DEVICE FOR AUTOMATIC CONTROL OF ELECTRICAL MACHINE TEMPERATURE Russian patent published in 1998 - IPC

FIELD: automatic temperature control for electrical machines including locomotives. SUBSTANCE: device has fan with adjustable drive; load current and machine voltage sensors; voltage drop sensor for entity under control; fan speed sensor; cooling agent temperature sensor; unit for dividing output signal of voltage sensor by output signal of load current sensor; unit for multiplying signal of electrical machine voltage sensor by signal of load current sensor; unit for calculating winding temperature using data on its temperature measured in hot state and for correcting control signal by varying load current, electrical machine power output, and coolant temperature; computer unit incorporating mathematical model of running automatic temperature control system enabling measurements of winding temperature upon load disconnection from electrical machine and amount of coolant by moment of load disconnection as well as coolant temperature to determine variations in winding temperature upon disconnection of machine load; control transfer unit that sends commands to transfer control functions either to unit calculating winding temperature by its resistance measured in hot state in case electrical machine terminal voltage is other than zero or to computer unit incorporating mathematical model enabling calculation of winding temperature upon disconnection of machine load. Device makes it possible to automatically maintain electrical machine winding temperature at desired level irrespective of variations in machine current and voltage, or its operating conditions. EFFECT: reduced power requirement for machine cooling, improved temperature control characteristics, improved reliability of electrical machine and fan drive. 1 dwg