ABB 615 series Technical Manual page 659

1MAC059074-MB A
615 series ANSI
Technical Manual
The pu leakage reactance X

V
n
X X

= ⋅
leak leakPU
Ω
(
I

n

GUID-7A3ABF69-50C4-4F5D-A466-61CAB055B604 V1 EN
The internal induced voltage E of the machine is calculated.
E V ( I I ) ( jX
= + − ⋅
AB A B leak
GUID-DBA66DD4-E087-4624-BDCE-E74167CAB5DE V1 EN
E = 11500∠0°+ (5600∠-63.57°- 5600∠176.42°) · (0.170378∠90°) = 12490 V
The excitation level M of the machine is calculated.
12490
Excitation level M =
11000
GUID-28DEBF41-9058-4C7B-985F-FA7131DF39A7 V1 EN
Example 2
The situation and the data are according to Example 1. In this case, the manufacturer of the
machine allows the continuous operation at 105 percent of the nominal voltage at the rated
load and this value to be used as the base for overexcitation.
Usually, the V/f characteristics are specified so that the ratio is 1.00 at the
nominal voltage and nominal frequency. Therefore, the value 100 percent
for the setting Voltage Max Cont is recommended.
If the Voltage Max Cont setting is 105 percent, the excitation level M of the machine is
calculated with the equation.
12490
Excitation level M =
11000
GUID-3422B6EB-4564-4EFD-B60A-50CB18850054 V1 EN
Example 3
In this case, the function operation is according to IDMT. The Operating curve type
setting is selected as "OvExt IDMT Crv2". The corresponding example settings for the
IDMT curve operation are given as: Pickup value = 110%, Voltage Max Cont = 100%,
Time multiplier = 4, Maximum trip time = 1000 s, Minimum trip time = 1 s and Cooling
time = 200 s.
is converted to ohms.
leakPU
 
0 2 11000
.
 
= ⋅
) (
3 7455
 
⋅
 
)
49 98 .
1 1359 .
=
1 00 .
⋅
50
49 98 .
1 0818 .
=
1 05 .
⋅
50
Protection functions

0 0 170378 . ohms

=
)
3

⋅

Section 4
(Equation 124)
(Equation 125)
(Equation 126)
(Equation 127)
653