Section 4
1MAC309294-MB F
Protection functions
224
RER620
Technical Manual
This time delay can be set and it is used to prevent unwanted load-shedding actions when
the system frequency recovers to the normal level.
Once the frequency has stabilized, 81S can restore the load that is shed during the
frequency disturbance. The restoration is possible manually or automatically.
The function contains a blocking functionality. It is possible to block function outputs,
timers or the function itself, if desired.
4.4.2.4
Operation principle
The function can be enabled and disabled with the
Operation
setting. The corresponding
parameter values are “On” and “Off”.
The operation of the load shedding and restoration function can be described using a
module diagram. All the modules are explained in the next sections.
Throughout this document, “high df/dt” is used to mean “a high rate of
change of the frequency in negative direction.”
Summary of Contents for RER620
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Page 22: ...Section 1MAC309294 MB F 16 RER620 Technical Manual ...
Page 88: ...Section 3 1MAC309294 MB F Basic functions 82 RER620 Technical Manual ...
Page 278: ...Section 4 1MAC309294 MB F Protection functions 272 RER620 Technical Manual ...
Page 362: ...Section 5 1MAC309294 MB F Control functions 356 RER620 Technical Manual ...
Page 418: ...Section 7 1MAC309294 MB F Measurement functions 412 RER620 Technical Manual ...
Page 428: ...Section 8 1MAC309294 MB F Recording functions 422 RER620 Technical Manual ...
Page 464: ...Section 9 1MAC309294 MB F Other functions 458 RER620 Technical Manual ...
Page 554: ...Section 10 1MAC309294 MB F General function block features 548 RER620 Technical Manual ...
Page 568: ...Section 12 1MAC309294 MB F Relay physical connections 562 RER620 Technical Manual ...
Page 574: ...Section 13 1MAC309294 MB F Technical data 568 RER620 Technical Manual ...
Page 576: ...Section 14 1MAC309294 MB F Relay and functionality tests 570 RER620 Technical Manual ...
Page 578: ...Section 15 1MAC309294 MB F Applicable standards and regulations 572 RER620 Technical Manual ...
Page 582: ...Section 16 1MAC309294 MB F Glossary 576 RER620 Technical Manual ...
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