An example vehicle comprises: (i) a source of direct current power, (ii) at least one electronically-commutated electric motor configured to drive a wheel of the vehicle, and (iii) a voltage bus connecting the source of direct current power with the electronically-commutated electric motor.

An example vehicle comprises: (i) a source of direct current power, (ii) at least one electronically-commutated electric motor configured to drive a wheel of the vehicle, and (iii) a voltage bus connecting the source of direct current power with the electronically-commutated electric motor.

A method for operating a permanent magnet synchronous motor comprises setting a maximum power, determining a current vector and an output voltage vector in the dq coordinate system. A setpoint amount for a setpoint voltage vector is calculated on the basis of the maximum power, the current vector and the output voltage vector. The setpoint voltage vector is generated with the setpoint amount, and then operating the permanent magnet synchronous motor at least with the setpoint voltage vector.

An electric power conversion system includes: an AC-DC conversion circuit converting AC charging power into DC power; a motor including a plurality of coils, one end of each being connected to a neutral point; a first switching device selectively allowing or blocking supply of output power from the AC-DC conversion circuit to the neutral point; an inverter including a plurality of motor connection terminals connected to the other ends of the coils of the motor, respectively, DC connection terminals including a positive terminal and a negative terminal, and a plurality of switching elements forming electrical connections between the DC connection terminals and the plurality of motor connection terminals; a battery connected to the DC connection terminals of the inverter; and a controller controlling operations of the AC-DC conversion circuit, the first switching device, and the inverter in accordance with whether or not the battery is charged.

An electric power conversion system includes: an AC-DC conversion circuit converting AC charging power into DC power; a motor including a plurality of coils, one end of each being connected to a neutral point; a first switching device selectively allowing or blocking supply of output power from the AC-DC conversion circuit to the neutral point; an inverter including a plurality of motor connection terminals connected to the other ends of the coils of the motor, respectively, DC connection terminals including a positive terminal and a negative terminal, and a plurality of switching elements forming electrical connections between the DC connection terminals and the plurality of motor connection terminals; a battery connected to the DC connection terminals of the inverter; and a controller controlling operations of the AC-DC conversion circuit, the first switching device, and the inverter in accordance with whether or not the battery is charged.

A vehicle drive system uses an in-wheel motor and has: a vehicle speed sensor; an in-wheel motor that is provided to a wheel of the vehicle and drives the wheel; an internal combustion engine that is provided in a vehicle body of the vehicle and drives the wheel; and control equipment that controls the in-wheel motor and the internal combustion engine. The control equipment causes the internal combustion engine to generate drive power and causes the in-wheel motor not to generate the drive power when the travel speed of the vehicle detected by the vehicle speed sensor is lower than a specified vehicle speed that is higher than zero. The internal combustion engine and the in-wheel motor generate the drive power in the case where the travel speed of the vehicle detected by the vehicle speed sensor is equal to or higher than the specified vehicle speed.

A vehicle drive system uses the in-wheel motor for driving the vehicle and has: an in-wheel motor that is provided in a wheel of a vehicle and drives the wheel; an internal combustion engine that is provided in a vehicle body of the vehicle and drives the wheel; and control equipment that controls the in-wheel motor and the internal combustion engine on the basis of requested output by a driver. The control equipment is configured to cause the internal combustion engine to generate drive power and cause the in-wheel motor not to generate the drive power when the requested output by the driver is lower than specified output. The control equipment is further configured to cause the internal combustion engine and the in-wheel motor to generate the drive power when the requested output by the driver is equal to or higher than the specified output.

A method for operating a permanent magnet synchronous motor comprises setting a maximum power, determining a current vector and an output voltage vector in the dq coordinate system. A setpoint amount for a setpoint voltage vector is calculated on the basis of the maximum power, the current vector and the output voltage vector. The setpoint voltage vector is generated with the setpoint amount, and then operating the permanent magnet synchronous motor at least with the setpoint voltage vector.

A dump truck 100 including: an engine 1; a generator 10 driven by the engine 1; and a pair of driving wheels 3L and 3R arranged to the left and right of a vehicle body frame 7 includes: a traveling electric motor 12L including a plurality of electric motors 12La, 12Lb, and 12Lc that are coupled to the driving wheel 3L and simultaneously drive the driving wheel 3L; and a traveling electric motor 12R including a plurality of electric motors 12Ra, 12Rb, and 12Rc that are coupled to the driving wheel 3R and simultaneously drive the driving wheel 3R. Thereby, drive systems corresponding to loads of dump trucks or the like can be configured using identical components.

An electric drive system for mechanical machinery. The electric drive system includes a first electrical bus and a second electrical bus each configured to operate at different voltages. A first generator is configured to provide electric current to the first electrical bus at a first voltage. A second generator is configured to provide electric current to the second electrical bus at a second voltage that is different from the first voltage. A first electric motor is coupled to the first electrical bus and configured to operate on electrical power from the first electrical bus at the first voltage. A second electric motor is coupled to the second electrical bus and configured to operate on electrical power from the second electrical bus at the second voltage. Mechanical power used to drive the mechanical machinery is generated by both the first electric motor and the second electric motor.