Auto Disconnection Logic (Anti-Islanding): Relay Control
Relay Control
| Code | Auto Trip Criteria | Current Status |
|---|---|---|
| A1 | Grid voltage/frequency exceeds limitOV>110% · UV<85% · OF>50.5Hz · UF<49.5Hz | Not Triggered |
| A2 | Grid power outage (no voltage)V<5V sustained >100ms | Not Triggered |
| A3 | ROCOF ≥ thresholdRate-of-change-of-frequency > 1.0 Hz/s | Not Triggered |
| A4 | Trip action completed52b contact confirmed — breaker mechanically open | Standby |
| A5 | Trip signal reported to EMSEvent logged · UI alert triggered | Standby |
| A6 | Island mode startup permittedBESS grid-forming · SOC · load coordination verified | Not Allowed |
Anti-Reverse Power Detection: Enabled
Set mode:
Enabled
/
Disable
| Code | Description | Status | Action Suggestion |
|---|---|---|---|
| R1 | Reverse power detected at POI | Not Triggered | No action required |
| R2 | PV/BESS output power = 0Required before reconnection attempt | Not Satisfied | Maintain current state |
| R3 | EMS enabled "Zero Export" strategy | Enabled | Reverse power protection active |
POI Active Power+84.1 kW
Reverse Power Limit10.0 kW
BESS Output+19.7 kW
Grid Reconnection (Breaker Close) Control Logic
Conditions met: 2/5
C1
C2
C3
C4
C5
CLOSE
| Code | Prerequisite | Status | Description |
|---|---|---|---|
| C1 | Stable grid voltage, frequency, phase ≥ 60sV:220–240V · f:49.8–50.2Hz · 60s window | Satisfied | Grid has been stable over 60s |
| C2 | Power flow is "inflow" or "zero export"POI flow must not be export before reconnect | Satisfied | No reverse power |
| C3 | PV/BESS is stopped or in standbyAll DER output must be zero — avoids power surge | Not Satisfied | BESS is still running |
| C4 | EMS authorized breaker closeSolely authorized by EMS via UI interlock engine | Not Allowed | — |
| C5 | Phase/frequency sync completeΔf<0.05Hz · ΔV<2V · Δθ<5° confirmed | Not synchronized | Parameters not matched |
C3
Assets Not Stopped — Primary Blocking Condition
BESS is actively discharging. Output power > 0 kW.
Required Action
Execute Force Stop BESS, confirm output = 0 kW before proceeding.
⚑ C4 (EMS Auth) and C5 (Phase Sync) cannot be evaluated until C3 is cleared.
Operator Guidance — Reconnection Sequence
Action Required
1
Verify grid stability ≥ 60s (C1)
Grid stable for 60s confirmed ✓
✓ COMPLETED
2
Confirm zero export / inflow only at POI (C2)
No reverse power ✓
✓ COMPLETED
3
Stop BESS & PV — wait until output = 0 kW (C3)
Use Force Stop BESS + Force Stop PV in control bar
⚠ ACTION
4
Await EMS authorization for breaker close (C4)
🔒 Requires C3 satisfied first
LOCKED
5
Phase sync complete — ΔV<2V · Δf<0.05Hz · Δθ<5° (C5)
🔒 Requires C3 + C4 first
LOCKED