Method and system for controlling electric motors of a common assembly

A system for controlling a first motor and a second motor of a common assembly, the system comprising:

• a first motor;
• a second motor;
• a first motor controller for generating a plurality of commanded speeds of a first rotor of the first electric motor for a first time interval and a second time interval within a series of time intervals;
• a first speed monitor for detecting a plurality of observed speeds of the first rotor for the first time interval and the second time interval, each one of the observed speeds corresponding to a respective commanded speed;
• a first persistence counter for determining a difference between the respective commanded speeds and the corresponding observed speeds for the first time interval and the second time interval, incrementing the persistence counter for the first motor if the difference increases during the series of time intervals;
• a first speed control module for estimating a first motor rate of change in first rotor speed of the first motor if the persistence counter exceeds a stall limit count;
• and
• a second motor controller for adjusting a target rotor speed of the second motor based on or to track the estimated first motor rate of change if the persistence counter exceeds the stall limit count.