Title:
SLOW STARTER FOR INDUCTION MOTOR
Document Type and Number:
Japanese Patent JPS55109180
Kind Code:
A
Abstract:
PURPOSE:To sufficiently slowly start a three-phase induction motor by further lowering the voltage to the motor when the current of the motor becomes less than set value and controlling the primary voltage in response to the primary current of the motor. CONSTITUTION:Since the output of a current detector 26 becomes zero due to large primary current of a three-phase induction motor IM when starting the motor IM, thyristors 1-3 are controlled by the set voltage by a variable resistor 12. As the speed of the motor is raised, the primary current of the motor reduced. When the primary current becomes less than predetermined value, the output of a current detector 26 becomes ''1''. Accordingly, the voltage set by the variable resistor 12 is stopped at an AND gate 30. Thus, the thyristors 1-3 are conrolled by the voltage set by the variable resistor 29. Thus, relatively uniform accelerating torque can be provided over the entire range of the accelerating period of the motor to slowly start the motor.
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Inventors:
SANAKA YOUZOU
Application Number:
JP1601179A
Publication Date:
August 22, 1980
Filing Date:
February 16, 1979
Export Citation:
Assignee:
TOKYO SHIBAURA ELECTRIC CO
International Classes:
H02P1/28; (IPC1-7): H02P1/28