| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an inverter device which can surely detect a fault such as the internal short circuit, etc. of an inverter device and can disconnect a faulty machine from a bus. <P>SOLUTION: This inverter device, which is used for parallel redundant operation of two or more units, has a disconnection means 13 which disconnects the output of its own machine from a parallel bus 3 to the output line of the above inverter device, a current detector 12 which detects the current flowing to the output line of the above inverter device, and a control circuit 14 which compares the polarity of the output current of the above inverter device detected by the above current detector with the polarity of the output voltage command value given to its own machine, and determines that internal short circuit has occurred in its own machine and controls the above disconnection means to disconnect its own machine from the bus, when a current of a polarity opposite to the above voltage command value beyond a preset current value, flows until a preset time passes. <P>COPYRIGHT: (C)2007,JPO&INPIT |
