Distributed Charge Controller

• US 20180323639A1
• Filed: 05/05/2017
• Published: 11/08/2018
• Est. Priority Date: 05/05/2017
• Status: Active Grant

• Current Assignee: Hall Labs, LLC
• Original Assignee: Hall Labs, LLC
• Inventors: Hall, David R., Myer, Seth, Fox, Joe
• Granted Patent: US 10,411,499 B2
• Time in Patent Office: Days
• CPC Class Codes: H01L 31/0504 specially adapted for series or parallel connection of solar cells in a module
• CPC Class Codes: H02J 7/00041 in response to measured battery parameters, e.g. voltage, current or temperature profile
• CPC Class Codes: H02J 7/00047 with provisions for charging different types of batteries
• CPC Class Codes: H02J 7/0013 acting upon several batteries simultaneously or sequentially H02J7/1423 takes precedence
• CPC Class Codes: H02J 7/0019 using switched or multiplexed charge circuits
• CPC Class Codes: H02J 7/0048 Detection of remaining charge capacity or state of charge [SOC]
• CPC Class Codes: H02J 7/005 Detection of state of health [SOH]
• CPC Class Codes: H02J 7/35 with light sensitive cells
• CPC Class Codes: H02S 40/38 Energy storage means, e.g. batteries, structurally associated with PV modules
• CPC Class Codes: H02S 50/00 Monitoring or testing of PV systems, e.g. load balancing or fault identification
• CPC Class Codes: Y02E 10/56 Power conversion systems, e.g. maximum power point trackers
• CPC Class Codes: Y02E 70/30 Systems combining energy storage with energy generation of non-fossil origin

Abstract

A distributed charge controller that matches a charging and power profile of each individual battery cell within a bank of batteries with one or more strings of photovoltaic (PV) cells in order to maintain battery health and performance. The charge controller further optimizes the performance of a solar module by allowing active unshaded strings of cells to operate independently of other strings within the module that may be shaded. Strings of PV cells are selectively matched to one or more battery cells as required.

Claims

1. A distributed charge control system comprising:

one or more photovoltaic (PV) modules producing a current, each PV module comprising one or more strings of PV cells connected in series;

a charge controller comprising a processor, memory and control electronics;

a battery bank comprising a plurality of battery cells connected in series; and

wherein the charge controller selectively connects each string of the one or more strings of PV cells to selectively charge one or more of the battery cells based on predefined logic.

2. The control system of claim 1, wherein each string of the one or more strings of PV cells is connected to a specific battery cell, the charge controller matching the voltage and current charging specifications of the specific battery cell.

3. The control system of claim 1, wherein two or more strings of the PV cells are connected to a first battery cell, the charge controller matching the voltage and current charging specifications of the first battery cell for a first period of time until the first cell is fully charged, whereupon the charge controller then switches charging to a second battery cell for a second period of time.

4. The control system of claim 1, wherein the charge controller further comprises maximum power point tracking logic and electronics.

5. The control system of claim 1, wherein the predefined logic comprises logic pre-programmed at a manufacturer;

user defined logic;

logic based on calculations from sensor inputs; and

logic based on calculations from charts and lookup tables stored in the memory.

6. The control system of claim 5, wherein the sensor inputs are received from sensors both within the control system and outside of the control system comprising sensors that sense voltage;

current;

temperature;

deformation of battery cells;

increase in internal pressure inside battery cells;

state of charge of individual battery cells;

charge rate of cells; and

discharge rate of cells

7. The control system of claim 1, wherein the battery cells comprise lithium iron phosphate chemistry.

8. The control system of claim 1, wherein the sensor inputs further comprise identifying inputs from sensors that indicate battery chemistry type.

9. The control system of claim 8, wherein the control system adjusts charging current, and charging rate based on the identifying inputs indicating battery type.

10. The control system of claim 1, wherein the sensor inputs indicate a time period during which an unproductive string of PV cells are not producing minimum voltage and current levels because they are shaded or obstructed, whereupon the charge controller switches charging to a productive string of PV cells.

11. The control system of claim 1, wherein the charge controller connects multiple strings of the two or more strings of PV cells in one or more PV modules in series in order to increase the voltage output.

12. The control system of claim 11, wherein the charge controller of a first PV module is in communication with one or more charge controllers of one or more additional PV modules allowing the extension of all of the functions of a single distributed charge control system to a combined system of PV modules.

13. The control system of claim 1, wherein the charge controller selectively connects two or more strings of PV cells from two or more PV modules to selectively charge one or more of the battery cells based on the predefined logic.

14. The control system of claim 1, wherein the charge controller determines from the sensor inputs, non-productive strings of the one or more strings of PV cells which are damaged or non-productive, and isolates the non-productive strings from the system.

15. The control system of claim 1, wherein the charge controller monitors and controls the use of each battery cell based on a scheduled health and maintenance profile stored in the memory, maintaining and updating the health and maintenance profile related to each individual battery cell.

16. The control system of claim 15, wherein the charge controller adjusts a unique battery cell specific charging profile and discharge profile for each individual battery cell according to the health and maintenance profile for that unique battery cell.

17. The control system of claim 15, wherein the charge controller calculates a target power based on a charging profile of the battery cell, and adjusts the charging and discharging of the battery cell based on the target power.

18. The control system of claim 1, wherein the charge controller calculates a target group power based on a charging profile of a specific group of battery cells, and adjusts the charging and discharging of the specific group of battery cells based on the target group power.

19. The control system of claim 18, wherein the charge controller selectively combines power outputs of one or more strings of PV cells and one or more battery cells to meet an electrical load based on power requirements of the electrical load, the target power of the battery cells, and the power available from the one or more strings of PV cells.

20. The control system of claim 1, wherein the one or more strings of PV cells are arranged in horizontal, vertical, circular, and or diagonal clusters, or a combination thereof having an equal or unequal number of cells.