Current transformer is a special transformer used to transform current. Its important function is that when the current passes through the primary, the secondary can linearly output a smaller current (5A/1A). They are widely used in power systems to isolate high and low voltages, measure power, and provide relay protection.
Traditional current transformers are generally made of silicon steel or Permalloy cores. Silicon steel is relatively cheap, but due to its low magnetic permeability, it is generally difficult to make a current transformer with a small current ratio and low accuracy. Although Permalloy has a high magnetic permeability, it is expensive and the cost is too high, which caused the accuracy of early current transformers to be generally low. Nanocrystals have greatly promoted the popularization of high-precision current transformers (0.5s, 0.2s) due to their excellent cost-effectiveness.
Product features:
High magnetic permeability, low measurement error
High saturation magnetic induction intensity, smaller and lighter than the transformer made of Permalloy 
Excellent temperature stability, can adapt to a wider range of working conditions Typical curves of iron loss angle of amorphous and nanocrystalline Permalloy
Material properties:
Comparison table of performance of different soft magnetic materials
Indicators
Nanocrystalline
Permalloy
Silicon steel
Saturation magnetic induction intensity (T)
1.25
0.76
2.03
Initial magnetic permeability (0.8mA/cm)
40000~90000
80000
1000
Maximum magnetic permeability
>250,000
>200,000
>40,000
Density (g/cm3)
7.2
8.85
7.65
Curie temperature (℃)
570
400
740
Strip thickness (mm)
0.0025~0.0040
0.1
0.23~0.35
Filling factor (%)
>75
90
95
Typical product specifications and features:
◆typical specifications of 0.5/0.66KV current transformer core:
Serial number
Transformation ratio
Load(VA)
Core specifications (mm)
Box specifications (mm)
Packaging method*
1
75A/5A
5
43/70*40
38/75*45
PBT
2
100A/5A
5
50/73*40
45/77*45
PBT
3
51/73*35
46/78*40
PBT
4
10
38/85*55
-
G
5
150A/5A
5
40/70*25
35/75*25
PBT
6
53/70*30
48/75*35
PBT
7
10
55/92*50
-
G
◆typical specifications of 10KV current transformer core:
Serial number
Transformation ratio
Load(VA)
Core specifications (mm)
Box specifications
(mm)
Packaging method*
1
200A/5A
10
80/130*35
75/135*40
L/B
2
80/135*30
75/140*35
L/B
3
75/120*40
70/125*45
L/B
4
300A/5A
10
80/110*25
75/115*30
L/B
5
85/115*25
80/120*30
L/B
6
75/100*30
70/105*35
L/B
7
15
85/125*30
80/130*35
L/B
8
85/130*25
80/135*30
L/B
9
400A/5A
10
80/105*25
75/110*30
L/B
10
85/110*25
80/115*30
L/B
13
15
80/120*25
75/125*30
L/B
14
80/112*30
75/117*35
L/B
◆typical specifications of 35KV current transformer core:
| Serial number | Current ratio | Load ( V A ) | Core specification (mm) | Box specifications (mm) | Packaging method* | ||||||
| 1 | 300A/5A | 15 | 115/175*30 | 110/180*35 | B | ||||||
| 2 | 125/195*35 | 120/200*40 | B | ||||||||
| 3 | 160/230*35 | 155/235*40 | B | ||||||||
| 4 | 300A/5A | 20 | 140/245*30 | 135/250*35 | B | ||||||
| 5 | 400A/5A | 15 | 100/135*20 | 95/140*26 | B | ||||||
| 6 | 110/140*25 | 105/145*31 | B | ||||||||
◆typical specifications of 110/220KV current transformer core:
| Serial number | Transformation ratio | Load (VA) |
Core specifications (mm) |
Box specifications (mm) |
Packaging method* | |||||||||
| 1 | 200A/5A | 15 | 190/270*80 | 184/276*92 | L/B | |||||||||
| 2 | 300A/5A | 20 | 190/270*40 | 184/276*46 | L/B | |||||||||
| 3 | 400A/5A | 30 | 200/265*40 | 194/271*46 | L/B | |||||||||
|
4 |
500A/5A |
25 |
185/245*25 | 180/250*31 | L/B | |||||||||
| 5 | 600A/5A | 25 | 175/210*30 | 170/215*35 | L/B | |||||||||
| 6 | 800A/5A | 25 | 175/225*15 | 170/230*20 | L/B | |||||||||
| 7 | 800A/5A | 30 | 207/258*20 | 200/265*27 | L/B | |||||||||
| 8 | 1000A/5A | 30 | 190/220*25 | 185/225*31 | L/B | |||||||||
| 9 | 1000A/5A | 50 | 260/350*15 | 255/360*21 | L/B | |||||||||
| 10 | 1000A/5A | 30 | 372/453*15 | 360/460*21 | L/B | |||||||||
◆Typical specifications of ultra-high voltage current transformer core:
| Serial number | Transformation ratio | Load (VA) |
Core specifications (mm) |
Box specifications (mm) |
Packaging method* | |||||||||
| 1 | 500/5 | 30 | 430/560*40 | 420/570*46 | B | |||||||||
| 2 | 800/5 | 10 | 560/680*10 | 550/690*20 | B | |||||||||
| 3 | 1000/5 | 10 | 625/715*15 | 615/725*25 | B | |||||||||
| 4 | 1000/1 | 10 | 670/755*10 | 660/765*20 | B | |||||||||
| 5 | 1250/5 | 10 | 840/960*10 | 830/970*30 | B | |||||||||
| 6 | 2000-1 | 10 | 1110/1140*15 | 1100/1150*25 | B | |||||||||
◆Typical specifications of square current transformer core:
| Serial number | Transformation ratio | Load (VA)) |
Core specifications (mm) |
Box specifications (mm) |
Packaging method* | |||||||||
| 1 | 300/5 | 10 | 70*90/100*120×30 | 65*85/105*125×36 | B | |||||||||
| 2 | 300/5 | 15 | 90*90/160*160×30 | 85*85/165*165×36 | B | |||||||||
| 3 | 400/5 | 15 | 75*95/105*125×25 | 70*90/110*130×30 | B | |||||||||
| 4 | 400/5 | 20 | 80*95/120*135×25 | 75*90/125*140×30 | B | |||||||||
◆Typical specifications of three-phase zero-sequence current transformer core:
| Serial number | Transformation ratio | Load (VA) |
Core specifications (mm) |
Box specifications (mm) |
Packaging method* | |||||||||
| 1 | 20A/1A | 0.1 | 85*385/135*435×40 | 80*380/140*440×46 | B | |||||||||
| 2 | 20A/1A | 0.1 | 99*369/142*412×40 | 94*364/147*417x46 | B | |||||||||
| 3 | 20A/2A | 0.1 | 83*513/117*547×30 | 78*508/122*552×36 | B | |||||||||
|
4 |
20A/3A |
0.1 |
91*511/127*547×30 | 86*506/132*552×36 |
B |
|||||||||
| 5 | 20A/1A | 0.1 | 100*370/151*421×20 | 95*365/156*426×26 | B | |||||||||
| 6 | 20A/1A | 0.1 | 103*613/114*614×45 | 98*608/118*628×51 | B | |||||||||
*PBT indicates that the core is protected by plastic box packaging Note: 1. Our company can make cores according to the size required by customers
G indicates that the end face is cured by epoxy resin and wrapped with crepe paper 2. Our company can design cores according to the coil parameters required by customers
B indicates that the core is protected by stainless steel box packaging
L indicates that the core is protected by aluminum box packaging 3. Our company can also provide core protection box according to customer requirements
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