PI controller design of a dc-dc Zeta converter for specific phase margin and cross-over frequency

Dc-dc Zeta converter is a buck-boost type of converter, which yields dc output voltage with same polarity that of the input voltage. It is widely used in various domestic and industrial applications. For good voltage regulation, fast dynamic response, and stable operation of this converter, a feedback control design is necessary. Therefore, in this paper, the duty cycle to output voltage small-signal transfer function of dc-dc Zeta converter is obtained using state-space technique and Leverrier algorithm. Then this transfer function is used for designing a PI controller using stability equations to meet specific phase margin and desired cross-over frequency. The simulation results display that compensated Zeta converter exhibits good dynamic and steady-state behavior in presence of line and load variations.