2008 and the technical parameters and GB/T 6451-2015 requirements. It has been checked up to the production standards and its final quality okeyed for sales, be qualified for delivery in conformity with Standards.