Power control method for secondary batteries

• US 8,080,898 B2
• Filed: 03/10/2008
• Issued: 12/20/2011
• Est. Priority Date: 03/16/2007
• Status: Active Grant

• Current Assignee: NGK Insulators Limited
• Original Assignee: NGK Insulators Limited
• Inventors: Fukuhara, Motohiro
• Primary Examiner(s): Muralidar, Richard V
• Application Number:
  US12/045,210
• Publication Number:
  US 20080224541A1
• Time in Patent Office: 1,380 Days
• Field of Search: 320/101, 307 43- 48
• US Class Current: 307/48
• CPC Class Codes: H02J 2300/20 The dispersed energy generation being of renewable origin
• CPC Class Codes: H02J 2300/24 of photovoltaic origin
• CPC Class Codes: H02J 2300/28 The renewable source being wind energy wind motors F03D
• CPC Class Codes: H02J 3/32 using batteries with converting means
• CPC Class Codes: H02J 3/381 Dispersed generators
• CPC Class Codes: H02J 3/466 Scheduling the operation of the generators, e.g. connecting or disconnecting generators to meet a given demand
• CPC Class Codes: Y02E 10/56 Power conversion systems, e.g. maximum power point trackers
• CPC Class Codes: Y02E 10/76 Power conversion electric or electronic aspects
• CPC Class Codes: Y02E 70/30 Systems combining energy storage with energy generation of non-fossil origin

Abstract

There is provided a power control method for secondary batteries constituting, in a grid connection system supplying electric power to a power system by combining a power generator where output power fluctuates with a power storage compensator, the power storage compensator and compensating fluctuation of output power of the power generator. The method includes the steps of: dividing the secondary batteries into a “constant power control” group and a “demand responsive” group, and distributing predetermined constant input-output power out of power to be input and output provided to all the secondary batteries in order to compensate fluctuation of output power of the power generator to the “constant power control group” and the remaining input-output power to the “demand responsive” group to control input-output power of the secondary batteries respectively depending on the belonging groups.

Claims

1. A power control method for secondary batteries constituting, in a grid connection system supplying electric power to a power system by combining a power generator whose output power fluctuates with a power storage compensator, the power storage compensator compensating for fluctuations of output power of the power generator;

the method comprising the steps of;

dividing the secondary batteries into a constant power control group and a demand responsive group, and

distributing a predetermined constant input-output power out of power to be input and output provided to all the secondary batteries in order to compensate for the fluctuations of output power of the power generator to the constant power control group and the remaining input-output power to the demand responsive group to control input-output power of the secondary batteries respectively depending on the belonging groups,

wherein the demand responsive group is further divided into a delay responsive group and an instant responsive group, input-output power subjected to a primary delay filter process out of the power to be input and output provided to the demand responsive group is distributed to the delay responsive group, and the remaining input-output power is distributed to the instant responsive group to control input-output power of the secondary batteries respectively depending on the belonging group, and

wherein an upper limit of the input-output power of each secondary battery is provided, differences between a value of power to be input and output provided to each secondary battery and the upper limit are summed up to obtain a total deficient power, and the total deficient power is redistributed to each secondary battery.

2. The power control method for secondary batteries according to claim 1, wherein the secondary batteries divided into the power control group and the demand responsive group are interchanged.

3. The power control method for secondary batteries according to claim 1, wherein the number of the secondary batteries belonging to the constant power control group and the demand responsive group are changed.

4. The power control method for secondary batteries according to claim 2, wherein the number of the secondary batteries belonging to the constant power control group and the demand responsive group are changed.

5. The power control method for secondary batteries according to claim 1, wherein the delay responsive group is further divided into plural groups, plural input-output powers subjected to a primary delay filter process with changing a time constant are distributed to each group to control input-output power of the secondary batteries respectively depending on the belonging group.

6. The power control method for secondary batteries according to claim 2, wherein the delay responsive group is further divided into plural groups, plural input-output powers subjected to a primary delay filter process with changing a time constant are distributed to each group to control input-output power of the secondary batteries respectively depending on the belonging group.

7. The power control method for secondary batteries according to claim 1, wherein the secondary batteries are sodium-sulfur batteries.

8. The power control method for secondary batteries according to claim 2, wherein the secondary batteries are sodium-sulfur batteries.

9. The power control method for secondary batteries according to claim 3, wherein the secondary batteries are sodium-sulfur batteries.

10. The power control method for secondary batteries according to claim 4, wherein the secondary batteries are sodium-sulfur batteries.

11. The power control method for secondary batteries according to claim 1, wherein the power generator whose output power fluctuates is a renewable power generator using at least one of wind power, solar light, and geothermal heat.