Rockwell Automation Technologies Incorporated

Ehsan Al-Nabi

Thomas Arthur Nondahl

Semyon Royak

Jingbo Liu

Jingya Dai

Peter B Schmidt

Ahmed Mohamed Sayed Ahmed

Sang Woo Nam

Zhendong Zhang

Lixiang Wei

Yuan Xiao

Robert J Breitzmann

Ye Zhang

Nirav Patel

Richard L Piekarz

Thomas M Cahill

An active rectifier with a controller including a feedforward component, a modulator and a modulation index controller. The modulator generates switching control signals according to a reference to convert AC input power from the AC input to control the DC bus voltage at the DC output. The feedforward component computes the reference according to an estimated total inductance of the AC input, a grid voltage of the AC input, a modulation index reference, and a reactive power offset signal, and the modulation index controller computes the reactive power offset signal according to an error between the modulation index reference and a feedback modulation index.

Reactive AFE power control

An active rectifier includes first and second DC nodes, a switching circuit, and a controller configured to compute a voltage reference according to a load signal of the DC output, and a non-linear relationship between a load condition of the DC output and a DC bus voltage at the DC output, and to generate rectifier switching control signals according to the voltage reference to cause the switching circuit to convert AC input power from the AC input to control the DC bus voltage at the DC output.

Multi-segment and nonlinear droop control for parallel operating active front end power converters

The disclosed examples provide an easy and low-loss solution to reduce voltage stress on motor and cable in inverter-fed motor systems by suppressing resonances on the motor cable with apparatus coupled between the inverter output and the motor cable. Disclosed examples include various methods to mitigate voltage stress on both motor and cable, including an output filter circuit with a cable side parallel RL circuit between an inverter output and a motor cable, and an inverter to provide an inverter output signal to the output filter circuit to drive a load through the motor cable, where the cable side parallel RL circuit includes a resistor coupled in series between the inverter output and the motor cable, and an inductor connected in parallel with the resistor.

Suppressing resonance in ultra long motor cable

Disclosed examples include motor drive power conversion systems with an inverter, as well as a controller methods to drive a motor in which output filter capacitor currents are computed and used to compensate the motor control in consideration of damping resistance values of an output filter.

Sensorless motor drive vector control with feedback compensation for filter capacitor current

Disclosed examples include power conversion systems, methods and computer readable mediums to operate an inverter to drive a motor load through an intervening filter, by computing a speed error value according to a speed reference value and a speed feedback value, computing a torque reference value according to the speed error value, computing a motor current reference value according to the torque reference value, compensating the motor current reference value according to capacitor currents of the output filter using a transfer function representing an output current to input current amplitude vs. frequency behavior of the output filter and the motor load, and controlling the inverter according to the inverter output current reference value.

Control of motor drives with output sinewave filter capacitor current compensation using sinewave filter transfer function

Motor drive control apparatus and methods are presented for speed reversal control for drives used with output filters and transformers using a high or maximal drive current command to facilitate dissipation of regenerative energy seen in this system during speed reversal with open loop control to reverse the spin direction of a driven motor while quickly transitioning through zero speed.

Method and apparatus for speed reversal control of motor drive

Methods and systems are presented for closed loop motor speed and torque control without a sensor at the motor, in which configuration parameters are received from a user interface to define operating characteristics of a filter, a transformer, a cable, and the motor coupled with the output of a motor drive, and an object model of the motor drive is configured according to the filter, transformer, cable and motor configuration parameters to facilitate sensorless closed loop motor speed and/or torque control.

Methods and systems for sensorless closed loop motor speed and torque control

Disclosed examples include methods, computer readable mediums and motor drive power conversion systems for sensorless speed control of a motor driven by an inverter through an intervening filter, a transformer and a motor cable, in which sensorless vector control is used to regulate the motor speed based on a speed feedback value computed according to voltage or current values associated with the motor drive using an observer having formulas and impedance parameters of the filter, the transformer, the motor cable and the motor.

Sensorless motor drive vector control

Motor drive control apparatus and methods are presented for sensorless control of a driven motor using open loop current regulated control during low-speed operation and an EMF-based position observer for position estimation during higher speed operation, with zero feedback speed during low-speed open-loop operation and feedback speed estimated by the EMF-based observer during high-speed operation and with velocity mode control over the full speed range and mode control hysteresis for smooth transitions between open loop and EMF-based observer control.

Transition scheme for position sensorless control of AC motor drives

Power converters and methods are presented for driving an AC load connected through an intervening filter circuit, in which at least one filter current or voltage signal or value is determined according to feedback signals or values representing an output parameter at an AC output of the power converter, and AC electrical output power is generated at the AC output based at least partially on the at least one filter current or voltage signal or value.

Growing community of inventors

Cambridge, Canada

Ehsan Al-Nabi