Power storage apparatus of power generation system and operating method of power storage apparatus

• US 8,575,886 B2
• Filed: 09/10/2009
• Issued: 11/05/2013
• Est. Priority Date: 09/10/2009
• Status: Active Grant

• Current Assignee: Hitachi Engineering & Services Company Limited (Hitachi, Ltd.)
• Original Assignee: Hitachi Engineering & Services Company Limited (Hitachi, Ltd.)
• Inventors: Oohara, Shinya, Hoshino, Naoki, Rikitake, Masaki
• Primary Examiner(s): DIAO, M BAYE
• Application Number:
  US12/865,108
• Publication Number:
  US 20110193516A1
• Time in Patent Office: 1,517 Days
• Field of Search: 320/101, 290/44
• US Class Current: 320/101
• CPC Class Codes: F03D 9/11 storing electrical energy
• CPC Class Codes: F03D 9/25 the apparatus being an electrical generator F03D9/22 takes precedence
• 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 7/0048 Detection of remaining charge capacity or state of charge [SOC]
• CPC Class Codes: Y02E 10/72 Wind turbines with rotation axis in wind direction
• 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

A power storage apparatus is installed in connection with a power generation system using natural energy generation power. The power storage apparatus is comprised of a control unit and a plurality of electricity storage devices. The control unit is structured to calculate a target value of power station output, to calculate a charge and discharge power instruction of each of the plurality of electricity storage devices, and to instruct the charge and discharge. The control unit calculates a correction value of the charge and discharge power to be charged and discharged by the power storage apparatus to permit the charge rate of the plurality of secondary batteries to follow an individual charge rate target value.

Claims

1. A power storage apparatus in connection with a power generation system using natural energy having a generation power which changes with time, the power storage apparatus mitigates changes to the generation power of the power generation system, the power storage apparatus comprising:

a plurality of electricity storage devices, where the plurality of electricity storage devices are composed of converters and secondary batteries, and the converters include a charge rate detector for detecting a charge rate of the secondary batteries; and

a control unit including a power station output target value calculator for calculating a target value of power station output, a charge and discharge power calculator for calculating a change relief charge and discharge instruction for executing charging and discharging by each of the plurality of electricity storage devices on the basis of the target value of the power station output, a charge rate target value calculator for calculating a charge rate target value of the plurality of electricity storage devices, and a charge rate management charge and discharge instruction calculator for correcting the change relief charge and discharge instruction on the basis of the charge rate target value and the charge rate detected by the charge rate detector and calculating a correction value of a charge and discharge power instruction for instructing the charging and discharging of the electricity storage devices,

wherein the converters are configured to control a charge and discharge power of the secondary batteries so as to follow the charge and discharge power instruction from the control unit and to mitigate changes to a combined power formed by adding the power outputted from the power generation system and the charge and discharge power outputted from the power storage apparatus, and

wherein the control unit includes a deterioration index calculator for calculating a correction value of the charge rate target value of the power storage apparatus according to characteristics or an operation history of the plurality of secondary batteries and instructing the charge rate target value calculator of the correction value.

2. The power storage apparatus of a power generation system according to claim 1, wherein:

the charge and discharge power instruction calculator includes a charge rate control charge and discharge power instruction calculator for calculating a charge rate control charge and discharge power instruction for controlling the charge rate of the secondary batteries from a difference between the charge rate target value and the detected charge rate, and

the charge rate management charge and discharge instruction calculator for calculating the correction value of the charge and discharge power instruction is a calculator for assuming an added value of the change relief charge and discharge instruction and the charge rate control charge and discharge power instruction as a correction value of the charge and discharge power instruction instructed to each of the electric storage devices.

3. The power storage apparatus of a power generation system according to claim 1, wherein:

the secondary batteries are lead-acid batteries and the charge rate target value calculator f, when deterioration of the secondary batteries is inferred by the deterioration condition inference calculator, is configured to set the charge rate target value of the secondary batteries to a charge rate value closer to a full charge than a charge rate target value of non-deteriorated secondary batteries.

4. The power storage apparatus of a power generation system according to claim 1, wherein:

the secondary batteries are lithium ion batteries and the charge rate target value calculator, when deterioration of the secondary batteries inferred by the deterioration condition inference calculator is inferred to progress, is configured to set the charge rate target value of the secondary batteries to a charge rate value closer to a discharge condition than a charge rate target value of non-deteriorated secondary batteries.

5. A power storage apparatus in connection with a power generation system using natural energy having a generation power which changes with time, the power storage apparatus mitigates changes to the generation power of the power generation system the power storage apparatus comprising:

a plurality of electricity storage devices, where the plurality of electricity storage devices are composed of converters and secondary batteries, and the converters include a charge rate calculator for calculating the charge rate of the secondary batteries; and

a control unit having a power station output target value calculator for calculating a target value of power station output, a charge and discharge power calculator for calculating a change relief charge and discharge instruction for executing charging and discharging by each of the plurality of electricity storage devices on the basis of the target value of the power station output, an external input unit for inputting a charge rate target value of the plurality of electricity storage devices, and a calculator for correcting the change relief charge and discharge instruction on the basis of the charge rate target value and the calculated charge rate and calculating a correction value of a charge and discharge power instruction for instructing the charging and discharging of the electricity storage devices.

6. An operating method of a power storage apparatus installed in connection with a power generation system using natural energy having a generation power which changes with time, the power storage apparatus mitigating changes to the generation power, where the power storage apparatus has a control unit and a plurality of electricity storage devices, the plurality of electricity storage devices being composed of converters and secondary batteries, the operating method comprising the steps of:

detecting a charge rate of the secondary batteries of the electricity storage devices by a charge rate calculator included in the converters,

calculating a power station output target value using power station output target value calculators included in the control unit, and calculating and outputting a charge and discharge power instruction for executing charging and discharging by each of the plurality of electricity storage devices by a charge and discharge power calculator on the basis of the power station output target value;

calculating a correction value of the charge and discharge power instruction calculated by the charge and discharge power calculator using a charge rate management charge and discharge instruction calculator included in the control unit on the basis of a detected charge rate of the secondary batteries and a charge rate target value;

calculating a correction value of the charge rate target value of the power storage apparatus using a deterioration index calculator included in the control unit according to one of characteristics and an operation history of the secondary batteries and instructing a charge rate target value calculator of the correction value of the charge rate target value, and

controlling the charging and discharging power of the secondary batteries by the converters so as to follow the charge and discharge power instruction from the control unit, and mitigating changes to a combined power formed by adding the power outputted from the power generation system and the charge and discharge power outputted from the power storage apparatus.

7. The operating method of a power storage apparatus of a power generation system according to claim 6, wherein:

the charge rate management charge and discharge instruction calculator calculates the correction value of the charge and discharge power instruction for controlling the charge rate of the secondary batteries from a difference between the charge rate target value calculated by the charge rate target value calculator and the charge rate detection value detected by the charge rate calculator and assumes an added value of correction values of a change relief charge and discharge instruction and the charge and discharge power instruction as a correction charge and discharge power instruction for correcting the charge and discharge power instruction.

8. The operating method of a power storage apparatus of a power generation system according to claim 6, wherein

the secondary batteries are lead-acid batteries and the charge rate target value of the secondary batteries set by the charge rate target value calculator, when deterioration of the secondary batteries is inferred by a deterioration index calculator, is set to a charge rate value closer to a full charge than to a charge rate target value of non-deteriorated secondary batteries.

9. The operating method of a power storage apparatus of a power generation system according to claim 6, wherein:

the secondary batteries are lithium ion batteries and the charge rate target value of the secondary batteries set by the charge rate target value calculator, when deterioration of the secondary batteries is inferred by a deterioration index calculator, is set to a charge rate value closer to a discharge condition than to a charge rate target value of non-deteriorated secondary batteries.

10. An operating method of a power storage apparatus where the power storage apparatus is installed in connection with a power generation system using natural energy having a generation power which changes with time, the power storage apparatus mitigating changes to the generation power, where the power storage apparatus has a control unit and a plurality of electricity storage devices and the plurality of electricity storage devices are composed of converters and secondary batteries, the operating method comprising the steps of:

calculating a power station output target value using a power station output target value calculator included in the control unit,

calculating a change relief charge and discharge instruction to be charged and discharged by each of the plurality of electricity storage devices by a charge and discharge power calculator included in the control unit on the basis of the power station output target value;

inputting a charge rate target value of the plurality of electricity storage devices by an external input device;

calculating a charge rate of the secondary batteries by a charge rate calculator included in the converters; and

correcting the change relief charge and discharge instruction on the basis of the charge rate target value and the charge rate of the secondary batteries calculated by the charge rate calculator included in the converters, calculating a correction value of the charge and discharge power instruction, and instructing the correction value of the charge and discharge power instruction to each electricity storage device.

11. The operating method of a power storage apparatus of a power generation system according to claim 10, wherein:

the secondary batteries are lead-acid batteries and the charge rate target value is set from a deterioration condition of the secondary batteries and when deterioration of the secondary batteries is inferred, the charge rate target value of the secondary batteries is set to a charge rate closer to a full charge than to a charge rate target value of non-deteriorated secondary batteries.

12. The operating method of a power storage apparatus of a power generation system according to claim 10, wherein:

the secondary batteries are lithium ion batteries and the charge rate target value is set from a deterioration condition of the secondary batteries and when deterioration of the secondary batteries is inferred, the charge rate target value of the secondary batteries is set to a charge rate closer to a discharge condition than to a charge rate target value of non-deteriorated secondary batteries.

13. The operating method of a power storage apparatus of a power generation system according to claim 11, wherein:

the deterioration of the secondary batteries is inferred from a measured discharge capacity of the secondary batteries and as the measured discharge capacity of the secondary batteries is reduced, the deterioration of the secondary batteries is inferred.