The invention relates to a method for operating an electric machine (100) having a power converter (100) and multiple phases, in which method, phase currents flowing through the phases during operation of the electric machine (100) are determined and are used for continued operation of the electric machine (100), the phase currents being determined taking account of a fundamental wave and at least one harmonic of the current profile of each phase current.

A fluctuating oscillator includes: a processor including a digital circuit, and the processor includes a random variable generation unit that generates a random variable, a lookup table that stores a waveform signal in advance, a computation unit that imparts fluctuation to the waveform signal based on the waveform signal read from the lookup table, the random variable generated by the random variable generation unit, and a pulse signal to be fed back, a threshold discrimination unit that generates a pulse signal by comparing a fluctuating signal output from the computation unit with a predetermined threshold, and a feedback loop that causes the pulse signal to be fed back to the computation unit.

The invention relates to a method and device for operating an electric machine (10) for outputting a predefined torque and a predefined rotational speed, comprising the following steps: providing (420) a first and a second operating mode for the operation of the electric machine (10); detecting (430) a temperature of the electric machine (10); and operating the electric machine (10) in the first operating mode (440) if the detected temperature falls below a threshold value, and operating the electric machine (10) in the second operating mode (450) if the detected temperature corresponds with the threshold value or exceeds same. During the operation of the electric machine (10) in the second operating mode (450), with the resulting output of the predefined torque and the predefined rotational speed, the magnetic stator flux of the electric machine (10) is reduced compared with the magnetic stator flux of the electric machine (10) during the operation of the electric machine (10) in the first operating mode (440), with the resulting output of the predefined torque and the predefined rotational speed.

A motor device for a vehicle includes a stator, a rotor, a bearing, an inverter, and a controller. The stator is attached into a housing and includes a concentrated winding coil. The rotor includes a permanent magnet. The bearing supports a rotating shaft of the rotor. The inverter controls an energization state of the concentrated winding coil. If a rotational speed of the rotor is greater than a threshold, the controller outputs a control signal to the inverter to execute field weakening control, and thereby makes a potential difference between the housing and the rotating shaft lower than a withstand voltage of the bearing. The control signal controls the energization state of the concentrated winding coil. The field weakening control generates magnetic flux of the concentrated winding coil in a direction of weakening magnetic flux of the permanent magnet.

A control circuit regulates the propagation delay of a field effect transistor (FET) before the FET transitions to the Miller region by applying a pre-charge current for a fixed duration to the gates of the FET. After the fixed duration, the current is reduced to a lower drive current level which is based on a desired output voltage slew rate. After the FET transitions to the Miller region, the output voltage slews down in accordance with the output voltage slew rate. By regulating the slew-rate of the output voltage in the Miller region and regulating the propagation delay of the FET prior to the Miller region, the control circuit reduces electromagnetic interference (EMI) caused by the switching of the FET, thereby improving electromagnetic compatibility (EMC) of switch mode driver systems without increasing the propagation delay of the FET.

A control circuit regulates the propagation delay of a field effect transistor (FET) before the FET transitions to the Miller region by applying a pre-charge current for a fixed duration to the gates of the FET. After the fixed duration, the current is reduced to a lower drive current level which is based on a desired output voltage slew rate. After the FET transitions to the Miller region, the output voltage slews down in accordance with the output voltage slew rate. By regulating the slew-rate of the output voltage in the Miller region and regulating the propagation delay of the FET prior to the Miller region, the control circuit reduces electromagnetic interference (EMI) caused by the switching of the FET, thereby improving electromagnetic compatibility (EMC) of switch mode driver systems without increasing the propagation delay of the FET.

A hybrid electrical machine containing surface mounted magnets which includes a magnetically permeable cylindrically shaped stator assembly having at least one stator winding formed about a plurality of stator teeth, a rotor assembly concentrically disposed within the stator assembly, including a magnetically permeable rotor backiron, a rotational drive mechanism coupled to the rotor backiron, and a plurality of protruding rotor poles, each including a magnetically permeable pole support assembly, a winding provided around the pole support assembly, and a radially magnetized permanent magnet assembly disposed about the pole support assembly.

A shift range control device switches a shift range by controlling driving of a motor. A learning unit learns, as a position correction value, a normal state time correction value calculated based on first and/or second reference angles when an output shaft signal is available when turning on of a start switch. The first reference angle is a motor angle when the output shaft signal changes in response to the rotation of the motor in a first direction. The second reference angle is the motor angle when the output shaft signal changes in response to the motor rotation in a second direction opposite to the first direction. A motor angle target value is set by using the normal state time correction value stored during a period from when all the output shaft signals are determined to be unavailable to when the start switch is turned off.

A method for controlling a planar drive system includes generating a position allocating function, in an allocation generating step; measuring a plurality of measuring values of the magnetic rotor field by magnetic field sensors for a position of the rotor relative to the stator module, in a magnetic rotor field determining step; applying the position determination function to the plurality of measuring values of the magnetic rotor field of the plurality of magnetic field sensors, in a measuring value analysis step; and determining the position of the rotor relative to the stator module on the basis of the measurements of the magnetic rotor field measured by the plurality of magnetic field sensors and based on the allocations of the position allocating function, in a position determining step. The application further relates to such a planar drive system.

An electric tool system includes a motor, a control unit, and an output shaft. The motor includes a stator and a rotor. The control unit performs vector control on the motor. The control unit includes a first acquisition unit, a second acquisition unit, and a command value generation unit. The command value generation unit calculates, based on a torque current acquisition value (current measured value) as a value related to a torque current as acquired by the first acquisition unit and an acceleration acquisition value as a value related to acceleration of the rotor as acquired by the second acquisition unit, at least one of a command value of the torque current to be supplied to the motor or a command value of an excitation current to be supplied to the motor.