Energy storage system and method employing secondary life electric vehicle batteries

Abstract

An integrated battery energy storage system and a method for integrating electric vehicle battery packs into an integrated battery energy storage system are disclosed. The integrated battery energy system includes a plurality of electric vehicle battery packs coupled in a series / parallel arrangement, the series / parallel arrangement including a plurality of series strings of the electric vehicle battery packs, each of the plurality of series strings of the electric vehicle battery packs including at least two of the plurality of electric vehicle battery packs coupled in series, and wherein the plurality of series strings of the electric vehicle battery packs are connected in parallel.

Description

Technical Field

[0001] This disclosure generally relates to energy storage systems and methods employing secondary-life electric vehicle batteries, and more specifically, to an integrated battery energy storage system comprising multiple electric vehicle battery packs connected in a series / parallel arrangement. Background Technology

[0002] Reducing the cost of energy storage systems (ESS) is a key objective for electricity taxpayers and policymakers. The primary metric for measuring ESS cost is the levelized cost of storage (LCOS), which is defined as the total lifespan cost of the ESS, including construction and operating costs, divided by the cumulative transmitted electricity stored in the system.

[0003] Reusing the electrochemical batteries of electric vehicles (EVs) for secondary use or secondary lifetime stationary storage applications can significantly reduce the LCOS of an ESS (Electric Power Storage System). Deploying EV batteries in stationary storage applications is the highest and best use of batteries when they are no longer suitable for use in EVs. Larger-scale ESSs require a large number of batteries deployed in series and parallel electrical configurations to deliver high voltage and high current levels of energy. Whether electrically connected before or after the customer's meter, the ESS must effectively integrate and manage the batteries over time and through charge / discharge cycles to ensure their efficient operation. Summary of the Invention

[0004] The expectation is to have systems that utilize multiple electric vehicle (EV) batteries in secondary lifespan fixed storage applications throughout the entire energy storage system (ESS).

[0005] According to one aspect, an integrated battery energy storage system is disclosed, the integrated battery energy system comprising: a plurality of electric vehicle battery packs connected in a series / parallel arrangement, the series / parallel arrangement including a plurality of series strings of the electric vehicle battery packs, each of the plurality of series strings of the electric vehicle battery packs including at least two of the plurality of electric vehicle battery packs connected in series; and wherein the plurality of series strings of the electric vehicle battery packs are connected in parallel.

[0006] According to another aspect, an integrated battery energy storage system is disclosed, comprising: a plurality of electric vehicle battery packs configured to store energy; a housing configured to enable outdoor deployment of the energy storage components; a plurality of removable external housing panels configured to facilitate installation and removal of the plurality of electric vehicle battery packs from the housing; a plurality of DC-DC converters configured to balance the voltage or energy storage capacity of the series-connected electric vehicle battery packs; an environmental control unit within the housing configured to extend the service life of the plurality of electric vehicle battery packs within the housing; a rack system for the plurality of electric vehicle battery packs configured to provide electrical and thermal isolation between the plurality of electric vehicle battery packs; and an electric vehicle battery pack controller configured to use an electric vehicle battery management system without altering the original manufacturer's design and intended functionality.

[0007] According to one aspect, a method for integrating an electric vehicle battery pack into an integrated battery energy storage system is disclosed, the method comprising: connecting a plurality of electric vehicle battery packs in a series / parallel arrangement, the series / parallel arrangement including a plurality of series strings of the electric vehicle battery packs, each of the plurality of series strings of the electric vehicle battery packs including at least two of the plurality of electric vehicle battery packs connected in series; and connecting the plurality of series strings of the electric vehicle battery packs in parallel. Attached Figure Description

[0008] Figure 1 This is a block diagram illustrating an entity as part of an energy storage system according to an exemplary embodiment.

[0009] Figure 2 This is a modified electrical single-line schematic diagram of an energy storage system according to an exemplary embodiment.

[0010] Figure 3 The illustration shows a battery pack controller (BPC) and a smart combiner (SC) according to an exemplary embodiment.

[0011] Figure 4 The illustration shows the mechanical layout of the housing assembly according to an exemplary embodiment. Detailed Implementation

[0012] For simplicity and illustrative purposes, the principles of the embodiments are described primarily by way of example with reference to the embodiments. Numerous specific details are set forth in the following description to provide a thorough understanding of the embodiments. However, it will be apparent to those skilled in the art that the embodiments can be practiced without limiting these specific details. In some cases, well-known methods and structures have not been described in detail to avoid unnecessarily obscuring the embodiments.

[0013] On one hand, the EV Pack Storage System (EPS) uses EV battery packs as integrated functional units or building blocks, where multiple EV battery packs are easily grouped together to serve as larger cells within the ESS. The batteries can be placed in a dedicated, environmentally controlled enclosure that allows the batteries to be installed in the original packaging housing within the EV. The dedicated environmentally controlled enclosure serves as the integrated EV Pack Storage Unit, and the EPS serves as a subsystem building block within the entire ESS. EV battery packs within the EPS can be electrically connected in series and parallel. Each series string is protected against overcurrent. The EPS enclosure is designed for easy installation, removal, and replacement of the EV battery packs. Each battery pack and string can be monitored using a proprietary Battery Pack Controller (BPC). The BPC helps ensure correct operating parameters and monitors the health status of each EV battery pack. The Battery Pack Controller (BPC) can monitor the health status of each EV battery pack by engaging with the EV Pack Integrated Battery Management System (BMS). The BPC manages the Smart Combiner (SC) to actively balance secondary-life batteries to efficiently utilize the charge-discharge cycles of each pack, thereby adjusting for capacity differences in each pack. The environment of the EPS enclosure is managed to maintain a suitable operating temperature and facilitate hazard detection. EPS operates within a larger ESS that also includes an inverter power conversion system (PCS) and monitoring and data acquisition (SCADA) systems. Multiple EPS can operate together in an integrated manner within an ESS. The ESS can be configured to be DC-connected or AC-connected to the inverter. EPS can be charged via on-site power generation (such as solar or wind power) or via power supplied by the AC power system. EPS within the ESS can be deployed directly in front of an inter-grid meter (IFM) or behind a grid meter (BTM) to compensate for customer load and demand.

[0014] According to an exemplary embodiment, an integrated system for deploying multiple secondary life electric vehicle (EV) battery packs within an energy storage system (ESS) is disclosed.

[0015] In this disclosure, the EV Pack Storage System (EPS) referred to herein is an integrated functional building block in which multiple EV battery packs are easily aggregated to act as a larger battery within the entire ESS. The composition and function of the EPS include: (1) utilizing EV battery packs mechanically and electrically, as they do in initial one-life vehicle applications, including a battery management system (BMS) for the battery packs, as well as similar digital serial data link formats and protocols; and (2) the EV battery packs are arranged in parallel and typically electrically configured in series. (3) Multiple EV battery packs are integrated in an environmentally controlled and monitored cabinet or enclosure that is not considered an occupied space as defined by building or fire regulations, and in which one or more enclosures can be integrated into the ESS; (4) The battery pack controller (BPC) is deployed as part of the EPS to integrate communication and control components that are necessary for the batteries to work together and coordinate their operation as a unified functional block; and (5) The intelligent circuit combiner provides electrical balance and overcurrent protection for all EV battery packs within the EPS.

[0016] Figure 1 This is a block diagram illustrating the present disclosure as part of a grid-connected energy storage system in a preferred embodiment. According to an exemplary embodiment, the EV group storage system (EPS) 100 can be implemented as part of an integrated energy storage system (ESS). All thick lines 600 with arrows indicate electrical connections and possible directions of power flow. All dashed lines 500 indicate bidirectional digital data bus connections.

[0017] The EPS100 includes multiple EV battery packs, which in... Figure 1 The cells are designated as blocks 1, N-1, and N to indicate any number (N) of identical EV battery packs. EV battery pack 1 contains battery 1.1 and battery management system (BMS) 1.2. Batteries 1.1 to N.1 of the EV battery pack are connected in series at a nominal voltage, which is a multiple of the nominal voltage of a single pack. The N EV battery packs are connected in series / parallel configurations or otherwise grouped within the smart combiner 130 to electrically act as the larger battery within the overall energy storage system. The smart combiner 130 is connected to a bidirectional DC-DC converter 603. The DC-DC converter 603 can provide optimal voltage matching between the aggregated EV battery packs and the inverter power conversion system (PCS) 605 as the maximum power point of the solar PV power generation 606 varies with temperature and load. The smart combiner (SC) 130 can be used to actively balance secondary-life batteries to efficiently utilize the charge-discharge cycles of the individual packs, thereby adjusting for capacity differences in each pack.

[0018] When the entire system delivers energy stored in the EV battery pack to, for example, the grid 610, DC power flows from the EV battery pack through the smart combiner 130 and the DC-DC converter 603. The DC power is then converted to AC power by the PCS 605 to supply energy to the grid 610. For example, power from the solar photovoltaic power generation 606 can also flow through the PCS 605 when available, which acts as a DC-AC power converter to discharge power into the grid 610. In this configuration, the total power entering the grid 610 can be, for example, a combination of battery-introduced power and solar photovoltaic-introduced power.

[0019] According to an exemplary embodiment, when the entire system is supplying energy to charge EV battery packs 1 to N, the PCS 605 acts as an AC-DC power converter by drawing AC power from the grid 610 and converting it into DC power. This DC power flows through the DC-DC converter 603 and then through the smart combiner 130 to all EV battery packs 1 to N. Power from the solar photovoltaic power generation 606, when available, can either be used to reduce the power required from the grid 610 to charge EV battery packs 1 to N, or, if the power from the available solar power generation 606 is greater than the power required to charge these EV battery packs, the excess power can be fed back to the grid 610. Some system variants will not include the solar PV field generation 606 and therefore may not require the DC-DC converter 603.

[0020] According to an exemplary embodiment, the Battery Management System (BMS) 1.2 monitors each cell in the EV battery pack 1, primarily to check for mismatched, undercharged, or overcharged cells in the series string. By monitoring and rebalancing mismatched cells, the lifespan of the EV battery pack can be enhanced, and safe operating parameters for the battery cells and battery pack can be ensured to avoid dangerous conditions. The Battery Pack Controller (BPC) 140 communicates with each of the EV battery packs 1 to N via a digital data bus. The Supervisory Control and Data Acquisition (SCADA) system 501 communicates with the BPC 140 to confirm the state of charge, health status, and overall availability of the aggregated EV battery packs. According to an exemplary embodiment, the SCADA system 501 receives top-level commands from the Power System Manager 503 via the Internet 502 to control the operation of the entire energy storage system.

[0021] SCADA 501 can also communicate with the cabinet control system 150. Within the EPS 100, the cabinet control system 150 can communicate with the thermal management block 151 and the hazard detection block 152. The thermal management block 151 provides air conditioning, dehumidification, ventilation, and air circulation as needed to maintain the optimal environment for EV battery packs 1 through N. The hazard detection block 152 monitors the environment inside the EPS 100 enclosure for smoke and excessive / insufficient temperatures.

[0022] Figure 2 This is a modified single-line electrical diagram of an energy storage system according to an exemplary embodiment, and it illustrates the power flow. However, this disclosure and description do not limit the scope of this disclosure to systems having the multiple elements and / or components described herein.

[0023] like Figure 2As illustrated, the energy storage system has, for example, four EV battery packs (EPS) 100, 200, 300, and 400. Each EPS 100, 200, 300, and 400 may be identical. However, each EPS may be different, and one or more of EPS 100, 200, 300, and 400 may be modified. According to an exemplary embodiment, EPS 100 includes 24 EV battery packs (EVBPs) designated 1-24. Within each EVBP are multiple battery modules connected in series or in series-parallel, shown as 1.1 in EVBP 1 to 24.1 in EVBP 24. Normally open contactors are also present, which may be configured as one or more contactors connected in series, designated as 1.3 in EVBP 1 to 24.3 in EVBP 24. EVBPs 1-24 may also include other power circuitry, such as, but not limited to, pre-charging of resistors and contactors. In this exemplary system, EVBPs 1 to 24 are connected in a 2S12P circuit arrangement, wherein EVBP pairs are connected in series and 12 of these series strings are connected in parallel. The series string pairs are 1 / 2, 3 / 4, 5 / 6, 7 / 8, 9 / 10, 11 / 12, 13 / 14, 15 / 16, 17 / 18, 19 / 20, 21 / 22, and 23 / 24. Each of the 12 series strings 1 / 2 to 23 / 24 is connected in the smart combiner 130 via fuses 101 to 112. Fuses 101 to 112 provide a second layer of overcurrent protection to protect EV batteries 1.1 to 24.1 from overcurrent under abnormal conditions. Fuses 101 to 112 also prevent contactors 1.3 to 24.3 from interrupting current exceeding the safety contactor limits. Contactors 1.3 to 24.3 can provide first-level overcurrent protection against currents less than the nominal values ​​of fuses 101 to 112, as well as other circuit isolation and connection control functions. The output of the intelligent combiner (SC) 130 is connected to switch 161, which connects or isolates the power circuit of EPS 100 from other energy storage system components. Fuse 162 protects the current-carrying capacity of the conductor and the breaking capacity of switch 161. According to an exemplary embodiment, circuit breakers or other overcurrent devices and systems can be replaced with... Figure 2 The fuse in the middle.

[0024] In this system example, EPS100 and 200 are connected to DC-DC converter 603. EPS300 and 400 are connected to DC-DC converter 604. DC-DC converter 603 can provide optimal voltage matching between the parallel-connected EPS100 and EPS200 and the inverter power conversion system (PCS) 605, thus providing optimal voltage matching as the maximum power point of the solar PV power generation 606 varies with temperature and illuminance. Both DC-DC converters 603 and 604 are capable of bidirectional power delivery to charge or discharge the EV battery pack. PCS 605 is also bidirectional for power flow.

[0025] When the entire system, for example, delivers energy stored in EPS100, 200, 300, and 400 batteries to the grid 610 and / or local load 607, DC power flows from EPS100 and 200 through DC-DC converter 603 and in parallel from EPS 300 and 400 through DC-DC power converter 604. The DC power can then be converted to AC power by PCS 605. The AC power then flows through distribution transformer 608 (where the voltage can be boosted to a more efficient distribution voltage level) and through meter 609 before being connected to the grid 610. Power from solar photovoltaic power generation 606 also flows through PCS 605 when available and utilized, and PCS 605 acts as a DC-AC power converter to introduce power into the grid 610 and / or local load 607. The total power entering the grid 610 can be the sum of battery power and solar photovoltaic power, minus the power used by local load 607. It can also support local loads without being connected to the power grid 610, in which case the PCS 605 operates in an "isolated" AC voltage regulation mode.

[0026] When the entire energy storage system is supplying energy to charge the EV battery packs in EPS100, 200, 300, and 400, PCS 605 acts as an AC-DC power converter by drawing AC power from the grid 610 and converting it to DC power. According to an exemplary embodiment, DC power flows through DC-DC converters 603 and 604 to charge the EV battery packs in EPS100, 200, 300, and 400. Power from the solar photovoltaic power generation 606 can, for example, be used, either to reduce the power required from the grid 610 to charge the EV battery packs when available, or, if the available power from the solar power generation 606 exceeds the power required to charge these EV battery packs and supply the local "behind-the-meter" load 607, the excess power can be fed back to the grid 610.

[0027] According to such Figure 2In the alternative embodiments shown, the energy storage system may include one or more of the following as part of the integrated EPS100: PCS 605, DC-DC converter 603, transformer 608, and power meter 609.

[0028] Figure 3 Is it like this? Figure 1 Detailed diagrams of the battery pack controller 140 and smart combiner 130 are shown. Reference numeral 1 indicates multiple EV battery packs (EVBPs), with EVBP 1 at the top. Reference numeral 2 indicates multiple EVBPs, with EVBP 2 at the top. In this EPS embodiment, EVBPs 1 and 2 are electrically connected in series as a first series pair. Each series pair in the EPS communicates with an EV BMS interface board (EVIB) in the BPC. In this first top-level case, BMS1.2 and BMS2.2 communicate with EVIB 141 via digital data buses 504 and 505, respectively. The communication protocol is the Controller Area Network Bus (CAN bus) used in original equipment manufacturer (OEM) electric vehicle applications. All other EVBP series pairs within the EPS communicate in a similar manner. Control circuitry 142 centralizes data from all EVIBs within the BPC 140 and provides a Modbus digital communication link 507 to a system controller outside the EPS and a Modbus link 506 to the smart combiner 130. According to an exemplary embodiment, Modbus digital communication link 507 communicates with the overall energy system SCADA (Supervisory Control and Data Acquisition) system. Figure 1 The component 501 communicates with the control circuitry 138 to report the health status, availability, and state of charge of the “composite” battery configured by the series / parallel connection of all EV battery packs. The Modbus data link 506 connects the control circuitry 142 to the control circuitry 138 to actively control the balancing of each EV battery pack in the series string.

[0029] According to an exemplary embodiment, by monitoring the voltage, current, and temperature of each EV battery pack, and then transferring energy from the higher voltage group to the lower voltage group in a series string, balancing of each EV battery pack in a series string can be achieved, for example. For instance, if EVBP 1 has a higher voltage than EVBP 2, semiconductor switch 132 closes, current flows from battery 1.1 through inductor 137, semiconductor switch 132 opens, and the current through inductor 137 flows through diode 135 and into battery 2.1, thus completing one energy transfer cycle. This energy transfer cycle repeats at a high frequency for a time proportional to the desired energy transfer. If EVBP 2 has a higher voltage than EVBP 1, semiconductor switch 134 closes, current flows from battery 2.1 through inductor 137, semiconductor switch 134 opens, and the current through inductor 137 flows through diode 133 into battery 1.1, thus completing one energy transfer cycle.

[0030] Figure 3 The illustration depicts a method for balancing batteries in a series battery string, but does not limit this disclosure to any particular battery balancing method or the number of EVBPs in the series string. According to an exemplary embodiment, the energy storage system includes interconnection and interaction capabilities via a battery pack controller 140, an EV battery pack management system (1.2 and 2.2 in this example), a smart combiner 130, and a system controller via a data link 507. Fuses 131 and 136 can be used to provide fault isolation between the EVBP 1 and 2 series strings and the parallel circuitry of the + bus 601 and - bus 602 of all series strings. According to an exemplary embodiment, for example, all other series strings can be protected in a similar manner.

[0031] According to an exemplary embodiment, the energy storage system may include Figure 1 Each of the components within the EV Pack Storage System (EPS) box 100 shown here, plus the weatherproof housing and rack system for the EV battery pack. Figure 4 An embodiment of the enclosure is illustrated, which may include a fixed and removable external insulation panel 60. The enclosure 50 may be designed, for example, as a cabinet, with the battery system and system controls accessible from outside the enclosure, and the enclosure or cabinet is not a space-occupying space as defined in building or fire codes. According to an exemplary embodiment, the enclosure 50 is an outdoor nominal enclosure that enables the deployment of energy storage components outdoors.

[0032] According to an exemplary embodiment, rack system 40 may be made of structural steel and configured to hold EV battery packs 1 to 24. For example, in the current construction of an EV pack storage system (EPS), each pack may weigh more than 600 pounds. Side panels 60 of housing 50 may be removable, for example, to allow forklift access for relatively easy installation and removal of EV battery packs 1 to 24. Additionally, rack system 40 is designed to allow airflow between EV battery packs. For example, each EV battery pack may be electrically isolated from rack system 40 via bracket 30. For example, EV battery packs may be cooled and heated by thermal management system 151 under the guidance of rack control system 150. Thermal management system 151 may include cooling, dehumidification, and other environmental controls as means to extend the lifespan of EV battery packs. Hazard detection system 152 may provide an alarm to rack control system 150 when smoke, gas, or temperature conditions outside the operating range are detected.

[0033] Combination Figure 1The description illustrates the functions of the intelligent combiner 130 and the battery pack controller 140. The intelligent combiner 130, battery pack controller 140, cabinet control system 150, thermal management system 151, and hazard detection system 152 are not shown to scale or do not have specific physical characteristics. In one or more of the intelligent combiners 130, the battery pack controller 140, cabinet control system 150, thermal management system 151, and hazard detection system 152 can be mounted to the EPS housing. According to an exemplary embodiment, the fixed and removable outer panel 60 of the housing 50 can be thermally insulated.

[0034] The technology consistent with this disclosure provides energy storage systems and methods that, among other features, particularly utilize secondary-life electric vehicle batteries. While various exemplary embodiments of the disclosed systems and methods have been described above, it should be understood that they are presented for illustrative purposes only and are not intended to be limiting. This is not exclusive and does not limit this disclosure to the precise form disclosed. Modifications and variations can be made to the above teachings, or can be obtained by practicing this disclosure without departing from its breadth or scope.

Claims

1. An integrated battery energy storage system, the integrated battery energy storage system comprising: Multiple electric vehicle battery packs are connected in a series / parallel arrangement, the series / parallel arrangement including multiple series strings of electric vehicle battery packs, each of the multiple series strings of electric vehicle battery packs including at least two of the multiple electric vehicle battery packs connected in series. The multiple series strings of the electric vehicle battery pack are connected in parallel; Among them, the plurality of electric vehicle battery packs are secondary life electric vehicle battery packs, which are batteries that are reused relative to the first life application in the electric vehicle. Each of the plurality of series strings is protected by a smart combiner comprising a plurality of DC-DC converters configured to balance two or more electric vehicle battery packs in a common series string by moving energy from one electric vehicle battery pack in the common series string to another, or by moving energy from another electric vehicle battery pack in the common series string to one electric vehicle battery pack; and A battery pack controller configured to communicate with and control the battery management system originally integrated by the original manufacturer into each of the plurality of electric vehicle battery packs.

2. The integrated battery energy storage system according to claim 1, wherein, The aforementioned multiple electric vehicle battery packs can be used without reconfiguring or modifying the original manufacturer's packaging casing or housing.

3. The integrated battery energy storage system according to claim 1, wherein, The smart combiner for each of the plurality of series strings also includes an overcurrent device.

4. The integrated battery energy storage system according to claim 1 further includes: A rack system for the plurality of electric vehicle battery packs; as well as A housing with internal environmental controls, the housing including a removable plate configured to facilitate the installation or replacement of the plurality of electric vehicle battery packs.

5. An integrated battery energy storage system, the integrated battery energy storage system comprising: Multiple electric vehicle battery packs are configured to store energy, wherein the multiple electric vehicle battery packs are secondary life electric vehicle battery packs, which are batteries reused relative to their first life application in an electric vehicle. An enclosure configured to enable the energy storage components to be deployed outdoors; Multiple removable outer housing panels are configured to facilitate the installation and removal of the multiple electric vehicle battery packs from the housing; The intelligent combiner includes multiple DC-DC converters configured to balance the voltage or energy storage capacity of series-connected electric vehicle battery packs by moving energy between two or more electric vehicle battery packs in a common series string. The environmental control components within the housing are configured to extend the service life of the plurality of electric vehicle battery packs within the housing. A rack system for the plurality of electric vehicle battery packs, the rack system being configured to provide electrical and thermal isolation between the plurality of electric vehicle battery packs; and An electric vehicle battery pack controller is configured to use an electric vehicle battery management system without altering the original manufacturer's design and intended functionality. The electric vehicle battery pack controller is configured to communicate with each electric vehicle battery management system via the original manufacturer's communication protocol.

6. The integrated battery energy storage system according to claim 5 further includes: A bidirectional power converter configured to convert DC electric vehicle battery pack power into AC grid power, or to convert AC grid power to charge DC electric vehicle battery pack.

7. The integrated battery energy storage system according to claim 5, wherein, The aforementioned multiple electric vehicle battery packs can be used without reconfiguring or modifying the original manufacturer's packaging casing or housing.

8. The integrated battery energy storage system according to claim 5, wherein, The smart combiner for each of the plurality of series strings also includes an overcurrent device.

9. A method for integrating an electric vehicle battery pack into an integrated battery energy storage system, the method comprising: Multiple electric vehicle battery packs are connected in a series / parallel arrangement, the series / parallel arrangement including multiple series strings of electric vehicle battery packs, each of the multiple series strings of electric vehicle battery packs including at least two of the multiple electric vehicle battery packs connected in series, wherein the multiple electric vehicle battery packs are secondary life electric vehicle battery packs, the secondary life electric vehicle battery packs being batteries reused relative to the first life application in the electric vehicle. Multiple series-parallel connections are made in the electric vehicle battery pack; Each of the plurality of series strings is protected by an intelligent combiner comprising multiple DC-DC converters, the intelligent combiner balancing two or more electric vehicle battery packs in a common series string by moving energy between electric vehicle battery packs in a common series string; and Each electric vehicle battery pack is controlled using a battery pack controller, which communicates with the battery management system initially integrated by the original manufacturer within the plurality of electric vehicle battery packs via the original manufacturer's communication protocol.

10. The method of claim 9, further comprising: The aforementioned multiple electric vehicle battery packs can be used without reconfiguring or modifying the original manufacturer's packaging casing or housing.

11. The method of claim 9, wherein the smart combiner for each of the plurality of series strings further comprises an overcurrent device.

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