RSV Power Flow Simulator
Load-flow model of the three DC switchboard sections (SARG-A / B / C), five 1512 ekW gensets, two 2508 kWh / 3200 kW energy storage strings and all drive feeders. Worst-case failure is the loss of a complete outer section; the default scenario runs the surviving thrusters at 75%, the crane at 50% and allows the surviving battery to boost the grid.
Scenario
Crane (2100 kW) is fed from SARG-A. If SARG-A is the lost section the crane is unavailable regardless of setting.
Base board load excluding the ROVs. Each transformer is 1500 kVA; ROV load is added on top of the value set here.
The 480 V / 208 V bus-ties are normally open. On loss of SARG-A or SARG-C the motorized breaker between the distribution transformer and its 480 V board opens, so the dead board cannot be back-fed even with the tie closed manually — ROVs must be transferred to the surviving board.
Live single-line balance
Fault: SARG-C lostAnalysis
Losing SARG-C removes 3 024 ekW of generation and one 2 508 kWh battery, but the crane stays available on SARG-A. This is the governing case for the power balance, because the crane load remains on a halved plant.
Load exceeds the online gensets by 1,050 kW. The surviving ESS covers it (33% of its 3 200 kW converter). With 1,756 kWh usable this can be sustained for 100 min before the reserve SOC is reached.
Each tie is 2 × DCGuard 3200 A at 1050 VDC = 6,720 kW. The surviving sections must be able to move power across the ties, so the DCGuards must stay closed after the fault — an FMEA-relevant point, since a spurious tie trip converts this into a second, deeper failure.
Maximum simultaneous thruster loading the surviving plant can sustain with the crane, 480 V board and ROV demand held constant.
1,756 kWh usable (SOC 90% down to 20% reserve). Beyond this the load must be back inside the diesel envelope, so the operation needs a defined ramp-down or a recovery plan within that window.
The selected 480 V board is de-energised: the motorized breaker between the distribution transformer and its board opens when the feeding SARG section is lost, so the board cannot be back-fed even after the 480 V / 208 V bus-ties are closed manually. The ROV must be transferred to the surviving board — a break-before-make operation.
480 V distribution transformers
Feeder schedule
| Tag | Consumer | Sec | Feeder | Rated | Demand | Load |
|---|---|---|---|---|---|---|
| MP1 | Main propulsion PS (cycloidal) | A | 1900 kW / 2080 A | 1,850 kW | 1,445 kW | 75% |
| RBT2 | Retractable bow thruster PS | A | 1300 kW / 1400 A | 1,350 kW | 1,055 kW | 75% |
| CRANE | Crane (dual motor 2 x 1300 A) | A | 1400 kW / 1500 A | 2,100 kW | 1,094 kW | 50% |
| TR1 | Distr. Trans No.1 → PS 480 V board(incl. 300 kW ROV) | A | 1552 kVA / 1500 kVA | 1,500 kW | 781 kW | 50% |
| DK1 | PS deck utility (690 V, Transf No.6) | A | 359 kVA | 400 kW | 132 kW | 32% |
| BTT1 | Bow tunnel thruster | B | 1350 kW | 1,350 kW | 1,055 kW | 75% |
| AUX2 | Aux Transf No.2 (660/480/208 V) | B | 283 kVA | 75 kW | 25 kW | 32% |
| MP2 | Main propulsion STB (cycloidal) | C | 2800 kW | 1,850 kW | 0 kW | 0% |
| RBT3 | Retractable bow thruster STB | C | 1300 kW / 1400 A | 1,350 kW | 0 kW | 0% |
| TR3 | Distr. Trans No.3 → STB 480 V board | C | 1552 kVA / 1500 kVA | 1,500 kW | 0 kW | 0% |
| DK3 | STB deck utility (690 V) | C | 352 kVA | 400 kW | 0 kW | 0% |
| ROV1 | ROV1 on PS 480 V board(via 480 V board) | A | 480 V / 630AF-450AT | 500 kW | 300 kW | 60% |
| ROV2 | ROV2 on STB 480 V board(board de-energised) | C | 480 V / 630AF-450AT | 500 kW | 0 kW | 0% |
Demand is referred to the DC bus and includes drive/transformer losses at the selected efficiency. ROV demand is drawn through the 480 V board it is assigned to, so it appears inside the TR1 / TR3 feeder figure and is not counted twice.