POWER STORAGE APPARATUS OF POWER GENERATION SYSTEM AND OPERATING METHOD OF POWER STORAGE APPARATUS

• US 20110193516A1
• Filed: 09/10/2009
• Published: 08/11/2011
• 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
• Granted Patent: US 8,575,886 B2
• Time in Patent Office: Days
• 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 installed in connection with a power generation system using natural energy generation power.

The power storage apparatus is composed of a control unit and a plurality of electricity storage devices. The control unit is structured so as to calculate a target value of power station output, calculate a charge and discharge power instruction of each of the plurality of electricity storage devices, and 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 so as to permit the charge rate of the plurality of secondary batteries to follow an individual charge rate target value according to the characteristics or operation history of the plurality of secondary batteries. This enables control of the charge and discharge of the plurality of electricity storage devices.

Claims

1. A power storage apparatus of a power generation system installed in connection with the power generation system using natural energy generation power of which changes with time for relieving generation power change of the power generation system by executing charge and discharge, wherein:

the power storage apparatus is composed of 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 control unit includes 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 to be charged and discharged by each of the plurality of electricity storage devices on the basis of the target value of the power station output calculated by the power station output target value calculator, a charge rate target value calculator for calculating a charge rate target value of the plurality of electricity storage devices, a charge rate calculator for detecting a charge rate of secondary batteries of the electricity storage devices, and a charge rate management charge and discharge instruction calculator for correcting the change relief charge and discharge instruction calculated by the charge and discharge power calculator on the basis of 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 calculating a correction value of a charge and discharge power instruction for instructing each of the electricity storage devices,

the converters are structured so as to control charge and discharge power of the secondary batteries so as to follow the charge and discharge power instruction instructed from the control unit and to relieve change of combined power formed by adding power outputted from the power generation system and charge and discharge power outputted from the power storage apparatus, and

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 composing the electricity storage devices and instructing the charge rate target value calculator.

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 calculated by the charge rate target value calculator and the charge rate detection value calculated by the charge rate calculator, and

the 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 calculated by the charge and discharge power calculator 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 composing the plurality of electricity storage devices are lead-acid batteries and the charge rate target value calculator for calculating the charge rate target value of the secondary batteries, when deterioration of the secondary batteries inferred by the deterioration condition inference calculator is inferred to progress, is structured so as to set the charge rate target value of the secondary batteries to a charge rate value close to full charge than the charge rate target value of the secondary batteries deterioration-unprogressed.

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

the secondary batteries composing the plurality of electricity storage devices are lithium ion batteries and the charge rate target value calculator for calculating the charge rate target value of the secondary batteries, when deterioration of the secondary batteries inferred by the deterioration condition inference calculator is inferred to progress, is structured so as to set the charge rate target value of the secondary batteries to a charge rate value close to a discharge condition than the charge rate target value of the secondary batteries deterioration-unprogressed.

5. A power storage apparatus of a power generation system installed in connection with the power generation system using natural energy generation power of which changes with time for relieving generation power change of the power generation system by executing charge and discharge, wherein:

the power storage apparatus is composed of a control unit and a plurality of electricity storage devices, and the plurality of electricity storage devices are composed of converters and secondary batteries,

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 to be charged and discharged by each of the plurality of electricity storage devices on the basis of the target value of the power station output calculated by the power station output target value calculator, an external input unit for inputting the charge rate target value of the plurality of electricity storage devices from outside, a charge rate calculator for calculating the charge rate of the secondary batteries composing the plurality of electricity storage devices, and a calculator for correcting the change relief charge and discharge instruction calculated by the charge and discharge power calculator on the basis of the charge rate target value inputted from the external input unit and the charge rate detection value detected by the charge rate calculator and calculating a correction value of a charge and discharge power instruction for instructing each of the electricity storage devices.

6. An operating method of a power storage apparatus of a power generation system installed in connection with the power generation system using natural energy generation power of which changes with time for relieving generation power change of the power generation system by executing charge and discharge, wherein the power storage apparatus is composed of a control unit and a plurality of electricity storage devices and the plurality of electricity storage devices are composed of converters and secondary batteries, 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 control unit,

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

calculating a correction value of the charge and discharge power instruction calculated by the charge and discharge power calculator by the charge rate management charge and discharge instruction calculator included in the control unit on the basis of the charge rate detection value of the secondary batteries of the electricity storage devices detected by the charge rate calculator and the charge rate target value calculated by the charge rate target value calculator,

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

controlling charge and discharge power of the secondary batteries by the converters so as to follow the charge and discharge power instruction instructed from the control unit, relieving change of combined power formed by adding power outputted from the power generation system and charge and discharge power outputted from the power storage apparatus, thereby operating the power storage apparatus of the power generation system.

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 the 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:

lead-acid batteries are used as the secondary batteries composing the plurality of electricity storage devices and the charge rate target value of the second batteries set by the charge rate target value calculator, when deterioration of the secondary batteries is inferred to progress by the deterioration index calculator, is set to a charge rate value close to full charge than the charge rate target value of the secondary batteries deterioration-unprogressed.

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

lithium ion batteries are used as the secondary batteries composing the plurality of electricity storage devices and the charge rate target value of the second batteries set by the charge rate target value calculator, when deterioration of the secondary batteries is inferred to progress by the deterioration index calculator, is set to a charge rate value close to a discharge condition than the charge rate target value of the secondary batteries deterioration-unprogressed.

10. An operating method of a power storage apparatus of a power generation system wherein the power storage apparatus installed in connection with the power generation system using natural energy generation power of which changes with time for relieving generation power change of the power generation system by executing charge and discharge is composed of a control unit and a plurality of electricity storage devices and the plurality of electricity storage devices are composed of converters and secondary batteries, and by charging and discharging by the power storage apparatus, change of combined power outputted by the power generation system and the power storage apparatus is relieved, comprising the steps of:

calculating a target value of power station output by 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 target value of the power station output calculated by the power station output target value calculator,

inputting a charge rate target value of the plurality of electricity storage devices from outside by the external input device included in the control unit,

calculating a charge rate of the secondary batteries composing the plurality of electricity storage devices by a charge rate calculator included in the control unit, and

correcting the change relief charge and discharge instruction calculated by the charge and discharge power calculator by the calculator included in the control unit on the basis of the charge rate target value inputted from the external input device and the charge rate detection value detected by the charge rate calculator, calculating the correction value of the charge and discharge power instruction, instructing the correction value of the charge and discharge power instruction to each electricity storage device, thereby operating the power storage apparatus of the power generation system.

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

lead-acid batteries are used as the secondary batteries composing the plurality of electricity storage devices and the charge rate target value inputted from the external input unit is set from a deterioration condition of the secondary batteries and when deterioration of the secondary batteries is inferred to progress, the charge rate target value of the secondary batteries is set to a charge rate close to full charge than the charge rate target value of the secondary batteries deterioration-unprogressed.

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

lithium ion batteries are used as the secondary batteries composing the plurality of electricity storage devices and the charge rate target value inputted from the external input unit is set from a deterioration condition of the secondary batteries and when deterioration of the secondary batteries is inferred to progress, the charge rate target value of the secondary batteries is set to a charge rate close to a discharge condition than the charge rate target value of the secondary batteries deterioration-unprogressed.

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

when setting the charge rate target value inputted from the external input unit from the deterioration condition of the secondary batteries, regarding inference of the deterioration condition of the secondary batteries, a dischargeable Ah capacity of the secondary batteries is measured and as the measured dischargeable Ah capacity is reduced, the deterioration is inferred to progress more.