Haptic power control techniques provide improved power control for the haptic generator to reduce deficiencies of operation and/or increase performance of the haptic generator across various thermal conditions. In some examples, a first resistance measurement can be obtained and used for estimating an actuation voltage limit for the haptic generator. In some examples, estimating the actuation voltage limit for the haptic generator using the first resistance measurement includes estimating a first actuation voltage limit for the haptic generator when the first resistance measurement is a first resistance value and estimating a second actuation voltage limit for the haptic generator when the first resistance measurement is a second resistance value.

Haptic power control techniques provide improved power control for the haptic generator to reduce deficiencies of operation and/or increase performance of the haptic generator across various thermal conditions. In some examples, a first resistance measurement can be obtained and used for estimating an actuation voltage limit for the haptic generator. In some examples, estimating the actuation voltage limit for the haptic generator using the first resistance measurement includes estimating a first actuation voltage limit for the haptic generator when the first resistance measurement is a first resistance value and estimating a second actuation voltage limit for the haptic generator when the first resistance measurement is a second resistance value.

A method and system for detecting a fault in a permanent magnet synchronous motor (PMSM), operably connected to a controller. The method includes receiving at a controller a stator voltages and currents for the PMSM, computing a negative sequence current and a negative sequence voltage for the PMSM; and determining if conditions are satisfied for monitoring for a fault of the PMSM. The method also includes ascertaining a change in the negative sequence current and a change in the negative sequence voltage for a selected time duration, calculating a ratio of the change in the negative sequence current and the negative sequence voltage corresponding to a negative sequence admittance for the PMSM, determining if the negative sequence admittance differs from a nominal value in excess of a threshold; and identifying the stator winding as faulted if the ratio exceeds the threshold.

A method and system for detecting a fault in a permanent magnet synchronous motor (PMSM), operably connected to a controller. The method includes receiving at a controller a stator voltages and currents for the PMSM, computing a negative sequence current and a negative sequence voltage for the PMSM; and determining if conditions are satisfied for monitoring for a fault of the PMSM. The method also includes ascertaining a change in the negative sequence current and a change in the negative sequence voltage for a selected time duration, calculating a ratio of the change in the negative sequence current and the negative sequence voltage corresponding to a negative sequence admittance for the PMSM, determining if the negative sequence admittance differs from a nominal value in excess of a threshold; and identifying the stator winding as faulted if the ratio exceeds the threshold.

The invention relates to a method for controlling a converter connected to an electric machine by a cable (Cx) via a filter (F), said method consisting in determining at least one sequence of a plurality of voltage pulses forming a square wave signal to be applied to each conductor so as to minimize an overvoltage level, said sequence comprising a number 2N of successive pulses, N being greater than or equal to 1, each pulse being defined by a distinct rank n, said sequence being generated such that each increasing voltage pulse of rank n exhibits a pulse width that is identical to that of a decreasing voltage pulse of rank equal to 2N+1n, and the method includes the following steps in particular: determining the number of successive pulses of said sequence; determining the width of each pulse of the sequence made suitable for minimizing the overvoltage level across the terminals of the electric machine (M).

The invention relates to a method for controlling a converter connected to an electric machine by a cable (Cx) via a filter (F), said method consisting in determining at least one sequence of a plurality of voltage pulses forming a square wave signal to be applied to each conductor so as to minimize an overvoltage level, said sequence comprising a number 2N of successive pulses, N being greater than or equal to 1, each pulse being defined by a distinct rank n, said sequence being generated such that each increasing voltage pulse of rank n exhibits a pulse width that is identical to that of a decreasing voltage pulse of rank equal to 2N+1n, and the method includes the following steps in particular: determining the number of successive pulses of said sequence; determining the width of each pulse of the sequence made suitable for minimizing the overvoltage level across the terminals of the electric machine (M).

A radial stabilizer is provided for stabilizing levitation passive bearing elements against lateral displacements. The stabilizer provides a means to introduce anisotropy in the radial stiffness of the stabilizer. The presence of anisotropic stiffness has a strongly stabilizing effect on whirl-type rotor-dynamic instabilities. The stabilizer design also provides a means for continuously monitoring the state of health of the rotor by signaling the onset of changes of balance that would be expected to precede any major failure.

A radial stabilizer is provided for stabilizing levitation passive bearing elements against lateral displacements. The stabilizer provides a means to introduce anisotropy in the radial stiffness of the stabilizer. The presence of anisotropic stiffness has a strongly stabilizing effect on whirl-type rotor-dynamic instabilities. The stabilizer design also provides a means for continuously monitoring the state of health of the rotor by signaling the onset of changes of balance that would be expected to precede any major failure.

A haptic actuator may include first and second bodies movable along an arcuate path of travel. The haptic actuator may also include a biasing member coupled between the first and second bodies. At least one electrical coil may be configured to move the first and second bodies to produce a haptic effect.

To provide a power tool capable of suppressing torque ripple and reducing power consumption without demagnetizing the permanent magnets in the rotor. The power tool includes a brushless motor, converting means, voltage detecting, and means conduction switching means. The brushless motor includes: a stator including a plurality of windings; and a rotor rotatable relative to the stator. The converting means is configured to convert an AC voltage supplied from an AC power supply into a varying DC voltage. The voltage detecting means is configured to detect the varying DC voltage. The conduction switching means includes an output line for applying the varying DC voltage to the plurality of windings. The conduction switching means is configured to perform: sequentially switching at least one winding to be applied with the varying DC voltage among the plurality of windings to rotate the rotor; and changing number of conducting windings on the basis of the varying DC voltage, the number of conducting windings being number of the at least one winding to be applied with the varying DC voltage.