Zeta converter: Kharitonov polynomials based interval reduced order modeling

This research proposes a continuous interval reduced-order model (ROM) for a fourth-order constant interval Zeta converter using Kharitonov polynomials. First, the fourth-order continuous interval transfer function is obtained using interval arithmetic for the Zeta converter. Then, this model is reduced to first, second, and third orders using Kharitonov polynomials. For this reduction, Kharitonov polynomials are derived for the denominator, and a Routh table is constructed for these polynomials. The ROM denominator is then obtained from the Routh table. The numerator is determined using time-moments (TiMo) and Markov parameters (MaPa) matching. Comparisons with other models demonstrate the efficacy of our method. Step and impulse responses, as well as the Bode and Nichols plots for the lower and upper bounds, are provided to illustrate the method's effectiveness. Time-domain specifications (TDS) and performance error criterion (PEC) are tabulated to support a comparative study. These results show that our method effectively reduces the order of the Zeta converter while maintaining accuracy and performance.