| 摘要 |
<p>The invention has an object of providing a power converting apparatus for system connection that can execute a system connection of an adverse current to a commercial power system having one phase as a grounding wire, in high power conversion efficiency, by keeping stabilization of currents and voltage of alternate-current power to be output and keeping positive and negative balance, without passing a leak current even when a direct-current power generation facility has a large grounded capacitance. To achieve this object, a grounding wire G from a commercial power system is connected to a series-connection end Y of a series connection between two capacitors C1, C2 that are connected in series between a positive electrode and a negative electrode to equally bear a direct-current voltage output from a direct-current power source E as the direct-current power generation facility. A CT 16 monitors an output current of an inverter unit in which four switching elements S1 to S4 and two diodes D1, D2 convert, at three levels, voltages at both ends of the series circuit of the two capacitors C1, C2. An operation control circuit 14 controls the generation of a PWM signal to be applied to the four switching elements, to minimize a difference between a current value detected by the CT 16 and a target current value.</p> |
