Multiple power source system and apparatus, motor driving apparatus, and hybrid vehicle with multiple power source system mounted thereon

• US 6,476,571 B1
• Filed: 03/06/2000
• Issued: 11/05/2002
• Est. Priority Date: 03/11/1999
• Status: Expired due to Fees

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Sasaki, Shoichi
• Primary Examiner(s): Nappi, Robert E.
• Assistant Examiner(s): SMITH, TYRONE W
• Application Number:
  US09/519,585
• Time in Patent Office: 974 Days
• Field of Search: 318/139, 318/245, 318/254, 320/32, 320/17, 320/40, 320/64, 322/46, 322/28, 322/90, 322/94, 180/65.1, 307/64, 307/66
• US Class Current: 318/139
• 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 6/445 Differential gearing distribution type
• CPC Class Codes: B60L 15/007 Physical arrangements or structures of drive train converters specially adapted for the propulsion motors of electric vehicles
• CPC Class Codes: B60L 50/16 with provision for separate direct mechanical propulsion
• CPC Class Codes: B60L 50/40 using propulsion power supplied by capacitors
• CPC Class Codes: B60L 50/61 by batteries charged by engine-driven generators, e.g. series hybrid electric vehicles
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 10/26 for electrical energy, e.g. batteries or capacitors
• CPC Class Codes: B60W 10/30 including control of auxiliary equipment, e.g. air-conditioning compressors or oil pumps
• CPC Class Codes: H02P 2209/01 Motors with neutral point connected to the power supply
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility
• 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: Y10S 903/903 having energy storing means, e.g. battery, capacitor
• CPC Class Codes: Y10S 903/906 Motor or generator
• CPC Class Codes: Y10S 903/907 Electricity storage, e.g. battery, capacitor

Abstract

In a multiple power source system of the present invention that has an inverter connected to a reactance, such as three-phase coils in a motor, a high voltage battery is connected with a low voltage battery via one transistor (Tr2) and one diode (D2) included in the inverter and one phase coil (U-phase coil) of the three-phase motor. The transistor Tr2 is turned on to make the electric current flow from the low voltage battery to the U-phase coil. The transistor Tr2 is subsequently turned off at a preset timing, so that the electric energy accumulated in the reactance, that is, the U-phase coil, flows through the diode D1 into the high voltage battery and thereby charges the high voltage battery. This arrangement enables the charging process from the low voltage battery to the high voltage battery without any complicated circuit structure for the voltage step-up. The three-phase motor may be unipolar driven with transistors connected to one side of the inverter. The arrangement of the present invention does not require any complicated structure, which undesirably increases the size of the multiple power source system, in order to ensure mutual supplement of the electric energy between electric systems having a large difference in voltage, for example, an electric system for driving a hybrid vehicle and an electric system for its control circuit.

Claims

1. A multiple power source system that supplies an electric power to a three-phase motor, said three-phase motor having Y-connected windings,

said multiple power source system comprising:

a first direct current power source;

a power control circuit that is disposed between said first direct current power source and the Y-connected windings of said three-phase motor and has switching elements, which are switched on and off to supply an electric power output from said first direct current power source to said three-phase motor;

a second direct current power source that is different from said first direct current power source; and

a unit that prevents said first direct current power source from being charged with the electric power output from said second direct current power source while said switching elements are switched off,

wherein one terminal of said second direct current power source is connected with a terminal of said first direct current power source having an identical polarity, and

the other terminal of said second direct current power source is connected with a neutral point of the Y-connected windings in said three-phase motor, said multiple power source system further comprising;

a charging control unit that controls the switching on and off of said switching elements and uses the windings of said three-phase motor to boost a voltage of said second direct current power source, and charges said first direct current power source with the boosted electric power output, when lack of the power supplied from said first direct current power source is detected, before said first direct current power source drives said three-phase motor.

2. A multiple power source system in accordance with claim 1, wherein said power control circuit comprises a pair of the switching elements that are provided for each of the windings of said three-phase motor and are interposed between a positive power line and a negative power line of said first direct current power source,

each of the switching elements being connected with a protection diode in a reverse direction,

a connection point of each pair of the switching elements being connected to the corresponding winding,

said charge unit switching on a switching element that is selected among the pairs of the switching elements and is included in a closed circuit including said second direct current power source and the corresponding winding, and subsequently turning off the selected switching element, so as to cause said first direct current power source to be charged via said protection diode.

3. A multiple power source system in accordance with claim 1, said multiple power source system further comprising:

a charge sensor that measures a charge level of said first direct current power source by said charge unit; and

a charge control circuit that controls a working condition of said charge unit, based on the observed charge level by said charge sensor.

4. A multiple power source system in accordance with claim 3, wherein said charge control circuit comprises:

a detection unit that detects a charging state of said first direct current power source, based on the observed charge level by said charge sensor; and

a working condition determination unit that determines the working condition of said charge unit, based on a result of the detection by said detection unit.

5. A multiple power source system in accordance with claim 1, said multiple power source system further comprising:

a connection switching unit that switches a connection of a circuit including said second direct current power source and the neutral point of the Y-connected windings between a substantially closed state and an open state; and

a connection control unit that, when said charge unit starts working, drives said connection switching unit to set the connection of the circuit including said second direct current power source and the neutral point of the Y-connected windings in the substantially closed state.

6. A multiple power source system in accordance with claim 1, wherein said first direct current power source is a battery.

7. A multiple power source system in accordance with claim 1, wherein said first direct current power source is a high-power capacitor.

8. A multiple power source system that supplies an electric power to a three-phase motor, said three-phase motor having Δ

-connected windings,

said multiple power source system comprising;

a first direct current power source that is chargeable;

a power control circuit that is disposed between said first direct current power source and the Δ

-connected windings of said three-phase motor and has switching elements, which are switched on and off to supply an electric power output from said first direct current power source to said three-phase motor;

a second direct current power source outputting the voltage that is lower than that of said first direct current power source, and a unit that prevents the first direct current power source from being charged with electric power output from said second direct current power source while said switching elements are switched off wherein one terminal of said second direct current power source is connected with a terminal of said first direct current power source having an identical polarity, and the other terminal of said second direct current power source is connected to one terminal of the Δ

-connected windings in said three-phase motor; and

a charge unit that controls switch-on and -off operations of a specific switching element that is connected to a specific winding, to which one terminal of said second direct current power source is not directly connected, in order to step up a voltage using the specific winding of said three-phase motor when a lack of power supplied from said first direct current power source is detected, before said first direct current power source drives said three phase-phase motor, thereby causing said first direct current power source to be charged with an electric power output from said second direct current power source.

9. An apparatus comprising an engine that is directly driven by means of a fuel and outputs a power to an output shaft, a three-phase motor that is connected with said output shaft of said engine and has Y-connected windings, and a multiple power source system that supplies an electric power to said three-phase motor,

said multiple power source system comprising:

a first direct current power source that outputs an electric power for driving said three-phase motor;

a power control circuit that is disposed between said first direct current power source and the Y-connected windings of said three-phase motor and has switching elements, which are switched on and off to supply the electric power output from said first direct current power source to said three-phase motor; and

a second direct current power source that is different from said first direct current power source and is used to control said apparatus,

wherein one terminal of said second direct current power source is connected with a terminal of said first direct current power source having an identical polarity, and

the other terminal of said second direct current power source is connected with a neutral point of the Y-connected windings in said three-phase motor,

said apparatus further comprising;

a start control unit that drives said three-phase motor to start said engine; and

a start-time charge unit that, when a remaining charge of said first direct current power source is insufficient for driving said three-phase motor to start said engine, controls switching-on and -off operations of a specific switching element, which is connected to a specific winding selected among the Y-connected windings of said three-phase motor, at a time of starting said three-phase motor, in order to step up a voltage using the specific winding, thereby causing said first direct current power source to be charged with an electric power output from said second direct current power source.

10. An apparatus in accordance with claim 9, wherein said engine is an internal combustion engine, and said apparatus is a hybrid vehicle that drives with at least either one of a power output from said internal combustion engine and a power output from said three-phase motor.

11. A vehicle comprising a three-phase motor that drives a compressor of an air conditioner and has Y-connected windings, and a multiple power source system that functions as a power source of said three-phase motor,

said multiple power source system comprising:

a first direct current power source that is a high-power capacitor to drive said three-phase motor;

a power control circuit that is disposed between said first direct current power source and the Y-connected windings of said three-phase motor and has switching elements, which are switched on and of f to supply an electric power output from said first direct current power source to said three-phase motor; and

a second direct current power source that is used to control said vehicle,

wherein one terminal of said second direct current power source is connected with a terminal of said first direct current power source having an identical polarity, and

the other terminal of said second direct current power source is connected with a neutral point of the Y-connected windings in said three-phase motor,

said vehicle further comprising;

a start control unit that starts said three-phase motor with an electric charge accumulated in said first direct current power source; and

a start-time charge unit that, when the electric charge accumulated in said first direct current power source is insufficient for starting said three-phase motor, controls switching-on and -off operations of a specific switching element, which is connected to a specific winding selected among the Y-connected windings of said three-phase motor, at a time of starting said three-phase motor, in order to step up a voltage using the specific winding, thereby causing said first direct current power source to be charged with an electric power output from said second direct current power source.

12. A motor driving apparatus that drives a three-phase motor with an electric power output from a multiple power source system,

said three-phase motor having Y-connected windings,

said multiple power source system comprising:

a first direct current power source;

a power control circuit that is disposed between said first direct current power source and the Y-connected windings of said three-phase motor and has switching elements, which are switched on and off to supply an electric power output from said first direct current power source to said three-phase motor; and

a second direct current power source that is different from said first direct current power source,

wherein one terminal of said second direct current power source is connected with a terminal of said first direct current power source having an identical polarity, and

the other terminal of said second direct current power source is connected with a neutral point of the Y-connected windings in said three-phase motor,

said motor driving apparatus further comprising;

a first motor drive unit that causes said power control circuit to drive said three-phase motor by means of said first direct current power source; and

a second motor drive unit that independently switches on and off the switching elements that are connected to power lines of the connection of said first direct current power source with said second direct current power source, and unipolar driving said three-phase motor by means of said second direct current power source.

13. A motor driving apparatus in accordance with claim 12, wherein said power control circuit comprises a pair of the switching elements that are provided for each of the windings of said three-phase motor and are interposed between a positive power line and a negative power line of said first direct current power source,

a connection point of each pair of the switching elements being connected to the corresponding winding,

said second motor drive unit successively switching on and off one of each pair of the switched elements to form a closed circuit including said second direct current power source and the corresponding winding, thereby generating a field in said three-phase motor.

14. A motor driving apparatus that drives a three-phase motor with an electric power output from a multiple power source system,

said three-phase motor having Δ

-connected windings,

said multiple power source system comprising;

a first direct current power source;

a power control circuit that is disposed between said first direct current power source and the Δ

-connected windings of said three-phase motor and has switching elements, which are switched on and off to supply an electric power output from said first direct current power source to said three-phase motor; and

a second direct current power source that is different from said first direct current power source,

wherein one terminal of said second direct current power source is connected with a terminal of said first direct current power source having an identical polarity, and

the other terminal of said second direct current power source is connected with one terminal of the Δ

-connected windings,

said motor driving apparatus further comprising;

a first motor drive unit that causes said power control circuit to drive said three-phase motor by means of said first direct current power source; and

a second motor drive unit that independently switches on and off switching elements, to which the other terminal of said second direct current power source is not directly connected, among the switching elements that are connected to power lines of the connection of said first direct current power source with said second direct current power source, and irregular unipolar driving said three-phase motor by means of said second direct current power source.

15. A hybrid vehicle comprising an engine that is mounted thereon and directly driven with a fuel, a three-phase motor that works as a power source to drive said hybrid vehicle, a multiple power source system that supplies an electric power to said three-phase motor, and a motor driving apparatus that drives said three-phase motor,

said three-phase motor having Y-connected windings,

said multiple power source system comprising:

a first direct current power source;

a power control circuit that is disposed between said first direct current power source and the Y-connected windings of said three-phase motor and has switching elements, which are switched on and off to supply an electric power output from said first direct current power source to said three-phase motor; and

a second direct current power source that is different from said first direct current power source,

wherein one terminal of said second direct current power source is connected with a terminal of said first direct current power source having an identical polarity, and

the other terminal of said second direct current power source is connected with a neutral point of the Y-connected windings in said three-phase motor,

said motor driving apparatus comprising;

a first motor drive unit that causes said power control circuit to drive said three-phase motor by means of said first direct current power source; and

a second motor drive unit that independently switches on and off the switching elements that are connected to power lines of the connection of said first direct current power source with said second direct current power source, and unipolar driving said three-phase motor by means of said second direct current power source,

said three-phase motor being connected with either one of a drive shaft of said hybrid vehicle and a rotating shaft of said engine,

said drive shaft being driven according to a driving state of said hybrid vehicle with at least one of a power output from said engine and a power output from said three-phase motor.