Patent ID: 9634593
Date: 2017-04-25
CPC Classifications: B60H,F25B,H02P,Y02T

Claim:
1. A method of operating an electric motor, the method comprising: starting the electric motor in an open loop control mode; using an estimator module, estimating derivatives of total flux linkages of the electric motor based on measured currents of the electric motor, an output speed of the electric motor, a commanded speed for the electric motor, and voltage commands for the electric motor; while the electric motor is in the open loop control mode, evaluating derivatives of the total flux linkages of the estimator module; in response to the evaluation of the derivatives of the total flux linkages, determining whether the estimator module has converged; in response to a determination that the estimator module has not converged within a predetermined period of time after starting the electric motor, signaling a first fault condition; and in response to the signaling of the first fault condition, at least one of: (i) shutting down the electric motor; and (ii) restarting the electric motor.