Abstract: A method for estimating a rotor position in an electrical machine is provided. The method is applicable to electrical machines that have magnetic saliency. The method includes extracting the rotor position from a demodulated output signal generated in response to an injected high frequency carrier signal and determining a position error compensation based upon a demodulation delay and a velocity or rotational frequency of the electrical machine. The method also includes estimating the rotor position by applying the position error compensation to the extracted rotor position.

Abstract: The invention includes a motor controller and method for controlling a permanent magnet motor. In accordance with one aspect of the present technique, a permanent magnet motor is controlled by, among other things, receiving a torque command, determining a normalized torque command by normalizing the torque command to a characteristic current of the motor, determining a normalized maximum available voltage, determining an inductance ratio of the motor, and determining a direct-axis current based upon the normalized torque command, the normalized maximum available voltage, and the inductance ratio of the motor.

Abstract: The present invention provides an improved current regulator for PWM based drives for electric motors. The invention provides compensation for the rotor position signal for delays introduced due to the PWM algorithm and for digital sampling present in such a drive. Current regulator commonly operate in a two-phase reference frame, requiring forward and reverse coordinate transformations between the physical current values and the two-phase reference frame variables. The present invention provides an improved compensation in the forward transformation by determining the phase lag between the commanded voltage reference and the output voltage reference and by further compensating the forward transformation for errors introduced due to sampling the current either at different sampling instances than the rotor position or at multiple sampling instances during a carrier period.

Abstract: A method for estimating a rotor position in an electrical machine is provided. The method is applicable to electrical machines that have magnetic saliency. The method includes extracting the rotor position from a demodulated output signal generated in response to an injected high frequency carrier signal and determining a position error compensation based upon a demodulation delay and a velocity or rotational frequency of the electrical machine. The method also includes estimating the rotor position by applying the position error compensation to the extracted rotor position.

Abstract: The present invention provides a simple, robust, and universal position observer for use with sensorless synchronous machines. The observer may be implemented using an equivalent EMF model of a synchronous machine or, alternately, using a sliding mode controller based on the equivalent EMF model of the synchronous machine. The observer may be used on any type of synchronous machine, including salient or non-salient pole machines such as a permanent magnet, interior permanent magnet, wound rotor, or reluctance synchronous machine. The observer provides low sensitivity to parameter variations and disturbances or transient conditions in the machine. In addition, no knowledge of speed is required as an input to the observer and an estimated position may be calculated using a subset of the machine parameters.

Abstract: A method and apparatus for determining electrical parameters for commissioning a sensor-less permanent magnet synchronous machine uses knowledge of the rotor position to apply balanced pulses along the rotor magnet axis and perpendicular to the rotor magnet axis allowing measurement of q- and d-inductance at multiple current levels without substantial rotor movement.

Abstract: Systems and methods that determine resonant frequencies of a motor system via employing an output of a velocity regulator. The velocity regulator enables the motor drive to command the rotation of the motor at predetermined rotations, by setting rotational speeds of the motor. The output of the velocity regulator can then be stored as a function of time, and a Fast Fourier Transform performed on such time data to obtain a frequency data and a signal power spectrum.

Abstract: A method and apparatus for estimating a system inertia and a load torque in a motor controller, the method comprising the steps of providing an acceleration command signal, determining a motor position, using the motor position to generate an acceleration feedback signal, mathematically combining the acceleration feedback signal and a load torque signal to generate a system inertia estimate, mathematically combining the system inertia estimate and the acceleration command signal to generate a motor torque signal, mathematically combining the system inertia estimate and the acceleration feedback signal to generate an inertia torque and mathematically combining the inertia torque and the motor torque signal to generate the load torque estimate.

Abstract: A system and method for controlling any of a variety of permanent magnet motors includes normalizing motor parameters with respect to demagnetization current of a motor and developing a torque-per-current relationship using the normalized motor parameters at approximately maximum torque. Using the developed torque-per-current relationship, it is possible to control any of a variety of permanent magnet motors without the need for extensive configuration of a motor control unit for a specific motor.

Abstract: The invention includes a motor controller and method for controlling a permanent magnet motor. In accordance with one aspect of the present technique, a permanent magnet motor is controlled by, among other things, receiving a torque command, determining a normalized torque command by normalizing the torque command to a characteristic current of the motor, determining a normalized maximum available voltage, determining an inductance ratio of the motor, and determining a direct-axis current based upon the normalized torque command, the normalized maximum available voltage, and the inductance ratio of the motor.

Abstract: A method and apparatus for estimating a system inertia and a load torque in a motor controller, the method comprising the steps of providing an acceleration command signal, determining a motor position, using the motor position to generate an acceleration feedback signal, mathematically combining the acceleration feedback signal and a load torque signal to generate a system inertia estimate, mathematically combining the system inertia estimate and the acceleration command signal to generate a motor torque signal, mathematically combining the system inertia estimate and the acceleration feedback signal to generate an inertia torque and mathematically combining the inertia torque and the motor torque signal to generate the load torque estimate.

Abstract: Systems and methods that determine resonant frequencies of a motor system via employing an output of a velocity regulator. The velocity regulator enables the motor drive to command the rotation of the motor at predetermined rotations, by setting rotational speeds of the motor. The output of the velocity regulator can then be stored as a function of time, and a Fast Fourier Transform performed on such time data to obtain a frequency data and a signal power spectrum.

Abstract: A method and apparatus for use with a plant drive system that receives a reference command signal and generates a torque command to drive a plant, the method for estimating plant inertia and comprising the steps of providing a reference model that models the plant, the model receiving the reference command signal and generating a model output signal as a function thereof, identifying a plant output signal, mathematically combining the reference command signal and the plant output signal to generate a first error value, mathematically combining the plant output signal and the model output signal to generate a second error value, mathematically combining the first and second error values to generate an inertia estimate value and using the inertia estimate value to modify the torque command thereby providing a modified torque command signal to drive the plant.

Abstract: A system and method for controlling any of a variety of permanent magnet motors includes normalizing motor parameters with respect to demagnetization current of a motor and developing a torque-per-current relationship using the normalized motor parameters at approximately maximum torque. Using the developed torque-per-current relationship, it is possible to control any of a variety of permanent magnet motors without the need for extensive configuration of a motor control unit for a specific motor.

Abstract: A method and apparatus for use with a motor controller that receives a command velocity and that applies voltages to drive a motor at the command velocity, the apparatus comprising a dual inertia lost motion assembly including a motor and a load couplable to the motor, the lost motion assembly characterized by at least some lost motion between the motor and the load, the motor and load together characterized by a total assembly inertia, an acceleration error determiner for generating an acceleration error that is the difference between a derivative of the command velocity and a motor acceleration value and a low pass acceleration error filter filtering the acceleration error and having a gain set as a percentage of the total assembly inertia, the acceleration error filter providing the filtered signal to the controller, the controller using the filtered signal to adjust the applied voltages.

Abstract: A method and apparatus for essentially eliminating cyclic disturbances in a motor control system, the method including identifying frequencies of undesirable components in a feedback signal that exceed a threshold level and generating a combined signal including sine wave components corresponding to each of the identified frequencies, delaying the combined signal to generate a plurality of identical but phase shifted combined signals, weighting each one of the delayed signals as a function of the magnitude of an instantaneous corrected signal which is the difference between a velocity error signal and a compensation signal and adding each of the weighted signals to generate the compensation signal.

Abstract: A method and apparatus for determining the absolute position of a rotor in a permanent magnet synchronous machine (e.g. motor or generator) at standstill wherein short positive and negative voltage pulses are separately provided to each stator winding and the rate of current change with respect to time for each current is determined, the rates are used to determine general rotor position angle and thereafter are used to determine correction angle for correcting the general angle.

Abstract: A method and apparatus for minimizing resonant oscillations in a dual inertia system characterized by minimally stable poles and both a resonant frequency and an anti-resonant frequency, the apparatus including a notch filter which is tuned so that notch filter zeros essentially cancel the minimally stable poles and so that at least one notch pole is located at the intersection of a real axis and an system anti-resonant zero radius on a root-loci plot, thereby rendering an exceptionally stable system, the method for tuning the notch filter as described.

Abstract: A method and apparatus for motor control tuning wherein an extremely accurate estimate of inertia is determined by using the second derivative of a desired motor velocity and the torque supplied to a motor is altered as a function of inertia.

Abstract: A control system for controlling the temperature within process machinery such as the feed assembly in an injection molding machine. The control system provides a six phase process for starting up the machine from cold conditions and controlling the machine temperature to rapidly and accurately attain a command temperature while identifying control parameters for use under steady state conditions for maintaining the command temperature.