Modified PWM algorithm for low duty in SRC

This paper shows modified PWM algorithm for control of the series resonant converter working with the low duty cycle in comparison with standard PWM. Proposed algorithm is used in combination with standard PWM to achieve lowest switching losses in whole output voltage range. The standard algorithm uses basic pulse-width modulation with pulses centered to the waveforms of current. That is disadvantageous, when the low output voltage is needed (low duty cycle). The proposed PWM algorithm uses two pulses, instead of one, in one half of period. The first pulse starts in instant, when the current crosses zero and the second pulse ends in time, when the current also crosses zero as shown in the paper.