Control system and control method of combined system having secondary battery and generator

• US 20010024105A1
• Filed: 03/23/2001
• Published: 09/27/2001
• Est. Priority Date: 03/24/2000
• Status: Active Grant

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Abe, Takaaki
• Granted Patent: US 6,388,421 B2
• Time in Patent Office: Days
• US Class Current: 320/132
• CPC Class Codes: B60L 2210/10 DC to DC converters
• CPC Class Codes: B60L 58/10 for monitoring or controlling batteries
• CPC Class Codes: B60L 58/40 for controlling a combination of batteries and fuel cells
• CPC Class Codes: H02J 7/1415 with a generator driven by a prime mover other than the motor of a vehicle
• CPC Class Codes: H02J 7/1438 in combination with power supplies for loads other than batteries
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility
• CPC Class Codes: Y02T 90/40 Application of hydrogen technology to transportation, e.g. using fuel cells

Abstract

A control system and a control method of a combined system having a secondary battery 15 and a fuel cell power generation system 12 are disclosed. wherein a vehicle controller 20 repeats a secondary battery-charging running mode wherein electric power output of the power generation system 12 is supplied to the secondary battery 15 and a motor 11, and a secondary battery-discharging running mode wherein electric power output of the power generation system 12 and electric power output discharged from the secondary battery 15 are supplied to the motor 11. In such a control, the amounts of electric power output of the power generation system 12 and electric power output discharged from the secondary battery 15 are set to values to provide the maximum total efficiency that is computed in conjunction with a charging efficiency of the secondary battery 15 during the secondary battery-charging running mode.

Claims

1. A control system controlling a combined system having a secondary battery and an electric power generator, and serving as a power supply for a load, the secondary battery being charged by use of the electric power generator, the control system comprising:

a charging efficiency calculating section calculating a charging efficiency of the secondary battery in conjunction with an electric power output of the electric power generator;

a total efficiency data calculating section calculating total efficiency data in response to a demanded electric power of the load; and

an electric power supply controlling section controlling allocation of an electric power output of the secondary battery and an electric power output of the electric power generator both to be supplied to the load;

wherein the electric power supply controlling section sets an electric power output of the secondary battery and an electric power output of the electric power generator both to be supplied to the load on the basis of the charging efficiency and the total efficiency data.

2. A control system according to

claim 1

, wherein the total efficiency data calculating section calculates the total efficiency data in response to the demanded electric power of the load, on the basis of an electric power generation efficiency of the electric power generator and a discharging efficiency of the secondary battery, for each charging efficiency of the secondary battery.

3. A control system according to

claim 2

, wherein the total efficiency corresponds to a total operating efficiency obtained when an electric power output is produced by the electric power generator, the secondary battery is charged by the electric power output, and the secondary battery is discharged.

4. A control system according to

claim 1

, wherein the electric power supply controlling section sets the electric power output of the secondary battery and the electric power output of the electric power generator both to be supplied to the load so as to provide a maximum total efficiency with respect to corresponding one of the charging efficiency of the second battery while using the total efficiency data.

5. A control system according to

claim 1

, wherein the charging efficiency calculating section calculates the charging efficiency of the secondary battery in such a manner that an average charging efficiency of the secondary battery is obtained when the secondary battery is charged with an electric power output of the electric power generator.

6. A control system according to

claim 1

, wherein the secondary battery and the electric power generator are installed in a vehicle and the load includes an electric motor of the vehicle driving the same, and wherein the electric power supply controlling section controls the allocation of the electric power output of the secondary battery and the electric power output of the electric power generator in correspondence with a first running mode wherein the electric power output of the electric power generator is supplied to the load for driving the same and to the second battery for charging the same, and with a second running mode wherein the electric power output of the electric power generator and an electric power output discharged from the secondary battery are supplied to the load for driving the same.

7. A control system according to

claim 6

, wherein the electric power supply controlling section sets the electric power output of the secondary battery and the electric power output of the electric power generator both to be supplied to the load on the basis of the charging efficiency and the total efficiency data in the first running mode.

8. A control system according to

claim 6

, wherein the charging efficiency calculating section calculates the charging efficiency of the secondary battery in conjunction with the electric power output of the electric power generator in the second running mode.

9. A control system controlling a combined system having a secondary battery and an electric power generator, and serving as a power supply for a load, the secondary battery being charged by use of the electric power generator, the control system comprising:

means for calculating a charging efficiency of the secondary battery in conjunction with an electric power output of the electric power generator;

means for calculating total efficiency data in response to a demanded electric power of the load; and

means for controlling allocation of an electric power output of the secondary battery and an electric power output of the electric power generator both to be supplied to the load, while setting an electric power output of the secondary battery and an electric power output of the electric power generator both to be supplied to the load on the basis of the charging efficiency and the total efficiency data.

10. A method of controlling a combined system having a secondary battery and an electric power generator, and serving as a power supply for a load, the secondary battery being charged by use of the electric power generator, the method comprising:

calculating a charging efficiency of the secondary battery in conjunction with an electric power output of the electric power generator;

calculating total efficiency data in response to a demanded electric power of the load; and

controlling allocation of an electric power output of the secondary battery and an electric power output of the electric power generator both to be supplied to the load, while setting an electric power output of the secondary battery and an electric power output of the electric power generator both to be supplied to the load on the basis of the charging efficiency and the total efficiency data.