Storage system that maximizes the utilization of renewable energy

• US 7,800,247 B2
• Filed: 05/30/2008
• Issued: 09/21/2010
• Est. Priority Date: 05/30/2008
• Status: Active Grant

• Current Assignee: Changs Ascending Enterprise Co., Ltd.
• Original Assignee: Chun-Chieh Chang, Olivia Pei-Hua Lee
• Inventors: Chang, Chun-Chieh, Lee, Olivia Pei-Hua
• Primary Examiner(s): KAPLAN, HAL IRA
• Application Number:
  US12/156,346
• Publication Number:
  US 20090295227A1
• Time in Patent Office: 844 Days
• Field of Search: 307/44, 307/45, 307/46, 307/48, 320/126, 320/152, 320/157
• US Class Current: 307/46
• CPC Class Codes: H02J 2300/24 of photovoltaic origin
• CPC Class Codes: H02J 2300/28 The renewable source being wind energy
• CPC Class Codes: H02J 3/32 using batteries with converting means
• CPC Class Codes: H02J 3/381 Dispersed generators
• CPC Class Codes: H02J 7/35 with light sensitive cells
• CPC Class Codes: Y02B 10/10 Photovoltaic [PV]
• CPC Class Codes: Y02B 10/30 Wind power
• 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

An electrical energy storage system for maximizing the utilization of renewable energy. In the system an inverter connected to at least one battery module is integrated with a grid power source and home or office electrical devices. Additionally, a renewable energy source can be included in the system. A controller is used to control the components for reducing demands on the grid power source during peak demand periods and for maximizing the utilization of the renewable energy source connected to the system.

Claims

1. An energy storage system, comprising a plurality of battery modules, electrically connected in parallel, each plurality of battery modules having an inverter electrically connected thereto to form a plurality of battery modules and inverter combination, the inverter having an AC output connected to one or more energy consuming devices and an AC input connected to a power grid,

each battery module of said plurality of battery modules having electrical properties similar to the remaining battery modules, and

each of the battery module having a maximum power output rating equal to or greater than a continuous maximum output power rating of the inverter, wherein

the plurality of battery modules and inverter combination is controlled to be in one of system control modes, said system control modes comprising:

1) an over-charge mode, wherein if a voltage detected from said battery module V is >

a sustainable high voltage limit V_H of the inverter, than then the inverter function is abandoned until a lower voltage limit V_H′

is reached;

2) an over-discharge mode, wherein if V<

a preset voltage V_L, than then the inverter is disconnected from the plurality of battery modules and the AC input of the inverter connected to the grid AC power source is connected, while disconnecting the battery power source, to the one or more energy consuming devices;

3) a recharge mode, wherein if V<

a preset voltage V″ and

if the time of day T is within a preset range R, then the plurality of battery modules is recharged from the inverter AC input connected to the power grid; and

4) a normal operating mode, wherein if V is V_H and if V is ≧

V_L and if T is not in the range R then the plurality of battery modules is connected to the inverter for providing energy through the inverter AC output to the one or more energy consuming devices.

2. The energy storage system of claim 1, further comprising

a maintenance mode, wherein if a period of time that has passed since being in the maintenance mode is a preset period of time, then the inverter provides a constant voltage charging at a voltage V′

″

to the plurality of battery modules for a preset period of time.

3. The energy storage system of claim 1, wherein

each battery module has therein at least one controller for monitoring the voltage of battery cells of the battery module.

4. The energy storage system of claim 1, wherein

each battery module has therein a relay for disconnecting the battery module.

5. The energy storage system of claim 1, wherein

each battery module has therein at least one means for disconnecting the battery module from the remaining battery modules and the inverter when the batteries is in the over-charge state V>

V_BH or over-discharge state V<

V_BL where V_BH is the battery over-charge voltage and V_BL is the battery over-discharge voltage.

6. The energy storage system of claim 5, wherein

each battery module has therein at least one means for reconnecting the battery module to the remaining battery modules and the inverter when the batteries exceeds the over-charge limit V>

B_H then followed by the condition of when V<

_BH′

where V_BH′

is a normal battery working voltage.

7. The energy storage system of claim 1, wherein each battery module when in an over-discharge state provides a visual or audible signal.

8. The energy storage system of claim 1, wherein

the inverter has a continuous power output in a range of 2 kW to 3 kW, and each battery module has a capacity range of 5 kWh to 10 kWh and an output voltage of 100 volts.

9. The energy storage system of claim 1, wherein

the inverter has a continuous power output in a range of 2 kW to 3 kW, and each battery module has a capacity range of 1 kWh to 10 kWh and an output voltage of 60 volts.

10. The energy storage system of claim 1, further comprising

a renewable energy source connected to the plurality of battery modules.

11. The energy storage system of claim 1, wherein

the inverter is disconnected from the plurality of battery modules with use of a relay.

12. The energy storage system of claim 1, wherein

the battery modules comprise Lithium Iron Phosphorous Oxide battery cells.

13. A combined energy storage system, comprising

a plurality of the energy storage systems of claim 1, wherein the plurality of battery modules of each energy storage system of claim 1 are connected in parallel to the plurality of battery modules of each other energy storage system of claim 1, and the number of battery modules is at least at least N+1 where N is the number of inverters.

14. An energy storage system, comprising

a battery module, each battery module having an inverter electrically connected thereto to form a battery module and inverter combination, the inverter having an AC output connected to one or more energy consuming devices and an AC input connected to a power grid,

the battery module having a maximum power output rating equal to or greater than a continuous maximum output power rating of the inverter, wherein

the battery module and inverter combination is controlled to be in one of system control modes, said system control modes comprising:

1) an over-charge mode, wherein if a voltage detected from said battery module V is >

a sustainable high voltage limit V_H of the inverter, then the inverter function is abandoned until a lower voltage limit V_H′

is reached;

2) an over-discharge mode, wherein if V<

a preset voltage V_L, then the inverter is disconnected from the battery module and the AC input of the inverter connected to the grid AC power source is connected, while disconnecting the battery power source, to the one or more energy consuming devices;

3) a recharge mode, wherein if V<

a preset voltage V″ and

if the time of day T is within a preset range R, then the battery module is recharged from the inverter AC input connected to the power grid; and

4) a normal operating mode, wherein if V is ≦

V_H and if V is ≧

V_L and if T is not in the range R then the battery module is connected to the inverter for providing energy through the inverter AC output to the one or more energy consuming devices.