ECE: Electrical & Computer Engineering
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Modeling EMI behavior for aerospace

Center for Power Electronics Systems

Read more about power electronics at www.cpes.vt.edu.

Power electronics researchers have developed fast, accurate, behavioral EMI-modeling techniques for higher frequencies (>10 MHz) that previously were not easily modeled.

“EMI models should be simple enough so that simulations can run on most computers,” says Hemant Bishnoi, a Ph.D. student who worked on the project. The models should also be accurate in the interested range of frequencies, he notes. “Unfortunately, with state-of-the-art in EMI modeling, these two goals cannot be met simultaneously at higher frequencies. A new breed of EMI models is needed that can facilitate size reduction of EMI filters, that usually take up to 30 percent of volume in a typical aerospace power supply.

The team solved the problem with behavioral modeling, involving a noise model with linear noise source and impedance, then fit the terminal behavior of the system at high frequency. The model was successfully tested on dc-fed half-bridge and three-phase inverter systems using measurements from outside the system on positive, negative, and ground terminals. The model runs in the frequency domain and simulations are very fast — usually lasting only several seconds.