Setting Guidelines - ABB REC670 Applications Manual

Section 10
Frequency protection
10.4.3
266
Prohibited Operation
62
60
Continuous operation
58
Restricted Time Operation
56
0.01 0.1 1
Time (Minutes)
62
Restricted Time Operation
Continuous operation
60
58
Restricted Time Operation
56
0.01 0.1 1
Time (Minutes)
IEC13000258 V1 EN-US
Figure 100: Examples of time frequency characteristics with various frequency
band limits
Another application for the FTAQFVR (81A) protection function is to supervise
variations from rated voltage-frequency. Generators are designed to accommodate the
IEC 60034-3:1996 requirement of continuous operation within the confines of their
capability curves over the ranges of +/-5% in voltage and +/-2% in frequency.
Operation of the machine at rated power outside these voltage-frequency limits lead to
increased temperatures and reduction of insulation life.

Setting guidelines

Among the generator protection functions, the frequency time accumulation protection
FTAQFVR (81A) may be used to protect the generator as well as the turbine.
Abnormal frequencies during normal operation cause material fatigue on turbine
blades, trip points and time delays should be established based on the turbine
manufacture's requirements and recommendations.
Continuous operation of the machine at rated power outside voltage-frequency limits
lead to increased rotor temperatures and reduction of insulation life. Setting of extent,
duration and frequency of occurrence should be set according to manufacture's
requirements and recommendations.
62
60
58
56
10 100 1000 0.01
Prohibited Operation
62
60
58
Prohibited Operation
56
10 100 1000 0.01
1MRK 511 401-UUS A
Prohibited Operation
Restricted Time Operation
Continuous operation
Restricted Time Operation
Prohibited Operation
0.1 1 10 100
Time (Minutes)
Prohibited Operation
Continuous operation
Restricted Time Operation
Prohibited Operation
0.1 1 10 100
Time (Minutes)
IEC13000258-1-en.ai
GUID-62C6D764-CAF2-4C2F-B91A-EBC611987D72 v3
Bay control REC670 2.2 ANSI
Application manual
1000
1000