Electricity: electrical systems and devices – Safety and protection of systems and devices – Motor protective condition responsive circuits
Patent
1994-05-12
1996-07-23
DeBoer, Todd
Electricity: electrical systems and devices
Safety and protection of systems and devices
Motor protective condition responsive circuits
361 25, 361 31, 361 33, H02H 708
Patent
active
055396011
ABSTRACT:
An apparatus for thermal protection of an electric motor is provided, including a monitoring device for generating a signal representative of the current in a conductor supplying electrical power to the electric motor. A control circuit processes the current signal and utilizes the processed signal and motor thermal parameters, including the thermal resistance and thermal capacitance of the rotor, to generate signals representative of the temperature of at least the rotor. A comparator circuit, which may be part of the control circuit, compares the temperature signals to reference maximum temperature signals and produces a control signal when the temperature signals and reference signals satisfy a predetermined relationship. The control signal may be applied to a contactor to interrupt current to the motor. A method for thermal protection of an electric motor is also provided, including thermal modeling of the rotor temperature.
REFERENCES:
patent: 3809960 (1974-05-01), Jossic et al.
patent: 3845354 (1974-10-01), Boothman et al.
patent: 4319298 (1982-03-01), Davis et al.
patent: 4434390 (1984-02-01), Elms
patent: 4453117 (1984-06-01), Elms
patent: 4456867 (1984-06-01), Mallick, Jr. et al.
patent: 4467260 (1984-08-01), Mallick, Jr. et al.
patent: 4647825 (1987-03-01), Profio et al.
patent: 4743818 (1988-05-01), Quayle et al.
patent: 4939437 (1990-07-01), Farag et al.
IQ-1000 Motor Protection System User's Manual, Westinghouse Electric Corporation--Control Division, Feb. 1987.
The IQ-2000 Motor Command System: A New Concept in Motor Command, Denis Mueller, Senior Engineer, General Control Division, Westinghouse Electric Corporation, (no date).
Siemens Engineering & Automation, vol. XIII, No. 1, 1991: Digital Motor Protection with New Thermal Replica of the Rotor Circuit, pp. 22-25.
ABB ProStar Motor Protection Relay, pp. 28-33 (no date).
DeBoer Todd
Siemens Energy & Automation Inc.
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