A motor controller is operable to control a motor. The motor has a first terminal and the motor controller includes an angular velocity transmission path having an input and an output. A current generator includes a velocity-torque input, an angular position input, and a motor drive output. The velocity-torque input is coupled to the output of the angular velocity transmission path. An angular velocity feedback path is coupled between a first terminal and a first location on the angular velocity transmission path. The first location is between the input and the output of the angular velocity transmission path. A current feedback path is coupled between the first terminal and a second location on the angular velocity transmission path. The second location is disposed between the first location on the angular velocity transmission path and the velocity-torque input of the current generator.

A test and measurement instrument includes one or more sensors configured to measure a mechanical position of a synchronous machine driven by analog three-phase signals, a converter to determine an instantaneous electrical angle from the measured mechanical position, a transform configured to generate DQ0 signals based on the instantaneous electrical angle, and a vector generator structured to produce a resultant vector from the DQ0 signals. Methods are also described.

A method is provided for operating a synchronous machine that can be operated in an efficient operating mode and an inefficient operating mode. In order to provide a working-point-specific torque the synchronous machine is controlled in the efficient operating mode such that a stator of the synchronous machine generates a synchronous rotary field which rotates synchronously with a rotor of the synchronous machine. In order to increase dissipated heat of the synchronous machine, which can be used to heat at least one component of the motor vehicle, the synchronous machine is transferred into the inefficient operating mode in which an asynchronous rotary field acts on the synchronous rotary field, said asynchronous rotary field superimposing dissipated heat-increasing harmonics on a fundamental wave of the synchronous rotary field while maintaining the working-point-specific torque.

The invention relates to a method and system for calibrating a control device, in particular an inverter control device, of an electric motor, comprising operating the electric motor as part of a force flow; performing a force measurement by means of piezo elements which are arranged in the force flow in such a way that the force flow is applied, in particular exclusively, to the piezo elements; and adapting a control characteristic the control device on the basis of at least one force component derived from the force measurement, in particular a change in the at least one force component and/or at least one torque component derived from the force measurement, in particular a change in the torque component.

Provided is a method for determining the rotational position of a rotor in a permanent magnet synchronous machine, wherein the stator includes windings for a first, second and third phase, including the steps: applying a first voltage pulse to the first phase, determining respective first measures for the current induced by the first voltage pulse in the second and third phase, selecting a first selected phase depending on the first measures for the current, wherein the first selected phase is either the second or the third phase, applying a second voltage pulse to the first selected phase, determining respective second measures for the current induced by the second voltage pulse in the phases of the stator that are not the first selected phase, and determining the rotational position of the rotor depending on the second measures of the current.

A method for starting a synchronous motor is provided. The synchronous motor includes a rotor for creating a first magnetic field and a stator with stator windings connected to an electrical energy converter for converting a supply voltage into a stator voltage to be applied to the stator windings to create a rotating second magnetic field interacting with the first magnetic field. The method includes applying reference stator voltages to the stator windings, where the reference stator voltages are determined from a reference current vector and a reference rotor speed, measuring stator currents, calculating an estimated rotor speed and rotor position from the applied stator voltages and the measured stator currents, calculating a speed error by subtracting the estimated rotor speed from the reference rotor speed, determining a reference torque producing current component from the speed error, and modifying the reference current vector with the reference torque producing current component.

The disclosure relates to a motor parameter measuring device and method. According to the disclosure, a motor parameter measuring device comprises a torque receiver receiving a motor torque of a motor rotated by an external force, a motor constant calculator calculating a motor constant based on the motor torque, and a parameter calculator controlling an inverter connected with the motor to form a closed circuit and calculating a parameter of the motor based on a current generated by the rotating motor in the closed circuit.

A motor drive method is a method of driving a motor by a motor drive apparatus. The motor drive apparatus includes an inverter that regulates supply power to the motor that is a synchronous machine and includes a controller that controls the inverter. The method includes changing, before loss of synchronism, a speed of the motor from a second speed range to a first speed range. A speed range in which the motor is operable at a substantially fixed speed is the first speed range, and a speed range that is lower than the first speed range and includes zero speed is the second speed range.

The present disclosure is constructed on the prior art inverter architecture, a pulse code width modulation (PCWM). This is an open loop motor control system without sensing its rotor position. The present disclosure employs a closed loop method to track the optimum efficiency motor operating point directly. A bench load test is conducted to gather information for an AI type control, which includes both load angle vs. voltage command charts and power factor vs. voltage command charts, with load levels as parameters for certain frequency command ranges. This way, the optimum efficiency motor operating points are generated a priori. The AI type control is mechanized to track the optimum efficiency motor operating points.

A drive motor (10) for a vacuum cleaner or a machine tool, wherein the drive motor (10) includes a stator (20) with a stator coil arrangement (26), and a rotor (30) wherein a sensor arrangement (60) is arranged in a stationary manner with respect to the stator in order to detect a respective angle of rotation position of the rotor (30) with respect to the stator, said sensor arrangement comprising at least two sensors (67A, 67b, 67C). It is provided that the at least two sensors are configured to detect two waves of a magnetic rotating field (FB) of the rotor (30) wherein the sensors generate the switching signals in a manner dependent on a wave of the magnetic rotating field (FB) exceeding or undershooting a switching threshold (SH, SL) of the sensor (67A, 67b, 67C).