ABB RELION REX640 Technical Manual page 1426

Section 9
Control functions
1420
GUID-A8B81F0B-0CE5-41FF-8711-CF5845684A27 V1 EN
Figure 763: Frequency matching pulses generation with variable command pulse
length
Frequency matching with variable command pulse off intervals
When the setting Frequency match mode is set to "Variable Interval", the frequency
matching is done with variable command pulse off intervals.
The voltage match command pulses are now the same length, but the intervals are
inversely proportional to the frequency slip.
Pulse length (tpf): adjustable with the setting Freq pulse Min Dur (tpfmin)
Pulse off interval (tsf): calculated as
1 1
tsf
= = ≤
f f f s
−
Gen Bus Gen
GUID-19176619-D659-49B5-9189-22B7F815DDEF V1 EN
s Measured frequency slip across the CB to be synchronized
f Measured generator side frequency
Gen
f Measured bus side frequency
Bus
Reset of frequency raise and lower command pulses
The generated frequency raise and lower command pulses RAISE_F and LOWER_F
are immediately reset if any of the following conditions is met.
• During matching of its own CB synchronization
30 [Sec]
1MRS759142 C
(Equation 329)
REX640
Technical Manual