The invention discloses a method for detecting the open-circuit fault of an
inverter circuit. The method comprises the following steps of: (1) defining fault characteristic quantities, wherein the three fault characteristic quantities are available in the method and respectively represent different meanings; (2) computing a three-phase
voltage fundamental
current amplitude, carrying out the phase shift and the Park conversion on the obtained three-phase
voltage in a sampling way respectively, obtaining the size of the fundamental
current amplitude by a conversion result, and filtering by a
digital filter in the process; (3) detecting the fault of a neural network, and outputting the former two characteristic quantities through the BP (pressure
transducer) neural network by the computation result in the step (2); and (4) positioning a fault power tube, testing the maximum value and the minimum value of the obtained three-phase
voltage in a sampling way respectively, obtaining the specific position of the fault power tube through simple logical judgment, and outputting the third fault characteristic quantity. According to the method disclosed by the invention, the fault information of the power tube of the
inverter circuit can be quickly and exactly obtained only by analyzing the output three-phase voltage, and the method can be realized only by a
software algorithm without adding other outer
hardware circuits, so that the cost can be reduced, the efficiency can be improved, the method is higher in application ability, and the method has the application value for researching the real-time fault detecting aspect of a
power electronic circuit.