Setting Guidelines; Setting Example - ABB Relion 670 Series Applications Manual

Section 11
System protection and control
measurement), etc. in order to report the extracted phasor values to the supervisory system (e.g.
MicroSCADA).
The following figure shoes typical configuration connections required to utilize this filter in
conjunction with multi-purpose function as non-directional overcurrent protection.
IEC13000179 V1 EN-US
Figure 99: Required ACT configuration
Such overcurrent arrangement can be for example used to achieve the subsynchronous resonance
protection for turbo generators.
11.1.3

Setting guidelines

11.1.3.1

Setting example

A relay type used for generator subsynchronous resonance overcurrent protection shall be
replaced. The relay had inverse time operating characteristic as given with the following formula:
=
t T
op 01
EQUATION13000029 V1 EN-US
Where:
• t is the operating time of the relay
op
• T
01
• K is a constant (setting)
• I is measured subsynchronous current in primary amperes
S
The existing relay was applied on a large 50Hz turbo generator which had shaft mechanical
resonance frequency at 18.5Hz. The relay settings were T
minimal subsynchronous current trip level was set at I
Solution:
First the IED configuration shall be arranged as shown in
HPAC filter and multipurpose function shall be derived from existing relay settings in the following
way:
240
K
+
I
s
is fixed time delay (setting)
IEC13000179-1-en.vsd
GUID-5A3F67BD-7D48-4734-948C-01DAF9470EF8 v2
01
= 0.64 seconds, K= 35566 Amperes and
=300 Amperes primary.
S0
Figure 99. Then the settings for SMAI
1MRK 511 358-UUS A
(Equation 108)
Application manual