High-density power modules in the first fully electric remote control vehicles in operation

Less than two years ago, Saab remotely operated vehicles (ROVs) descended more than 3.000 meters into the icy waters of Antarctica in search of Ernest Shackleton's ship, the Endurance, which sank in 1915. The story of this British explorer is a legendary tale of brave leadership and perseverance. Saab's Seaeye ROVs played a part in the mission's success by using sophisticated technology to locate, examine and film the wreck, eliminating the need to endanger people's lives by exploring the seabed. This achievement reflects Saab's commitment to safety, innovation and environmental responsibility.

Professional divers have always taken enormous risks when carrying out their underwater work inspecting oil and gas pipelines, high-voltage electrical cables, wind turbines and other critical infrastructure. It is inevitable that such an inhospitable environment puts lives at risk. Saab has changed this dynamic by converting its knowledge of seabed exploration into commercial underwater applications.

With the aim of protecting people and society, the development of the ROVs in the Seaeye range is based on the design of more agile and modular systems, adding sensors, articulated arms and other specialized payloads with higher performance. Saab Seaeye systems are capable of performing a wide variety of tasks, from observation and inspection to more complex functions such as underwater maintenance.

This evolution has culminated in the development of the world's first operational fully electric ROV (eWROV), which is characterized by its versatility and maneuverability. Unlike traditional hydraulic ROVs, the eWROV eliminates the need for hydraulic fluid, thereby reducing environmental risks.

eWROV: All-electric ROV

Faced with a thriving ocean economy, Saab's eWROV competes with traditional hydraulic ROVs and offers performance equivalent to a 250HP underwater vehicle. The eWROV uses limited hydraulic systems and an environmentally friendly oil that eliminates the risk of accidental release of pollutants into the ocean that could affect the surrounding ecosystem.

The adoption of electric propulsion offers several advantages. First, reliability is greatly improved with fewer high-pressure systems, thus lengthening the time between maintenance tasks. Electrification, and the advances it brings to sensing and diagnostic data, allow the vehicle itself to continuously monitor its performance, calibrating and providing advance warning of maintenance needs.

Power density: a competitive advantage

The advanced features incorporated in Saab eWROVs are made possible in large part by their exceptionally high power density, which adds significant payload space while outperforming larger hydraulic ROVs.

Since size and weight are imperative in the design of any underwater vehicle, the eWROV's power design focuses on high-voltage DC transmission and conversion, as opposed to traditional AC transmission. The robust DC power system not only reduces size and weight but also allows for higher performance power subsystems. This improved efficiency significantly reduces CO₂ emissions compared to hydraulic systems.

By maintaining a constant voltage level underwater, the DC power system optimizes the power supply to the ROV components, thereby reducing the overall power consumption of the surface power systems. Therefore, lower energy demand leads to lower CO₂ emissions from above-ground power generation, making operations greener.

High-density modular power achieves compact, scalable design

Conventional DC-DC power converters are not ideal because they are too large to install in the limited space available on the eWROV. The main specifications of the eWROV power converter are size, mass and thermal dissipation because the electronic systems are located inside hermetic casings where space is at a premium and conventional convection cooling is not possible.

To meet these requirements, Saab chose Vicor power modules for their high density and efficiency. These modules facilitate efficient distributed powering of various components in the eWROV, such as propellers, manipulators and onboard electronics. Vicor power modules allow Saab to adapt Seaeye subsystems to the standard 24V and 48V levels required by the vehicle's computers, sensors, video cameras, lights and navigation equipment, thus improving its reliability and overall performance.

These high-density power modules also leave free space in the eWROV, making it easier to integrate other electronic devices; This improves power and data specifications. Saab's innovative use of Vicor modules represents a significant advance for ROV technology and sets new benchmarks for safety, efficiency and versatility in underwater exploration.

Saab has been an innovative company since 1937 with the mission of “protecting people and society.” With a wide range of versatile ROVs for one of the fastest growing markets, Saab has distinguished itself by developing a compact hybrid eWROV with a high power density that is both agile and powerful. This next-generation ROV is a model for the industry with its high-performance power network that helps design smaller ROVs but capable of handling high-power loads. Saab's innovative hybrid approach to design and operation is further cemented by the company's global leadership in ROV products and services.