| 摘要 |
PURPOSE:To protect the inveter by separating it from parallel operation when a detector sensing an inverter's abnormal operation and a sensor which works simultaneously with the indication of output current's unbalanced volume beyond the prescribed value, concurrently work. CONSTITUTION:The inverters 1, 2 converts AC current 3 to DC current by means of a power rectifier 11 and supplies AC current to a load 4 through a inverter 12. The output of an unbalance detector 5 provided between the inverters 1, 2 is applied to a level detector 18. At the same time, the inverter 12's abnormality is sensed by means of a pulse-width abnormality detector 17. These outputs are input to an AND circuit 19 and then to an interrupter 14 which separates the inveters 1, 2 from parallel-operation. Consequently, it is possible to separate the faulty inverter from parallel-operation when the detectors and 17 concurrently work, thus eliminating erroneous operation and continuing steady power supply to the load. |
