Rockwell Automation Technologies Incorporated

Imagen Energy, LLC

Allen-bradley Company, LLC

Jerry Dee Thunes

Takayoshi Matsuo

Ezana T Mekonnen

Adel Nasiri

Russel J Kerkman

John Joseph Golownia, Jr

Lixiang Wei

Timothy M Rowan

Thomas J Rehm

David W Schlegel

Gary R Woltersdorf

Masahiro Tsuyoshi

Jeffrey M Theisen

John T Steicher

Provided is a novel multi-level inverter with mixed device types and methods of controlling same. This novel multi-level inverter topology and control method allows the use of high frequency switching devices for controlled PWM switching, while also using lower frequency switching devices for directional switches. This combination of high frequency PWM switching devices with low frequency directional switching devices allows a cost reduction without a significant performance degradation.

Multi-level inverter with mixed device types

A dynamic braking circuit for an electronic motor drive shunts the DC link of the drive with a resistor using two control strategies. The first control strategy used for lower levels of braking employs a pulse width modulated signal and the second control strategy used for higher levels of braking uses a hysteretic signal significantly reducing switching losses in the semiconductor devices controlling the dynamic braking resistor allowing higher braking capacity.

Electric motor drive employing hybrid, hysteretic/pulse-width-modulated dynamic braking

An electronic drive for vector control of an induction motor controls slip and operating frequency in response to changes in stator voltage. The drive includes a torque control loop, a flux control loop and a frequency control loop. The control is based on a commanded stator current that is resolved into a torque-producing, or q-axis, current component and a flux-producing, or d-axis, current component that are in quadrature. The frequency control loop includes slip control in which a slip frequency command is produces based on a value for the leakage inductance of the motor. The leakage inductance value dynamically varies as a function of the q-axis current reference command.

Leakage inductance saturation compensation for a slip control technique of a motor drive

A method and apparatus for use with a controller for controlling a machine wherein a torque reference value is provided, the method for identifying an error representative of the difference between the torque reference value and the torque applied to the machine and using the error value to modify machine operation.

Method and apparatus to regulate torque provided to loads

Methods and apparatus for controlling switching in a DC-to-AC inverter to prevent overvoltages applied to an AC motor by determining the switching order of the phase voltage signals, providing gating signals at switching intervals by modulating a carrier wave with the phase voltage signals, comparing the switching intervals to a predetermined minimum time interval sufficient for reflected wave transients to dissipate, and adjusting the switching intervals to be at least equal to the predetermined minimum time interval.

Adjusting gate pulse time intervals for reflected wave mitigation

An apparatus for decreasing speed of an inverter driven inertial load within a time period for use with a dynamic brake across a DC link including a controller for controlling the inverter to regulate the power returned to the brake such that, when a brake command is received, the power is increased during a power-up period while motor deceleration begins and up to a constant power level after which the constant power level is maintained by increasing torque such that the dynamic brake is fully used during the majority of a braking cycle and a method to accomplish the same.

Dynamic braking method and apparatus

A method and apparatus used with a motor controller for determining transient inductance and rotor resistance upon commissioning of the motor. The estimator drives a single phase of the motor with an excitation current at an operating frequency, determines the d-q axis stator synchronous feedback voltages, divides the excitation current by 2 to produce a positive current signal, multiplies the operating frequency by the positive current signal to produce a current frequency signal and then divides the q-axis voltage feedback by the current frequency signal to produce the transient inductance estimate, divides the d-axis voltage feedback signal by the positive current signal and subtracts stator resistance estimate therefrom to obtain a rotor resistance estimate.

Growing community of inventors

Greenfield, WI, United States of America

Jerry Dee Thunes