JPS57208888A - Speed detecting system for induction motor - Google Patents

Speed detecting system for induction motor

Info

Publication number
JPS57208888A
JPS57208888A JP56092173A JP9217381A JPS57208888A JP S57208888 A JPS57208888 A JP S57208888A JP 56092173 A JP56092173 A JP 56092173A JP 9217381 A JP9217381 A JP 9217381A JP S57208888 A JPS57208888 A JP S57208888A
Authority
JP
Japan
Prior art keywords
frequency
induction motor
electromotive force
counter
output
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP56092173A
Other languages
Japanese (ja)
Inventor
Yoji Kishida
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Toshiba Corp
Original Assignee
Toshiba Corp
Tokyo Shibaura Electric Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Toshiba Corp, Tokyo Shibaura Electric Co Ltd filed Critical Toshiba Corp
Priority to JP56092173A priority Critical patent/JPS57208888A/en
Publication of JPS57208888A publication Critical patent/JPS57208888A/en
Pending legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
    • G01P3/00—Measuring linear or angular speed; Measuring differences of linear or angular speeds
    • G01P3/42—Devices characterised by the use of electric or magnetic means
    • G01P3/44—Devices characterised by the use of electric or magnetic means for measuring angular speed
    • G01P3/48—Devices characterised by the use of electric or magnetic means for measuring angular speed by measuring frequency of generated current or voltage

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Control Of Ac Motors In General (AREA)

Abstract

PURPOSE:To detect induction motor coasting rotational speed without using a sensor, by a method wherein the frequency of counter-electromotive force of induction motor is detected. CONSTITUTION:In an induction motor 10, an electromotive force is induced in its secondary winding by DC excitation generated by a current supplied from a DC exciting source 41. A counter-electromotive force equal in frequency to that induced in the secondary wiring is generated in the primary winding, as is the case of a transformer. When a switch 24 is closed, a current, an AC with the DC component removed while in a filter circuit 42, is supplied to a frequency detecting circuit 43, wherefrom pulses, developed from the AC component and in proportion thereto is sent into a frequency/voltage converter 44 wherein an analogus voltage output in proportion to the counter-electromotive force frequency is obtained. The output is compared in a coincidence detecting circuit 45 with an output of a frequency setter 31 belonging in the inverter unit 30. Coincidence of the signals activates the inverter unit 30, at the same time opening switches 23, 24 and closing a switch 21.
JP56092173A 1981-06-17 1981-06-17 Speed detecting system for induction motor Pending JPS57208888A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP56092173A JPS57208888A (en) 1981-06-17 1981-06-17 Speed detecting system for induction motor

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP56092173A JPS57208888A (en) 1981-06-17 1981-06-17 Speed detecting system for induction motor

Publications (1)

Publication Number Publication Date
JPS57208888A true JPS57208888A (en) 1982-12-22

Family

ID=14047036

Family Applications (1)

Application Number Title Priority Date Filing Date
JP56092173A Pending JPS57208888A (en) 1981-06-17 1981-06-17 Speed detecting system for induction motor

Country Status (1)

Country Link
JP (1) JPS57208888A (en)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6169395A (en) * 1984-09-13 1986-04-09 Hitachi Ltd Restarter of induction motor
JPH02290196A (en) * 1990-04-04 1990-11-30 Takasago Thermal Eng Co Ltd Electric facility utilizing inverter unit
FR2697089A1 (en) * 1992-10-20 1994-04-22 Electricite De France Speed measurement appts. for free running electric motor - uses measurement of voltage induced by residual magnetism or rotor induced pulses
JPH0775381A (en) * 1994-05-12 1995-03-17 Hitachi Ltd Operation control method of induction electric motor
JPH0775382A (en) * 1994-05-12 1995-03-17 Hitachi Ltd Method and device for controlling operation of induction electric motor
JPH07274588A (en) * 1995-04-27 1995-10-20 Hitachi Ltd Control method for induction motor operation

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6169395A (en) * 1984-09-13 1986-04-09 Hitachi Ltd Restarter of induction motor
JPH02290196A (en) * 1990-04-04 1990-11-30 Takasago Thermal Eng Co Ltd Electric facility utilizing inverter unit
FR2697089A1 (en) * 1992-10-20 1994-04-22 Electricite De France Speed measurement appts. for free running electric motor - uses measurement of voltage induced by residual magnetism or rotor induced pulses
JPH0775381A (en) * 1994-05-12 1995-03-17 Hitachi Ltd Operation control method of induction electric motor
JPH0775382A (en) * 1994-05-12 1995-03-17 Hitachi Ltd Method and device for controlling operation of induction electric motor
JPH07274588A (en) * 1995-04-27 1995-10-20 Hitachi Ltd Control method for induction motor operation

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