SBIR Phase I:Novel High Performance Power Converters with Input-Output Linearization

This Small Business Innovation Research (SBIR) Phase I project proposes to develop a new class of DC-DC converters by employing modern control methods to map nonlinear power converters such as the boost and buck-boost topologies to linear models resulting in a simple and reliable converter design. A novel and breakthrough control strategy is proposed that allows nonlinear DC-DC converters to behave linearly for the full output voltage range and respond quickly to load and source changes. The invention provides significantly better performance and supports a wider range of output voltage compared to existing commercial products and offers a cost competitive solution compared to existing design techniques by reducing the design effort. The methods can be employed for any nonlinear converter resulting in faster response, lower cost, and higher efficiency. The design is independent of desired output voltage and stabilizing gain, and is free of right-half-plane zero effects. The concepts will be demonstrated by simulating and designing boost and buck-boost converters using input-output linearization. Parameters in the control laws will be transformed to simple algorithms that can be implemented in a small foot-print application specific integrated circuit. Key applications such as solar systems and light emitting diode lighting will be targeted. The broader impact/commercial potential of this project involves development of energy efficient power electronic systems that are becoming increasingly critical in a broad range of industrial, portable, consumer, military, and medical applications. Efficient power electronics that minimize idle power and improve power factor can reduce the loading on the grid. Existing applications that employ nonlinear converters such as boost and buck-boost topologies will benefit from elimination from the right-half-plane zero and stability problems, thus achieving higher bandwidth. This indirectly helps improve efficiency. Further, the proposed method allows these converters to be designed in a much simpler fashion thus reducing the design effort, time, and cost. Also, a single controller can be employed for a wide operating range, reducing inventory requirements as compared to present techniques that require different linear models and designs for different operating points. This will allow nonlinear converters to be employed in new portable electronics and other applications that use lower voltage batteries rather than employ buck converters with higher voltage batteries. The broader technical and commercialization vision involves efficient power management systems that are cost effective for manufacturability and deployment. These issues have been key limitations to date for large scale deployment of these converters.