A new technique for right half plane zero elimination from dynamics of a boost converter using magnetic coupling concept

Abstract

Purpose Control-signal-to-output-voltage transfer function of the conventional boost converter has at least one right-half plane zero (RHPZ) in the continuous conduction mode which can restrict the open-loop bandwidth of the converter. This problem can complicate the control design for the load voltage regulation and conversely, impact on the stability of the closed-loop system. To remove this positive zero and improve the dynamic performance, this paper aims to suggest a novel boost topology with a step-up voltage gain by developing the circuit diagram of a conventional boost converter. Design/methodology/approach Using a transformer, two different pathways are provided for a classical boost circuit. Hence, the effect of the RHPZ can be easily canceled and the voltage gain can be enhanced which provides conditions for achieving a smaller working duty cycle and reducing the voltage stress of the power switch. Using this technique makes it possible to achieve a good dynamic response compared to the classical boost converter. Findings The observations show that the phase margin of the proposed boost converter can be adequately improved, its bandwidth is largely increased, due to its minimum-phase structure through RHPZ cancellation. It is suitable for fast dynamic response applications such as micro-inverters and fuel cells. Originality/value The introduced method is analytically studied via determining the state-space model and necessary criteria are obtained to achieve a minimum-phase structure. Practical observations of a constructed prototype for the voltage conversion from 24 V to 100 V and various load conditions are shown.

Analysis and circuit design of isolated forward SEPIC converter with minimum-phase stability

“…A wellknown method is to use a converter with no RHP zero, instead of an expensive controller. Therefore, several nonisolated topologies have been introduced in recent years with no RHP zero in their dynamics, such as tristate converter (Kapat et al, 2009), KY converters (Hwu and Yau, 2009), diode-capacitorbased converter (Zhang et al, 2017b), third-order converter (Veerachary, 2018) and coupled-inductor converters (Restrepo et al, 2011;Singh and Mishra, 2013;Gu et al, 2015;Garg et al, 2016;Liu and Zhang, 2017;Kumar et al, 2020;Goudarzian et al, 2020aGoudarzian et al, , 2020bGoudarzian et al, , 2021Goudarzian, 2022Goudarzian, , 2023b. However, the maximum voltage gain of some converters is small.…”