Source Type Soft-switching Inverter Research Articles

Feasible enhancement of a three‐phase soft‐switching inverter with an auxiliary resonant DC link snubber

AbstractThe purpose of this paper is to improve power conversion efficiency of a three‐phase voltage source type soft‐switching inverter with a single auxiliary resonant DC link (ARDCL) snubber. First, the operating principle of an ARDCL snubber discussed here is described. Second, this paper proposes an effective pulse pattern generation method of the zero voltage space vector of the three‐phase soft‐switching inverter using IGBTs or power modules that can reduce power losses in the ARDCL snubber treated here. In particular, a zero voltage holding interval in the DC rail busline of this three‐phase soft‐switching inverter is to be regulated according to the generation method of the zero voltage space vector. Third, the maximum modulation depth Mmax under the condition of correction of the instantaneous voltage space vector can be improved by using a new zero voltage space vector generation method. Finally, the feasible experimental results of this inverter are obtained confirming the operating characteristics such as power conversion actual efficiency, as well as conventional efficiency THD and RMS value of the balanced three‐phase output voltage for an experimentally built three‐phase voltage source type soft‐switching pulse modulated inverter using the latest IGBT modules and evaluated from the standpoint of practical applications in industry UPS and new energy systems. © 2003 Wiley Periodicals, Inc. Electr Eng Jpn, 146(1): 89–99, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10234

Performance Evaluations of A Single Inductor Type Resonant AC Link Snubber-Assisted Three-Phase Voltage Source Soft-Switching Inverter

This paper presents a novel three-phase voltage source type soft-switching inverter using the main and auxiliary IGBT power module packages in order to reduce their switching power losses as well as its electromagnetic noises. A single inductor-assisted resonant AC link snubber circuit as one of some resonant snubbers to achieve the zero voltage soft-switching for the three-phase voltage source inverter (VSI) with instantaneous space voltage vector sinewave modulation strategy is originally demonstrated as compared with the other resonant AC link snubber circuit topologies. In addition to this, its operation principle and unique features are described in this paper for resistive and inductive loads. Furthermore, the practical basic operating performances of the new instananeous space vector modulated soft-switching VSI using IGBT power modules are evaluated and discussed on the basis of power conversion efficiency and electromagnetic conductive and radiative noises from an experimental point of view, as compared with those of hard-switching VSI.