Regenerative switched reluctance motor driving system

• US 8,400,084 B2
• Filed: 06/10/2008
• Issued: 03/19/2013
• Est. Priority Date: 06/10/2008
• Status: Expired due to Fees

• Current Assignee: EV Motor-Systems Co., Ltd.
• Original Assignee: EV Motor-Systems Co., Ltd.
• Inventors: Umemori, Takashi, Tanaka, Makoto
• Primary Examiner(s): Ip, Paul
• Application Number:
  US12/995,544
• Publication Number:
  US 20110148333A1
• Time in Patent Office: 1,743 Days
• Field of Search: 318/376, 318/439, 318/254, 318/629, 318/400.1, 318/400.09, 318/400.11, 318/400.22, 318/400.34
• US Class Current: 318/376
• CPC Class Codes: B60L 2200/26 Rail vehicles
• CPC Class Codes: B60L 2220/18 Reluctance machines
• CPC Class Codes: B60L 7/10 Dynamic electric regenerative braking B60L7/22 takes precedence
• CPC Class Codes: H02K 19/103 Motors having windings on the stator and a variable reluctance soft-iron rotor without windings
• CPC Class Codes: H02P 25/08 Reluctance motors
• CPC Class Codes: H02P 3/14 by regenerative braking
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility

Abstract

Provided is a regenerative switched reluctance motor driving system which allows a motor to have a reduced size and weight and an increased efficiency as well as improved energy recovery efficiency at the time of regenerative braking without using a neodymium magnet. Based on an angular position of a rotor in the motor, a constant current flip-flop circuit 2 renders two current paths alternately conductive so as to allow a rectangular-wave current having a width of an electrical angle of 180° to alternately flow in two coils in the motor 3, and shifts the timing of rendering the two current paths alternately conductive, between when driving and when braking the motor 3, by a time during which the rotor is rotated by an angle corresponding to an electrical angle of 180°. When driving the motor, a DC constant current power supply unit 1 discharges a DC power supply, while when braking the motor, it receives an input current through a negative terminal of the DC power supply, and outputs a DC current to the constant current flip-flop circuit 2, and further outputs a DC current regenerated from the motor 3 through the constant current flip-flop circuit 2 to a positive terminal of, and thereby charges, the DC power supply.

Claims

1. A regenerative switched reluctance motor driving system comprising:

a power supply unit comprising a DC power supply and voltage control means connected to the DC power supply;

a flip-flop circuit having an input terminal and an output terminal connected to the power supply unit and rendering first and second current paths alternately conductive; and

a motor having a two-phase structure comprising a rotor made of iron with 2n (n;

integer) salient portions provided at equal intervals on an outer periphery of a cylindrical structural body with a rotary shaft, and further comprising a stator made of iron with 4n magnetic poles annularly arranged at equal intervals around an outer periphery of the rotor via a gap from the salient portions, and still further comprising a first coil wound on every other one of the magnetic poles and a second coil wound on the magnetic poles without the first coil wound thereon, in which the first coil is connected to the first current path, and the second coil is connected to the second current path,

wherein the voltage control means receives an input current from the DC power supply, and controls an output voltage to allow an output current to the flip-flop circuit to be a DC current with a magnitude of a commanded value regardless of the polarity and magnitude of load electromotive force,

wherein the flip-flop circuit, while allowing the DC current to flow from the input terminal to the output terminal, renders the first and second current paths alternately conductive based on an angular position of the rotor so as to allow a rectangular-wave current having a width of an electrical angle of 180°

to alternately flow in the first and second coils, and shifts the timing of rendering the first and second current paths alternately conductive, between when driving and when braking the motor, by a time during which the rotor is rotated by an angle corresponding to an electrical angle of 180°

, and

wherein when driving the motor, the voltage control means receives an input current through a positive terminal of the DC power supply, and outputs the DC current to the flip-flop circuit, and further receives and outputs the DC current input thereto from the flip-flop circuit to a negative terminal of the DC power supply so as to discharge the DC power supply, while when braking the motor, the voltage control means receives an input current through the negative terminal of the DC power supply, and outputs the DC current to the flip-flop circuit, and further receives and outputs the DC current regenerated from the motor through the flip-flop circuit and input thereto to the positive terminal of the DC power supply so as to charge the DC power supply.

2. A regenerative switched reluctance motor driving system comprising:

a power supply unit comprising a DC power supply and voltage control means connected to the DC power supply;

m (m;

integer) flip-flop circuits having an input terminal and an output terminal connected to the power supply unit and rendering first and second current paths alternately conductive; and

m motors having a two-phase structure comprising a rotor made of iron with 2n (n;

integer) salient portions provided at equal intervals on an outer periphery of a cylindrical structural body with a rotary shaft, and further comprising a stator made of iron with 4n magnetic poles annularly arranged at equal intervals around an outer periphery of the rotor via a gap from the salient portions, and still further comprising a first coil wound on every other one of the magnetic poles and a second coil wound on the magnetic poles without the first coil wound thereon, in which the first coil is connected to the first current path of a corresponding flip-flop circuit of the m flip-flop circuits, and the second coil is connected to the second current path of the corresponding flip-flop circuit of the m flip-flop circuits,

wherein the m motors have the rotary shaft in common, in which positions of the salient portions on the respective rotors in a rotational direction of the rotary shaft are the same, while reference positions in the respective stators are at intervals of 90°

/m in the rotational direction of the rotary shaft,

wherein the voltage control means receives an input current from the DC power supply, and controls an output voltage to allow an output current to the flip-flop circuit to be a DC current with a magnitude of a commanded value regardless of the polarity and magnitude of load electromotive force,

wherein the m flip-flop circuits, while allowing the DC current to flow from the input terminal to the output terminal, render the first and second current paths alternately conductive based on an angular position of the corresponding rotor so as to allow a rectangular-wave current having a width of an electrical angle of 180°

to alternately flow in the first and second coils, and shift the timing of rendering the first and second current paths alternately conductive, between when driving and when braking the motor, by a time during which the rotor is rotated by an angle corresponding to an electrical angle of 180°

, and

wherein when driving the motor, the voltage control means receives an input current through a positive terminal of the DC power supply, and outputs the DC current to the flip-flop circuit, and further receives and outputs the DC current input thereto from the flip-flop circuit to a negative terminal of the DC power supply so as to discharge the DC power supply, while when braking the motor, the voltage control means receives an input current through the negative terminal of the DC power supply, and outputs the DC current to the flip-flop circuit, and further receives and outputs the DC current regenerated from the motor through the flip-flop circuit and input thereto to the positive terminal of the DC power supply so as to charge the DC power supply.