Patent ID: 6847187
Filing Date: 2005-01-25
Classification: H02H

Abstract:
1. A method for determining the health of a cooling system on a vehicle driven by at least one electric traction motor coupled to a wheel for the vehicle, with the cooling system directing cooling air past the traction motor, the method comprising: monitoring the temperature and pressure of the air available to the cooling system for cooling the traction motor; monitoring operating parameters of the traction motor; estimating motor beat losses generated by the operation of the motor based on the motor operating parameters, and motor cooling by operation of the cooling system based on the temperature and pressure of the air available to the cooling system; establishing an estimated motor temperature based on the estimated heat losses and cooling; monitoring electrical power input parameters to the electric traction motor, including voltage and current; determining the electrical resistance of the motor winding; calculating a motor temperature indicative of the actual motor temperature based on the electrical resistance of the motor winding; comparing the calculated actual motor temperature and the estimated motor temperature; and determining if the calculated actual motor temperature exceeds the estimated motor temperature by more than a predetermined amount.