How Applied Motion Systems engineered a marine-grade power conversion and storage system to capture, condition, and deliver renewable energy from the open ocean

The Problem: Converting Chaotic Ocean Energy into Usable Power

Wave energy is abundant. The engineering problem is that it doesn’t behave like power from a grid.

Oscilla Power had developed something genuinely novel. The TRITON-C, a 100 kW-rated wave energy converter designed to bring renewable power to remote and isolated coastal communities. The device works by capturing relative motion between a surface floating vessel and a submerged reaction ring, extracting energy from ocean waves across all six degrees of freedom, something most wave energy systems can’t do.

But converting that mechanical energy into electricity that can connect to the grid is a different problem entirely. The ocean doesn’t deliver consistent power. Energetic sea states produce large peak currents and voltages. Between those peaks, output drops to near nothing. Conventional utility power electronics can’t handle that variability. The hardware also has to survive the same environment it harvests energy from: saltwater, constant motion, storm conditions, and years of offshore deployment.

The ask: design and build an electrical power system that could handle unpredictable generator output, smooth it into stable exportable utility grade power, store energy for grid reliability and black-start capability — all inside a vessel deployed offshore Hawaii.

The Solution: A Marine-Grade Power Conversion and Storage Architecture

AMS engineered the complete electrical power system for the TRITON-C, working within the constraints of the vessel’s physical space, the offshore environment, and the highly variable nature of wave energy generation.

The system runs on a 720 VDC bus. This voltage level provides enough headroom to handle peak generator output while maintaining a stable export level to shore. Three independent hydraulic drivetrains feed three generators. AMS designed a Siemens Sinamics-based inverter drive system to manage all three generators simultaneously. A Sinamics CU320-2 controller handles inverter based generator commutation, current and torque limits, and generator velocity, adapting in real time to ocean conditions.

Layered Energy Storage: Supercapacitors and LFP Batteries

The energy storage architecture is layered. A supercapacitor bank with 11 Farads of capacitance at bus voltage absorbs and releases energy quickly, smoothing the power spikes and gaps inherent to wave energy. A fourth cabinet houses Lithium Iron Phosphate batteries at 310 VDC. A 30 kW DC-to-DC converter links them to the system, allowing bidirectional power flow between the 720VDC and 310VDC buses. Together, these allow the system to ride through gaps in wave activity and restart from a de-energized state without external power.

Custom Control Algorithms for Wave Energy

The control system draws on AMS’s prior experience with energy recovery applications. AMS adapted algorithms from a previous turbine-in-pipe project in Portland’s municipal water infrastructure to handle simultaneous voltage and current control across a wide power input range. This is not standard inverter territory. Consequently, the application required custom control logic purpose-built for this specific power profile. Power exports to shore at a steady-state 720 VDC, delivering up to 100 kW continuous to an onshore UL1741 rated grid connected inverter.

Purpose Engineered Mounting and Enclosure System

All hardware is shock-mounted in reinforced, marine-rated enclosures. AMS designed everything aboard the vessel to withstand high-energy sea states, not as a specification afterthought, but as a basic requirement for a system that may be deployed thousands of miles from the nearest service facility.

The Results: What the System Delivered

Stable power export in a fundamentally unstable environment. Supercapacitor buffering and custom inverter control algorithms allow the TRITON-C to deliver consistent, conditioned power to shore even as wave conditions vary. The variability problem, one of the central engineering challenges of wave energy, is addressed in the onboard power electronics and energy storage at sea, rather than worked around onshore.

A system designed for where it will operate. Marine deployments don’t allow for easy service calls. AMS selected the Siemens-based architecture in part because components are globally available and field-serviceable wherever these systems are eventually deployed. That’s a practical consideration, not a marketing point.

A platform built for scale. The TRITON-C is Oscilla Power’s community-scale system. The larger TRITON, targeting 1 MW output in utility-scale arrays, is designed around the same architecture. The electrical system AMS built for the 100 kW prototype carries forward directly into that next phase.

AMS’s involvement continued beyond the original TRITON-C deployment. When Oscilla Power began developing a 1:6 scale TRITON prototype for testing off the coast of Maine, they again named AMS a core engineering partner.

Read the full story from Siemens here.

About Applied Motion Systems

AMS is a systems integrator and machine builder. Our work spans motion control and industrial automation systems across paper converting, web handling equipment, aerospace tooling, renewable energy, and applications most companies haven’t tried before.

We design for the environment the system will operate in, taking care to investigate every detail of deployment. And we think about what the system looks like five, ten, and twnety years after commissioning, because that’s when the value of building it right becomes obvious.

If you are working through a motion to grid challenge in a difficult environment, we would welcome the conversation.