Inline Gas Discharge Tube Breaker for Meshed MVDC Grids

Project Term:
08/02/2019 - 08/01/2022

Critical Need:

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.

Project Innovation + Advantages:

GE Research will develop a medium voltage direct current (MVDC) circuit breaker using gas discharge tubes (GDTs) with exceptionally fast response time. GDTs switch using no mechanical motion by transitioning the internal gas between its ordinary insulating state and a highly conductive plasma state. The team will develop a new cathode and control grid to reduce power loss during normal operation and meet program performance and efficiency targets. A fast MVDC breaker is an important component in uprating existing AC distribution corridors in congested urban areas to MVDC, and connecting distributed renewable energy sources to a growing number of high-power applications.

Potential Impact:

The proposed breaker is installed close to loads to rapidly detect and react to the short-circuit fault. Thus, it could enable an increased number of electronic loads that operate using DC, such as ultra-fast electric vehicle charging stations and utility scale energy storage battery units, to connect to the MV distribution grid. This would improve overall power delivery efficiency.


DC circuit breakers respond significantly faster than their AC counterparts, enabling prompt isolation and protection of assets from electrical faults. MVDC circuit breakers and grids enable greater resiliency to cyber and other attacks through targeted isolation of affected nodes.


MVDC breaker-enabled microgrids could facilitate greater deployment and adoption of distributed renewable resources, greatly reducing power sector emissions. Electrification of transportation (e.g., ships, aviation) with DC systems could also reduce emissions.


Proliferation of MVDC systems protected by more effective DC circuit breakers could drive higher energy efficiency, lower equipment costs, and bolster grid resiliency.


ARPA-E Program Director:
Dr. Isik Kizilyalli
Project Contact:
Dr. David Smith
Press and General Inquiries Email:
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