Conditions Limiting the Formation of the ZVZCT Switching in SAZZ Converter

The paper reports on formation of soft switching conditions in SAZZ converter topology. Abbreviation SAZZ represents snubber assisted zero voltage and zero current transition converter. In [2,3,4,5] high efficiency around 98% was reported for 100 kHz and 50 kHz converter with output power of 8 kW and 25 kW respectively. However, extreme changes of duty ratio could result in loss of soft switching. For the boost operation of SAZZ chopper circuit, when the output to input voltage ratio decreases below 2, the partial hard switching appears. Similarly for the buck operation, when the output to input voltage ratio decreases below 1/2, the partial hard switching appears. The theoretical analysis and simulation studies of SAZZ soft switching range are presented in this paper. The analysis is supported by experiments on 100 kHz- 8 kW SAZZ converter prototype.

[1]  Y. Tsuruta,et al.  A New Circuit Geometry SAZZ for An EV Drive Application , 2006, Conference Record of the 2006 IEEE Industry Applications Conference Forty-First IAS Annual Meeting.

[2]  Atsuo Kawamura,et al.  A High Frequency, High Efficiency and High Power Chopper SAZZ and the Test Evaluation at 100kHz-8kW , 2006 .

[3]  Y. Tsuruta,et al.  Proposal of Bilateral Buck and Boost Chopper Circuit SAZZ-1 for EV Drive Application and the Test Evaluation at 25kW , 2006, 2006 IEEE International Conference on Industrial Technology.

[4]  Y. Tsuruta,et al.  A new zero-voltage-zero-current-transition chopper SAZZ for a FCEV drive , 2005, 31st Annual Conference of IEEE Industrial Electronics Society, 2005. IECON 2005..

[5]  F. Lee,et al.  Novel zero-voltage-transition PWM converters , 1992, PESC '92 Record. 23rd Annual IEEE Power Electronics Specialists Conference.