| 摘要 |
<P>PROBLEM TO BE SOLVED: To obtain a power supply device wherein a current between a commercial power supply and an inverter can be limited to a small current when power supply is changed from commercial feed to inverter feed. <P>SOLUTION: The power supply device is so constructed that: a first circuit constructed of a series circuit of the commercial power supply and a semiconductor switch and a second circuit constructed of a series circuit of the inverter and a filter circuit for removing a harmonic component from the output of the inverter are connected in parallel; the inverter and the commercial power supply are synchronized with each other; and power is fed to a load from the inverter or the commercial power supply by switching them. The power supply device includes: a first current detector for detecting a current to the load; a second current detector for detecting a current obtained by subtracting a current to a capacitor constructing the filter circuit from the current of the inverter; a computation unit that subtracts the output of the first current detector from the output of the second current detector; and a control unit that controls the inverter so that the output of the first current detector and the output of the second current detector become equal to each other based on the output of the computation unit. <P>COPYRIGHT: (C)2007,JPO&INPIT |
