At least one example embodiment discloses a method of controlling an alternating current (ac) machine. The method includes determining or retrieving a current limit for the ac machine, determining a characterized peak current value based on a voltage-to-speed ratio of the ac machine, determining current command values for the ac machine based on at least one of the torque command limit and a torque command for the ac machine, determining current command values for the ac machine based on the torque command limit and controlling the ac machine based on the current command values.

A numerically controlled machine tool in which a numerical control program acquired from a reading and interpreting unit of a numerical control device is executed by a distribution interpolating unit and servo control units, to drive a feed shaft configured from a coarse movement mechanism and a fine movement mechanism, causing a tool to move relative to a workpiece, and thereby machining the workpiece, wherein the difference between a movement command for the feed shaft, and an output value which varies on the basis of said movement command is obtained, a movement command for the coarse movement mechanism is generated on the basis of said movement command, and a movement command for the fine movement mechanism is generated on the basis of said difference.

A numerically controlled machine tool in which a numerical control program acquired from a reading and interpreting unit of a numerical control device is executed by a distribution interpolating unit and servo control units, to drive a feed shaft configured from a coarse movement mechanism and a fine movement mechanism, causing a tool to move relative to a workpiece, and thereby machining the workpiece, wherein the difference between a movement command for the feed shaft, and an output value which varies on the basis of said movement command is obtained, a movement command for the coarse movement mechanism is generated on the basis of said movement command, and a movement command for the fine movement mechanism is generated on the basis of said difference.

A vehicle control apparatus capable of protecting a pre-charge circuit is provided. When a voltage has entered an operating voltage range, a microcomputer determines whether a preset period has elapsed from then. Upon determining that the preset period has elapsed, the microcomputer starts initial check. To carry out the initial check, the microcomputer starts charging a capacitor for power supply stabilization of a drive circuit by turning on the pre-charge circuit and, when the charging of the capacitor is completed, turns on a power supply relay provided on a power supply line that connects between a battery and the drive circuit.

A vehicle control apparatus capable of protecting a pre-charge circuit is provided. When a voltage has entered an operating voltage range, a microcomputer determines whether a preset period has elapsed from then. Upon determining that the preset period has elapsed, the microcomputer starts initial check. To carry out the initial check, the microcomputer starts charging a capacitor for power supply stabilization of a drive circuit by turning on the pre-charge circuit and, when the charging of the capacitor is completed, turns on a power supply relay provided on a power supply line that connects between a battery and the drive circuit.

The invention relates to a power supply system of an electric motor (1) comprising a power circuit (3), the input terminals of which are connected to a DC voltage source, and an electronic circuit (4) for controlling the electric motor (1) based on a control signal representative of the set speed of the motor. According to the invention, the system comprises a means (6) capable of reducing the DC voltage value received by the power circuit (3) during the starting of the electric motor (1) and/or during operating phases in which the set speed of the electric motor (1) is below a threshold speed.

A motor drive device includes: an inverter circuit having a smoothing capacitor; a drive circuit portion which outputs an operation signal to the inverter circuit; a control portion which controls the drive circuit portion; and an operating voltage generation portion which supplies power to the drive circuit portion and the control portion by generating an operating voltage for the drive circuit portion and the control portion. The inverter circuit converts a DC voltage from a first power supply to an AC voltage and outputs the AC voltage to a multi-phase motor coil. The control portion outputs a signal to the drive circuit portion according to a command value from a high-level control device operating on power from a second power supply outputting a voltage lower than the first power supply. The operating voltage generation portion is capable of generating the operating voltage using power fed from either of the first power supply and the second power supply.

A controller is integrated with a rotary electric machine and configured to control driving of the rotary electric machine. The controller of the rotary electric machine includes a plurality of power modules each including a switching element that is a component of a power conversion circuit, a smoothing capacitor configured to smooth an electric current input to the plurality of power modules, and a cylindrical casing configured to accommodate the plurality of power modules and the smoothing capacitor. The plurality of power modules is arranged at an interval in a circumferential direction of the casing and contacts with an inner circumferential surface of the casing, and the smoothing capacitor is continuously arranged along inner surfaces of the plurality of power modules.

A controller is integrated with a rotary electric machine and configured to control driving of the rotary electric machine. The controller of the rotary electric machine includes a plurality of power modules each including a switching element that is a component of a power conversion circuit, a smoothing capacitor configured to smooth an electric current input to the plurality of power modules, and a cylindrical casing configured to accommodate the plurality of power modules and the smoothing capacitor. The plurality of power modules is arranged at an interval in a circumferential direction of the casing and contacts with an inner circumferential surface of the casing, and the smoothing capacitor is continuously arranged along inner surfaces of the plurality of power modules.

In a motor drive device 120, a phase compensation amount calculation unit 110 calculates a phase compensation amount Δθ for compensating a voltage phase θv* when a control mode is switched in a control selection unit 90. The control selection unit 90 outputs the three-phase voltage command Vuvw* according to any one of the plurality of control modes based on the modulation factor Kh*, the voltage phase θv*, and the phase compensation amount Δθ. A PWM control unit 100 outputs gate signals Gun, Gup, Gvn, Gvp, Gwn, and Gwv based on the three-phase voltage command Vuvw* and a rotor position θd. The inverter 20 has a plurality of switching elements, and controls the plurality of switching elements based on gate signals Gun, Gup, Gvn, Gyp, Gwn, and Gwv to drive the AC motor 10.