High gain, naturally clamped Dc to Dc converter for X-ray application

The paper presents a novel converter for a medical X-ray machine application. A resonant, current fed inverter is proposed. The high voltage transformer step up ratio is kept very low to reduce the effects of its leakage inductance and other non-idealities. Moreover this leakage inductance and the parasitic capacitance of HV transformer and switches are used as resonating components for attaining a soft switched conversion. The switches are soft switched with ZCS, which works over a wide load range. A set of Cockroft Walton multiplier is employed on the secondary side of the transformer accomplishes the final output. The converter operates at 100 kHz frequency with overlap time switching to achieve 100kV and 2.5 mA required by the X-ray machine. A very systematically elaborated analysis for selection of every discrete component in this particular topology is discussed in this paper.

[1]  Chung-Yuen Won,et al.  Fuel Cell Generation System With a New Active Clamping Current-Fed Half-Bridge Converter , 2007, IEEE Transactions on Energy Conversion.

[2]  Robert L. Steigerwald,et al.  A comparison of high power DC-to-DC soft-switched converter topologies , 1994 .

[3]  K. M. Smith,et al.  A comparison of voltage-mode soft-switching methods for PWM converters , 1997 .

[4]  Ming-Hui Chen,et al.  Cascade Cockcroft–Walton Voltage Multiplier Applied to Transformerless High Step-Up DC–DC Converter , 2013, IEEE Transactions on Industrial Electronics.

[5]  Sang-Kyoo Han,et al.  A new active clamping zero-voltage switching PWM current-fed half-bridge converter , 2005, IEEE Transactions on Power Electronics.

[6]  Ioannis C Kobougias,et al.  Optimal Design of a Half-Wave Cockcroft–Walton Voltage Multiplier With Minimum Total Capacitance , 2010, IEEE Transactions on Power Electronics.

[7]  Jiann-Fuh Chen,et al.  Study and Implementation of a Current-Fed Full-Bridge Boost DC–DC Converter With Zero-Current Switching for High-Voltage Applications , 2008, IEEE Transactions on Industry Applications.

[8]  Mutsuo Nakaoka,et al.  Series resonant high-voltage PFM DC-DC converter with voltage multiplier based a two-step frequency switching control for medical-use X ray power generator , 2000, Proceedings IPEMC 2000. Third International Power Electronics and Motion Control Conference (IEEE Cat. No.00EX435).

[9]  Junming Sun,et al.  Series resonant ZCS-PFM DC-DC converter with multistage rectified voltage multiplier and dual-mode PFM control scheme for medical-use high-voltage X-ray power generator , 2000 .

[10]  Akshay Kumar Rathore,et al.  Comparison of soft-switching voltage-fed and current-fed bi-directional isolated Dc/Dc converters for fuel cell vehicles , 2012, 2012 IEEE International Symposium on Industrial Electronics.