POWER CONVERTER

摘要

A power converter which steps up a solar voltage, converts it to an AC voltage, and supplies the AC power to a load or a system. To one of the two AC-side terminals of a first inverter (3B-INV) whose DC source is the DC voltage V_3B generated by stepping up solar voltage V_O by a chopper circuit (3), a second inverter (1B-INV) is connected in series; and to the other, a third inverter (2B-INV) is connected in series. The output voltages of the second and third inverters (1B-INV, 2B-INV) are controlled so as to be equal to each other, and the sum of the generated voltages of the first to third inverters is used as the output voltage. Thus, the midpoint voltage of the DC power supply V_3B is made equal to the intermediate potential of the output voltage of the power converter, that is, the midpoint potential (earth potential) of a system (5).