Abstract: A problem to be solved by the present invention is to eliminate variation in potential in a turn-off time period of each GTO element, and to stabilize a gate drawing current by surely performing the turn-off of the GTO element. In an inverter apparatus having a three-phase inverter configured to include paired GTO elements an inverter control portion has a simultaneous switching prevention function of delaying a turn-on operation of each of the GTO elements which correspond to phases other than a phase corresponding to an optional one of the GTO elements and also correspond to an electrode opposite to an electrode corresponding to the optional one of the GTO elements by a predetermined time in a case where a turn-on command signal for turning on each of the GTO elements is generated within a predetermined time period since the turn-off of the optional one of the GTO elements.

Abstract: A problem to be solved by the present invention is to eliminate variation in potential in a turn-off time period of each GTO element, and to stabilize a gate drawing current by surely performing the turn-off of the GTO element.

Abstract: A DC—DC converter has converter circuit portions 11 and 12, transformers Tr1 and Tr2, and rectifier circuit portions 21 and 22. Two sets of converter circuit portions 11 and 12 respectively include two pairs of switching elements Q1 to Q4, and two pairs of switching elements Q5 to Q8 connected in full bridge configuration, series capacitors C1 and C2 are inserted and connected between the converter circuit portions 11 and 12 and the transformers Tr1 and Tr2 respectively. The switching phase of one switching element Q4 or Q8 is shifted by a 1/3n period from the switching phase of the other switching element Q1 or Q5 in the pair of switching elements. The switching phases of corresponding switching elements Q1 and Q5 in the converter circuit portions 11 and 12 are shifted by a 1/2n period from each other.

Abstract: A DC-DC converter has converter circuit portions 11 and 12, transformers Tr1 and T r2, and rectifier circuit portions 21 and 22. Two sets of converter circuit portions 11 and 12 respectively include two pairs of switching elements Q1 to Q4, and two pairs of switching elements Q5 to Q8 connected in full bridge configuration, series capacitors C1 and C2 are inserted and connected between the converter circuit portions 11 and 12 and the transformers Tr1 and Tr2 respectively. The switching phase of one switching element Q4 or Q8 is shifted by a 1/3n period from the switching phase of the other switching element Q1 or Q5 in the pair of switching elements. The switching phases of corresponding switching elements Q1 and Q5 in the converter circuit portions 11 and 12 are shifted by a 1/2n period from each other.