Eaton Corporation

Today’s power grid relies primarily on alternating-current (AC) electricity as opposed to direct-current (DC). DC has advantages over AC such as lower distribution losses, higher power carrying capacity, and reduced conductor materials, which make it well suited to industrial applications, transportation, and energy production. However, the risk associated with electrical faults, such as short circuits, and system overloads, continues to hinder the growth of DC markets. Inherently, AC electricity periodically alternates direction, providing a brief “zero crossing,” where no current flows. This characteristic allows electrical faults to be interrupted by conventional electro-mechanical breakers. DC networks deliver power without zero crossings, which make conventional circuit breakers ineffectual in fault scenarios. To fully benefit from medium voltage (MV) DC usage, fast, highly reliable, scalable breakers must be developed for commercial deployment.

Eaton will build an ultra-high efficiency, medium voltage direct current (MVDC), electro-mechanical/solid-state hybrid circuit breaker (HCB) that offers both low conduction losses and fast response times. The team will also develop a high-speed actuator/vacuum switch (HSVS) combined with a novel transient commutation current injector (TCCI). This switch will transfer power to a separate solid-state device, interrupting the current in the event of a fault. The design should allow for scaling in voltage and current, enabling a range of circuit breakers across the MV application space.