Gm Global Technolgoy Operations, Inc.

Aayush Gupta

Yo Chan Son

Bon Ho Bae

Dwarakanath V Simili

Si-hyung Lee

A motor drive system for controlling operation of an electric machine is described. An inverter includes paired power transistors that are electrically connected to the electric machine, wherein the inverter is electrically connected to a DC power source via a high-voltage electrical power bus. A motor controller includes a first controller and an acoustic signal generator, wherein the first controller is disposed to control the paired power transistors of the inverter. The first controller determines an initial output voltage based upon a torque command and the acoustic signal generator is disposed to generate a sound injection voltage. The motor controller combines the initial output voltage and the sound injection voltage. The motor controller generates PWM commands to control the paired power transistors of the inverter, wherein the PWM commands are determined based upon the initial output voltage and the sound injection voltage.

Method and apparatus for acoustic signal generation

An electric machine assembly includes an electric machine having a stator configured to have a stator current and a controller configured to receive a torque command (T). The controller has a processor and tangible, non-transitory memory on which is recorded instructions for executing a method of modifying the stator current for enhanced flux weakening. The controller is programmed to obtain a base stator current [I, I] from a look-up table based at least partially on the torque command (T). The controller is programmed to obtain a characteristic angle (&#x3b8;, i=1, 2, 3) based at least partially on a value of the torque command (T) and the base stator current [I, I]. A stator current modifier [&#x394;I, &#x394;I] is obtained based at least partially on the characteristic angle (&#x3b8;, i=1, 2, 3) and a flux weakening factor (&#x394;I) such that: &#x394;I=(&#x394;I*cosine (&#x3b8;)) and &#x394;I=(&#x394;I*sine (&#x3b8;)).

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Rochester Hills, MI, United States of America

Aayush Gupta