POWER SUPPLY FOR A VEHICLE

• US 20070216452A1
• Filed: 03/16/2007
• Published: 09/20/2007
• Est. Priority Date: 03/17/2006
• Status: Active Grant

• Current Assignee: Yamaha Hatsudoki Kabushiki Kaisha (Yamaha Corporation)
• Original Assignee: Yamaha Hatsudoki Kabushiki Kaisha (Yamaha Corporation)
• Inventors: Ikeda, Takeshi, Suzuki, Shigeto, Matsumoto, Takaie, Fukudome, Toshinori, Hosoi, Yukiharu
• Granted Patent: US 7,667,342 B2
• Time in Patent Office: Days
• US Class Current: 327/116
• CPC Class Codes: B60K 6/26 characterised by the motors or the generators
• CPC Class Codes: B60K 6/28 characterised by the electric energy storing means, e.g. batteries or capacitors
• CPC Class Codes: B60K 6/48 Parallel type
• CPC Class Codes: B60L 2200/12 Bikes
• CPC Class Codes: B60L 50/15 with additional electric power supply with capacitors charged by engine-driven generators B60L50/40; with batteries charged by engine-driven generators B60L50/61
• CPC Class Codes: B60L 50/61 by batteries charged by engine-driven generators, e.g. series hybrid electric vehicles
• CPC Class Codes: B60Y 2200/12 Motorcycles, Trikes; Quads; Scooters
• CPC Class Codes: H02M 7/483 Converters with outputs that each can have more than two voltages levels
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• 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

Abstract

A power supply system that supplies high-voltage power to a vehicle drive motor is provided to achieve reduction in size, weight and cost of power supply. The power supply system includes a plurality of battery modules connected in series. With the intermediate connection point of the battery modules as an electrical neutral point, power is supplied to a three-level inverter via a three-level-potential high-voltage power supply line having potentials of +150V and −150V relative to this neutral point. In the three-level inverter, direct-current electric power is converted into three-phase alternating-current electric power to drive an electric motor. Accordingly, the withstand-voltage performance required of control units or control elements connected to the high-voltage power supply line can be halved as compared with the related art, thereby allowing a reduction in the size, weight, and cost of the power supply system. Further, the electric power generated by a generator is converted into direct-current electric power by a three-level converter and supplied to the high-voltage power supply line to charge the battery modules.

Claims

1. A power supply for a vehicle, in which a plurality of batteries are serially connected, and in which a high voltage obtained from the serially connected batteries is supplied as a power source to a vehicle-driving electric motor, comprising:

a three-level power line forming a direct-current power supply line with an intermediate connection position of the serially connected batteries serving as a neutral point, the three-level power line including a neutral line connected to the neutral point, a positive potential line connected to a plus-side end of a row of the serially connected batteries, and a negative potential line connected to a minus-side end of the row of the serially connected batteries; and

a three-level inverter for converting direct-current power supplied from the three-level power line into alternating-current power supplied to the electric motor.

2. The power supply of claim 1,

wherein the vehicle is a hybrid type vehicle including a generator that is driven by at least an internal combustion engine to generate electric power;

and

the power supply further comprises a three-level converter for converting an alternating-current output of the generator into a three-level-potential direct-current voltage supplied to the three-level power line.

3. The power supply of claim 1, further comprising:

a low-voltage auxiliary battery that is different from the batteries for supplying power to the three-level power line; and

a DC-DC converter for converting a power source voltage supplied to the three-level power line into a rated voltage of the low-voltage auxiliary battery,

wherein an output of the DC-DC converter is connected to a power supply line for the low-voltage auxiliary battery, and wherein a negative-side of the power supply line for the low-voltage auxiliary battery is connected to the neutral line of the three-level power line.

4. The power supply of claim 1, wherein the relative absolute potential between the positive potential line and the neutral line and between the negative potential line and neutral line is substantially the same.

5. A power supply for a hybrid vehicle having a generator driven by an internal combustion engine to generate electric power and having a plurality of batteries serially connected to each other, in which a high voltage obtained from the serially connected batteries is supplied as a power source to a vehicle-driving electric motor, comprising:

a three-level power line forming a direct-current power supply line with an intermediate connection position of the serially connected batteries serving as a neutral point, the three-level power line including a neutral line connected to the neutral point, a positive potential line connected to a plus-side end of a row of the serially connected batteries, and a negative potential line connected to a minus-side end of the row of the serially connected batteries;

a three-level inverter for converting direct-current power supplied from the three-level power line into alternating-current power supplied to the electric motor;

and

a three-level converter for converting an alternating-current output of the generator into a three-level-potential direct-current voltage supplied to the three-level power line.

6. The power supply of claim 5, further comprising:

a low-voltage auxiliary battery; and

a DC-DC converter for converting a power source voltage supplied to the three-level power line into a rated voltage of the low-voltage auxiliary battery,

wherein an output of the DC-DC converter is connected to a power supply line for the low-voltage auxiliary battery, and wherein a negative-side of the power supply line for the low-voltage auxiliary battery is connected to the neutral line of the three-level power line.

7. The power supply of claim 5, wherein the electric motor is arranged to power a single wheel of the vehicle.

8. A power supply for a vehicle, in which a plurality of batteries are serially connected, and in which a high voltage obtained from the serially connected batteries is supplied as a power source to a vehicle-driving electric motor, comprising:

a power supply cable capable of supplying at least three levels of voltage and forming a direct-current power supply line with an intermediate connection position of the serially connected batteries serving as a neutral point, the power supply cable comprising a neutral line connected to the neutral point, a positive potential line connected to a plus-side end of a row of the serially connected batteries, and a negative potential line connected to a minus-side end of the row of the serially connected batteries; and

a three-level inverter for converting direct-current power supplied from the power supply cable into alternating-current power supplied to the electric motor to drive the electric motor, a voltage applied between the neutral line and the positive potential line having substantially the same absolute value as a voltage applied between the neutral line and the negative potential line.

9. A power supply for a vehicle, in which a plurality of batteries are serially connected, and in which a high voltage obtained from the serially connected batteries is supplied as a power source to a vehicle-driving electric motor, comprising:

a power supply cable capable of supplying at least three levels of voltage and forming a direct-current power supply line with an intermediate connection position of the serially connected batteries serving as a neutral point, the power supply cable comprising a neutral line connected to the neutral point, a positive potential line connected to a plus-side end of a row of the serially connected batteries, and a negative potential line connected to a minus-side end of the row of the serially connected batteries; and

a three-level inverter for converting direct-current power supplied from the power supply cable into alternating-current power supplied to the electric motor.

10. The power supply of claim 9, wherein the withstand voltage required of control units coupled to the power line is halved.

11. The power supply of claim 9,

wherein the vehicle is a hybrid type vehicle including a generator that is driven by at least an internal combustion engine to generate electric power;

and

the power supply further comprises a three-level converter for converting an alternating-current output of the generator into a three-level-potential direct-current voltage supplied to the power supply cable.