Steady state analysis of the galvanically isolated DC/DC converter with a commutating LC filter

Abstract

This paper presents an analysis of the continuous current and the discontinuous current mode operation of the transformer of a step-up DC/DC converter topology intended for applications with widely changing input voltages. The proposed topology consists of a LC network coupled with a single-phase inverter on the primary side and a full-bridge rectifier on the secondary side of an isolation transformer. When the input voltage is above the nominal value, the converter operates in the buck mode, but when the input voltage level is below the nominal value, the converter operates in the boost mode. I.

Comparative Analysis of Semiconductor Power Losses of Galvanically Isolated Quasi-Z-Source and Full-Bridge Boost DC-DC Converters

“…Analytical expressions of semiconductor losses in both topologies are well described in [9], [11], [15]- [17]. Here some of the resulting expressions adapted for the discussed converters and applications are presented.…”

“…All four inverter stage switches are conducting, the boost inductor LIN is accumulating energy, the clamping switch SCL is turned off; -b) diagonal switches S1 and S4 are conducting, energy is transferred to the output filter capacitor C2, the clamping switch SCL is turned on to protect inverter switches from the voltage overshoot during the transition from the shoot-through to the active state and back; -d) diagonal switches S2 and S3 are conducting, energy is transferred to the output filter capacitor C1, the clamping switch SCL is turned on to protect inverter switches from the voltage stress during the transition from the shoot-through to the active state and back. The operation principle of the IFBB DC-DC converter is detailed in [10], [11].…”

“…where PCL_con is the clamping switch conduction losses, PCL_on and PCL_off are the clamping MOSFET turn-on and turn-off losses [11], [16]:…”

New active clamp circuit for current-fed galvanically isolated DC/DC converters

“…1) is taken for analysis, as it has advantages like higher efficiency compared to voltage-fed topologies and low input current ripple [1][2][3]. Nevertheless, such converters demand implementation of additional clamping circuits in order to limit the transient overvoltages on power switches [1,4,5] caused by energy storing in the leakage inductance of the transformer. This is a benefit for implementation of MOSFETs with lower operating voltage and drain-source resistance (R ds ).…”

“…The traditional active clamp circuit (ACC) [1,4,5] presented in Fig. 1 includes a switch S a , a diode D a and a capacitor C a (topology ACC-1).…”