What this covers
- Dynamic contingency calculation — continuous comparison of spinning reserve against operating load, so the shedding table reflects the plant's actual running configuration.
- Fast load shedding — priority-table feeder tripping executed within roughly 50 to 80 ms of the trigger event.
- Under-frequency and under-voltage staged shedding as the fallback layer when fast shedding is insufficient or unavailable.
- Active and reactive power sharing — dispatch to generator governors and AVRs to balance load and hold bus voltage.
- Redundant architecture — S7-1500H redundant CPUs with ET 200SP distributed I/O over fault-tolerant Profinet (MRP) rings.
- Interaction with protection — defining which protection trips initiate shedding and, just as importantly, which must not.
What you receive
- Functional Design Specification stating the shedding algorithm, trigger criteria and contingency tables
- Redundant PLC control code with the priority matrix documented
- Factory Acceptance Test protocol with contingency test scripts per scenario
- Operator interface for reserve status, shed priority and event history
Standards and references
Contingency cases are derived from load flow and stability studies prepared to IEEE 399 and IEEE 1110, with control logic to IEC 61131-3 and redundant Ethernet to IEC 62439 (MRP).
Related services
ATS & Main-Tie-Main Control Schemes
Multi-source transfer logic that fixed-function controllers cannot handle.
Substation SCADA & ECMS
A monitoring layer over your MV and LV network that operators can actually act on.
Legacy PLC Migration & Retrofit
Moving obsolete switchboard controllers to current platforms without losing the logic.
Need this scoped?
Tell us about the switchboard, the source configuration and the specification you have been handed.
Get in Touch