Described embodiments relate to motor control for synchronous motors, and more specifically, some embodiments relate to motor-current control for permanent-magnet synchronous motors. Embodiments of a current controller are described that include an adaptive controller configured to adapt to changing system dynamics of a PMSM. Embodiments of adaptive control techniques are described that involve estimating system parameters of a PMSM and adapting control actions to compensate for such estimated system parameters. Such adapted control actions may be expected to track an observed motor current to a desired motor current. Systems, methods and devices related to the above are also described.

A motor controlling device includes a high-side first switching element corresponding to each phase of a three-phase brushless motor, a low-side second switching element corresponding to each phase, a shunt resistor disposed between and connected to the second switching element and a grounding line, and a power controlling section for controlling the first switching element and the second switching element. The device further includes a decision section configured to effect abnormality decision based on a sum of values of currents flowing in the shunt resistors of all the phases acquired by using the power controlling section to switch OFF the first switching element of any one phase whose duty ratio is found equal to or greater than a threshold value for a predetermined period and also to switch ON the second switching element of the same one phase for the predetermined period.

A drive support unit of a turbo compressor includes at least one bearingless motor. The at least one bearingless motor includes a rotor-stator pair constituted by a rotor and a stator, and is configured to rotationally drive a drive shaft and to support a radial load of the drive shaft in a contactless manner. Accordingly, it is possible to provide a turbo compressor to which a bearingless motor is applied.

In a method and a compensation arrangement for compensating detent torques of identically constructed synchronous motors, a no-load detent torque and a bad detent torque are measured on a reference motor as a function of a rotor position relative to a stator. A differential detent torque for the reference motor is determined by subtracting the measured no-load detent torque from each measured bad detent torque, and an operating-point-dependent spectral component of the differential detent torque is determined, A model function modeling the spectral component as a function of the operating point is then formed, and a first compensation current, which generates a compensation torque that compensates a detent torque at the instantaneous operating point with a value of the model function, is superimposed for each of the identically constructed synchronous motors on a setpoint current when operating at an instantaneous operating point in a predetermined first operating range.

An electric drive system includes a permanent magnet machine having a rotor and a stator and a power converter electrically coupled to the permanent magnet machine and configured to convert a DC link voltage to an AC output voltage to drive the permanent magnet machine. The power converter includes a plurality of silicon carbide switching devices having a voltage rating that exceeds a peak line-to-line back electromotive force of the permanent magnet machine at a maximum speed of the permanent magnet machine.

An electric drive system includes a permanent magnet machine having a rotor and a stator and a power converter electrically coupled to the permanent magnet machine and configured to convert a DC link voltage to an AC output voltage to drive the permanent magnet machine. The power converter includes a plurality of silicon carbide switching devices having a voltage rating that exceeds a peak line-to-line back electromotive force of the permanent magnet machine at a maximum speed of the permanent magnet machine.

An electrical converter with at least two output phases includes a rectifier and a thyristor-based inverter interconnected by a DC link with an inductor, wherein the thyristor-based inverter includes a half-bridge with at least two half-bridge arms for each output phase of the electrical converter and each arm being provided by a thyristor. A method for switching the electrical converter includes: cyclically switching the thyristors of the inverter, such that at least one time instant, two thyristors of different half-bridge arms are switched on simultaneously, such that a pulse number, which determines at how many time instants thyristors of the inverter are switched during one stator voltage period, is lower than the number of half-bridge arms of the inverter.

An electrical converter with at least two output phases includes a rectifier and a thyristor-based inverter interconnected by a DC link with an inductor, wherein the thyristor-based inverter includes a half-bridge with at least two half-bridge arms for each output phase of the electrical converter and each arm being provided by a thyristor. A method for switching the electrical converter includes: cyclically switching the thyristors of the inverter, such that at least one time instant, two thyristors of different half-bridge arms are switched on simultaneously, such that a pulse number, which determines at how many time instants thyristors of the inverter are switched during one stator voltage period, is lower than the number of half-bridge arms of the inverter.

A rotary electric machine in an embodiment includes a stator, and a rotor capable of rotating around a rotation center. The rotor includes a first rotor core, a second rotor core, and a magnet. The first rotor core includes first rotor magnetic poles that are arranged being spaced apart from one another in a circumferential direction and that face first stator magnetic poles, and is annular. The second rotor core includes second rotor magnetic poles that are arranged being spaced apart from one another in the circumferential direction and that face second stator magnetic poles, and is annular. The magnet is located between the first rotor core and the second rotor core and provided with a slit-like magnet separation portion that separates at least a part thereof in the circumferential direction, and is annular.

A rotary electric machine in an embodiment includes a stator, and a rotor capable of rotating around a rotation center. The rotor includes a first rotor core, a second rotor core, and a magnet. The first rotor core includes first rotor magnetic poles that are arranged being spaced apart from one another in a circumferential direction and that face first stator magnetic poles, and is annular. The second rotor core includes second rotor magnetic poles that are arranged being spaced apart from one another in the circumferential direction and that face second stator magnetic poles, and is annular. The magnet is located between the first rotor core and the second rotor core and provided with a slit-like magnet separation portion that separates at least a part thereof in the circumferential direction, and is annular.