| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a power conversion device wherein switch elements can be checked for normal operations before the utility link operation is started. <P>SOLUTION: The power conversion device 2 comprises a power converting portion, a control unit 8, and a parallel off switch 9. The power converting portion comprises a boosting circuit 5 which boosts the output of a solar cell 1, an inverter circuit 6 which converts the output of the boosting circuit 5 into alternating-current voltage, and a filter circuit 7 which smoothes the output of the inverter circuit 6 to obtain sinusoidal output waveform. A voltage detecting portion 11 is provided between the output terminals of the filter circuit 7 for detecting output voltage. In no-load state (state in which the parallel off switch 9 is off) before utility interactive operation is started at start, the control unit 8 performs the following operation, and it controls the output voltage of the inverter circuit 6. Further, it judges whether the operation of the switch elements 61 to 64 is normal or not based on the output voltage detected by the voltage detecting portion 11. If the operation is normal, the control unit turns on the parallel off switch 9 to cause the operation to transition into utility interactive operation. <P>COPYRIGHT: (C)2004,JPO |
