Siemens Aktiengesellschaft

Stefan Künzel

Hubert Schierling

Elmar Schäfers

Günter Schwesig

Carsten Hamm

Hans-Georg Köpken

Bernd Wedel

Heiko Zatocil

Carsten Spindler

Franz Bauer

Gerhard Forster

Mihaly Nemeth-Csoka

Christoph Fritsch

Theo Reichel

Michael Jäntsch

Andreas Uhlich

Alexander Kubik

Nico Spieckermann

Daniel Bönke

Matthias Kaiser

A temperature determination method for magnet temperatures on magnets of electric motors has a test mode. A first voltage is applied to a test winding of a test motor with test magnets for impressing a first voltage-time area at first angles of a test motor rotating field. The test magnets are subject to a predefined magnet temperature. First current values are ascertained at the first angles and stored based on the predefined magnet temperature. In a normal mode, a second voltage is applied to a motor winding of an operations motor with motor magnets for impressing a second voltage-time area at second angles of a motor rotating field. The motor magnets have an operation-dependent magnet temperature. Second current values are determined at the second angles and stored based on the operation-dependent magnet temperature. The operation-dependent magnet temperature is determined by comparing a second current value with a first current value.

Temperature determination method for magnet temperatures on magnets of electric motors

A drive controller controls an electric drive of an electric machine receiving electric energy via a converter. The drive controller has a normal operating mode and a special operating mode. In the special operating mode, the drive controller determines control signals for the converter and rotates the rotor shaft first at a starting rotational speed. The rotor shaft then coasts without an applied external force, with the drive controller determining from raw signals continuously received from a position sensor raw positions of the rotor shaft, and determining therefrom correction variables for use in the normal operating mode. In the normal operating mode, the drive controller determines from continuously received raw signals in combination with the correction variables determined in the special operating mode an actual position of the rotor shaft and controls the converter with control signals based on the actual position or rotational speed of the electrical machine.

Drive controller with self-contained correction function of position errors

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.

Compensation of detent torques of synchronous motors

A method for attenuating load oscillations in a load mechanism having a controlled drive, wherein a load is coupled mechanically to a motor via a spring element, includes determining an actual motor torque value, determining an actual angular velocity value, determining a motor inertial torque, calculating a spring torque from the actual angular velocity value, the motor inertial torque and the actual motor torque value, and supplying the calculated spring torque to an attenuator connection for attenuating the load oscillations.

Attenuation of load oscillations without additional measuring means on the load side

A first active part of a poly-phase electric machine is connected to a converter having a control facility. The control facility updates a base commutation angle using the target speed value and determines direct-axis and quadrature-axis component values of currents and a commutation angle supplied to the machine. Target and component quadrature-axis values are provided to a quadrature-axis portion of a current controller that determines a target value of the quadrature-axis voltage component. Target and component current values are supplied to a direct-axis portion of the current controller, which determines a target value of the direct-axis voltage component therefrom. The target value of the direct-axis and quadrature-axis voltage components and the commutation angle are used to determine the target output voltages provided to the converter. A damping commutation angle determined using target values of the quadrature-axis and direct axis voltage components is used to adjust the of the voltage.

Efficient damping of vibrations of an electric machine

A method for determining an electrical torque of an electrical machine includes determining an electrical torque in a first speed range with a first algorithm, and determining the electrical torque in a second speed range with a second algorithm which differs from the first algorithm. An upper limit of the second speed range is slightly higher than a lower limit of the first speed range. An apparatus is provided to determine the electrical torque of the electrical machine with the aforedescribed method.

Method and apparatus for determining an electrical torque of an electrical machine

A method and device for controlling an electric motor, in particular a machine tool drive, wherein during a sensorless open-loop control mode of operation of the electric motor the speed and the torque are determined from the motor current and the motor voltage, and the moment of inertia of the electric motor torque are determined from the determined motor current and the determined motor voltage, wherefrom then a control torque is determined, which is then associated with an open-loop torque control value and supplied as the torque setpoint value to a control element for setting the motor current and/or the motor voltage in the open-loop mode of operation. As long as the speed is below a minimum speed, the control element receives as input variable a control or pilot control torque generated from a predefined moment of inertia for a sensorless closed-loop control mode of operation of the electric motor.

Method and device for controlling an electric motor

In a method for determining the rotor position of a synchronous motor, a plurality of current vectors having different directions is applied to the synchronous motor. Absolute values of required ones of the current vectors are determined to obtain a defined excursion of the rotor. Inverse values of the determined current vectors are then digitally filtered using several of the inverse values to determine Fourier coefficients of the first harmonic of the inverse values. The rotor position of the synchronous motor can then accurately be computed with the determined Fourier coefficients.

Method for determining a rotor position of a synchronous motor

A method and a system for identifying a faulty rotor position angle signal of a synchronous motor powered by a converter, wherein a first flux angle is determined from the rotor position angle signal, wherein from the motor currents of the synchronous motor a current pointer is determined, wherein from a voltage pointer of the motor voltages of the synchronous motor and the current pointer a second flux angle is determined using a flux modeler of the synchronous motor, and wherein in the event of insufficient agreement between the first and second flux angle a faulty rotor position angle signal is identified.

Method and device for identifying a faulty rotor position angle signal

Damping of mechanical oscillation in a shaft that is provided by feedback wherein the output signals of multiple feedback devices are negatively coupled and added to a desired speed signal of a motor speed controller of the driving motor is disclosed. At least one sensor and/or measuring system can be provided for measuring an actual position value. The actual speed of the shaft can be determined by differentiation from the shaft position value measurements or by integration from shaft acceleration measurements. The measured or actual speed of the shaft can be supplied as an input signal to each feedback element. Each feedback element is specifically tuned to an oscillation frequency range of the shaft that is to be damped. The invention provides an easy and cost-effective way of damping mechanical oscillations that have limited frequency ranges.

Method and apparatus for damping mechanical oscillations of a shaft in machine tools, manufacturing machines and robots

According to the invention, the controller cascades are suitably divided up and the oscillation damped only in the load rotational-speed controller. Here, a motor rotational-speed setpoint value (z) of a quickly regulated motor rotational-speed controller () and not the motor torque, is selected as the connection point for a load acceleration (i). In order to achieve a shorter transient response time, according the invention the difference between a setpoint rotational speed (x) and load rotational speed (y) is connected to the motor rotational-speed setpoint value (z). The solution in principle according to the invention which is presented has, in contrast to other known methods, the advantage that the actuation of the corresponding controllers is comparatively simple with very good control results.

Method and control structure for damping low-frequency load oscillations in drives with a motor and load

A process and device for field-oriented control of a polyphase machine, where a torque-producing quantity is regulated via a speed control circuit and a flux-producing quantity is regulated via a field control circuit that determines the magnitude and angle of the flux. The flux magnitude is injected through the field control circuit. Orientation errors in the field axis are corrected through frequency adjustment, specifically by adjusting the slip frequency according to the difference between the transformation angle used and the flux angle. The voltages and currents that create the rotational field of the machine are generated via a current control circuit in accordance with the corrected reference values.

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Erlangen, Germany

Stefan Künzel