Renewable energy system with integrated home power

• US 9,559,521 B1
• Filed: 12/09/2015
• Issued: 01/31/2017
• Est. Priority Date: 12/09/2015
• Status: Active Grant

• Current Assignee: King Electric Vehicles Inc.
• Original Assignee: King Electric Vehicles Inc.
• Inventors: King, Robert Dean
• Primary Examiner(s): Fureman, Jared
• Assistant Examiner(s): Pacheco, Rafael
• Application Number:
  US14/963,458
• Time in Patent Office: 419 Days
• US Class Current: 1/1
• CPC Class Codes: G05B 19/048 Monitoring; Safety
• CPC Class Codes: G05B 2219/40458 Grid adaptive optimization
• CPC Class Codes: G05F 1/66 Regulating electric power
• CPC Class Codes: H02J 2300/10 The dispersed energy generation being of fossil origin, e.g. diesel generators
• CPC Class Codes: H02J 2300/20 The dispersed energy generation being of renewable origin
• CPC Class Codes: H02J 2300/24 of photovoltaic origin
• CPC Class Codes: H02J 3/32 using batteries with converting means
• CPC Class Codes: H02J 3/381 Dispersed generators
• CPC Class Codes: H02J 3/46 Controlling of the sharing of output between the generators, converters, or transformers
• CPC Class Codes: H02J 7/007182 in response to battery voltage
• CPC Class Codes: H02J 7/34 Parallel operation in networks using both storage and other dc sources, e.g. providing buffering H02J7/14 takes precedence
• CPC Class Codes: H02J 7/35 with light sensitive cells
• CPC Class Codes: H02J 9/06 with automatic change-over , e.g. UPS systems
• CPC Class Codes: H02J 9/062 for AC powered loads
• CPC Class Codes: Y02B 10/10 Photovoltaic [PV]
• CPC Class Codes: Y02B 10/70 Hybrid systems, e.g. uninterruptible or back-up power supplies integrating renewable energies
• 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 renewable energy system that includes a grid-tied renewable energy source and home power supply system is disclosed. The grid-tied renewable energy source has a first inverter and distribution panel connected thereto on a first connection path. The power supply system is connected to the renewable energy source along a second connection path in parallel with the first connection path, with the power supply system including a voltage modification circuit, at least one energy storage device, and a second inverter, such that the power supply system may output an AC power to the distribution panel via the second connection path. A bi-directional utility meter measures a net flow of AC power output from the first and second inverters and a grid power to the load based on a power requirement of the load, and a controller controls an amount of power received by and output from the power supply system.

Claims

1. A renewable energy system comprising:

a renewable energy source configured to generate a power output;

a first inverter connected to the renewable energy source to convert at least a portion of the power output of the renewable energy source to a first AC power output;

a distribution panel operable to selectively connect the first inverter to each of a utility grid and a load, so as to selectively connect the first AC power output to one or more of the load and the utility grid;

a first connection path connecting the first inverter to the distribution panel to provide a transfer of the first AC power output to the distribution panel;

a power supply system connected to the renewable energy source along a second connection path in parallel with the first connection path, the power supply system comprising;

a voltage modification circuit configured to condition power received thereby to generate a DC power output;

at least one energy storage device configured to store the DC power output from the voltage modification circuit; and

a second inverter connected to the at least one energy storage device to receive DC power therefrom and convert the DC power to a second AC power output, with an output of the second inverter connected to the distribution panel via the second connection path;

a bi-directional utility meter configured to measure a net flow of the first AC power output, the second AC power output, and a grid power to the load from each of the renewable energy source, the power supply system, and the utility grid, respectively, based on a power requirement of the load; and

a controller in operable communication with the power supply system to control an amount of power received by the power supply system and control an amount of the second AC power output generated by the power supply system;

wherein the power supply system and the controller operate to provide a DC voltage on the second parallel connection path that is separately controllable from a DC voltage on the first connection path.

2. The renewable energy system of claim 1 further comprising a mode switch including one or more switching mechanisms, the mode switch operable in a normal mode and an emergency mode.

3. The renewable energy system of claim 2 wherein operation of the switch in the normal mode provides for a transfer of each of the first AC power output and the second AC power output to both the load and the utility grid;

and

wherein operation of the switch in the emergency mode;

prevents a transfer of each of the first AC power output and the second AC power output to the utility grid; and

provides for a transfer of at least one of the first AC power output and the second AC power output to the load.

4. The renewable energy system of claim 3 wherein the controller is programmed to:

identify an operative state of the utility grid, the operative state comprising one of a fully functioning utility grid and a utility grid failure;

operate the mode switch in the normal mode when the operative state of the utility grid is identified as being a fully functioning utility grid; and

operate the mode switch in the emergency mode when the operative state of the utility grid is identified as being a utility grid failure.

5. The renewable energy system of claim 1 wherein the controller is programmed to:

determine the power requirement of the load;

compare the power requirement of the load to the power output from the renewable energy source;

identify a state-of-charge (SOC) of the at least one energy storage device of the power supply system; and

selectively control a flow of the output power of the renewable energy source to the load and to the power supply system based on the comparison of the power requirement of the load to the power output from the renewable energy source and based on the SOC of the at least one energy storage device.

6. The renewable energy system of claim 5 wherein, when the power requirement of the load is approximately equal to the power output from the renewable energy source, the controller is programmed to cause approximately an entirety of the first AC power output from the first inverter to be provided to the load, with the power supply system providing no power to the load.

7. The renewable energy system of claim 5 wherein, when the power requirement of the load comprises a transient power requirement that periodically exceeds the power output from the renewable energy source, the controller is programmed to:

cause a portion of the first AC power output adequate to meet an average power requirement of the load to be provided from the first inverter to the load; and

cause the second AC power output to be provided from the second inverter to the load to meet transient portions of the power requirement of the load that exceed the power output from the renewable energy source.

8. The renewable energy system of claim 5 wherein, when the power requirement of the load exceeds the power output from the renewable energy source, the controller is programmed to:

cause the first AC power output from the first inverter to be provided to the load; and

selectively cause the second AC power output from the second inverter and grid power from the utility grid to be provided to the load; and

wherein, in selectively causing the second AC power output from the second inverter and grid power from the utility grid to be provided to the load, the controller is further programmed to;

monitor the SOC of the at least one energy storage device;

provide the second AC power output from the second inverter to the load as long as the SOC of the at least one energy storage device is above a pre-determined threshold; and

cause grid power to be provided to the load if the power requirement of the load exceeds the power available from both the first AC power output and the second AC power output or if the SOC of the at least one energy storage device falls below the pre-determined threshold.

9. The renewable energy system of claim 5 wherein, when the power requirement of the load is less than the power output from the renewable energy source, the controller is programmed to:

cause a portion of the power output of the renewable energy source to be provided to the first inverter, with the first inverter outputting a first AC power output adequate to meet the requirement of the load; and

cause another portion of the power output of the renewable energy source to be provided to the power supply system to charge the at least one energy storage device.

10. The renewable energy system of claim 9 wherein, the controller is programmed to:

determine when each of the at least one energy storage devices has reached a full charge; and

upon each of the at least one energy storage device having reached a full charge, cause an entirety of the power output of the renewable energy source to be provided to the first inverter, with the first inverter supplying the first AC power output to power additional loads and to provide power back to the utility grid.

11. The renewable energy system of claim 1 wherein the renewable energy source comprises a photovoltaic (PV) array and the first inverter comprises a plurality of micro-inverters configured to convert a power output of each of a plurality of cells of the PV array to an AC power output;

and

wherein the renewable energy system further comprises a combiner circuit configured to combine the AC power output of each of the plurality of micro-inverters into the first AC power output.

12. The renewable energy system of claim 1 wherein the first AC power output and the second AC power output are synchronized with the grid power from the utility grid, such that each of the first AC power output and the second AC power output have a same voltage, frequency, and phase as the grid power.

13. The renewable energy system of claim 1 further comprising an AC disconnect positioned between the distribution panel and the first inverter to selectively prevent a transfer of the first AC power output from the first inverter to the distribution panel.

14. The renewable energy system of claim 1 wherein the at least one energy storage device comprises:

a stationary energy storage device electrically coupled to a first voltage converter of the voltage modification circuit and comprising one or more home batteries; and

a mobile energy storage device bi-directionally electrically coupled to a second voltage converter of the voltage modification circuit, the mobile energy storage device incorporated into one of a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), an electric vehicle (EV), a fuel cell electric vehicle or fuel cell system with energy storage, or an internal combustion engine (ICE) vehicle.

15. The renewable energy system of claim 14 wherein the first voltage converter comprises one of:

an AC-DC voltage converter battery charger with AC interface electronics that receives AC power output from the first inverter when the first inverter comprises a plurality of micro-inverters, the AC-DC voltage converter battery charger configured to;

rectify and condition the received first AC power output to generate the DC power output; and

provide the DC power output to the at least one energy storage device or to both the at least one energy storage device and the second inverter; and

a DC-DC voltage converter that receives DC power output from the renewable energy source, the DC-DC voltage converter configured to;

condition the DC power from the renewable energy source to generate the DC power output; and

provide the DC power output to the at least one energy storage device or to both the at least one energy storage device and the second inverter.

16. The renewable energy system of claim 14 wherein the second voltage converter comprises one of:

an AC-DC voltage converter with AC interface electronics that receives AC power output from a generator device associated with the mobile energy storage device, the AC-DC voltage converter battery charger configured to;

rectify and condition AC power received from the generator device to generate a DC power output; and

provide the DC power output to the stationary energy storage device or to both the stationary energy storage device and the second inverter; and

a bi-directional DC-DC voltage converter selectively operable to;

provide DC power to the mobile energy storage device from at least one of the first voltage converter and the stationary energy storage device; and

receive DC power from the mobile energy storage device, the received DC power being conditioned to provide to the stationary energy storage device or to both the stationary energy storage device and the second inverter.

17. A home power supply system retrofittable for use with a grid-tied renewable energy system to selectively store power from a grid-tied renewable energy source and provide power to a load, the home power supply system comprising:

a voltage modification circuit coupleable to the renewable energy source to condition one of an AC power and a DC power received therefrom and generate a DC power output;

an energy storage system electrically coupled to the voltage modification circuit to store the DC power output;

a power supply DC-AC inverter electrically coupled to the energy storage system to receive DC power therefrom and convert the DC power to an AC power output, the energy storage system comprising one or more energy storage devices; and

a controller in operable communication with the voltage modification circuit, the at least one energy storage device, and the power supply DC-AC inverter, the controller being programmed to;

determine a power requirement of the load;

receive an input comprising a power output of the renewable energy source;

determine a state-of-charge (SOC) of the energy storage system; and

control an amount of power provided to the voltage modification circuit from the renewable energy source and an amount of the AC power output from the power supply DC-AC inverter based on each of the determined power requirement of the load, the power output of the renewable energy source, and the determined state of charge of the energy storage system.

18. The home power supply system of claim 17 wherein, when the power requirement of the load is less than the power output from the renewable energy source, the controller is further programmed to:

determine whether the SOC of the energy storage system is above or below a pre-determined threshold;

cause a portion of the power output of the renewable energy source to be provided to the voltage modification circuit when the SOC of the energy storage system is below the pre-determined threshold; and

cause an entirety of the power output of the renewable energy source to be diverted from the voltage modification circuit for supplying to the load and to one or more additional loads or a utility grid when the SOC of the energy storage system is above the pre-determined threshold.

19. The home power supply system of claim 17 wherein the controller is programmed to:

identify a voltage, frequency, and phase of an AC power output from a renewable energy inverter external to the home power supply system and connected in parallel therewith to the load, the renewable energy inverter also receiving a power output of the renewable energy source; and

control the power supply DC-AC inverter such that the voltage, frequency, and phase of the AC power output therefrom is synchronized with an AC power from a utility grid tied to the renewable energy inverter.

20. The home power supply system of claim 17 wherein the energy storage system comprises:

a stationary energy storage device electrically coupled to a first voltage converter of the voltage modification circuit and comprising one or more home batteries; and

a mobile energy storage device bi-directionally electrically coupled to a second voltage converter of the voltage modification circuit, the mobile energy storage device incorporated into one of a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), a fuel cell electric vehicle, a fuel cell system with energy storage, electric vehicle (EV), or an internal combustion engine (ICE) vehicle;

wherein the mobile energy storage device receives DC power from the second voltage converter of the voltage modification circuit during charging thereof and provides DC power to the voltage modification circuit during discharging thereof.

21. The home power supply system of claim 17 wherein a component voltage and power rating of the voltage modification circuit and the power supply DC-AC inverter is set based on the characteristics of the energy storage system in the home power supply system.