Regan A. Zane

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Prof. Zane's research program is focused on a unique combination of power electronics, control systems, custom integrated circuits and embedded systems, and analog and digital circuit techniques. Research sponsors include industry members of the Colorado Power Electronics Center (CoPEC) and multiple government and private agencies, including DOE, ONR, NSF, DARPA, NASA, DOT, DoEd, and the various private institutions. For additional information on the research program and areas, graduate students and publications, see the CoPEC home page.

Research Interests

  • All aspects of design and control of high efficiency, high frequency, high power density, and high performance dc-dc, ac-dc, dc-ac power converters in emerging applications, e.g. bi-directional power converters for hybrid ac and dc power systems in commercial and military applications, data centers, micro-grids, grid-integration of renewables, and electric vehicles
  • Application of advanced digital control techniques to power electronic systems such as stability and control of series/parallel combinations in modular and distributed systems, adaptive tuning in multi-input, multi-output control loops and online identification of loop stability, converter health, bus or line impedance
  • Energy efficiency in lighting and building systems, e.g. solid-state lighting and dc power distribution
  • Analog and mixed signal integrated circuit design
  • Low power energy harvesting and power management in wireless sensors and networking systems

Energy efficient solid-state lighting solutions There are many exciting new developments in the solid-state LED lighting (SSL) area. Recent forecasts predict competitive penetration of SSL into commercial and residential markets for general lighting within the next five years, offering a high efficiency, environmentally friendly alternative to existing lighting solutions. We are researching new circuit architectures and drive techniques for large arrays of high brightness LED's with a focus on high efficiency, modularity and low cost component integration.

Bidirectional power converters for ac and dc power systems Next generation ac and dc power systems employ multiple power sources, complex and dynamic loads and distributed energy storage. Primary motivations include improved efficeincy and reliability, integration of renewable energy sources, and strict requirements of electronic loads. We are researching full resonant and resonant transition power converter topologies with complex multi-angle control to achieve record efficiency and power density. Our solutions can be used as multi-purpose converter modules in scalable power systems, from multiple kilo-watts to mega-watts.

Low-power energy harvesting for wireless devices There is an exponentially growing demand for real-time information in all aspects of engineering systems, from intelligent building controls to health care systems, environmental control systems, structural integrity monitoring, and entertainment and marketing systems. The demand is fueling proliferation of wireless sensors and interactive devices that communicate via low power wireless networks. We are researching approaches for harvesting energy for maintenance free, wireless devices. Energy sources include RF, vibrational, solar, wind and biological.

High efficiency power manamgent in data centers With the rise of cloud computing, online data storage, social networks, etc., data centers are becoming a significant target for improved energy efficiency. Present solutions require multiple power conversion steps from grid to processor, resulting in relatively low efficiency. We are researching new solutions to allow higher voltage dc distribution in data centers with high efficiency grid connection and integration of renewable and backup power sources. Primary challenges include very high efficiency, high power density power conversion with large step-down conversion ratio and wide range of load conditions.

Intelligent monitoring and control of power conversion systems The goal here is to improve power quality and reliability by integrating intelligent controls into power converter modules to allow them to self adapt to the environment, including dynamic changes in the power bus at the input, the load characteristics or internal variations due to component temperature and aging. We are applying digital control techniques to perform online identification of the converter dynamics, auto-tuning of the feedback controller and self diagnostics that can report health and performance metrics to the power system in spacecraft, aircraft, naval ships or even computer workstations.

High efficiency electric discharge lamps High efficiency lighting systems are dominated by electric discharge type lamps, including high intensity discharge (HID) high and low pressure sodium and metal halide lamps and linear and compact fluorescent lamps (LFL and CFL). A number of challenges exist in driving these lamps with high efficiency and long life due to their highly nonlinear and dynamic behavior, requiring high voltage ignition pulses, lamp current regulation and multiple modes of operation and protection. We have performed extensive design oriented modeling and analysis of the resonant drive circuits and lamps and have ongoing research into high efficiency and performance ballasts.

© R. Zane