Indexed compensation for a motor drive system

A system controller for a motor drive system, comprising:

• a state controller coupled to receive a command from a user input and configured to output a target duty ratio for the motor drive system;
• an indexed compensator coupled to receive the target duty ratio and comprising:
• a synchronizer coupled to receive a sensed input voltage signal representative of an input voltage of the motor drive system, wherein the synchronizer is configured to determine a current index value and a total number of segments of the sensed input voltage signal;
• a selector coupled to receive the current index value, the total number of segments, a total number of bands, and an offset factor, wherein the selector is configured to determine an access band value based on the current index value;
• a memory configured to output a compensation factor in response to the access band value;
• and
• an arithmetic operator configured to output a compensated duty ratio in response to a product of the compensation factor, the target duty ratio, and a scaling factor;
• and
• a control signal generator configured to generate control signals for a plurality of devices that operate to drive the motor drive system in response to the compensated duty ratio.

A method for compensating a target duty ratio of a motor drive system, the method comprising:

• receiving a sensed input voltage signal representative of an input voltage of the motor drive system and the target duty ratio;
• determining a total number of segments and a current index value of the sensed input voltage signal;
• determining an access index value based on the current index value;
• selecting a stored compensation factor in response to the access index value;
• and
• outputting a compensated duty ratio in response to a product of the stored compensation factor and the target duty ratio.