A new model-order reduction technique for linear dynamic systems is presented. The idea behind this technique is to transform the dynamic system function from the s-domain into the z-domain via the bilinear transformation, then use Prony’s [1] least-squares approximation method instead of the commonly employed Pad´e approximation method, and finally transform the reduced system back into the s-domain using the inverse bilinear transformation. Simulation results for large practical systems show that this technique based on Prony’s method gives much higher accuracy than the traditional Pad´e method, and results in lower-order approximations without significant increase in simulation time.
Makram M. Mansour, Amit Mehrotra