An electric motor control system includes a power inverter and control circuitry configured to control the power inverter either according to a target voltage in a voltage-based control mode or according to a target current in a current-based control mode. A controller is operable to switch operation of the control circuitry between the voltage-based control mode and the current-based control mode. The controller may be configured to operate the control circuitry in the current-based control mode at lower motor operating speeds where stator current margin is of greater significance, and to operate the control circuitry in the voltage-based control mode at higher motor operating speeds where stator voltage margin is of greater significance.

An electric motor control system includes a power inverter and control circuitry configured to control the power inverter either according to a target voltage in a voltage-based control mode or according to a target current in a current-based control mode. A controller is operable to switch operation of the control circuitry between the voltage-based control mode and the current-based control mode. The controller may be configured to operate the control circuitry in the current-based control mode at lower motor operating speeds where stator current margin is of greater significance, and to operate the control circuitry in the voltage-based control mode at higher motor operating speeds where stator voltage margin is of greater significance.

A back electromotive force of a rotating motor is converted into a voltage for a load by driving, in accordance with a duty cycle, at least one switching circuit that couples the back electromotive force to a load through a rectifying circuit. An error signal is generated that is a difference between the load voltage and a reference voltage. The duty cycle is controlled as a function of the error signal to cause the load voltage to approach the reference voltage.

A back electromotive force of a rotating motor is converted into a voltage for a load by driving, in accordance with a duty cycle, at least one switching circuit that couples the back electromotive force to a load through a rectifying circuit. An error signal is generated that is a difference between the load voltage and a reference voltage. The duty cycle is controlled as a function of the error signal to cause the load voltage to approach the reference voltage.

A motor control device includes DC voltage circuitry which obtains a DC voltage, an inverter which converts the DC voltage obtained by the DC voltage circuitry into an AC voltage that is output to a motor, a voltage detector which detects the DC voltage obtained by the DC voltage circuitry, and regenerative controller circuitry which controls actuation of the regenerative circuit based on the DC voltage detected by the voltage detector. The regenerative controller circuitry waits until a predetermined waiting time period has elapsed and thereafter actuates a regenerative circuit in the DC voltage circuitry, independently of actuation control by second regenerative controller circuitry in a second motor control device that also obtains the DC voltage, after the voltage detector detects that the DC voltage exceeds a predetermined threshold voltage.

A motor control device includes DC voltage circuitry which obtains a DC voltage, an inverter which converts the DC voltage obtained by the DC voltage circuitry into an AC voltage that is output to a motor, a voltage detector which detects the DC voltage obtained by the DC voltage circuitry, and regenerative controller circuitry which controls actuation of the regenerative circuit based on the DC voltage detected by the voltage detector. The regenerative controller circuitry waits until a predetermined waiting time period has elapsed and thereafter actuates a regenerative circuit in the DC voltage circuitry, independently of actuation control by second regenerative controller circuitry in a second motor control device that also obtains the DC voltage, after the voltage detector detects that the DC voltage exceeds a predetermined threshold voltage.

A functional safety system with high reliability is provided. The functional safety system includes power source apparatuses VS1 and VS2, voltage monitoring apparatuses VM1 and VM2, semiconductor devices SC1 and SC2, interruption circuits IN1 and IN2, and a motor MT. A the voltage converting circuit DA1 of the voltage monitoring apparatus VM1 generates a detected voltage VA1 from a power source voltage VDD1 on the basis of a switching signal VC1, and a voltage converting circuit DA2 of the voltage monitoring apparatus VM1 generates a detected voltage VA2 from the power source voltage VDD1 on the basis of a switching signal VC1.

The regenerative braking controlling system includes an armature current sampling module, a calculating module, and an adjusting module. The calculating module includes a power calculating unit, an optimum phase angle calculating unit, an optimum regenerative current calculating unit, and a sub-optimum regenerative current calculating unit. The armature current sampling module samples current of the three phase armature windings. The power calculating unit determines a relationship between a regenerative power and a phase angle of the armature currents. The optimum phase angle calculating unit calculates an optimum phase angle, and obtain a phase regenerative path based on the optimum phase angle. The optimum regenerative current calculating unit calculates an optimum regenerative current limit point. The sub-optimum regenerative current calculating unit calculates a sub-optimum regenerative current limit point. The adjusting module adjusts regenerative current according to the optimum regenerative current limit point and the sub-optimum regenerative current limit point.

The regenerative braking controlling system includes an armature current sampling module, a calculating module, and an adjusting module. The calculating module includes a power calculating unit, an optimum phase angle calculating unit, an optimum regenerative current calculating unit, and a sub-optimum regenerative current calculating unit. The armature current sampling module samples current of the three phase armature windings. The power calculating unit determines a relationship between a regenerative power and a phase angle of the armature currents. The optimum phase angle calculating unit calculates an optimum phase angle, and obtain a phase regenerative path based on the optimum phase angle. The optimum regenerative current calculating unit calculates an optimum regenerative current limit point. The sub-optimum regenerative current calculating unit calculates a sub-optimum regenerative current limit point. The adjusting module adjusts regenerative current according to the optimum regenerative current limit point and the sub-optimum regenerative current limit point.

A battery state estimating apparatus as an embodiment includes a state estimator, a power estimator, and a determiner. The state estimator estimates a state of a battery. The power estimator estimates first power amount charged/discharged by the battery within a charging/discharging period, based on the state. The determiner compares the first power amount with second power amount inputted/outputted to/from the battery within the charging/discharging period and thereby determines validity of the state.