MCP3909RD-3PH3 Microchip Technology, MCP3909RD-3PH3 Datasheet - Page 95

• Manufacturer Part Number: MCP3909RD-3PH3
• Description: REF DESIGN FOR MCP3909 W/18F2520
• Manufacturer: Microchip Technology

Specifications of MCP3909RD-3PH3

• Main Purpose: Power Management, Energy/Power Meter
• Utilized Ic / Part: MCP3909, PIC18F2520, PIC18F4550
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Secondary Attributes: -
• Embedded: -
• Primary Attributes: -
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

C.13 COMPENSATION FOR RATIO ERROR AND PHASE LAG
TABLE C-1:
© 2009 Microchip Technology Inc.
0.1
0.2
0.5
1
3
5
1
50
3
5
Rated Current (%)
Rated Current (%)
0.75
0.4
1.5
Ratio Error± (%)
5
3
ACCURACY CLASS AND ERROR LIMIT FOR THE CURRENT TRANSFORMER
The error of the current transformer (CT) is a complex, which can usually be expressed
by two orthogonal parts, current error (f) and phase lag (δ).
EQUATION C-63:
The current error, also known as ratio error, can be written in percentage as:
EQUATION C-64:
Phase lag, also known as angle error, is the phase difference between primary and
secondary current vector, in 'minute'.
Different current transformers have different errors. Current transformers are classified
into different accuracy classes depending on their error magnitudes. The accuracy
class of a transformer is nominated by the percentage of the maximal ratio error
allowed for a given rated current.
Accuracy classes and corresponding error limits for a current transformer are listed in
Table C-1.
0.35
0.75
0.2
1.5
20
100
120
0.1
0.2
0.5
1.0
3
5
Where:
120
0.1
0.2
0.5
1.0
K
I
I
n
1
2
1
=
=
=
Phase difference of class 3 and class 5 are not specified.
Rated Current (%)
180
15
30
90
5
the rated current ratio
the primary current
the secondary current that passes I
under the test condition
± (%)
f
20
15
45
90
8
Power Calculation Theory
=
ε
100
=
100
10
30
60
f
(
------------------------ -
5
k
+
n
Phase difference
I
j
2
I
δ ⋅
1
–
120
Phase lag
10
30
60
I
5
1
)
1
Rated Current (%)
0.45
0.9
2.7
5.4
5
± (Grad)
1
0.24
0.45
1.35
2.7
20
DS51723A-page 95
0.15
100
0.3
0.9
1.8
0.15
120
0.9
0.3
1.8