National Technology & Engineering Solutions of Sandia, LLC

The University of New Mexico

Jacob Mueller

Jason C Neely

John C Hewson

Yuliya Preger

Luciano Andres Garcia Rodriguez

Lee Gill

Robert Kaplar

Jack David Flicker

Harold P Hjalmarson

Jane Lehr

Gregory W Pickrell

Andrew Kurzawski

Emily Ann Schrock

A method and system for dispersing stored energy in an energy storage system to delay or arrest propagation of thermal runaway and thermally-induced cascading failures. The system includes a plurality of battery sub-assemblies and DC-DC converters connected to a shared DC bus through which energy may be exchanged. The system may be interfaced to an AC power grid or DC power system through an additional power converter. The method of dispersing stored energy uses this system to charge and discharge sub-assemblies such that the system is less susceptible to propagation of thermal runaway. The method determines, based on awareness of current system state, battery types, and electrical and thermal structure, the sequence of charging and discharging actions to best inhibit thermal runaway while preserving the system's ability to perform subsequent energy redistribution.

Dispersion of stored energy within a battery system at risk of failure

A disclosed switching apparatus, such as a circuit breaker, includes a transistor switch circuit connected between a power input terminal and a load terminal, and, connected to the power input terminal and bypassing the transistor switch circuit, a switchable bypass leg that is optically switched by a series-connected photoconductive semiconductor switch (PCSS). The transistor switch circuit includes at least one cascade of three or more series-connected transistors, and at least one resistor network configured to divide a voltage from a voltage source across a cascade of series-connected transistors. Operating the switch apparatus includes detecting whether a sensed electric current is in a fault condition, opening the transistor switch circuit upon detecting a fault condition, and then closing the PCSS so that the electric current is diverted onto a switchable bypass path. The opening of the transistor switch circuit comprises turning OFF a normally-ON transistor switch circuit.

Optically switched circuit breaker with cascaded transistor topology

A switching apparatus includes three or more series-connected transistors, and it further includes a balancing network. The balancing network includes a resistor network configured to divide a voltage from a voltage source across the series-connected transistors. The resistor network includes at least two resistive legs connected in parallel. In each resistive leg, two or more resistors are connected in series. The balancing network may further comprise at least one capacitive leg of series-connected capacitors connected across the series-connected transistors, and it may further comprise at least one leg of series-connected avalanche diodes connected across the series-connected transistors for overvoltage protection. In example embodiments, the series-connected transistors are JFETs. In other example embodiments, the series-connected transistors may be HEMTs or GaN transistors.

High voltage switch with cascaded transistor topology

Growing community of inventors

Albuquerque, NM, United States of America

Jacob Mueller