Wärtsilä Electric Propulsion Systems

A Wärtsilä electric propulsion system uses electric motors to drive the propellers, with power from generating sets, batteries or a hybrid energy mix, controlled by an energy management system (EMS). Separating power production from thrust lets gensets run near optimal load even when propulsion demand varies. Wärtsilä has delivered electric propulsion systems to more than 350 vessels.

Converter topologies

• AC system: low voltage (440/690 V) or medium voltage (6.6/11 kV), with switchboard, transformers and AFE or DFE converters per propulsor
• DC system: low voltage (1000 V) DC Hub combining switchboard and converter modules; connects variable-speed gensets and batteries directly
• Low Loss Solution (patented): fewer transformers, lower electrical losses and increased redundancy; 200+ installations, market standard for DP/offshore vessels

Key benefits

• Fuel savings by matching the number of online gensets to demand
• Lower NOx, CO, CO2 and soot emissions
• Low noise and vibration
• Configurable redundancy
• Fast propeller speed changes and reversals for manoeuvring and DP; high torque at propeller standstill
• Minimal harmonics and voltage drops
• Automatic and manual control from any console, with monitoring against operating errors and overloads
• Fewer engines and constant-speed operation reduce maintenance
• Easy replacement of gensets with future-fuel engines, batteries or fuel cells

Scope

Integrated systems can include propulsors and gears, thrusters, controls, energy management and shore power.

Applications

Cruise ships, ferries, offshore and DP vessels, tugs, research and special vessels, and merchant vessels with varying speed or high hotel load such as feeders, RoRos, short-sea PCTCs, small tankers and large LNG carriers.