Efficiency

Georgia Tech is developing a novel hybrid direct current (DC) circuit breaker that could enable multi-terminal DC power systems. The breaker’s mechanical switch enables switching speeds 10 times faster than existing technology, severing the mechanical linkage, while the power electronics-based circuit handles the fault current. A new configuration of the fast switch and solid-state devices/circuits will reduce steady-state losses compared to state-of-the-art hybrid circuit breakers.

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.

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.

Drexel University is proposing a solid-state MV circuit breaker based on silicon carbide devices, a resonant topology, and capacitive wireless power transfer that aims to significantly improve breaker performance for the MVDC ecosystem. The project combines innovations in using an active resonant circuit to realize zero-current switching, wireless capacitive coupling between the conduction and breaker branches to avoid direct metal-to-metal contact for rapid response speed, and wireless powering to drive the MV switches for improved system reliability.

Marquette University will leverage the technology gap presented by the lack of DC breaker technology. The project objective is to create an industry standard DC breaker that is compact, efficient, ultra-fast, lightweight, resilient, and scalable. The proposed solution will use a novel current source to force a zero current in the main current conduction path, providing a soft transition when turning on the DC breaker. A state-of-the-art actuator that can produce significantly more force than current solutions will also be used.

Sheetak is developing a thermoelectric-based solid state cooling system that is more efficient, more reliable, and more affordable than today’s best systems. Many air conditioners are based on vapor compression, in which a liquid refrigerant circulates within the air conditioner, absorbs heat, and then pumps it out into the external environment. Sheetak’s system, by contrast, relies on an electrical current passing through the junction of two different conducting materials to change temperature.

ADMA Products is developing a foil-like membrane for air conditioners that efficiently removes moisture from humid air. ADMA Products' metal foil-like membrane consists of a paper-thin, porous metal sheet coated with a layer of water-loving molecules. This new membrane allows water vapor to permeate across the membrane at high fluxes, at the same time blocking air penetration and resulting in high selectivity. The high selectivity of the membrane translates to less energy use, while the high permeation fluxes result in a more compact device.

Pacific Northwest National Laboratory (PNNL) is designing more efficient adsorption chillers by incorporating significant improvements in materials that adsorb liquids or gases. An adsorption chiller is a type of air conditioner that is powered by heat, solar or waste heat, or combustion of natural gas. Unlike typical chillers, an adsorption chiller has few moving parts and uses almost no electricity to operate.

Dais Analytic Corporation is developing a product called NanoAir which dehumidifies the air entering a building to make air conditioning more energy efficient. The system uses a polymer membrane that allows moisture but not air to pass through it. A vacuum behind the membrane pulls water vapor from the air, and a second set of membranes releases the water vapor outside. The membrane's high selectivity translates into reduced energy consumption for dehumidification. Dais' design goals for NanoAir are the use of proprietary materials and processes and industry-standard installation techniques.

American Superconductor (AMSC) is developing a freezer that does not rely on harmful refrigerants and is more energy efficient than conventional systems. Many freezers are based on vapor compression, in which a liquid refrigerant circulates within the freezer, absorbs heat, and then pumps it out into the external environment. Unfortunately, these systems can be expensive and inefficient. ITC's freezer uses helium gas as its refrigerant, representing a safe, affordable, and environmentally friendly approach to cooling.