Patent US2241967A successfully refreshed from Google Patents.
Patent EP0175154A2 successfully refreshed from Google Patents.
EP0175154A2
Expired / Lapsed
EP
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Method of controlling inverter-driven induction motor
Assignee: Hitachi Ltd
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Filing: 1985-08-19
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Granted: —
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Expires: 2005-08-19
Abstract
Abstract An induction motor (2) is driven by a voltage-type inverter (1). Torque current component (i q ) is determined by detecting a primary current (i,) flowing to the induction motor. On the basis of the torque current component determined, output voltage and frequency of the voltage-type inverter are controlled. Additionally, rotational speed (ω̂ r ) of the induction motor is estimated on the basis of the detected torque current component. Rotational speed of the induction motor is so controlled that an estimated speed signal (ω̂ r ) coincides with a speed command signal (ω r *).
Inventors
- 👤 Toshiaki Okuyama
- 👤 Takayuki Matsui
- 👤 Noboru Fujimoto
- 👤 Yuzuru Kubota
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-27 22:28
CPC Classifications
H; H02; H02P; H02P21/00; H02P21/04
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
150 words
A method of controlling an induction motor (2) driven by a voltage-type inverter (1), wherein magnitude and phase of a primary current (il = i u , i , i ) supplied to said induction motor are controlled by commanding a torque current component (iq * ) and an exciting current component (i d * ) independent of each other, said method comprising steps of determining said torque current component by detecting the primary current (i l ) flowing to said induction motor (2), controlling output voltage and frequency of said voltage-type inverter (1) in accordance with said torque current component, estimating rotational speed (ω r ) of said induction motor on the basis of said detected torque current component, and controlling the rotational speed of said induction motor in dependence on the result of comparison of said estimated rotational speed signal with a speed command signal (ω r *).
Claim 2
Independent Claim
150 words
A method of controlling an induction motor (2) driven by a voltage-type inverter (1), wherein magnitude and phase of a primary current (il = i u , i , i ) supplied to said induction motor are controlled by commanding a torque current component (iq * ) and an exciting current component (i d * ) independent of each other, said method comprising steps of determining said torque current component by detecting the primary current (i l ) flowing to said induction motor (2), controlling output voltage and frequency of said voltage-type inverter (1) in accordance with said torque current component, estimating rotational speed (ω r ) of said induction motor on the basis of said detected torque current component, and controlling the rotational speed of said induction motor in dependence on the result of comparison of said estimated rotational speed signal with a speed command signal (ω r *).
Claim 3
Dependent Claim
101 words
A method of controlling an induction motor according to claim 1, wherein in precedence to actual operation of said induction motor, characteristic relation of the inverter output current to an inverter output voltage command is determined to store data representative of voltage command value corresponding to the inverter output current value (Fig. 6), the voltage command value corresponding to the output current value of the inverter being read out from the storage in the operation of said induction motor and added to said inverter output voltage command for compensating for voltage drop in said inverter, said induction motor and connections therebetween.
References Cited (Backward Citations)
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