Analyzing a four quadrant dc-dc Luo converter by means of signal flow graph modeling technique

Abstract

In this paper, the signal flow graph technique and Mason gain formula are applied for extracting small signal model and transfer functions from control to output and from input to output. In order to investigate a rather complex system, a four quadrant dc-dc Luo converter known as a second generation and high order power electronic converter is chosen for modeling and analyzing purposes. This converter has received the least attention and its dynamic modeling and analysis is not reported in literature. To get rid of complex equations in modeling high order converters, signal flow graph method is applied to manipulate the equations. Hence, the small signal models for two converters in different states are derived in detail and the obtained models are used to achieve the frequency responses and do stability analysis. The whole paper shows that using the proposed method, derivation of small signal models for all states and frequency domain analysis can be easily carried out in detail. Keywords: Frequency response, Four quadrant Luo converter, Mason gain formula, Modeling, Signal flow graph