Described examples include a method that includes setting a reference i.sub.q signal in a field-oriented control of a motor such that the field-oriented control modulates power from a power supply using a modulator to apply a torque on the motor that is opposite to a kinetic energy applied to the motor. The method also includes setting a reference i.sub.d signal in the field-oriented control such that the motor current provided to the power supply is reduced.

Described examples include a method that includes setting a reference i.sub.q signal in a field-oriented control of a motor such that the field-oriented control modulates power from a power supply using a modulator to apply a torque on the motor that is opposite to a kinetic energy applied to the motor. The method also includes setting a reference i.sub.d signal in the field-oriented control such that the motor current provided to the power supply is reduced.

To provide a control apparatus for AC rotary machine and an electric power steering apparatus which can reduce the error component of the current detection value close to the mechanical resonance period of AC rotary machine. A control apparatus for AC rotary machine detects currents which flow into three-phase windings at a current detection period which is a first natural number times of a carrier period; calculates current detection values, by performing a current addition processing which adds current detection values detected at this time, and current detection values detected before an addition period which is a second natural number times of the current detection period; and calculates the voltage command values of three-phase based on the current detection values after current addition processing, wherein the second natural number is set to a natural number that the addition period becomes the closest to the half period of the mechanical resonance period.

A current detection unit includes current detection elements provided to phases on a high potential side of an upper arm element or on a low potential side of a lower arm element. A detection target element is the upper arm element or the lower arm element to which the current detection elements are provided. A target duty is a duty ratio of the detection target element. The control unit includes a current acquisition unit, an energization control unit, and an abnormality determination unit. The current acquisition unit acquires a current detection value from the current detection unit. The abnormality determination unit performs an abnormality determination based on the current detection value. The abnormality determination unit varies a determination threshold, which is used for the abnormality determination based on the current detection value, according to the target duty.

A motor driving apparatus which drives a motor including a plurality of windings corresponding to a plurality of phases, respectively, includes: a first inverter including a plurality of first switching elements and connected to a first end of each of the windings; a second inverter including a plurality of second switching elements and connected to a second end of each of the windings; and a controller obtaining a vector corresponding to a voltage command of the motor by combining switching vectors which cause difference between a common mode voltage of the first inverter and a common mode voltage of the second inverter to be zero and configured to control the plurality of first switching elements and the plurality of second switching elements in a pulse width modulation method based on the obtained vector.

A motor driving apparatus which drives a motor including a plurality of windings corresponding to a plurality of phases, respectively, includes: a first inverter including a plurality of first switching elements and connected to a first end of each of the windings; a second inverter including a plurality of second switching elements and connected to a second end of each of the windings; and a controller obtaining a vector corresponding to a voltage command of the motor by combining switching vectors which cause difference between a common mode voltage of the first inverter and a common mode voltage of the second inverter to be zero and configured to control the plurality of first switching elements and the plurality of second switching elements in a pulse width modulation method based on the obtained vector.

A controller for a motor system includes an input terminal to receive a signal indicating a speed of an electric motor and a regenerative brake current interpolator to indicate a brake current to be applied to the electric motor responsive to the speed of the electric motor. Values of the brake current vary with variation of the speed of the electric motor.

A controller for a motor system includes an input terminal to receive a signal indicating a speed of an electric motor and a regenerative brake current interpolator to indicate a brake current to be applied to the electric motor responsive to the speed of the electric motor. Values of the brake current vary with variation of the speed of the electric motor.

A system in a vehicle includes a current regulator to obtain current commands from a controller based on a torque input and provide voltage commands and an inverter to use the voltage commands from the current regulator and direct current (DC) supplied by a battery to provide alternating current (AC). The system also includes an electric traction motor to provide drive power to a transmission of the vehicle based on injection of the AC from the inverter. The current regulator adjusts parameters of a transfer function implemented by the current regulator, based on feedback of an input to and an output from the electric traction motor to achieve the AC corresponding with the torque input in no more than two control cycles.

A motor driving apparatus which drives a motor having a plurality of windings corresponding to a plurality of phases includes: a first inverter having a plurality of first switching elements and connected to a first end of each winding; a second inverter having a plurality of second switching elements and connected to a second end of each winding; and a controller configured to control pulse width modulation, by distributing a preset voltage command of the motor into a voltage command of the first inverter and a voltage command of the second inverter at the same rate and by generating duties of the first switching elements, wherein the controller determines the duties of the second switching elements and determines the duties of the first switching elements on and the duties of the first switching elements.