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There is considerable need for a mobile, reliable, efficient, and compact prime power supply for use in a host of directed energy applications. Recent improvements in the energy and power density of electrochemical lithium-ion batteries have made them a very viable option for these types of applications where fast and rep-rate operation is of interest. Despite the proven ability of lithium-ion batteries to source high currents, it is still unclear how they age when they are used to repeatedly source high-rate currents in a pulsed manner, as they must when used in a repetitive rate prime power supply. Similarly, it is unclear how elevated rate recharge affects the life of the battery. Research has been performed at University of Texas at Arlington in which high-power, 2.6 Ah lithium-ion batteries have been repeatedly discharged and recharged at high pulsed rates. This paper will discuss the potential of lithiumion batteries for use in these applications and will present experimental results performed when two 2.6 Ah cells were both discharged at 28 A (10.8C) and recharged at 9 A (3.5C) to 2.5 and 2.0 V, respectively.

Research and development are currently being performed to transform the US's utility electric grid into a "smart grid [1], [2]." Smart meters are among the first intelligent metering devices used within the "smart grid" concept. They have been deployed in thousands of commercial and residential electrical installations around the US [3], [4]. While the wide-scale deployment of these devices has initially proven very successful, there is still much that is unknown about how they will impact the long-term operation of a large utility grid or the electrical devices sourced by them [5]. One such device, whose operation appears to be impacted by the smart meter, under specific conditions, is a ground-fault circuit interrupter (GFCI). It has been reported that the RF transmissions from smart meters can induce false tripping events on GFCI outlets installed on temporary construction poles. In an effort to understand why this may happen, a research study, which is presented here, has been performed to understand the correlation between RF transmissions and GFCI tripping events on construction poles.Index Terms-Electromagnetic compatibility, electromagnetic interference, ferrite, ground-fault circuit interrupter (GFCI), RF, smart meter.

There is considerable need for a mobile, reliable, efficient, and compact prime power supply for a host of applications including directed energy and electrical grid backup among others. Electrochemical energy storage devices, which possess either high power density or high energy density, have been developed recently and are very applicable for use in these applications. The need for both high energy and high power, however, makes the design and implementation of such a prime power supply a non-trivial task. While lithium-ion batteries (LIBs) are available, which possess both high power and energy density, operation at high power reduces their cycle life, decreasing the reliability and increasing the cost of the system when replacement becomes necessary more frequently. One method proposed involves optimally combining high energy batteries with high power electric double layer capacitors (EDLCs) using actively controlled power electronics to regulate the current to and from each respective device. In such a scheme, energy can be slowly sourced to and from the batteries while the capacitors are used to supply or accept the bulk of the current when the demand is high, especially during fast transients. This type of scheme should not only maximize the batteries' cycle life and ensure that both the energy and power required of the load(s) is always available, but will also increase the instantaneous power capabilities of the system, offering a well-rounded solution to sourcing steady and/or transient loads. At UTA, an actively controlled, high rate HESM has been constructed to evaluate its performance under the typical load condition of directed energy weapon operation. It has been assembled using lithium-ion batteries, EDLCs, and commercial off the shelf (COTS) power electronic converters. A discussion about the future of HESMs, the experimental setup at UTA and the results obtained thus far will be presented here.