Abstract: A system and method for controlling an electric machine via an inverter comprises an speed estimator that is configured to estimate a rotor speed of an electric motor to determine whether to control the inverter to operate the electric motor in a first mode or a second mode. For example, the first mode comprises a current-frequency control mode and the second mode comprises a back electromagnetic force (BEMF) mode. An electronic data processor or controller is configured to determine a first (current) command associated with a first mode of operating the electric motor, if the estimated rotor speed is a less than a speed threshold. The electronic data processor or controller is configured to determine a second (current) command associated with a second mode of operating the electric motor if the estimated rotor speed is equal to or greater than the speed threshold.

Abstract: An electronic data processor comprises a data storage device in communication with the electronic data processor. A control module stored in the data storage device, the control module comprising software instructions for execution by the electronic data processor to change dynamically the fundamental switching frequency of the control signals to reduce electromagnetic noise within a target frequency band if the fundamental switching frequency is equal to or greater than a threshold fundamental switching frequency.

Abstract: A system and method for controlling an electric machine via an inverter comprises an speed estimator that is configured to estimate a rotor speed of an electric motor to determine whether to control the inverter to operate the electric motor in a first mode or a second mode. For example, the first mode comprises a current-frequency control mode and the second mode comprises a back electromagnetic force (BEMF) mode. An electronic data processor or controller is configured to determine a first (current) command associated with a first mode of operating the electric motor, if the estimated rotor speed is a less than a speed threshold. The electronic data processor or controller is configured to determine a second (current) command associated with a second mode of operating the electric motor if the estimated rotor speed is equal to or greater than the speed threshold.

Abstract: An electronic data processor comprises a data storage device in communication with the electronic data processor. A control module stored in the data storage device, the control module comprising software instructions for execution by the electronic data processor to change dynamically the fundamental switching frequency of the control signals to reduce electromagnetic noise within a target frequency band if the fundamental switching frequency is equal to or greater than a threshold fundamental switching frequency.