Patent EP0144161A2 successfully refreshed from Google Patents.
EP0144161A2
Expired / Lapsed
EP
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Control system for an ac motor
Assignee: Toshiba Corp
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Filing: 1984-11-05
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Granted: —
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Expires: 2004-11-05
Abstract
Abstract A control system for an AC motor comprises a converter fed from a source and a thyristor inverter fed from the converter and supplying a load. The control lead angle of the inverter is controlled in response to the detected overlap angle of the inverter and a signal representing a pre-set value of the overlap angle is used to control the inverter when the acceleration-deceleration of the motor exceeds a predetermined value.
Inventors
- 👤 Akio C/O Patent Division Hirata
- 👤 Yoshio C/O Patent Division Naito
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 23:36
CPC Classifications
H; H02; H02P; H02P25/00; H02P25/02; H02P25/022; H02P25/024
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
141 words
A control system for an AC motor comprising a controllable thyristor converter (12) for converting AC current from a power source (10) to DC current, a thyristor inverter (14) arranged to receive smoothed DC current from the converter and to convert it to AC current which is supplied to said AC motor (15); means (23) for detecting the overlap angle (u) of said inverter; and means (21) for controlling the control lead angle of the inverter in response to said detected overlap angle; characterised in the provision of means (26) for providing a signal representing a predetermined overlap angle, means (25) for detecting the rate of acceleration-deceleration of the motor and wherein the control means (21) controls the lead angle of the inverter in response to said signal representing said predetermined overlap angle when the acceleration-deceleration rate exceeds a predetermined value.
Claim 2
Dependent Claim
141 words
A control system for an AC motor comprising a controllable thyristor converter (12) for converting AC current from a power source (10) to DC current, a thyristor inverter (14) arranged to receive smoothed DC current from the converter and to convert it to AC current which is supplied to said AC motor (15); means (23) for detecting the overlap angle (u) of said inverter; and means (21) for controlling the control lead angle of the inverter in response to said detected overlap angle; characterised in the provision of means (26) for providing a signal representing a predetermined overlap angle, means (25) for detecting the rate of acceleration-deceleration of the motor and wherein the control means (21) controls the lead angle of the inverter in response to said signal representing said predetermined overlap angle when the acceleration-deceleration rate exceeds a predetermined value.
Claim 3
Dependent Claim
62 words
A cntrol system as claimed in claim 1, characterised in the provision of switch means (27) aranged to connect the output of the detecting means (23) to the control means (21) until the detecting mians (25) detect an acceleration-deceleration rate exceeding said predetermined value whereupon the switch means connect the output of the signal providing means (26) to the control means (21).
Claim 4
Dependent Claim
25 words
A control system as claimed as claim 1 or 2, characterised in that the detecting means (25) is responsive to the speed of the motor.
Claim 5
Dependent Claim
26 words
A control system as claimed in claim 1 or 2, characterised in that the detecting means (25) is responsive to the current supplied to the converter.
Claim 6
Dependent Claim
58 words
A control system as claimed in claim 1, 2, 3, or 4, characterised in the provision of a commutation marginal time controller (28) which produces a signal representating marginal angle (α) and which is added to the output signal representing overlap angle (u) from the detecting means 23 when the acceleration-deceleration rate does not exceed the predetermined value.
Claim 7
Dependent Claim
40 words
A control system as claimed in claim 1, 2, 3, or 4, characterised in the provision of a commutation marginal time controller (28) which produces a signal representing marginal angle (α), said signal being supplied to the control means 21.
References Cited (Backward Citations)
No citation records indexed.
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