Abstract: This three-phase AC motor drive device is provided with: a load; an inverter device 1 for driving the load; an MCOK_A_4 connected between the inverter device 1 and the load and electrically connecting or disconnecting the inverter device 1 to or from the load; a voltage detector 21a having terminals respectively connected to the circuits of at least two phases to detect the voltages between the three phases; and a current detector 11 for detecting the currents of the three phases. In the connection from the inverter device 1 to the load, the inverter device 1, the MCOK_A_4, the voltage detector 21a, the current detector 11, and the load are aligned in this order.

Abstract: This three-phase AC motor drive device is provided with: a load; an inverter device 1 for driving the load; an MCOK_A_4 connected between the inverter device 1 and the load and electrically connecting or disconnecting the inverter device 1 to or from the load; a voltage detector 21a having terminals respectively connected to the circuits of at least two phases to detect the voltages between the three phases; and a current detector 11 for detecting the currents of the three phases. In the connection from the inverter device 1 to the load, the inverter device 1, the MCOK_A_4, the voltage detector 21a, the current detector 11, and the load are aligned in this order.

Abstract: Provided is a vehicle drive system capable of suppressing a feeling of acceleration drop and free running, thereby improving vehicle riding comfort. The vehicle drive system includes: an internal combustion engine for driving a primary drive wheel; a stepped variable transmission; an assist motor for driving a secondary drive wheel; and a motor control device for controlling the assist motor, wherein the stepped variable transmission is a seamless-shift transmission configured such that a drive force to be transmitted therethrough is interrupted during shifting down, but not substantially interrupted during shifting up, and the motor control device is operable, during the shifting down by the stepped variable transmission, to cause the assist motor to generate a drive force to compensate for the interruption of the drive force.

Abstract: Provided is a vehicle drive system capable of suppressing a feeling of acceleration drop and free running, thereby improving vehicle riding comfort. The vehicle drive system includes: an internal combustion engine for driving a primary drive wheel; a stepped variable transmission; an assist motor for driving a secondary drive wheel; and a motor control device for controlling the assist motor, wherein the stepped variable transmission is a seamless-shift transmission configured such that a drive force to be transmitted therethrough is interrupted during shifting down, but not substantially interrupted during shifting up, and the motor control device is operable, during the shifting down by the stepped variable transmission, to cause the assist motor to generate a drive force to compensate for the interruption of the drive force.