Rockwell Automation Technologies Incorporated

Adam M Shea

Jonathan D Hoffman

Gary Leonard Skibinski

Zoran Vrankovic

Gennadi Sizov

Todd M Oestreich

David A Figie

Yao Da

Robert J Miklosovic

A motor drive receives a position feedback signal from a position sensor operatively connected to a motor. The motor drive receives a command signal defining a desired operation of the motor. A processor in the motor drive generates an acceleration feedforward signal from the command signal and an acceleration reference signal from the command signal and the position feedback signal. The processor also generates an estimated disturbance acceleration from the acceleration reference signal. The acceleration feedforward signal is multiplied by a first gain to obtain a first product, and the estimated disturbance acceleration by a second gain to obtain a second product. The first and second gains are functions of first and second portions of the system inertia. A current reference signal is generated based on the first product and second products, and an output voltage to the motor is generated from the current reference signal.

System and method for inertial compensation in a motor drive

A motor drive monitors operation of a motor and adaptively track disturbances experienced by the motor. The motor drive receives a command signal and a cycle position signal. An estimated disturbance observed throughout a cycle of operation is stored in a look up table, and the motor drive uses the stored values as a feedforward value into a control module. The motor drive adaptively monitors operation of the motor and generates a new estimated disturbance value throughout each subsequent cycle of operation. The values of the estimated disturbance are updated within the look up table as a function of the new estimated disturbance values and of the previously stored values. The stored disturbance values adaptively track cyclic disturbances in the controlled machine or process and to reduce the effects of these cyclic disturbances on tracking error in the controlled machine or process.

System and method for determining a cyclic disturbance in an industrial control system

A power converter is configured to measure an output current and to determine a multi-phase voltage reference as a function of the output current. Within the same switching period the voltage reference is determined, a modulation routine determines a modulation index for each phase of the output voltage. In some instances, one or more phases must start modulation during the switching period before the new modulation index is determined. The modulation routine stores the value of the modulation index generated from the prior switching period and uses the stored value when a new value is not yet ready. An offset value for the phase voltage which used a modulation index from the prior switching period is determined in order to compensate the phase voltages of the other phases and to maintain a desired line-to-line voltage output from the power converter.

System and method for reducing delay in the modulation of a multi-phase output voltage from an inverter

A motor drive that outputs a sinusoidal waveform utilizes power switching devices operable at high switching frequencies. The switching devices may be operated, for example, between twenty kilohertz and one megahertz. A first filter is included at the output of the motor drive which has a bandwidth selected to attenuate voltage components at the output which are at the switching frequency or multiples thereof such that the output voltage waveform is generally sinusoidal. Additional filtering is included within the motor drive to establish a circulation path for common mode currents within the motor drive. Further, a shield is provided adjacent to those components within the motor drive that may experience voltage or current waveforms at the switching frequency or multiples thereof to cause radiated emissions to establish eddy currents within the EMI shield rather than passing through the shield into the environment.

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Fox Point, WI, United States of America

Adam M Shea