Title:
OPERATING SYSTEM FOR AC MOTOR
Document Type and Number:
Japanese Patent JPS5517271
Kind Code:
A
Abstract:
PURPOSE:To recognize the start of operation by a variable frequency power source by detecting the electricity amount inherent to ac motors in starting the operation by the variable frequency power source. CONSTITUTION:If a speed-down instruction is given during an operation of an induction motor 13 by a commercial power source 11, a switch 122 is opened so that the induction motor 13 is put to an idle operation and the speed drops. After a fixed period of time, an inverter operation starts at a frequency corresponding to a speed n0 set in a speed reference 312. A comparator circuit 8 recognizes that the induction motor 13 is put to the inverter operation with the fact that the output current of the inverter has exceeded an excitation current I0. Then the switch 321 is closed and the comparator circuit 38 serves to set the speed reference n to start the operation after being put to the speed reference 311 condition.
Inventors:
SAITOU SUZUO
SUGI KAZUHIRO
SUGI KAZUHIRO
Application Number:
JP8997178A
Publication Date:
February 06, 1980
Filing Date:
July 25, 1978
Export Citation:
Assignee:
TOKYO SHIBAURA ELECTRIC CO
International Classes:
H02P1/26; H02P27/06; (IPC1-7): H02P1/26; H02P7/62