EP0059924A1
Expired / Lapsed
EP
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Control apparatus for electric cars propelled by induction motor
Assignee: Hitachi Ltd
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Filing: 1982-03-02
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Granted: —
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Expires: 2002-03-02
Abstract
Abstract Power is supplied from a DC electric car line (1) through an L-C filter (3) to a PWM inverter (4). The three-phase AC output from the inverter (4) is applied to an induction motor (5) for driving an electric car. The output frequency of the inverter (4) is determined by adding or subtracting the slip frequency to or from the speed frequency of car. On the other hand, the output voltage of the inverter (4) is controlled by PWM so that the deviation as a result of comparing the current command to motor and the actual motor current is reduced to zero. In this case, an electric oscillation of current flowing from the DC electric car line (1) to the filter (3) is detected by a CT (13) with an air gap, and the electric oscillation is suppressed by adjusting the output voltage or frequency of the inverter.
Inventors
- 👤 Tokunosuke Tanamachi
- 👤 Masahiko Ibamoto
- 👤 Matsuhiro Terunuma
- 👤 Takashi Tsuboi
- 👤 Katsuaki Suzuki
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-30 02:36
CPC Classifications
B; B60; B60L; B60L9/00; B60L9/16; B60L9/18; B60L9/22; B60L9/005; H; H02; H02P; H02P23/00; H02P23/06; H02P23/07; B60L2200/00; B60L2200/26; B60L2220/00; B60L2220/10; B60L2220/12
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
153 words
A control apparatus for an electric car driven by an induction motor comprising: an inverter (4) supplied with electric power from a DC power supply (1) through a filter circuit (3); induction motors (5) for traction energized by said inverter (4); means (6) for generating a speed frequency corresponding to a car speed; means (7) for setting up a slip frequency corresponding to the slip of said induction motor (5); frequency control means (8) for adding or subtracting said slip frequency to or from said speed frequency to control the output frequncy of said inverter (4); voltage control means for controlling the output voltage of said inverter (4); means for detecting an oscillating variation of electric quantity in a circuit between said DC power supply (1) and said induction motor (5); and means for adjusting the output voltage from said inverter (4) in accordance with the output of said oscillating variation detecting means.
Claim 2
Dependent Claim
153 words
A control apparatus for an electric car driven by an induction motor comprising: an inverter (4) supplied with electric power from a DC power supply (1) through a filter circuit (3); induction motors (5) for traction energized by said inverter (4); means (6) for generating a speed frequency corresponding to a car speed; means (7) for setting up a slip frequency corresponding to the slip of said induction motor (5); frequency control means (8) for adding or subtracting said slip frequency to or from said speed frequency to control the output frequncy of said inverter (4); voltage control means for controlling the output voltage of said inverter (4); means for detecting an oscillating variation of electric quantity in a circuit between said DC power supply (1) and said induction motor (5); and means for adjusting the output voltage from said inverter (4) in accordance with the output of said oscillating variation detecting means.
Claim 3
Dependent Claim
69 words
A control apparatus according to Claim 1, wherein said voltage control means comprises motor current command means (9), motor current detecting means (10), means (11) for comparing said current command and said motor current detected signal, and means (12) for adjusting the duty ratio of said inverter in accordance with the output of said comparing means and said output voltage adjusting means utilizes said duty ratio adjusting means (12).
Claim 4
Dependent Claim
40 words
A control apparatus according to Claim 1, wherein said inverter (4) is formed of phase arms (41)-(46) each having a forced commutation ability, and said voltage control means is formed of means for controlling said inverter by pulse width modulation.
Claim 5
Dependent Claim
38 words
A control apparatus according to Claim 1, wherein said oscillating variation detecting means is formed of means for detecting an AC component included in a DC current between said DC power supply (1) and said filter circuit (3).
Claim 6
Dependent Claim
60 words
A control apparatus according to Claim 1, wherein said oscillating variation detecting means comprises a current transformer (13) with an air gap, a series circuit of a resistor (141) and a choke coil (142) for permitting the output current from the transformer to be flowed therethrough and circuit means (15) for taking out the voltage from said choke coil (142).
Claim 7
Dependent Claim
29 words
A control apparatus according to Claim 1, wherein said oscillating variation detecting means comprises a band-pass filter circuit for tuning to the resonant frequency of said filter circuit (3).
Claim 8
Dependent Claim
155 words
A control apparatus for an electric car driven by an induction motor comprising: an inverter (4) supplied with electric power from a DC power supply (1) through a filter circuit (3); induction motors (5) for traction energized by said inverter (4); means (6) for generating a speed frequency corresponding to a car speed; means (7) for setting up a slip frequency corresponding to the slip of said induction motor (5); frequency control means (8) for adding or subtracting said slip frequency to or from said speed frequency to control the output frequency of said inverter (4) : voltage control means for controlling the output voltage from said inverter (4); means for detecting an oscillating variation of electric quantity in a circuit between said DC power supply (1) and said induction motor (5) ; and means for adjusting the output frequency of said inverter (4) in accordance with the output of said oscillating variation detecting means.
Claim 9
Dependent Claim
155 words
A control apparatus for an electric car driven by an induction motor comprising: an inverter (4) supplied with electric power from a DC power supply (1) through a filter circuit (3); induction motors (5) for traction energized by said inverter (4); means (6) for generating a speed frequency corresponding to a car speed; means (7) for setting up a slip frequency corresponding to the slip of said induction motor (5); frequency control means (8) for adding or subtracting said slip frequency to or from said speed frequency to control the output frequency of said inverter (4) : voltage control means for controlling the output voltage from said inverter (4); means for detecting an oscillating variation of electric quantity in a circuit between said DC power supply (1) and said induction motor (5) ; and means for adjusting the output frequency of said inverter (4) in accordance with the output of said oscillating variation detecting means.
Claim 10
Dependent Claim
70 words
A control apparatus according to Claim 7, wherein said voltage control means comprises motor current command means (9), motor current detecting means (10), means (11) for comparing said current command and said motor current detected signal and means (12) for adjusting the duty ratio of said inverter (4) in accordance with the output of said comparing means (11), and said output voltage adjusting means utilizes said duty ratio'controlling means (12).
Claim 11
Dependent Claim
36 words
A control apparatus according to Claim 7, wherein said inverter (4) comprises arms (41)-(46) each having a forced commutation ability, and said voltage control means comprises means for controlling said inverter (4) by pulse width modulation.
Claim 12
Dependent Claim
38 words
A control apparatus according to Claim 7, wherein said oscillating variation detecting means is formed of means for detecting an AC component included in a DC current between said DC power supply (1) and said filter circuit (3).
Claim 13
Dependent Claim
60 words
A control apparatus according to Claim 7, wherein said oscillating variation detecting means is formed of a current transformer (13) with an air gap, a series circuit of a resistor (141) and a choke coil (142) for permitting the output current therefrom to be flowed therethrough, and circuit mens (15) for taking out a voltage from said choke coil (142).
Claim 14
Dependent Claim
29 words
A control apparatus according to Claim 7, wherein said oscillating variation detecting means comprises a band-pass filter circuit for tuning to the resonant frequency of said filter circuit (3).
References Cited (Backward Citations)
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