ABB Solid-State DC Circuit Breaker Advantages!

Fully electric commercial vessels are becoming increasingly popular, with DC power systems being the preferred choice for onboard power distribution due to their ability to handle high power flows within limited space at higher system efficiency and lower lifecycle costs.

Commercial vessels equipped with onboard DC grids have proven capable of operating at peak energy efficiency while minimizing emissions. This results in significant power savings and reduced operating costs across maritime applications, from cargo ships to cruise liners. Figure 1 illustrates an example of a DC power distribution system for commercial vessels.

The power supply requirements and performance of DC systems depend on extremely fast fault protection to ensure protection selectivity, high survivability, and reconfigurability after a fault event. In practice, fault protection and isolation remain among the key challenges for shipboard DC distribution systems.

Due to the characteristics of power semiconductor devices, solid-state DC circuit breakers (SS DCCBs) can provide extremely short response times and rapid current interruption—up to 1,000 times faster than electromechanical breakers. ABB has developed a solid-state DC circuit breaker featuring extremely low conduction losses, high power density, and ultra-fast response time, capable of meeting the demanding protection requirements of marine DC power distribution systems.

This solution is based on a parallel connection of Si Reverse-Blocking IGCTs (RB-IGCTs), a customized semiconductor device optimized for low losses, developed by Corporate Research in Lenzburg and ABB Semiconductors, along with optimized metal-oxide varistors (MOVs). The RB-IGCT is 1,000 times faster than any electromechanical contact and optimized for low conduction losses. The optimized MOVs can dissipate high system inductive energy and enable fast current interruption and isolation.

High-current solid-state DC circuit breakers bring revolutionary system protection to safe, arc-free, and efficient DC systems. The developed platform targets system voltages up to 1,000 Vdc, with rated currents ranging from 1,000 A to 5,000 A. The technology achieves efficiency of up to 99.8%, compared to 99.5% for Si IGBT-based solutions. The solid-state breakers can be water-cooled for maximum power density or use advanced two-phase cooling, which simplifies air cooling while delivering performance close to liquid cooling, ensuring lower installation and maintenance costs and longer asset life.

Its power loss is 70% lower than that of similar solutions. Within ten years, it can save up to $200,000 on ferries and up to $1 million on cruise ships. The new circuit breaker can also be used in many other applications, such as grid-connected battery energy storage systems, data centers, and electric vehicle charging infrastructures. In fact, ABB has won project funding from the U.S. Department of Energy to develop DC circuit breakers for electric vehicle charging applications. Solid-state circuit breakers will make power distribution systems more reliable and efficient, reduce maintenance costs, and at the same time meet the durability requirements of the next-generation power grid.