Sneak Circuits of Power Electronic Converters

Chapter 5Sneak Circuits of other Power Electronic Converters

5.1 Introduction

Most topologies of power electronic converters are significantly dependent on the inspirations and experiences of designers and there are no rigorous theories or methods to follow, which may lead to some paths or states in the power electronic converter, which are unknown to the designers. The sneak circuit phenomena existed in some common power electronic converters have been described in Chapters 2–4. In this chapter, two new types of power electronic converters, the Z-source inverter and the synchronous rectifier DC-DC converter, will be discussed.

5.2 Sneak Circuits of Z-Source Inverter

The impedance-source (or impedance-fed) power electronic converter (abbreviated as the Z-source converter) is a new type of power electronic converter, which couples the converter (or inverter) to the dc source or load by introducing an impedance network. The general structure of a Z-source converter is presented in Figure 5.1, where the unique impedance network consists of split inductors L₁ and L₂ and capacitors C₁ and C₂ connected in an X-shape [1]. By selecting a suitable control method, the Z-source converter can implement DC-AC, AC-DC, AC-AC, and DC-DC power conversion, and operate in open or short circuit states that cannot be observed in traditional voltage-source and current-source converters. The advantage of the Z-source converter is that it can connect the power source in any form to the converter ...