Methods, systems and apparatus for generating voltage command signals for controlling operation of an electric machine

A system for generating voltage command signals controlling an electric machine, the system comprising:

• a current regulator module configured to compute presently computed voltage command signals at a first time, and previously computed voltage command signals at a second time occurring prior to the first time;
• memory for storing the previously computed voltage command signals and for holding a version of the presently computed voltage command signals as held versions of the presently computed voltage command signals;
• a processor comprising a voltage command modification module that is configured to output voltage command signals, the voltage command modification module comprising:
• a timer that is started in response to a start signal, wherein a timer-on flag is set in response to the start signal;
• a voltage command selection signal generator module configured to generate a first selection signal when a timer value of the timer is determined to be less than a first timer value that is determined based on an electrical angular frequency signal, to generate a second selection signal when the timer value of the timer is determined to be greater than or equal to the first timer value and to be less than a second timer value that is determined based on the electrical angular frequency signal;
• a voltage command modifier module configured to compute modified voltage command signals based on the held versions of the presently computed voltage command signals and previously computed voltage command signals;
• a voltage command selection module configured to select and output a plurality of different voltage command signals that comprise:
• the presently computed voltage command signals in response to a third selection signal that is generated when a transient stator voltage satisfies at least one of condition;
• the modified voltage command signals in response to the first selection signal, and
• the held versions of the presently computed voltage command signals in response to the second selection signal.

A processor comprising:

• a voltage command modification module that is configured to output a plurality of different voltage command signals, comprising:
• presently computed voltage command signals when a transient stator voltage satisfies at least two conditions;
• modified voltage command signals when a timer value of a timer is determined to be less than or equal to a first timer value;
• and held versions of the presently computed voltage command signals when the timer value of the timer is determined to be greater than or equal to the first timer value and is less than a second timer value,
• wherein the voltage command modification module is configured to compute the modified voltage command signals based on the held versions of the presently computed voltage command signals and previously computed voltage command signals.