Sneak Circuits of Power Electronic Converters

Chapter 8Elimination of Sneak Circuits in Power Electronic Converters

8.1 Introduction

Based on the definition of a sneak circuit, the sneak circuit of a power electronic converter is a current path hidden in that converter, which will appear when a specific parameter condition is satisfied. As a result, the operating stages increase or change and the energy balance under normal operating mode is destroyed, which will lead to changes of the converter's characteristics and so the desired performance of the converter cannot be achieved. Thus, sneak circuits should be eliminated in the power electronic converter.

Apparently, the emergence of sneak circuits should satisfy two conditions. Firstly, there must be potential paths existing in the power electronic converter; if not, the sneak circuit phenomenon will not occur. Secondly, sneak circuits will appear on specific operating parameters, but if the converter parameters are designed appropriately or the converter's operating conditions are set within normal ranges, then sneak circuit phenomenon cannot occur. Chapters 2–5 demonstrated the sneak circuit phenomena in some typical power electronic converters, and proved the correctness of the above sneak circuit conditions. Therefore, in order to eliminate sneak circuits in power electronic converters, two methods can be used based on the conditions under which sneak circuit appear. One is parameter design, which can avoid the emergence of a sneak circuit through reasonable design ...