EP0153751A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Power converter for AC load
Assignee: Toshiba Corp
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Filing: 1985-02-28
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Granted: —
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Expires: 2005-02-28
Abstract
Abstract A power converter for starting an AC induction motor includes a frequency detector (41) which compares the frequency of an AC output of the converter with a predetermined frequency and generates a detection signal (SX) if the AC output frequency is lower than the predetermined frequency; a current controller (18, 26-29, 42-45) which controls the power converter such that an AC output current (lac) supplied to the motor (16) is determined in accordance with a given current reference (lref = S2) if the detection signal (SX) is generated; and a voltage controller (17, 18, 21-29, 31, 32, 43, 45) which controls the power converter so that an AC output voltage (Vac) applied to the motor (16) is regulated in accordance with a given voltage reference (Eref = E22) if the detection signal (SX) disappears.
Inventors
- 👤 Suzuo C/O Patent Division Saito
- 👤 Tadao C/O Patent Division Mose
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-02 09:17
CPC Classifications
H; H02; H02M; H02M5/00; H02M5/40; H02M5/42; H02M5/44; H02M5/443; H02M5/45; H02M5/451; H02P; H02P27/00; H02P27/04; H02P27/06; H02M5/4505; H02M7/00; H02M7/66; H02M7/68; H02M7/72; H02M7/75; H02M7/757; H02P1/00; H02P1/16; H02P1/26; H02P1/30; H02P2201/00; H02P2201/03
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
149 words
A power converter for an AC load comprising: detector means (41) for detecting whether or not the frequency of an AC output from the power converter falls within a predetermined frequency range, and generating a detection signal (SX) when the frequency of said AC output falls within said predetermined frequency range; current control means (18, 26-29, 42-45) coupled to said detector means (41) for determining an AC output current (lac) of the power converter in accordance with a given current reference (Iref = S2) when said detection signal (SX) is generated, said AC output current (Iac) being supplied to the AC load (16); and voltage control means (17, 18, 21-29, 31, 32, 43, 45) coupled to said detector means (41) for regulating an AC output voltage (Vac) applied to said AC load (16) in accordance with a given voltage reference (Eref = E22) when the detection signal (SX) disappears.
Claim 2
Dependent Claim
149 words
A power converter for an AC load comprising: detector means (41) for detecting whether or not the frequency of an AC output from the power converter falls within a predetermined frequency range, and generating a detection signal (SX) when the frequency of said AC output falls within said predetermined frequency range; current control means (18, 26-29, 42-45) coupled to said detector means (41) for determining an AC output current (lac) of the power converter in accordance with a given current reference (Iref = S2) when said detection signal (SX) is generated, said AC output current (Iac) being supplied to the AC load (16); and voltage control means (17, 18, 21-29, 31, 32, 43, 45) coupled to said detector means (41) for regulating an AC output voltage (Vac) applied to said AC load (16) in accordance with a given voltage reference (Eref = E22) when the detection signal (SX) disappears.
Claim 3
Dependent Claim
159 words
A power converter for an AC load comprising: detector means (41X) for detecting whether or not an AC output voltage (Vac) applied to the AC load (16) falls below a given value (EcompX in Fig. 3E), and generating a detection signal (SX) when the AC output voltage (Vac) falls below said given value (EcompX); current control means (18, 26-29, 42-45) coupled to said detector means (41X) for determining an AC output current (Iac) of the power converter in accordance with a given current reference (Iref = S2) when said detection signal (SX) is generated, said AC output current (Iac) being supplied to said AC load (16); and voltage control means (17, 18, 21-29, 31, 32, 43, 45) coupled to said detector means (41X) for regulating said AC output voltage (Vac) in accordance with a given voltage reference (Eref = E22) when said detection signal (SX) disappears, said given voltage reference (Eref) being independent of said given current reference (Iref).
Claim 4
Dependent Claim
159 words
A power converter for an AC load comprising: detector means (41X) for detecting whether or not an AC output voltage (Vac) applied to the AC load (16) falls below a given value (EcompX in Fig. 3E), and generating a detection signal (SX) when the AC output voltage (Vac) falls below said given value (EcompX); current control means (18, 26-29, 42-45) coupled to said detector means (41X) for determining an AC output current (Iac) of the power converter in accordance with a given current reference (Iref = S2) when said detection signal (SX) is generated, said AC output current (Iac) being supplied to said AC load (16); and voltage control means (17, 18, 21-29, 31, 32, 43, 45) coupled to said detector means (41X) for regulating said AC output voltage (Vac) in accordance with a given voltage reference (Eref = E22) when said detection signal (SX) disappears, said given voltage reference (Eref) being independent of said given current reference (Iref).
Claim 5
Dependent Claim
168 words
A power converter for an AC load comprising: detector means (41) for detecting whether or not an input impedance of the AC load (16) is low, and generating a detection signal (SX) when the AC load impedance is low, the low impedance of said AC load (16) resulting in substantially short-circuiting an AC output circuit of the power converter; current control means (18, 26-29, 42-45) coupled to said detector means (41) for determining an AC output current (Iac) of the power converter in accordance with a given current reference (Iref = S2) when said detection signal (SX) is generated, said AC output current (Iac) being supplied to said AC load (16); and voltage control means (17, 18, 21-29, 31, 32, 43, 45) coupled to said detector means (41) for regulating an AC output voltage (Vac) of the power converter in accordance with a given voltage reference (Eref = E22) when said detection signal (SX) disappears, said given voltage reference (Eref) being independent of said given current reference (Iref).
Claim 6
Dependent Claim
168 words
A power converter for an AC load comprising: detector means (41) for detecting whether or not an input impedance of the AC load (16) is low, and generating a detection signal (SX) when the AC load impedance is low, the low impedance of said AC load (16) resulting in substantially short-circuiting an AC output circuit of the power converter; current control means (18, 26-29, 42-45) coupled to said detector means (41) for determining an AC output current (Iac) of the power converter in accordance with a given current reference (Iref = S2) when said detection signal (SX) is generated, said AC output current (Iac) being supplied to said AC load (16); and voltage control means (17, 18, 21-29, 31, 32, 43, 45) coupled to said detector means (41) for regulating an AC output voltage (Vac) of the power converter in accordance with a given voltage reference (Eref = E22) when said detection signal (SX) disappears, said given voltage reference (Eref) being independent of said given current reference (Iref).
Claim 7
Dependent Claim
160 words
A power converter for an AC load which includes an AC motor, comprising: detector means (41) for detecting whether or not the rotor of said AC motor (16) is in a substantial stationary condition, and generating a detection signal (SX) when the rotor is in the substantial stationary condition; current control means (18, 26-29, 42-45) coupled to said detector means (41) for determining an AC output current (Iac) of the power converter in accordance with a given current reference (Iref = S2) when said detection signal (SX) is generated, said AC output current (Iac) being supplied to said AC motor (16); and voltage control means (17, 18, 21-29, 31, 32, 43, 45) coupled to said detector means (41) for regulating an AC output voltage (Vac) applied to said AC motor (16) in accordance with a given voltage reference (Eref = E22) when said detection signal (SX) disappears, said given voltage reference (Eref) being independent of said given current reference (Iref).
Claim 8
Dependent Claim
160 words
A power converter for an AC load which includes an AC motor, comprising: detector means (41) for detecting whether or not the rotor of said AC motor (16) is in a substantial stationary condition, and generating a detection signal (SX) when the rotor is in the substantial stationary condition; current control means (18, 26-29, 42-45) coupled to said detector means (41) for determining an AC output current (Iac) of the power converter in accordance with a given current reference (Iref = S2) when said detection signal (SX) is generated, said AC output current (Iac) being supplied to said AC motor (16); and voltage control means (17, 18, 21-29, 31, 32, 43, 45) coupled to said detector means (41) for regulating an AC output voltage (Vac) applied to said AC motor (16) in accordance with a given voltage reference (Eref = E22) when said detection signal (SX) disappears, said given voltage reference (Eref) being independent of said given current reference (Iref).
Claim 9
Dependent Claim
39 words
A power converter according to claim 1, characterized in that said predetermined frequency range represents a condition that an AC output voltage (Vac) applied to said AC load (16) is less than a given value (EcompX in Fig. 3E).
Claim 10
Dependent Claim
48 words
A power converter according to claim 1, characterized in that said AC load (16) includes an AC motor which generates a counterelectromotive force with the rotation of a rotor thereof, and said predetermined frequency range represents a condition that the counterelectromotive force is lower than a prescribed value.
Claim 11
Dependent Claim
75 words
A power converter according to claim 1, characterized in that said AC load (16) includes an AC motor whose AC input impedance is lower than a prescribed value when a rotor of said motor (16) is substantially stopped, and said predetermined frequency range represents a condition that an AC output circuit of the power converter is substantially short-circuited with the AC input impedance of said AC motor (16) which is lower than said prescribed value.
Claim 12
Dependent Claim
31 words
A power converter according to claim 1, characterized in that said given current reference (Iref) obtained when said detection signal (SX) is generated is independent of said given voltage reference (Eref).
Claim 13
Dependent Claim
41 words
A power converter according to claim 8, characterized in that said AC load (16) includes an A C motor, and said predetermined frequency range represents a condition that the rotation speed of said motor (16) is lower than a prescribed value.
Claim 14
Dependent Claim
35 words
A power converter according to claim 9, characterized in that said given current reference (Iref = S2) is so determined that said AC output current (Iac) ensures a sufficient starting torque to said motor (16).
References Cited (Backward Citations)
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