Multiplex pulse-width modulation power converter

• US 6,058,032 A
• Filed: 12/17/1998
• Issued: 05/02/2000
• Est. Priority Date: 06/17/1996
• Status: Expired due to Term

• Current Assignee: Kabushiki Kaisha Yaskawa Denki
• Original Assignee: Kabushiki Kaisha Yaskawa Denki
• Inventors: Tajima, Eijiro, Yamanaka, Katsutoshi, Sawa, Toshihiro
• Primary Examiner(s): HAN, YOUNGHUIE JESSICA
• Application Number:
  US09/147,399
• Time in Patent Office: 502 Days
• Field of Search: 363/65, 363/71, 363/97, 363/98, 363/131, 363/132, 318/767, 318/768, 318/769
• US Class Current: 363/71
• CPC Class Codes: B60L 2210/20 AC to AC converters
• CPC Class Codes: B60L 50/51 characterised by AC-motors
• CPC Class Codes: B60L 53/11 DC charging controlled by the charging station, e.g. mode 4
• CPC Class Codes: H02J 2207/20 Charging or discharging characterised by the power electronics converter
• CPC Class Codes: H02J 7/0013 acting upon several batteries simultaneously or sequentially H02J7/1423 takes precedence
• CPC Class Codes: H02M 7/49 Combination of the output voltage waveforms of a plurality of converters
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility
• CPC Class Codes: Y02T 90/12 Electric charging stations
• CPC Class Codes: Y02T 90/14 Plug-in electric vehicles

Abstract

A multiple pulse-width modulation power conversion device for variable-speed drive of a three-phase AC motor comprises three units (11₁, 11₂, and 11₃), each unit including n (n≧2) batteries (12₁₁, 12₁₂, and 12₁₃), each made up of a DC power supply or at least one battery cell, and n power converters (13₁₁, 13₁₂, and 13₁₃) for converting the DC power of each of these batteries to single-phase AC power. Single-phase AC terminals within each unit are connected in series, and of the single-phase AC terminals within each unit, one of the single-phase AC terminals that is not connected to the single-phase AC terminal of another power converter is connected to a star connection, and the other is connected to a respective one of three input terminals of a three-phase AC motor. The power conversion device further comprises control circuits (14₁₁, 14₁₂, . . . , 14₃₃) for controlling the power converters such that the AC outputs applied to the single-phase AC terminals of the n power converters within each unit are of the same phase, and further, for effecting multiple pulse-width modulation such that the AC outputs from the three units are separated by an electrical angle of 120°.

Claims

1. A multiple pulse-width modulation power conversion device for variable-speed drive of a three-phase AC motor, comprising:

three units, each unit including n (n≧

2) batteries each made up of a DC power supply or at least one battery cell, n power converters for converting DC power of each of said batteries to single-phase AC power, and n residual capacitance detectors for detecting residual capacitance of said batteries;

wherein single-phase AC terminals within each unit are connected in series, one of the single-phase AC terminals that is not connected to a single-phase terminal of another power converter is connected to a star connection, and the other single-phase AC terminal that is not connected is connected to a respective one of three input terminals of said three-phase AC motor;

further comprising control circuits for controlling said power converters such that AC applied to single-phase AC terminals of said n power converters within each unit are of the same phase, and moreover, for effecting multiple pulse-width modulation such that AC outputs from the three units are separated by an electrical angle of 120°

, and

each unit further comprising means for determining the ratio of fundamental wave amplitude of AC voltages from said n power converters connected in series, based on residual capacitance detected by each of said residual capacitance detectors.

2. A multiple pulse-width modulation power conversion device for variable-speed drive of a three-phase AC motor, comprising:

three units, each unit including n (n≧

2) batteries each made up of a DC power supply or at least one battery cell, and n power converters for converting DC power of each of said batteries to single-phase AC power;

wherein single-phase AC terminals within each unit are connected in series, one of the single-phase AC terminals that is not connected to a single-phase terminal of another power converter is connected to a star connection, and the other single-phase AC terminal that is not connected is connected to a respective one of three input terminals of said three-phase AC motor;

further comprising control circuits for controlling said power converters such that AC outputs applied to single-phase AC terminals of said n power converters within each unit are of the same phase, and moreover, for effecting multiple pulse-width modulation such that AC outputs from the three units are separated by an electrical angle of 120°

, and

wherein a charging power supply and an ON/OFF switch are connected in series between the star connection point of the single-phase AC terminals of said three units and a neutral point of winding of said three-phase AC motor; and

after turning on said ON/OFF switch, switching of conductive states of switch elements in a power converter causes individual charging or batch charging of batteries of that power converter.

3. A multiple pulse-width modulation power conversion device for variable-speed drive of a three-phase AC motor, comprising:

a battery made up of a DC power supply or at least one battery cell; and

three units, each unit including n (n≧

2) first power converters for converting DC power of said battery to AC power, n transformers for insulating output from each first power converter, and n second power converters for converting power from each transformer to single-phase AC power;

wherein single-phase AC terminals within each unit are connected in series, one of the single-phase AC terminals that are not connected to the single-phase AC terminal of another second power converter is connected to a star connection, and the other single-phase AC terminal that is not connected is connected to a respective one of three input terminals of said three-phase AC motor; and

further comprising control circuits for controlling second power converters such that AC outputs applied to single-phase AC terminals of n second power converters within each unit are of the same phase, and moreover, for effecting multiple pulse-width modulation such that AC outputs from the three units are separated by an electrical angle of 120°

;

wherein charging power supply and an ON/OFF switch are connected in series between the star connection point of the single-phase AC terminals of said three units and a neutral point of winding of said three-phase AC motor; and

after turning on said ON/OFF switch, switching of conductive states of switch elements of a power converter causes individual charging or batch charging of batteries of that power converter.

4. A multiple pulse-width modulation power conversion device for variable-speed drive of a three-phase AC motor, comprising:

a battery made up of a DC power supply or at least one battery cell;

a first power converter for converting DC power of said battery to AC power;

a transformer taking output of said first power converter as primary-side input and having insulated output on its secondary side; and

three units, each unit including n (n≧

2) second power converters for converting insulated power from said transformer to single-phase AC power;

wherein single-phase AC terminals within each unit are connected in series, one of the single-phase AC terminals that is not connected to a single-phase AC terminal of another second power converter is connected to a star connection, and the other single-phase AC terminal that is not connected is connected to a respective one of three input terminals of said three-phase AC motor; and

further comprising control circuits for controlling second power converters such that AC outputs applied to single-phase AC terminals of n second power converters within each unit are of the same phase, and moreover, for effecting multiple pulse-width modulation such that AC outputs from the three units are separated by an electrical angle of 120°

;

wherein a charging power supply and an ON/OFF switch are connected in series between the star connection point of the single-phase AC terminals of said three units and a neutral point of winding of said three-phase AC motor; and

after turning on the ON/OFF switch, switching of conductive states of switch elements of a power converter causes individual charging or batch charging of batteries of that power converter.

5. A power conversion device according to claim 4 wherein one each of said battery, said first power converter, and said transformer are provided in each unit.