System of controlling changeover of an electric power source for an electric motor vehicle

• US 5,389,825 A
• Filed: 03/17/1993
• Issued: 02/14/1995
• Est. Priority Date: 04/24/1991
• Status: Expired due to Fees

• Current Assignee: Aisin AW Company Limited (Aisin Corp.)
• Original Assignee: Aisin AW Company Limited (Aisin Corp.)
• Inventors: Minezawa, Yukihiro, Ishikawa, Masami
• Primary Examiner(s): Pellinen, A. D.
• Assistant Examiner(s): Fleming, Fritz M.
• Application Number:
  US08/032,699
• Time in Patent Office: 699 Days
• Field of Search: 180/65.1, 180/65.4, 180/65.8, 290/16, 290/17, 290/95, 290/40 R, 290/40 A, 290/40 C, 307/9.1, 307/10.1, 307/10.7, 307/80, 307/64, 307/66, 307/86, 307/120, 307/71, 307/81, 307/85, 307/87, 307/131, 307/124, 318/139
• US Class Current: 307/10.1
• CPC Class Codes: B60L 15/2045 for optimising the use of energy
• CPC Class Codes: B60L 50/61 by batteries charged by engine-driven generators, e.g. series hybrid electric vehicles
• 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: Y02T 10/72 Electric energy management in electromobility

Abstract

A system of changing over an electric power source for an electric motor vehicle including a secondary battery and a generator. The system is provided with a changeover circuit for changing over a state of connection between the secondary battery and the generator; and a controller for determining a power supply mode on the basis of a vehicle speed and an electric current value for driving a motor, the controller being adapted to instruct a changeover to the power supply mode to the switching circuit, thereby allowing high-speed and long-distance running.

Claims

1. A system of changing over an electric power source for an electric motor vehicle including a battery unit and a generator, comprising:

a changeover circuit for changing over a state of connection between said battery unit and said generator including a parallel connection state where said battery unit and said generator are connected in parallel and a series connection state where said battery unit and said generator are connected in series;

means for determining a speed of the vehicle;

means for measuring a current value of an electric motor of said vehicle;

a controller for determining a power supply mode, said controller being adapted to instruct a changeover of the state of connection to said changeover circuit based upon said determined power supply mode, wherein said controller estimates a current value of said electric motor, determines a first proposed power supply mode on the basis of said vehicle speed and said estimated current value and a second proposed power supply mode on the basis of said vehicle speed and said measured current value, compares said estimated current value and said measured current value, and selects the determined power supply mode from said first and second proposed power supply modes in accordance with the comparison, said determining of the first proposed power supply mode including defining the first proposed power supply mode as being the parallel connection state when the estimated current value is larger than a predetermined value and defining the first proposed power supply mode as being the series connection state when the estimated current value is less than the predetermined value, said determining of the second proposed power supply mode including defining the second proposed power supply mode as being the parallel connection state when the measured current value is larger than the predetermined value and defining the second proposed power supply mode as being the series connection state when the measured current value is less than the predetermined value.

2. A system of changing over an electric power source for an electric motor vehicle according to claim 1, wherein said controller selects the first proposed power supply mode as said determined power supply mode when said estimated current value is greater than said measured current value and selects the second proposed power supply mode as said determined power supply mode when said measured current value is greater than said estimated current value.

3. A system of changing over an electric power source for an electric motor vehicle according to claim 1, wherein said controller determines said estimated current value from a previous torque value of the electric motor, a previous measured current value of the electric motor and a present torque value of the electric motor.

4. A system of changing over an electric power source for an electric motor vehicle according to claim 1, wherein said changeover circuit includes transistors for changing over a state of connection between said battery and said generator, and said controller instructs the changeover of the state of connection according to whether or not a current is flowing in said changeover circuit.

5. A system of changing over an electric power source for an electric motor vehicle according to claim 1, wherein the controller adjusts the output current of the generator to maintain the generator current equal to or less than a predetermined level.