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U.S. Department of Energy
Office of Scientific and Technical Information

Precision electronic speed controller for an alternating-current

Patent ·
OSTI ID:5019731

The patent describes a controller for controlling the speed of a multiphase induction motor so as to maintain the motor in phase with an alternating-current power supply signal that is subject to meandering in frequency about a nominal line frequency. The motor includes power amplifiers having outputs which drive the respective stator windings of the motor, comprising: shaft revolution sensor means operable to provide a feedback pulse train signal having frequency representative of the speed of the motor; phase error signal representative of the phase difference between the alternating-current power supply signal and the feedback pulse train signal; speed error signal generator means for generating a speed error signal that is representative of the different between the speed of the motor and a predetermined desired speed; drift error signal generator means for generating a drift error signal representative of the integral of the phase error signal over time; a summing amplifier for combining the speed phase and drift error signals to produce a single motor control signal.

Assignee:
Dept. of Energy, Washington, DC
Patent Number(s):
US 4731572
OSTI ID:
5019731
Country of Publication:
United States
Language:
English