ABB rec670 Applications Manual

56
0.01 0.1 1 10 100 1000
58
Frequency (Hz)
Time (Minutes)
Time (Minutes)
Time (Minutes)
Time (Minutes)
IEC13000258-1-en.ai
Continuous operation
Prohibited Operation
60
62
56
0.01 0.1 1 10 100 1000
58
Frequency (Hz)
Continuous operation
60
62
56
0.01 0.1 1 10 100 1000
58
Frequency (Hz)
60
62
Continuous operation
56
0.01 0.1 1 10 100 1000
58
Frequency (Hz)
Continuous operation
60
62
Restricted Time Operation
Prohibited Operation
Prohibited Operation
Restricted Time Operation
Restricted Time Operation
Prohibited Operation
Prohibited Operation
Prohibited Operation
Prohibited Operation
Restricted Time Operation
Restricted Time Operation
Restricted Time Operation
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.
10.4.3 Setting guidelines
GUID-62C6D764-CAF2-4C2F-B91A-EBC611987D72 v3
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.
Section 10 1MRK 511 401-UUS A
Frequency protection
266 Bay control REC670 2.2 ANSI
Application manual

ABB rec670 Specifications

General

Brand	ABB
Model	rec670
Category	Control Unit
Language	English