A motor drive apparatus, comprising: a plurality of multiphase AC motors ( MG1, MG2) coupled to be capable of outputting motive power to a common output shaft; a plurality of power converting devices ( 14, 31) connected to said plurality of multiphase AC motors ( MG1, MG2), respectively; and a controller for controlling said plurality of power converting devices ( 14, 31), each of said plurality of power converting devices ( 14, 31) including a plurality of arm circuits ( 15, 16, 17) connected to respective phase coils of said multiphase AC motor, and each of said plurality of arm circuits ( 15, 16, 17) having first and second switching elements connected in series between first and second power supply lines ( VL, SL) with a connection point to said each phase coil interposed, and said controller including an abnormality control means which is configured to, when a first power converting device among said plurality of power converting devices ( 14, 31) is abnormal which means that the first power converting device has a short-circuit fault in which a switching element is maintained in an ON state, instruct an abnormal state operation using a second multiphase AC motor different from a first multiphase AC motor connected to said first power converting device, a short circuit detecting means configured to detect a short-circuited switching element based on a current flowing through said first power converting device as a result of operation of said second multiphase AC motor, in said abnormal state operation, a first motor control means configured to control the current flowing through said first power converting device by bringing into conduction a switching element connected in series to said short-circuited switching element with said connection point interposed, in said abnormal state operation, a second motor control means configured to control the current flowing through said first power converting device by bringing into conduction all of switching elements connected in parallel to said short-circuited switching element in any one of the first and second power supply lines ( VL, SL) in which the short-circuit switching element is connected, in said abnormal state operation, and a selecting means configured to selectively set said first motor control means and said second motor control means in accordance with a rotation speed of said first multiphase AC motor, wherein said selecting means is configured to select said first motor control means when the rotation speed of said first multiphase AC motor is less than or equal to a prescribed reference rotation speed, and to select said second motor control means when the rotation speed of said first multiphase AC motor exceeds said prescribed reference rotation speed. a plurality of multiphase AC motors ( MG1, MG2) coupled to be capable of outputting motive power to a common output shaft; a plurality of power converting devices ( 14, 31) connected to said plurality of multiphase AC motors ( MG1, MG2), respectively; and a controller for controlling said plurality of power converting devices ( 14, 31), each of said plurality of power converting devices ( 14, 31) including a plurality of arm circuits ( 15, 16, 17) connected to respective phase coils of said multiphase AC motor, and each of said plurality of arm circuits ( 15, 16, 17) having first and second switching elements connected in series between first and second power supply lines ( VL, SL) with a connection point to said each phase coil interposed, and said controller including an abnormality control means which is configured to, when a first power converting device among said plurality of power converting devices ( 14, 31) is abnormal which means that the first power converting device has a short-circuit fault in which a switching element is maintained in an ON state, instruct an abnormal state operation using a second multiphase AC motor different from a first multiphase AC motor connected to said first power converting device, a short circuit detecting means configured to detect a short-circuited switching element based on a current flowing through said first power converting device as a result of operation of said second multiphase AC motor, in said abnormal state operation, a first motor control means configured to control the current flowing through said first power converting device by bringing into conduction a switching element connected in series to said short-circuited switching element with said connection point interposed, in said abnormal state operation, a second motor control means configured to control the current flowing through said first power converting device by bringing into conduction all of switching elements connected in parallel to said short-circuited switching element in any one of the first and second power supply lines ( VL, SL) in which the short-circuit switching element is connected, in said abnormal state operation, and a selecting means configured to selectively set said first motor control means and said second motor control means in accordance with a rotation speed of said first multiphase AC motor, wherein said selecting means is configured to select said first motor control means when the rotation speed of said first multiphase AC motor is less than or equal to a prescribed reference rotation speed, and to select said second motor control means when the rotation speed of said first multiphase AC motor exceeds said prescribed reference rotation speed.