The present disclosure relates to a motor control device and method. The motor control device includes an inverter for driving a motor, a first shunt resistor connected to a first low-side switching element included in the inverter, a second shunt resistor connected to a second low-side switching element included in the inverter, a DC-link shunt resistor in series with the inverter, and a controller for controlling the inverter based on first current value measured through the first and second shunt resistors and a second current value measured through the DC-link shunt resistor.

A control device for an AC rotary machine includes: a DC power supply; an inverter; a magnetic flux generator; an angle detector; and a control arithmetic unit; wherein the control arithmetic unit is configured to: calculate, based on a positional relationship between a current path and the angle detector, a correction signal for correcting signal errors of a cosine signal and a sine signal, which are caused by a noise magnetic flux component due to at least one of a DC current flowing between the DC power supply and the inverter and multi-phase AC currents flowing between the inverter and armature windings; and control the inverter by using angle information obtained from values after the correction by the correction signal.

In summary, the invention relates to a device and method for open-loop or closed-loop control of a movement of a die cushion of a die cushion press. The device has a control value encoder (11), a speed controller (12), a current controller (13), and a motor control device (14) for providing a nominal current for an electrical drive (15) of a fluid-hydraulic motor pump unit (20) for moving a die cushion of a die cushion press. The control value encoder (11) is provided in order to calculate a setpoint speed based on a die cushion control value command and a die cushion information. The speed controller (12) calculates a setpoint current based on the setpoint speed. The current controller (13) calculates a control signal based on the setpoint current, and the motor control device (14) calculates the nominal current based on the control current. In this respect, the dynamics of the control of the electrical machine can be improved.

A method of controlling a BLDC electric motor having a stator and a rotor, the stator having a plurality of magnet coils, the rotor having a permanent magnet driven by the plurality of magnet coils, comprising a) supplying a voltage to a first of the plurality of magnet coils, b) short-circuiting a second of the plurality of magnet coils during a).

A method for determining an error in the angular position measurement of a timepiece motor having one or more phases, including: detecting (3) each instant (14) when the value of one of the back electromotive forces is zero, storing (4) a time corresponding to each detected instant, measuring (5) several time intervals between two instants (14) detected in the same revolution of the motor, comparing (6) the measured time intervals to reference time intervals to deduce the reference intervals to which they correspond, and determining (7) an angular position measurement error if the measured intervals do not correspond to the expected reference intervals. The invention also relates to a method for correcting the angular position measurement. Also, a determination and correction system for implementing the methods and a timepiece including such a system.

Embodiments of the disclosure provide a comb drive, a comb drive system, and a method of operating the comb drive to rotate bi-directionally in a MEMS environment. An exemplary comb drive system may include a comb drive, at least one power source, and a controller. The comb drive may include a stator comb having a first electrically conductive layer spaced apart from a second electrically conductive layer. The comb drive may also include a rotor comb having a first electrically conductive layer spaced apart from a second electrically conductive layer. The controller may be configured to apply first and second voltage levels having opposite polarities to the first and second electrically conductive layers of the rotor comb, respectively. The controller may also be configured to apply an intermediate voltage level to one of the first or second electrically conductive layers of the stator comb.

Embodiments of the disclosure provide a comb drive, a comb drive system, and a method of operating the comb drive to rotate bi-directionally in a MEMS environment. An exemplary comb drive system may include a comb drive, at least one power source, and a controller. The comb drive may include a stator comb having a first electrically conductive layer spaced apart from a second electrically conductive layer. The comb drive may also include a rotor comb having a first electrically conductive layer spaced apart from a second electrically conductive layer. The controller may be configured to apply first and second voltage levels having opposite polarities to the first and second electrically conductive layers of the rotor comb, respectively. The controller may also be configured to apply an intermediate voltage level to one of the first or second electrically conductive layers of the stator comb.

An abnormality determination means performs detection of abnormality of one of the pairs of detection means at a normal speed, and performs detection of abnormality of the other of the pairs at a speed not higher than the normal speed, and, when a sign of abnormality of the detection means is detected at the normal speed, a CPU performs switching to the other normal pair and continues control, and the abnormality determination means performs detection of abnormality of the other normal pair at the normal speed, and meanwhile, continues to perform detection of abnormality of the abnormal pair at a speed not higher than the normal speed.

An abnormality determination means performs detection of abnormality of one of the pairs of detection means at a normal speed, and performs detection of abnormality of the other of the pairs at a speed not higher than the normal speed, and, when a sign of abnormality of the detection means is detected at the normal speed, a CPU performs switching to the other normal pair and continues control, and the abnormality determination means performs detection of abnormality of the other normal pair at the normal speed, and meanwhile, continues to perform detection of abnormality of the abnormal pair at a speed not higher than the normal speed.

An electric motor is disclosed that includes a stator winding defining a plurality of poles, with the winding being controllable to switch between a first number of poles and a second number of poles. A rotor rotatable within the stator includes a first group of magnetic flux barriers being without permanent magnet material and a second group of magnetic flux barriers at least partially filled with a permanent magnet material. A method of operating a line-start electric motor is also disclosed.