| 摘要 |
PURPOSE:To exactly judge the voltage variations by the opening of a power system and the instantaneous voltage variations such as thunder surge, etc., by providing a power conversion means to convert the power from a DC power source into AC power and supplies to the power system and a judgement means from the result in comparing the output current of this power conversion means with the current reference value. CONSTITUTION:In case a linkage breaker 14 is turned ON, the DC power of a DC power source 11 is supplied to a power conversion device 12, the output of which is supplied to a power system 15. The output current of the power conversion device 12 is detected by a current detector 16 and the current signal iS is given to a judgement section 131 of a control/protection circuit 13 where it is judged whether the current reference value i/the current signal iS=infinity . In case the power system 15 is sound, the judgement will be NO and the gate command for continuous operation is given to the power conversion device 12 from the control/protection circuit 13. If the power system is found abnormal, then the current signal iS from the current detector 16 becomes zero and when the judgement with the judgement section 131 becomes YES on whether the current reference value i/the current signal iS=infinity , the power conversion system 12 is stopped. |
