Power electronic systems with switching power converters produce trains of power pulses transmitted between the source and load. Periodicity of these pulses results in electromagnetic interference (EMI) concentrated in frequency bands around multiples of the switching frequency. The EMI disturbs operation of sensitive communication systems, often intertwined with the power electronic systems. Communications would greatly improve if channels for them were carved in the noise spectrum. Pulse width modulation with randomly varied switching frequency has been proven to be an effective tool for EMI mitigation. In the proposed work, random-rate switching strategies for power electronic converters will be developed such that a spectral null is produced at a specified frequency, f0, in the noise spectrum. Suppressed noise at and near f0 would result in a high signal-to-noise ratio in power communication transmission links.
Intellectual merit: The proposed approach consists in chopping an existing switching signal into shorter pulses. Decomposition of a "parent" pulse into "children" pulses adds degrees of freedom to the design of frequency spectra of the signal, making it possible to place a null at a desired location. Theoretical analyses, simulations, and experiments will define the scope, quality, necessary conditions, and limitations of the proposed technique. Significance of the project lies in the joint approach to communication and power control, normally treated separately.
Broader Impacts: Enhanced communications in power electronic systems, and the envisioned widespread application of the developed methods in industry, household, and warfare, constitute the major expected broader impact of the study. The idea of carving communication channels in the noise generated by power electronic converters may have broad implications on EMI mitigation, power control, and power line communications. An experimental setup to enhance teaching will be setup.
