Explorer Yacht Electrical System Design – Power System

Explorer Yacht Electrical System Design – Power System

We split Vanguard’s electrical system into three core components:

1. Power System

2. Hotel System

3. Instrumentation System

Because explorer yachts must operate reliably in remote conditions, redundancy drives the entire design strategy. We categorize components into:

• Fully redundant (duplicated and parallel)

• High MTBF (such as hull, anchoring gear)

• Alternative-based redundancy (shore power vs onboard generation)

• Non-critical systems (luxury items, entertainment)

Main Hybrid E-Motors and Power Philosophy

Vanguard, like Mobius before her, uses a battery-centric power strategy:

• Shore power, solar, and the main engines feed the high-capacity banks

• Propulsion, hotel loads, and navigation draw from these banks

• Two independent 60kWh banks provide full 50% redundancy

Lithium technology was selected for its rapid charge/discharge performance, with design allowances for thermal constraints and safety.

High Voltage DC Bus & Propulsion Inverters

The power bank floats between 550–770VDC. Instead of multiple complex harness runs, we use a DC bus bar, improving reliability and simplifying fault tracing.

Each hybrid motor:

• Draws power via a VFD inverter

• Also functions as a charger when the diesel engines back-drive the hybrid units

Each engine can be completely electrically isolated, maintaining safe redundancy pathways.

AC Distribution, Transformers & Shore Isolation

Two independent transformer systems (20–25kVA each) cleanly supply the 230VAC three-phase hotel load bus.

Key features:

• Active-front-end inverters for pure sine wave AC

• Delta-configured output windings

• Harmonic filtering

• Shore power isolated via dedicated transformer winding

• Full galvanic and electrical separation from marina earth

This prevents hull corrosion and protects crew from floating-neutral faults.

Solar, DC Systems & Cold Start Capability

An 8kW solar array feeds the hotel system through MPPT controllers. Once the house batteries are full, excess solar is routed back through power inverters to charge the main banks — a cascade charging architecture.

House batteries supply:

• 24VDC

• 48VDC

• Emergency cold-start capability

Firefly/lead-acid chemistry provides superior performance in low temperatures compared to lithium.

Power & Energy Management Systems

The yacht includes:

• Power management: handles shore charging, switching, and source control

• Energy management: oversees hybrid drives, thruster systems, inverters, and diesel engines in generation mode

The system is duplicated and accessible from:

• Bridge

• Flybridge

• Engine room

• MFD displays

Cooling Systems & Future Expandability

All major inverters and hybrid drives use:

• Redundant water/glycol cooling loops

• Hull skin tanks

• 50/50 fluid mix

• <35°C inlet temperature

The architecture allows for future hybrid or battery upgrades without redesigning the entire electrical system.

A full Factory Acceptance Test (FAT) is scheduled before shipping to catch issues early