| 摘要 |
An electric power converting device is provided which supplies a constant voltage to a load (6) while suppressing voltage variation in an ac power source (1). The breakdown voltages of semiconductor switching elements are reduced for reducing duties and costs. First to third switching element series circuits and a capacitor (30) are connected in parallel, one end of an ac power source (1) and one end of a load (6) are connected to each other, and capacitors (32) and (33) are connected in parallel. The one end of the power source (1) is connected to a series connection point of the first switching element series circuit through a reactor (40), the other end of the power source (1) is connected to a series connection point in the second switching element series circuit, and the other end of the load (6) is connected to a series connection point in the third switching element series circuit through a reactor (41). Change in the power source voltage is compensated by a series converter including the second and third switching element series circuits, and change in voltage of the capacitor (30) due to the compensating operation is compensated by charging and discharging operation by a parallel converter including the first and second switching element series circuits. <IMAGE> |
