Case Study: Lightweight 85kW Marine Generator with YASA 750R

In the absence of a commercially available alternative, the company HYPS Hybrid Power Systems developed a revolutionary variable-speed genset (VSG) for hybrid power and propulsion systems in leisure and light commercial vessels.
Typically, gensets are built to operate continuously at fixed speeds for many hours and are large, heavy and not always fuel efficient.

Complete 85kW marine genset 130 x 90 x 90cm 

Conventional gensets are perfectly serviceable for commercial craft logging thousands of operational hours each year. However, leisure craft typically have different operational profiles, so the project HYPS was working on required a different type of genset with new and distinct performance parameters. Owners of leisure craft typically demand lightweight, small size gensets capable of managing variable loads with a light to medium operating profile of around 600 hours a year. Reliability, fuel efficiency (even at partial loads) and low noise are other items important to considerations. Such a genset would have applications in leisure craft – both hybrid and conventionally powered – as well as in commercial vessels with a light-duty generator profile.

Challenge accepted

The company designed, developed and tested the HYPS 85kW variable-speed genset (VSG). The Volvo D3 -150 diesel engine was selected based on factors including its low weight and volume, low noise and minimal environmental impact. After a careful survey, a YASA 750R motor-generator was chosen as the electric generator. As well as the YASA’s significant imact on the overall size and weight of the genset, the YASA 750R is a robust, low speed (3250 rpm) motor ideally suited to coupling to a diesel engine. The Volvo engine drives the YASA at up to 90kW, which in turn feeds an Aradex converter. An engine-control system monitors and manages performance and links directly to the onboard hybrid power and energy management system.

The overall result is a quiet, compact generator set that weighs just 480kg (dry weight) and measures 130x 90x 90cm. Output is 700 Vdc and fuel efficiency is high at both nominal and partial loads. The design and choice of components ensure reliability, safety, ruggedness and efficient functionality.

HyPS YASA 85kVA compared to a conventional genset:


60% less volume
62% less weight
High fuel efficiency at full load
as well as partial load
Topic briefing:  Marine generation and hybrisation.

For further information about YASA motors, generators and controllers, please contact YASA.