A system includes a motor-driven component, a motor configured to operate the motor-driven component, and a motor drive circuit configured to power the motor. The motor drive circuit includes at least one complementary stage, where each stage includes a first transistor and a second transistor. During operation of the motor drive circuit, the first transistor is switched on when the second transistor is switched off. The system includes a controller communicatively coupled to the motor drive circuit. A load condition associated with the component is monitored. Based on the load condition, the controller determines whether the component is operating at a light load condition. If the component is operating at the light load condition, a switching frequency of each of stages is changed from a first switching frequency to a second switching frequency, which is less than the first switching frequency.

A system includes a motor-driven component, a motor configured to operate the motor-driven component, and a motor drive circuit configured to power the motor. The motor drive circuit includes at least one complementary stage, where each stage includes a first transistor and a second transistor. During operation of the motor drive circuit, the first transistor is switched on when the second transistor is switched off. The system includes a controller communicatively coupled to the motor drive circuit. A load condition associated with the component is monitored. Based on the load condition, the controller determines whether the component is operating at a light load condition. If the component is operating at the light load condition, a switching frequency of each of stages is changed from a first switching frequency to a second switching frequency, which is less than the first switching frequency.

A system includes a motor-driven component, a motor configured to operate the motor-driven component, and a motor drive circuit configured to power the motor. The motor drive circuit includes at least one complementary stage, where each stage includes a first transistor and a second transistor. During operation of the motor drive circuit, the first transistor is switched on when the second transistor is switched off. The system includes a controller communicatively coupled to the motor drive circuit. A load condition associated with the component is monitored. Based on the load condition, the controller determines whether the component is operating at a light load condition. If the component is operating at the light load condition, a switching frequency of each of stages is changed from a first switching frequency to a second switching frequency, which is less than the first switching frequency.

An air supply control method and system for a fuel cell controlling a switching frequency of an inverter at which power consumption of the air compressor becomes minimal includes: calculating a revolution per minute (RPM) of a motor of an air compressor; calculating a switching frequency of an inverter of the motor of the air compressor at which power consumption becomes minimal based on the calculated RPM of the motor; and controlling the inverter with the calculated switching frequency.

An air supply control method and system for a fuel cell controlling a switching frequency of an inverter at which power consumption of the air compressor becomes minimal includes: calculating a revolution per minute (RPM) of a motor of an air compressor; calculating a switching frequency of an inverter of the motor of the air compressor at which power consumption becomes minimal based on the calculated RPM of the motor; and controlling the inverter with the calculated switching frequency.

This motor control device is provided with: a control unit which controls the number of rotations of a motor in accordance with a required number of rotations by implementing a first control which enables high-torque and precise control with respect to the motor, or a second control enabling more efficient control than the first control with respect to the motor; and a switching determination unit which, if an actual measurement value of the number of rotations of the motor is greater than a prescribed threshold value of the number of rotations, switches the first control to the second control. The switching determination unit further switches the first control to the second control if the actual measurement value of the number of rotations is not more than the threshold value of the number of rotations, and when a prescribed time has passed from a point in time at which the actual measurement value of the number of rotations matched the required number of rotations.

According to one embodiment, a driving device includes a voltage controller, a parameter setter, and a phase adjuster. The voltage controller causes an electric power converter to apply a drive voltage to the electric motor, the electric power converter converting input electric power to A/C electric power having desired voltage and frequency and supplying the converted electric power to an electric motor. The parameter setter sets at least one of a rotation speed of the electric motor and a parameter related to the rotation speed as speed information. The phase adjuster adjusts a phase of the drive voltage in such a manner that an index calculated based on a current flowing in the electric motor and the speed information set in the parameter setter becomes smaller.

A boost circuit is arranged to reduce rise and fall times of pulsed power used for pulsed control operation of electric machines. Magnetic energy present in the electric machine at the end of a pulse is extracted by the boost circuit to reduce the pulse fall time. The energy is stored by the boost circuit and then applied at the beginning of a subsequent pulse to reduce the rise time. By reducing rise and fall times compared to not using such a boost circuit, machine efficiency is improved.

An electrical system includes a multi-level traction power inverter module (TPIM), a polyphase electric machine, and a controller. The TPIM has multiple switching sets collectively operable for inverting a DC voltage on a DC voltage bus into an AC voltage on an AC voltage bus. The electric machine has (m) multiple electrical phases. Each of the (m) multiple electrical phases is connected to and driven by a respective one of the switching sets of the TPIM. The controller determines when the electric machine enters a predetermined partial-load region of operation, and, responsive to entry into the predetermined partial-load region, selectively deactivates a predetermined number (n) of the (m) multiple electrical phases. This is done via switching state signals to corresponding ones of the switching sets, with nm2.

An electrical system includes a multi-level traction power inverter module (TPIM), a polyphase electric machine, and a controller. The TPIM has multiple switching sets collectively operable for inverting a DC voltage on a DC voltage bus into an AC voltage on an AC voltage bus. The electric machine has (m) multiple electrical phases. Each of the (m) multiple electrical phases is connected to and driven by a respective one of the switching sets of the TPIM. The controller determines when the electric machine enters a predetermined partial-load region of operation, and, responsive to entry into the predetermined partial-load region, selectively deactivates a predetermined number (n) of the (m) multiple electrical phases. This is done via switching state signals to corresponding ones of the switching sets, with nm2.