A general approach to synthesis and analysis of quasi-resonant converters

Abstract

Abstract-A method for systematic synthesis of quasi-resonant (QR) topologies by addition of resonant elements to a parent PWM converter network is proposed. It is found that there are six QR classes with two resonant elements, including two novel classes. More complex QR converters can be generated by a recursive application of the synthesis method. Topological definitions of all known and novel QR classes follow directly from the synthesis method and topological properties of PWM parents. The synthesis of QR converters is augmented by a study of possible switch realizations and operating modes. In particular, it is demonstrated that a controllable rectifier can be used to accomplish the constant-frequency control in all QR classes. Links between the QR converters and the underlying PWM networks are extended to general dc and small-signal ac models, in which the model of the PWM parent is explicitly exposed. Results of steady-state analyses of selected QR classes and operating modes include boundaries of operating regions, dc characteristics, a comparison of switching transitions and switch stresses, and a discussion of relevant design trade-offs.

Constant-frequency control of quasi-resonant converters

“…In order to compute the DC conversion ratio for any particular QR topology, one should only substitute m for duty ratio D in the well-known function M ( D ) of the PWM parent. This unifying method, originally devised in [lo] for zero-current and zerovoltage QR classes, and applied to all QR classes in [13], renders unnecessary and redundant repeated analyses of numerous variations of QR topologies.…”

Simulation of PWM DC-DC converters using eigenvalues and eigenvectors

“…Most of the families of DC-DC converters have even number of switches [13]. Each switch has two operation modes: on and off.…”

“…According to [13] PWM converter can have two continuous conduction modes and a number of discontinuous conduction modes. They can operate in discontinuous quasi resonant mode (DQRM) when both discontinuous modes, DICM and DCVM, occur during one switching interval.…”

Resonant Power Converters: An Overview with Multiple Elements in the Resonant Tank Network

“…Analysis of the characteristics of QRCs is presented in [23]- [26]. The optimization and design of QRCs are carried out in [27], while applications of QRCs to induction cookers and induction heating equipment are illustrated in [28] and [29], respectively.…”