SPRACM9B June 2019 – November 2020 TMS320F28384D , TMS320F28384S , TMS320F28386D , TMS320F28386S , TMS320F28388D , TMS320F28388S , TMS320F28P650DH , TMS320F28P650DK , TMS320F28P650SH , TMS320F28P650SK , TMS320F28P659DK-Q1
The SFRA test can be performed at zero speed (by rigidly locking the shaft if needed) to get one plot as reference. The gain crossover frequency and phase margin at zero speed may be noted down. Then, at different speeds and load conditions, this test can be repeated to verify if there is any change in bandwidth or phase margin. Any variation in the plot at different speed is indicative of the quality of decoupling in current loops.