Patent ID: 7484377

Claim:
A control system for controlling an alternating current machine, the control system comprising: a current control subsystem to generate current control signals; a cooling system control subsystem to generate cooling system control signals; a sensor system to sense an operating condition of the machine; and a cooling system failure detection subsystem communicatively coupled to the current control subsystem, the cooling system control subsystem and the sensor system, wherein the cooling system failure detection subsystem is configured to: selectively initiate a cooling system failure detection cycle; generate a control signal to cause generation of waste heat by generating a second control signal causing the current control subsystem to generate a control signal to increase a flux current without increasing a torque current in the machine during the cooling system failure detection cycle; monitor the sensor system during the cooling system failure detection cycle; and terminate the cooling system failure detection cycle and generate a signal indicating a failure, if the monitoring of the sensor system indicates a change in the sensed operating condition exceeds a threshold value.