SYNTHETIC_INERTIA
Synthetic inertia: power injection proportional to rate-of-change-of-frequency, emulating the stored energy of rotating mass.
When to use it
Use SYNTHETIC_INERTIA when an inverter-dominated microgrid has lost enough rotating mass that the rate of change of frequency, not the frequency error, is what breaks it, and a converter is to emulate an inertia constant H.
Interface
The published port signature. This is the whole of what the block exposes to your program — the implementation body is not shown here and ships with the download.
Inputs
| Port | Type | Unit |
|---|---|---|
| ENABLE | BOOL | — |
| FREQ | REAL | Hz |
| DFDT | REAL | Hz/s |
| MEAS_OK | BOOL | — |
| F_NOM | REAL | Hz |
| H_EMUL | REAL | s |
| S_BASE_KW | REAL | kW |
| P_MAX | REAL | kW |
| DFDT_DEADBAND | REAL | Hz/s |
| F_MIN_VALID | REAL | Hz |
| F_MAX_VALID | REAL | Hz |
| SOC_PCT | REAL | % |
| SOC_OK | BOOL | — |
| SOC_MIN_PCT | REAL | % |
| SOC_MAX_PCT | REAL | % |
| ACK | BOOL | — |
Outputs
| Port | Type | Unit |
|---|---|---|
| P_INERTIA | REAL | kW |
| ACTIVE | BOOL | — |
| AT_LIMIT | BOOL | — |
| SOC_BLOCKED | BOOL | — |
| VALID | BOOL | — |
| ALM_MEAS_FAULT | BOOL | — |
| ALM_CFG_ERR | BOOL | — |
IEC 61499 event interface
EI INIT, REQ·EO INITO, CNF
Validation evidence
- Tests
- 9
- Simulated scans
- 57
- Simulator
- v0.1.0
Complete IEC 61131-3 implementation with a published test suite that runs on the vplant simulator. The counts above are that suite, executed on this build.
- Conforms to IEC 61131-3
- Conforms to IEC 61499
Download SYNTHETIC_INERTIA — free
Create a free Ri Tech account to download the block. You get the Structured Text body, the Rockwell Add-On Instruction (.L5X), the Schneider Control Expert DFB (.XDB), PLCopen XML, the IEC 61499 function block type (.fbt) and the datasheet.
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Source is never published on this page. The implementation is released to a signed-in Ri Tech account — free of charge, but never anonymously.