Three-Level Phase-Shifted ZVS-PWM DC-DC Converter with High Frequency Link

摘要

This paper presents some experimental results and practical evaluations of neutral point clamping and flying capacitor-based soft switching quasi-resonant three-level phase shift soft switching PWM DC-DC high power converter with high frequency transformer and center-tapped rectifier for a variety of arc welding machines in industry. This new DC-DC converter for TIG, MIG and MAG arc welders is implemented by modifying the high-frequency-linked HB soft switching PWM DC-DC power converter with high side and low side two active edge resonant modulars, which is designed for symmetrical PWM control scheme. The operating principle of the practical three-level soft-switching PWM DC-DC converter and its experimental and simulation results including phase-shifted angle vs. power regulation characteristics and power conversion efficiency characteristics in addition to power loss analysis are illustrated and discussed from an application point of view, along with the remarkable advantageous points as compared with previously-developed soft switching PWM DC-DC converter by the authors. Finally, the improved three-level soft switching PWM converter version is also considered in which the circulating current due to phase shift pulse modulation principle. The comparative study of three-level soft-switching PWM power converter treated here is discussed in this paper. The dual pulse modulation strategy is effectively considered to extend its soft switching transition operation range.