Storage battery system and solar power generation system having the same

Patent metadata

Field	Value
Publication number	US-9941734-B2
Application number	US-201615007492-A
Country	US
Kind code	B2
Filing date	Jan 27, 2016
Priority date	Jan 28, 2015
Publication date	Apr 10, 2018
Grant date	Apr 10, 2018

Abstract

A solar power generation system includes a storage battery, a solar power generation device that is provided on the side of the storage battery and outputs solar generated power, and a power control device. The power control device includes a variation component extraction unit that extracts a shade variation component from a generated power signal measured by the solar power generation device, a smoothing unit that smoothens the shade variation component obtained by the variation component extraction unit, a system output correction unit that obtains a system output power target value which is a combined output between a discharge output of the storage battery and the solar generated power on the basis of an output signal from the smoothing unit, and a charge/discharge output correction unit that corrects a charge/discharge target value which is a difference between the system output power target value and the generated power signal on the basis of a current time and a state of charge of the storage battery.

First claim

What is claimed is:

1. A solar power generation system comprising:
a storage battery;
a solar power generation device that is provided on the side of the storage battery and outputs solar generated power; and
a power control device,
wherein the power control device includes
a variation component extraction unit that extracts a shade variation component from a generated power signal measured by the solar power generation device;
a smoothing unit that smoothens the shade variation component obtained by the variation component extraction unit;
a system output correction unit that obtains a system output power target value which is a combined output between a discharge output of the storage battery and the solar generated power on the basis of an output signal from the smoothing unit; and
a charge/discharge output correction unit that corrects a charge/discharge target value which is a difference between the system output power target value and the generated power signal on the basis of a current time and a state of charge of the storage battery.

2. The solar power generation system according to claim 1 ,
wherein the power control device further includes a standard generated power calculation unit that obtains generated power obtained by the solar power generation device in fine weather as standard generated power, and
wherein the variation component extraction unit extracts the shade variation component on the basis of the generated power signal and the standard generated power.

3. The solar power generation system according to claim 2 ,
wherein the charge/discharge output correction unit holds a threshold value of the state of charge in a preset nighttime period, and corrects the charge/discharge target value in a case where the current time is the set nighttime period and the state of charge of the storage battery exceeds the threshold value.

4. The solar power generation system according to claim 3 ,
wherein the charge/discharge output correction unit holds information for defining different correspondence relationships between states of charge and deterioration tendencies depending on the type of storage battery, and sets a threshold value of the state of charge on the basis of the correspondence relationships between the states of charge and the deterioration tendencies.

5. The solar power generation system according to claim 3 ,
wherein the system output correction unit calculates a change rate of a system output power target value at the current time on the basis of a current value and a system output power target value at a predetermined time before the current time among the system output power target values obtained in a predetermined cycle, obtains forced termination upper limit power having a change rate which is higher than the calculated change rate, and combines the obtained forced termination upper limit power with a system output power target value up to the current time so as to generate a corrected system output power target value.

6. The solar power generation system according to claim 5 ,
wherein the power control device further includes a terminal provided with an insolation meter measuring an insolation amount and a display unit,
wherein the display unit of the terminal includes
a first display region that displays generated power output results of the solar power generation device and/or history of the insolation amount;
a second display region that displays a system diagram of the solar power generation system; and
a third display region that receives inputting of a parameter for defining the standard generated power.

7. A storage battery system comprising:
a storage battery that performs charging and discharging with solar generated power output from a solar power generation device; and
a power control device,
wherein the power control device includes
a variation component extraction unit that extracts a shade variation component from a generated power signal measured by the solar power generation device;
a smoothing unit that smoothens the shade variation component obtained by the variation component extraction unit;
a system output correction unit that obtains a system output power target value which is a combined output between a discharge output of the storage battery and the solar generated power on the basis of an output signal from the smoothing unit; and
a charge/discharge output correction unit that corrects a charge/discharge target value which is a difference between the system output power target value and the generated power signal on the basis of a current time and a state of charge of the storage battery.

8. The storage battery system according to claim 7 ,
wherein the power control device further includes a standard generated power calculation unit that obtains generated power obtained by the solar power generation device in fine weather as standard generated power, and
wherein the variation component extraction unit extracts the shade variation component on the basis of the generated power signal and the standard generated power.

9. The storage battery system according to claim 8 ,
wherein the charge/discharge output correction unit holds a threshold value of the state of charge in a preset nighttime period, and corrects the charge/discharge target value in a case where the current time is the set nighttime period and the state of charge of the storage battery exceeds the threshold value.

10. The storage battery system according to claim 9 ,
wherein the charge/discharge output correction unit holds information for defining different correspondence relationships between states of charge and deterioration tendencies depending on the type of storage battery, and sets a threshold value of the state of charge on the basis of the correspondence relationships between the states of charge and the deterioration tendencies.

11. The storage battery system according to claim 9 ,
wherein the system output correction unit calculates a change rate of a system output power target value at the current time on the basis of a current value and a system output power target value at a predetermined time before the current time among the system output power target values obtained in a predetermined cycle, obtains forced termination upper limit power having a change rate which is higher than the calculated change rate, and combines the obtained forced termination upper limit power with a system output power target value up to the current time so as to generate a corrected system output power target value.

12. A power control device comprising:
a variation component extraction unit that extracts a shade variation component from a generated power signal measured by a solar power generation device;
a smoothing unit that smoothens the shade variation component obtained by the variation component extraction unit;
a system output correction unit that obtains a system output power target value which is a combined output between a discharge output of a storage battery and the solar generated power on the basis of an output signal from the smoothing unit; and
a charge/discharge output correction unit that corrects a charge/discharge target value which is a difference between the system output power target value and the generated power signal on the basis of a current time and a state of charge of the storage battery.

13. The power control device according to claim 12 , further comprising:
a standard generated power calculation unit that obtains generated power obtained by the solar power generation device in fine weather as standard generated power,
wherein the variation component extraction unit e

Assignees

• Hitachi Ltd

Inventors

• Sano Yuko
• Takeda Kenji
• BEPPU Kenichirou
• Nagashima Yuuji
• Nomura Taichi

Classifications

• H02S40/30

  Electrical components · CPC title

• H02S40/38

  Energy storage means, e.g. batteries, structurally associated with PV modules · CPC title

• Y02E70/30

  Systems combining energy storage with energy generation of non-fossil origin · CPC title

• H02J7/35 Primary

  with light sensitive cells · CPC title

• H02J2101/24

  Photovoltaics · CPC title