Correction to ´Lyapunov stability designs for switching regulator/low-pass filter system´

It is noted that the results obtained in the above-titled paper (ibid., vol.25, no.5, p.602-610, Sept. 1989) are erroneous since the Lyapunov matrix equation was not solved correctly and completely. Also, erroneous conclusions resulted because a solution to the ten simultaneous equations which result from the evaluation of that equation was not obtained. These errors are corrected and the Lyapunov simultaneous equations are solved. From the design of this fourth-order system, a comparison of the Lyapunov and Routh-Hurwitz methodologies for achieving asymptotic stability is obtained. It is shown that a design per the second method of Lyapunov simplifies the stability design calculations for this higher-order system.<>