INVERTER WITH ABNORMALITY DETECTING CIRCUIT

摘要

PURPOSE:To accurately detect the abnormal operation state of an inverter by examining the varying period of a binary signal from the current waveform supplied from a power inverter. CONSTITUTION:A current waveform supplied to a power inverter 16 is detected by a current detector 3. This current waveform is imputted through a filter 4 to a waveform shaper 8 to shape the binary signal in a rectangular wave. The output of the shaper 8 and the signal of a V/f converter 6 are inputted to an abnormality detector 9. The detector 9 outputs the abnormal signal when the varying period of the binary signal outputted from the shaper 8 exceeds the range of the predetermined varying period. This abnormal signal is supplied to an alarm output circuit 11.