Brushless DC motor inverter open-circuit fault diagnosis method

The invention discloses a brushless direct current motor inverter open-circuit fault diagnosis method, which aims at a three-phase brushless direct current motor full-bridge drive circuit formed by six power tubes, and forms phase currents of motor three-phase windings ia, ib and ic in the three-phase brushless direct current motor full-bridge drive circuit. Comprising the following steps: acquiring three-phase current of a motor three-phase winding of a full-bridge drive circuit of the three-phase brushless direct current motor in a working state; calculating an average value of the normalized phase current through the three-phase current; and according to the obtained average value of the normalized phase current, whether a fault occurs in the full-bridge drive circuit of the three-phase brushless direct current motor is judged. According to the invention, fault diagnosis can be carried out on the power tube of the brushless direct current motor, fault points can be effectively determined, and maintenance i