Patent ID: 8649887

Claim:
A method, comprising: iteratively executing a slow-rate task processing loop that executes at a relatively slow-rate during a first task processing period (T TASK2 ), wherein the step of iteratively executing the slow-rate task processing loop comprises: computing, once during each first task processing period (T TASK2 ), an average switching frequency (f SW — avg ) and a dither span frequency (f span ), wherein the dither span frequency (f span ) corresponds to an amount of frequency variation allowed when dithering switching frequency (f SW ) to generate switching signals that are applied to an inverter module; iteratively executing an intermediate-rate task processing loop that executes at an intermediate-rate during a second task processing period (T TASK1 ), wherein the relatively slow-rate is less than the intermediate-rate, iteratively executing a fast-rate task processing loop that executes at a relatively fast-rate during a third task processing period (T Task0 ), wherein the intermediate-rate is less than the relatively fast-rate; wherein iteratively executing an intermediate-rate task processing loop, comprises: computing, at the intermediate-rate (T TASK1 ) during execution of intermediate-rate task processing loop: a pseudo-random number (K rand ), and a new instantaneous switching frequency (f SW — new ) based on the average switching frequency (f SW — avg ), the dither span frequency (f span ) and a scaled version of the pseudo-random number (K rand ); and regularly and consecutively re-initializing time-dependent parameter values used during the fast-rate task processing based on the new instantaneous switching frequency (f SW — new ) so that all of the time-dependent parameter values used during the fast-rate task processing have been updated with correct values representative of the new instantaneous switching frequency (f SW — new ), wherein iteratively executing the fast-rate task processing loop comprises: executing a pre-fast-rate task processing loop of the fast-rate task processing loop, wherein the pseudo-random number (K rand ) and the new instantaneous switching frequency (f SW — new ) are computed prior to the execution of the pre-fast-rate task processing loop; and executing a post-fast-rate task processing loop of the fast-rate task processing loop.