| 摘要 |
FIELD: electricity.SUBSTANCE: multilevel DC/AC converter contains three inputs (IN1, IN2, IN3) of direct current to receive three voltages (V1, V2, V3) respectively, so that V1>V2>V3, one alternating-current output (OUT1) to transfer alternating voltage (Va), a group of at least six switching elements (T1, T2, T3, T4, T5, T6) placed as a symmetrical pyramidal scheme as specified in Fig. 1, and a switching control scheme to control the ON/OFF state of each element out of the six switching elements. The switching control scheme is configured so that switching ON and OFF of the two uppermost elements in the scheme (T5, T6) is made in a complimentary way, exclusively with the main frequency (Fa) of the alternating voltage transferred to an output (OUT1) of the alternating current, while switching (ON) and OFF at least for some of the remaining switching elements (T1, T2, T3, T4) is made at a higher frequency. In result, the above two uppermost elements (T5, T6) in the scheme introduce lesser losses for switching, thus increasing the total efficiency of the converter.EFFECT: increasing the total efficiency of the converter.6 cl, 9 dwg |
