Energy storage controller, system including the controller, and method of using the same

Abstract

Provided are an electric energy storage system, a controller, and a method for using the same. The system includes battery packs connected in parallel, one or more battery power management units, one or more power converters, and a controller. The controller includes one or more processors and at least one tangible, non-transitory, machine-readable medium encoded with one or more programs, the programs being configured to execute steps for discharging or charging. The steps include: reading data including state of health (SOH) and state of charge (SOC) from each battery pack, connecting the corresponding battery pack to the corresponding power converter; receiving a power command from an energy management system, calculating the corresponding power ratio of each battery pack based on the data of SOH, SOC and the power command, and discharging from the battery pack to the grid or charging to the battery pack based on the power ratio of each battery pack.

Description

Technical Field

[0001] The present disclosure generally relates to systems and methods for energy storage. More particularly, the disclosed subject matter relates to a controller for stationary energy storage, a system including the controller, and a method for controlling stationary energy storage. Background Art

[0002] As concerns about environmental issues such as global warming increase, clean and renewable energy sources are becoming increasingly important. These energy sources include solar and wind power, as well as rechargeable batteries. Renewable energy sources are inflexible because they cannot be dispatched when needed to meet the ever-changing needs of energy consumers. Energy storage systems are expected to address this flexibility challenge. Fixed energy storage systems can store energy and release it in the form of electricity when needed. Summary of the Invention

[0003] The present disclosure provides a controller for an electrical energy storage system, an electrical energy storage system including such a controller, and a method for using the same. The system may be referred to as a distributed power energy storage system (DPESS). The controller utilizes multi-source intelligent input technology (MIST) and may be referred to as a MIST controller.

[0004] According to some embodiments, an electrical energy storage system includes a plurality of battery packs connected in parallel, one or more battery power management units (BPMUs), one or more power converters, and a controller. Each BPMU is connected to one or more battery packs and is configured to monitor and control the one or more battery packs or corresponding battery packs. Each power converter, or power conversion system (PCS) device, is coupled to at least one battery pack and is configured to convert direct current (DC) from the corresponding battery pack into alternating current (AC) or vice versa.

[0005] The controller uses multi-source input intelligent technology (MIST) and includes one or more processors and at least one tangible, non-transitory machine-readable medium encoded with one or more programs, the programs being configured to perform steps for discharging or charging. In some embodiments, these steps may include: reading data including state of health (SOH) and state of charge (SOC) from each battery pack, connecting the corresponding battery pack to a corresponding power converter, receiving a power command from a superior energy management system (EMS), calculating a corresponding power rate for each battery pack based on the SOH and SOC of each battery pack and the power command from the EMS, and discharging from or charging to multiple battery packs based on the power rate of each battery pack.

[0006] In some embodiments, the plurality of battery packs are heterogeneous battery packs selected from new batteries, second-hand electric vehicle (EV) batteries, or a combination thereof. The used EV batteries can be directly used in the system without prior selection or disassembly. Each battery pack includes an inverter and an internal battery management unit (BMU) within the battery pack.

[0007] In some embodiments, the controller is configured to read the data from the inverter and BMU of each battery pack and monitor the inverter and BMU of each battery pack. This can be done by each corresponding BPMU connected to each battery pack.

[0008] In some embodiments, the system further includes a plurality of automatic circuit breakers, each of which may be disposed between the battery pack and the corresponding power converter and configured to connect or disconnect the corresponding battery pack and the corresponding power converter.

[0009] The controller is configured to discharge power from the plurality of direct current battery packs to an alternating current grid, or to charge power from the grid to the plurality of battery packs.

[0010] In some embodiments, the controller is configured to calculate the corresponding power ratio (P i ):

[0011] and

[0012] P i =min(P iMax ,P T *a i ) (2),

[0013] Among them, SOH i and SOC i are the SOH and SOC of each battery pack, P T is the power command from EMS, P iMax is the maximum capacity of each battery pack, and a i is a multiplier representing the dispatch share of each battery pack (in percentage). The subscript "i" represents the number of each corresponding battery pack in the plurality of battery packs. The power ratio (P i ) is included P iMax and P T *a i The minimum (or smaller) of the two values ​​​​of .

[0014] In some embodiments, the controller is configured to send a signal with instructions for discharging or charging to each converter and / or each battery pack based on the respective power ratios of each battery pack. Alternatively, the controller is configured to send feedback to the EMS if the power command exceeds the maximum limit of the system.

[0015] On the other hand, the present disclosure provides a controller for an electrical energy storage system. The controller uses multi-source input intelligent technology (MIST) and includes one or more processors and at least one tangible, non-transitory machine-readable medium encoded with one or more programs, the programs being configured to perform steps for discharging or charging. In some embodiments, these steps include: reading data including state of health (SOH) and state of charge (SOC) from each of a plurality of battery packs connected in parallel, and connecting the corresponding battery pack to a corresponding power converter. The steps of reading SOH and SOC data can be performed by one or more battery power management units (BPMUs), which can be used to monitor and control the corresponding battery packs in the plurality of battery packs. The power converter is coupled to at least one battery pack and is configured to convert direct current (DC) from the corresponding battery pack to alternating current (AC), or vice versa. The plurality of battery packs are heterogeneous battery packs selected from new batteries, secondary electric vehicle (EV) batteries, or a combination thereof.

[0016] The controller is configured to further perform the following steps: receiving a power command from an upper-level energy management system (EMS); calculating a corresponding power ratio of each battery pack based on the SOH and SOC of each battery pack and the power command from the EMS; and discharging from or charging to the multiple battery packs based on the power ratio of each battery pack.

[0017] In some embodiments, the controller is configured to calculate the corresponding power ratio (P i ). In equation (1), SOH i and SOC i The subscript "i" represents the number of each corresponding battery pack in the plurality of battery packs. T is the power command from EMS, P iMax is the maximum capacity of each battery pack, and a i Is a multiplier representing the dispatch share of each battery group. The power ratio of each battery group (P i ) is included P iMax and P T *a i The minimum (or smaller) of the two values ​​​​of .

[0018] The controller is configured to discharge power from the plurality of battery packs to the grid, or to charge power from the grid to the plurality of battery packs. In some embodiments, the controller is configured to send a signal with a discharge or charge instruction to each converter and / or each battery pack based on the respective power ratios of each battery pack. The controller is further configured to send feedback to the EMS if the power command exceeds a maximum limit of the system.

[0019] In another aspect, the present disclosure provides a method for operating an electrical energy storage system as described by a controller therein, or a method of using a controller as described. The method comprises the steps described herein. Data including state of health (SOH) and state of charge (SOC) are obtained and read from each of the plurality of battery packs connected in parallel. In some embodiments, the controller can be used to read this data directly from the battery pack or through one or more battery power management units (BPMUs) for monitoring and controlling the plurality of battery packs.

[0020] In some embodiments, the method further comprises the following steps: connecting the corresponding battery packs to the corresponding power converters; receiving power commands from a superior energy management system (EMS); calculating the corresponding power ratio of each battery pack based on the SOH and SOC of each battery pack and the power command from the EMS; and discharging the power from the multiple battery packs to the grid or charging the power from the grid to the multiple battery packs based on the power ratio of each battery pack. Each power converter is coupled to at least one battery pack and can convert direct current (DC) from the corresponding battery pack to alternating current (AC) during the discharge process, or vice versa during the charging process. The multiple battery packs are heterogeneous battery packs selected from new batteries, secondary used electric vehicle (EV) batteries, or a combination thereof. In some embodiments, the multiple battery packs are secondary used electric vehicle (EV) batteries.

[0021] In some embodiments, in the controller, the corresponding power ratio (P i ). In equation (1), SOH i and SOC i The subscript "i" represents the number of each corresponding battery pack in the plurality of battery packs. T is the power command from EMS, P iMax is the maximum capacity of each battery pack, and a i Is a multiplier representing the dispatch share of each battery group. The power ratio of each battery group (P i ) is included PiMax and P T *a i The minimum (or smaller) of the two values ​​​​of .

[0022] In some embodiments, the method further includes sending instructions from the controller to each converter and / or each battery pack to discharge or charge based on the corresponding power ratio of each battery pack, or sending feedback from the controller to the EMS if the power command exceeds the maximum limit of the system.

[0023] The systems, controllers, and methods provided in this disclosure offer numerous advantages. For example, the system is a decentralized design. A variety of new and used EV battery packs of varying quality can be used. No preselection or removal of battery packs is required. If a battery pack and / or a converter fails to respond, the system still has the ability to supply power to the load to meet the power demand. The systems, controllers, and methods extend the life of each battery pack and provide flexibility in maintaining and upgrading the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present disclosure is best understood from the following detailed description when read in conjunction with the accompanying drawings. It is emphasized that, according to common practice, the various features of the drawings are not necessarily drawn to scale. Rather, the dimensions of the various features are arbitrarily expanded or reduced for clarity. Throughout the specification and drawings, the same reference numerals represent the same features.

[0025] Figure 1 is a block diagram illustrating an exemplary system, a distributed power energy storage system (DPESS) including a multi-source input intelligent technology (MIST) controller, according to some embodiments.

[0026] Figure 2 It shows that Figure 1 Block diagram of multiple battery packs used in an exemplary system.

[0027] Figure 3 is a diagram showing the Figure 1 Block diagram of an exemplary system designed and including six second-use electric vehicle (EV) battery packs and three power conversion systems (PCS).

[0028] Figure 4 An exemplary battery pack management unit (BPMU) is shown in accordance with some embodiments.

[0029] Figure 5is a block diagram illustrating an exemplary controller (e.g., a MIST controller) or a computer-implemented controller for controlling the discharge or charging of a battery pack according to some embodiments, the computer-implemented controller including one or more processors and at least one tangible, non-transitory machine-readable medium encoded with one or more programs.

[0030] Figures 6A-6B is a flow chart illustrating an exemplary method for controlling the discharge or charge of a battery pack according to some embodiments.

[0031] Figure 7 is a flow chart illustrating an exemplary procedure for controlling the discharge or charge of a battery pack according to some embodiments.

[0032] Figure 8 Shows the use Figure 3 Example of discharging six battery packs in a system.

[0033] Figure 9 Shows the use Figure 3 Example of charging six battery packs in a system. DETAILED DESCRIPTION

[0034] The description of the exemplary embodiments is intended to be read in conjunction with the accompanying drawings, which are to be considered a part of the entire written description. In the specification, relative terms such as "lower," "upper," "horizontally," "vertically," "above," "beneath," "upwardly," "downwardly," "top," and "bottom," and derivatives thereof (e.g., "horizontally," "downwardly," "upwardly," etc.), should be interpreted as referring to orientations as subsequently described or as shown in the drawings in question. These relative terms are for convenience of description and do not require that the apparatus be constructed or operated in a particular orientation. Terms relating to attachment, coupling, and the like (e.g., "connected" and "interconnected") refer to a relationship wherein structures are affixed or attached to one another, directly or indirectly through intermediate structures, as well as movable or rigid connections or relationships, unless expressly described otherwise.

[0035] For the purposes of the following description, it should be understood that the embodiments described below may take alternative variations and embodiments. It should also be understood that the specific articles, compositions and / or methods described herein are exemplary and should not be considered limiting.

[0036] In this disclosure, the singular forms "a", "an" and "the" include plural references, and references to a particular numerical value include at least that particular value unless the context clearly indicates otherwise. When a value is expressed as an approximation by using the antecedent "about", it should be understood that the particular value forms another embodiment. As used herein, "about X" (wherein X is a numerical value) preferably refers to ±10% of the cited value, inclusive. For example, the phrase "about 8" preferably refers to values ​​from 7.2 to 8.8, inclusive. When present, all ranges are inclusive and combinable. For example, when a range of "1 to 5" is listed, the listed ranges should be interpreted as including the ranges "1 to 4", "1 to 3", "1-2 and 4-5", "1-3 and 5", "2-5", etc. In addition, when a list of alternatives is affirmatively provided, such a list can be interpreted to mean that any alternative can be excluded, for example, by exclusion by a negative limitation in the claim. For example, when a range of "1 to 5" is recited, the recited range can be interpreted as including the case where any of 1, 2, 3, 4, or 5 is negatively excluded; thus, the recitation of "1 to 5" can be interpreted as "1 and 3-5, but not 2," or simply "where 2 is not included." Any component, element, attribute, or step explicitly recited herein may be explicitly excluded from the claims, regardless of whether such component, element, attribute, or step is listed as an alternative or whether or not it is recited individually.

[0037] Chinese patent application CN110518667A discloses a parallel system for second-life batteries and a control method thereof, which includes a battery module and a DC / DC power converter module. This battery module includes a power supply battery module and a battery management module. The power supply battery module includes multiple groups of battery packs connected in parallel, each of which is composed of several battery packs connected in series. The battery packs are connected in series to provide similar voltages in the corresponding battery packs connected in parallel. The battery management module is used to monitor the charging or discharging status of the power supply battery module. The terminal control module determines the operating mode of the parallel battery system based on data received from the battery management module and sends a charge or discharge command to the DC / DC power converter module. The DC / DC power converter module charges or discharges each battery in the parallel group according to the control command of the terminal control module.

[0038] The system disclosed in CN110518667A utilizes a DC / DC converter and a battery management module to control a battery system comprising multiple parallel groups of series-connected battery packs. This system ignores variations in the batteries used in the series-connected battery packs and the existing circulating current. The system and method do not provide detailed control methods for coordination between the DC / DC converters.

[0039] CN110518667A does not disclose whether the system is suitable for connection to the power grid, and the disclosed technology limits the expansion of such a system to the power grid. A DC-DC converter is an electronic circuit or electromechanical device that converts a direct current (DC) source from one voltage level to another. If the battery system is connected to the power grid, an additional AC / DC converter is still required. If a system such as that disclosed in CN110518667A is connected to the power grid, adding more DC / DC converters will significantly increase the total DC current and increase the hardware requirements for the AC / DC converter.

[0040] The present disclosure provides a controller for an electrical energy storage system, an electrical energy storage system including such a controller, and a method for using the same. The system may be referred to as a distributed power energy storage system (DPESS). The controller utilizes multi-source intelligent input technology (MIST) and may be referred to as a MIST controller.

[0041] According to some embodiments, the present disclosure provides systems and methods for appropriately utilizing batteries, such as secondary use electric vehicle (EV) battery packs, in stationary energy storage applications. Each battery pack is operated individually based on its characteristics (e.g., state of health (SOH), state of charge (SOC), and battery pack terminal voltage). No pre-selection of battery packs is required. The lack of series connections between battery packs eliminates circulating currents and losses. The system directly uses a grid-tied AC / DC converter with scalability. No additional power conversion system is required for grid-tied applications.

[0042] According to some embodiments, the present invention provides a distributed power energy storage system (DPESS) utilizing second-hand (or used) electric vehicle (EV) battery packs and its Multi-Source Input Intelligent Technology (MIST) controller. In the system provided by the present invention, the MIST controller optimally estimates the charge / discharge rate of each battery pack. The DPESS accepts various conditions of second-hand EV battery packs from selected brands and / or from other automakers.

[0043] The main benefit of the present invention is to effectively manage the diversity of battery packs, such as new batteries, second-life EV battery packs or their combination in stationary energy storage applications. The utilization rate of stronger (healthier) battery packs in a multi-battery system can be improved. The life span of EV battery packs can be uniformed and the overall life of the system can be extended. The reliability, stability and safety of the battery energy storage system (BESS) are improved. No additional labor and cost are involved.

[0044] Unless otherwise specified, abbreviations are used herein to represent abbreviations. For example, "DPESS" refers to a distributed power energy storage system (DPESS), "BESS" refers to a battery energy storage system, "BPMU" refers to a battery pack management unit, and "MIST" refers to a multi-source input intelligence technology.

[0045] The controllers, systems, and methods provided in the present disclosure are applicable to different battery packs, which are heterogeneous battery packs. "Heterogeneous battery packs" referred to herein refer to battery packs or modules with different capacities, SOCs, and / or SOHs, and can be selected from new batteries (e.g., from different manufacturers), second-hand electric vehicle (EV) batteries, or a combination thereof. Second-hand EV batteries are used for illustrative purposes. References to "discharging" or "charging" multiple battery packs are to be understood as multiple battery packs being discharged or charged together, while some battery packs may remain idle (not charged or discharged).

[0046] Unless otherwise specified, references herein to "MIST" or "Multi-Source Input Intelligence Technology" refer to cloud-based computing technology that is internet-based and can perform computations locally. The term may also be referred to as "Master Intelligent Signal Converter (MIST)." This technology converts the languages ​​of different sources, such as inverter and BMS languages ​​(e.g., CAN, Modbus, DNP3, or any other suitable language). Using this technology, the controller and the different devices or units in the system described herein can communicate with each other.

[0047] Unless otherwise expressly stated, references herein to "state of health (SOH)" are to be understood as referring to a figure of merit representing the condition of a battery, cell, or pack compared to its ideal condition. SOH is expressed as a percentage (%). Ideally, a condition matching specifications is 100%. SOH can decrease with time and use.

[0048] Unless otherwise expressly stated, "State of Charge" (SOC) as used herein is defined as the charge level of a battery relative to its capacity. The unit of SoC is percentage points, with 0% representing empty and 100% representing full.

[0049] The term "human-machine interface (HMI)" as used herein is understood to refer to the user interface (UI), which is the space where the interaction between humans and machines occurs. The human-machine interface (HMI) can involve the interface between humans and machines with physical input hardware, such as a keyboard, mouse, or any other human-machine interaction based on touch, vision, or hearing. Such a user interface can include other layers, such as output hardware, such as a computer monitor, speakers, and printers.

[0050] As used herein, the term "energy management system (EMS)" refers to a system of computer-aided tools used by the operator of a utility grid to monitor, control, and optimize the performance of the power generation or transmission system.

[0051] In this disclosure, the terms "power demand" and "power requirement" are used interchangeably, and the terms "converter" and "inverter" are used interchangeably. Each battery pack includes an inverter and a battery management unit (BMU) therein. For ease of description, the terms "power inverter" or "AC / DC power converter" are used to describe the internal components in a battery pack, and the terms "power converter" or "power conversion system (PCS)" are used to describe the converter connected to one or more battery packs. The terms "battery management unit (BMU)" or "battery management system (BMS)" are used to describe the internal components in a battery pack. The term "battery power management unit (BPMU)" is used to describe a battery management unit connected to one or more battery packs.

[0052] Unless otherwise expressly stated, the terms "connected" or "coupled" as used herein are understood to encompass various connections or couplings between components to conduct power or transmit signals for communication. Such connections or couplings may be through wired, wireless, or cloud-based modes.

[0053] exist Figure 1-5 In the drawings, like items are denoted by like reference numerals, and for the sake of brevity, the description of the structure provided above with reference to the previous drawings will not be repeated. Figure 1-5 The exemplary structure described in Figures 6A-6B and the method described in 7.

[0054] refer to Figure 1 , shows a framework of an exemplary system 100, which is a distributed power energy storage system (DPESS). Figure 2 It shows that Figure 1 1 is a block diagram of a plurality of battery packs 20 used in an exemplary system. Figure 3 is an example of a system 100 in some embodiments. Such a system 100 includes a controller 60, which is a Multi-Source Input Intelligent Technology (MIST) controller according to some embodiments. In a decentralized design, more energy can be used in the battery pack.

[0055] refer to Figure 1-3 According to some embodiments, an electrical energy storage system 100 includes a plurality of battery packs 20, one or more battery power management units (BPMUs) 30, and a controller 60. The system 100 also includes a power converter 10, which is also referred to as a power conversion system (PCS). Figure 1 The controller 60 marked as "MIST server" in FIG. 6 can be connected to other components in a wired or wireless mode. Figure 1 The dashed line 22 in FIG. 1 shows that the controller 60 can operate in a cloud-based mode and can function as a real-time local cloud. The system 100 can be used to discharge power from the battery pack 20 to the grid 85, or to charge the battery pack 20 from the grid 85. Wires 12 can be used to connect the battery pack 20. A bus 80 can exist between the system 100 and the grid 85.

[0056] The plurality of battery packs 20 are connected in a parallel configuration 50. In some embodiments, the plurality of battery packs 20 are secondary (ie, used) electric vehicle (EV) batteries. The used EV batteries can be used directly in the system without prior selection or disassembly. Figure 1 As shown, each battery pack 20 includes one or more cells, an internal battery management unit (BMU) 25, and an inverter 40. The EV battery pack 20 is removed from the vehicle and not disassembled into modules. These EV battery packs 20 can be subjected to simple tests to verify their SOH.

[0057] Using the systems and methods provided in the present disclosure, the energy stored in EV battery packs can be properly cycled through their own ratios to avoid uneven performance across the battery pack.

[0058] Reference Figure 2 , six battery packs 20 are shown. Figure 2 The length of the bars in shows the health or capacity of each battery pack. When the weaker battery packs (e.g., battery pack 20b) are full / empty, the better battery packs (e.g., battery pack 20a) with more remaining capacity can be cycled further. Therefore, the available energy is limited by the weakest battery pack (e.g., battery pack 20b). The capacity 23 of the weakest battery pack is the baseline. The additional power capacity 24 above this baseline is the energy available in the system 100 for discharge. In the early stages, the system 100 will use the better battery packs more and bring them to the same condition as the weaker battery packs. The system 100 will operate with the same condition of all battery packs. The overall life of the system can be extended.

[0059] refer to Figure 3 For illustration purposes only, an exemplary system 200 as the system 100 includes six battery packs 20 connected in parallel. Each BPMU 30 is connected to at least one battery pack 20 and is configured to monitor and control the corresponding battery pack(s) 20. Figure 3 As shown, the BPMU 30 a is connected to one battery pack 20 at one port, and the BPMU 30 b having at least five ports is connected to five battery packs 20 . Figure 3The configuration in FIG is for illustration only. Each BPMU 30 can be connected to any suitable number of battery packs 20, which can be 2, 3, 4, 6, or any other suitable integer. In some embodiments, the BPMU 30 is developed based on the brand of EV battery pack.

[0060] Each power converter 10 is coupled to at least one battery pack 20 and is configured to convert direct current (DC) from the corresponding battery pack 20 into alternating current (AC), or vice versa. Figure 3 As shown, three power converters 10 including (PCS No. 1-3) are used. Each of them is connected to two battery packs 20. Figure 3 The configuration in FIG is for illustration only. Each power converter 10 can be connected to any suitable number of battery packs 10. Such a suitable number can be 2, 3, 4, 6, or any other suitable integer.

[0061] In some embodiments, the system 100 further includes a plurality of automatic circuit breakers 14. One or two circuit breakers 14 may be provided between the battery pack 20 and the corresponding power converter 10 and configured to connect or disconnect the corresponding battery pack 20 and the corresponding power converter 10.

[0062] Figure 3 An exemplary system is shown having secondary-use EV battery packs 20 and their associated circuit breakers 14, two types of BPMUs 30 (including one for controlling five battery packs 20 and another connected to one battery pack), three power converters 10, and a MIST controller 60. The controller 60 can be connected via a wired or wireless or cloud-based mode. Figure 3 In some embodiments, all connections between the controller 60 and other components can be wireless and cloud-based. In some embodiments, the connections between other components can be through wires.

[0063] Reference Figure 3 Each EV battery pack 20 is connected to a single power converter 10 (or a separate DC port on the converter 10) through a set of automatic DC breakers 14. The converter 10 (or DC port) controls whether to charge or discharge the individual EV battery pack 20. The MIST controller 60 is configured to adjust the charge / discharge ratio based on the condition of the EV battery pack (e.g., SOC, SOH, voltage, and temperature).

[0064] The controller 60 also controls system safety by controlling the circuit breaker 14 between the power converter 10 and the battery pack 20. The circuit breaker 14 protects the corresponding EV battery pack 20 from inrush current and arcing during system startup. The controller 60 collects battery pack 20 data and precharges the DC port on the converter 10. It then closes the circuit breaker 14 via a functional relay and a switching motor on the circuit breaker.

[0065] refer to Figure 4 , an exemplary battery pack management unit (BPMU) 30 is shown. The exemplary BPMU 30 includes a microcontroller 32 and a processor 34, such as a personal computer, within a housing 36. The microcontroller 32 is connected to and communicates with the corresponding battery pack 20 via a digital I / O interface. Through the microcontroller 32, the BPMU 30 is configured to monitor and control the corresponding battery pack 20 by coordinating with the controller 60. The microcontroller 32 and processor 34 are connected to and communicate with each other. The processor 34 is connected to the network of the controller 60.

[0066] refer to Figure 1 In some embodiments, system 100 can be directly connected to a 480V 3-phase grid. All components in system 100 (including HMI, converters, BPMUs, and protection relays) are linked or coupled to MIST via a TCP / IP network. The controller 60 is networked with all components via TCP / IP 22. Users 90 can access the network.

[0067] refer to Figure 1 、 3In accordance with 5, the controller 60 utilizes multi-source input intelligence technology (MIST) and includes one or more processors 62 and at least one tangible, non-transitory, machine-readable medium encoded with one or more programs 74 to be executed by the one or more processors. The processor(s) 62 may include a central MIST control 64, which includes a parameter input module 66, a model module 68, a parameter control module 70, and an information and instruction module 72. The parameter input module 66 coordinates with the battery pack 20 and the HMI or EMS 110 to read data from the battery pack 20 and power requirements from the HMI or EMS 110. The parameter input module 66 also coordinates with each power converter 10 and the BPMU 30. The parameter control module 70 also coordinates with each power converter 10, each battery pack 20, each BPMU 30, and the HMI / EMS 110 to control the discharge or charge process. Together with the one or more programs 74, the model module 68 is configured to perform simulations based on input parameters to provide information and instructions to the parameter control module 70 and the information and instruction module 72. The processor 62 may optionally be connected to one or more displays 76 for displaying information and instructions from the module 72 and to an operator.

[0068] The controller 60, having the program 74 and the processor 62, is configured to perform the discharging or charging steps described herein. In some embodiments, these steps may include reading data including state of charge (SOH) and state of operation (SOC) of each battery pack, connecting the corresponding battery pack 20 to the corresponding power converter 10, receiving a power command from a higher-level energy management system (EMS) 110, calculating a corresponding power ratio for each battery pack 20 based on the SOH and SOC of each battery pack 20 and the power command from the EMS 110, and discharging or charging the plurality of battery packs 20 based on the power ratio of each battery pack 20. In some embodiments, the controller 60 is configured to read data from and monitor the BMU 25 and inverter 40 of each battery pack 20. In some embodiments, this may be accomplished by each corresponding BPMU 30 connected to each battery pack 20.

[0069] According to some embodiments, the present invention provides a distributed power energy storage system (DPESS) 100 (using second-hand (or used) electric vehicle (EV) battery packs 20) and its multi-source input intelligent technology (MIST) controller 60. The DPESS includes the MIST controller 60, one or more second-hand EV battery packs 20, one or more AC / DC battery power conversion systems (PCSs) (i.e., power converters 10), one or more battery pack management units (BPMUs) 30, and multiple automatic circuit breakers 14, as described herein. A single EV battery pack is monitored and controlled by a BPMU 30 or a communication port on the BPMU 30 and is connected to a single converter 10 (or separate DC ports on the converter 10) via a set of automatic circuit breakers (one for each polarity). One or more PCSs or a collection of converters 10 and battery packs 20 are housed as a DPESS and connected to a power grid 85. The MIST controller 60 collects real-time data from the PCSs 10 and BPMUs 30 and estimates the power ratio of each individual EV battery pack 20. The DPESS in this disclosure is a decentralized system, with each EV battery pack operating from its own converter. The MIST controller monitors and controls all components in the system. Disassembly of EV battery packs is unnecessary, eliminating circulating current between battery packs. This extends the efficiency and lifespan of secondary batteries.

[0070] In the system provided by the present invention, each battery pack 20 is connected to a separate power converter 10 (or PCS) or to an independent DC port on the PCS. A battery pack 20 can operate as a separate system. The MIST controller 60 serves as a bridge between the decentralized system and the upper-level energy management system (EMS). The MIST controller has bidirectional communication capabilities. The MIST controller 60 collects data from the power converter 10 and the battery pack 20, summarizes the data, and sends it to the upper-level EMS 110. The MIST controller 60 also receives charge / discharge commands and power ratios from the EMS 110, calculates the appropriate power ratios for each battery pack 20, and then sends action signals to the converter 10 (and the battery inverter 40). The battery pack 20 is used according to its state of charge (SOC) and state of health (SOH) values.

[0071] The battery packs 20 are connected to their corresponding individual converters 10 (or independent DC ports on the converters 10). The converters 10 (or the DC ports) are controlled to charge and discharge the individual battery packs 20. The MIST controller will adjust the charge / discharge ratio according to the conditions of the battery packs 20, such as SOC, SOH, voltage and temperature. The energy stored in the battery packs (e.g., EV battery packs) can be properly circulated through their own ratios to avoid uneven performance across the battery packs. When the weaker battery packs are full / empty, better (or healthier) battery packs with more remaining capacity can be further circulated. At an early stage, the DPESS will utilize the better battery packs and degrade them towards the same condition as the weaker battery packs. The system will operate under the same conditions for all battery packs. The overall life of the system can be extended.

[0072] Decentralized systems offer advantages over centralized energy storage systems. For example, in centralized battery energy storage systems, multiple battery packs 20 are connected to a power conversion system (PCS). Because all batteries are bundled together, the system's performance is limited by the weakest battery pack. Furthermore, because all batteries are connected to the same DC bus, significant circulating currents exist. These circulating currents lead to self-discharge in the battery pack, which reduces battery life.

[0073] As an advantage of this decentralized system, if one battery bank (and / or one converter) fails to respond, the system still has the ability to supply the load. It also provides flexibility in terms of maintaining and upgrading the system.

[0074] Another benefit is the extended life of the battery pack. Figure 2 As shown, the weakest battery pack 20b controls the discharge or charge process in the centralized energy storage system, and when the weakest battery pack 20b is full / empty, the discharge or charge process must stop charging / discharging. The energy above area 23 cannot be used. Most battery packs cannot get a complete cycle and their lifespan is reduced after a short period of operation. With a decentralized system, the performance of the system is not limited by the weakest battery pack. Each battery pack is controlled by its own PCS (or independent DC port). The energy stored in the battery pack can be fully utilized. The controller calculates the power ratio to help the battery pack balance the SOC.

[0075] Another advantage is plug-and-play operation. System 100 does not require all battery packs to have identical characteristics. Old and new battery packs of different types, different brands, original and repackaged battery packs can all be used in system 100. This is not possible with any existing energy storage system. Furthermore, even if some part of the system fails, system 100 can still operate partially. The damaged part can be easily isolated without removing the entire system from production.

[0076] The present disclosure provides a method for operating an electrical energy storage system 100 as described via a controller 60 therein, or a method of using a controller 60 as described.

[0077] refer to Figures 6A-6B , an exemplary method 300 for controlling the discharge or charge of a battery pack is shown according to some embodiments. The steps described here are also the steps that the controller 60 is configured to perform through a program.

[0078] Before and during operation of the system 100, the main process may include the following steps. Multiple battery packs (e.g., secondary electric vehicle (EV) batteries) are connected in parallel as described in the system. One battery pack 20 is configured to connect to one power converter 10 or a DC port on the converter 10 via two circuit breakers. The circuit breakers are electrically powered and connected to the MIST via a functional relay. The parallel-connected converters 10 or converters 10 are connected to the grid. One or more BPMUs 30 are used to activate the internal battery BMUs 25, interpret the battery data, and send it to the MIST. All components of the system (including the HMI, converters 10, BPMUs 30, and protective relays) are linked to the MIST controller 60 via a TCP / IP network. The MIST controller 60 collects data and receives commands from the HMI or a higher-level energy management system (EMS), then performs calculations based on the battery pack's condition and total power demand. The MIST controller issues commands to operate the battery converters and monitors and controls the entire system. When the SOH, SOC, and battery pack voltage reach given thresholds, the MIST controller 60 adjusts the battery pack's power ratio. The MIST controller 60 logs all system data and tracks error information.

[0079] exist Figure 6A In step 302, data including state of health (SOH) and state of charge (SOC) are obtained and read from each of the plurality of battery packs 20 connected in parallel. In some embodiments, the controller 60 can be configured to read this data directly from the battery packs 20 or through one or more battery power management units (BPMUs) 30 configured to monitor and control the plurality of battery packs.

[0080] At step 304, the corresponding battery pack 20 is connected to the corresponding power converter 10. As described above, the battery pack 20 can be connected to one power converter 10 or a DC port on the converter 10 via two circuit breakers. The circuit breakers are electrically powered and connected to the controller 60 via functional relays.

[0081] At step 306 , a power command is received from a superior energy management system (EMS) 110 .

[0082] At step 308 , a corresponding power ratio of each battery pack is calculated based on the SOH and SOC of each battery pack 20 and the power command from the EMS 110 .

[0083] At step 310, based on the power ratio of each battery pack, power is discharged from the plurality of battery packs to the grid, or power from the grid is charged to the plurality of battery packs. The charging or discharging is based on demand from the EMS 110. Each power converter 10 is coupled to at least one battery pack 20 and can convert DC power from the corresponding battery pack 20 to AC power during a discharge process, or vice versa during a charge process. The controller 60 is configured to discharge power from the plurality of battery packs 20 in DC to the AC grid, or to charge power from the grid to the plurality of battery packs.

[0084] In some embodiments, the controller is configured to calculate the corresponding power ratio (P i ):

[0085] and

[0086] P i =min(P iMax ,P T *a i ) (2),

[0087] Among them, SOH i and SOC i are the SOH and SOC of each battery pack, P T is the power command from EMS, P iMax is the maximum capacity of each battery pack, and a i is a multiplier (in percentage) representing the dispatch share (or ratio) of each battery group. The subscript "i" represents the number of each corresponding battery group in the plurality of battery groups. The respective power ratio (P i ) is package P iMax and P T *a i The minimum (or smaller) of the two values ​​​​of .

[0088] The above equation (1) comprises two independent equations, which include 1(a) for charging and 1(b) for discharging:

[0089] and

[0090]

[0091] In addition to the above steps, the controller 60 is also configured to perform other steps, such as Figure 6B , and steps 312, 314, and 316 are shown in FIG.

[0092] At step 312 , a signal is sent to each converter and / or each battery pack with instructions to discharge or charge based on the respective power ratio of each battery pack.

[0093] At step 314, optionally, feedback is sent to the EMS if the power command exceeds a maximum limit of the system.

[0094] At step 316, the BMU 25 and inverter 40 of each battery pack 20 are monitored and the data is read from them. Step 316 may overlap with step 302. The method then loops back to Figure 6A Step 302.

[0095] An important function of the MIST controller 60 is to dispatch power from the battery pack during discharge or to dispatch power to the battery pack during charging. Due to changes in the first life, the SOC and SOH of the secondary used battery pack are different in the system 100. The charge / discharge power must be divided according to the condition of the battery pack. The dispatch power ratio is proportional to the energy stored in the battery pack. Equation (1) is used to calculate the dispatch ratio of the i-th battery pack. Then, the power is calculated using equation (2), and the power is subject to power limit.

[0096] refer to Figure 7 An exemplary flowchart 400 illustrates the steps and algorithms used in some embodiments. Each box represents a step or criterion. At box 92, the system is started. At box 94, the controller 60 communicates with the BMUs 25 and inverters 40 in the battery packs 20 to check the status of the BMUs 25 and inverters 40 and read data at box 96. At box 98, if communication with a battery pack 20 fails, the controller 60 lists the failed BMUs 25 and / or inverters 40 and checks the next battery pack. If communication with a battery pack does not fail, at box 102, the controller 60 reads the voltage of the battery pack 20. At box 104, DC voltage is pumped to the inverter 40 to close the circuit breaker between the battery pack 20 and the port of the corresponding power converter 10, connecting the battery pack 20 and the corresponding power converter 10 together. These processes prepare the system for the discharge or charge steps.

[0097] In box 106, the power command is read from the upper-level energy management system (EMS) 110. In box 108, the SOC and SOH of each battery pack are checked, and the power ratio of each battery pack is calculated, for example, using equations (1) and (2) as described above. The power allocation is planned accordingly. At box 112, the power limit of the battery pack 20 is checked. If the power demand of the battery pack 20 exceeds its limit, then at box 114, such battery pack is restricted from being allocated power, and then the power ratios of the other battery packs are recalculated by returning to boxes 106 and 108. If the power demand of the battery pack 20 is within its limit (i.e., its power limit is not violated) at box 112, then a check is performed at box 118 to see if the total power demand exceeds the limit of the system 100. If the total power from the battery packs cannot meet the requirements of the power command from the EMS 110, then at box 120, feedback is sent to the EMS 110 and a new and smaller power command is requested. If the total power from the battery pack can meet the requirements of the power command from the EMS 110, the command and instruction are sent to the battery pack 20 including the inverter 40. Figure 7 The steps of blocks 106 to 122 may be repeated in a loop before ending at block 124.

[0098] As described above, the present disclosure provides a controller 60 for an electrical energy storage system.

[0099] In some embodiments, the MIST controller 60 is the local controller of the system. It acts as the brain to oversee the system. The controller 60 checks communication with all hardware components, collects data, and displays errors if any. The controller 60 operates the converter and circuit breaker to connect the battery pack to the converter DC port. It also receives commands from the HMI or upper-level EMS. The controller 60 calculates the power ratio of each battery pack and distributes the power ratio to the converter for charging / discharging. The controller 60 monitors the status and condition of each battery pack and re-estimates the power ratio accordingly. The controller 60 records the data in a local and / or cloud database. The controller 60 monitors data including the SOH, SOC, and voltage values ​​of each battery pack and determines the new power ratio in real time. The MIST controller also operates the circuit breaker between the battery pack and the converter to prevent overcharging / discharging.

[0100] Example

[0101] Just for illustration, Figure 3 The system 200 is used for evaluation. In the following example, the power demand is 24KW and constant scheduling is used.

[0102] Figure 8 and Table 1 shows the use of Figure 3 An example of discharging six battery packs in system 200.

[0103] Table 1

[0104]

[0105] Figure 9 and Table 2 shows the use of Figure 3 Example of charging six battery packs in a system.

[0106] Table 2

[0107]

[0108] The systems, controllers, and methods provided in this disclosure offer numerous advantages. For example, the system is a decentralized design. A variety of battery packs of varying quality, such as used EV battery packs, can be used. No preselection or removal of battery packs is required. If a battery pack and / or a converter fails to respond, the system still has the ability to supply power to the load to meet the power demand. The systems, controllers, and methods extend the life of each battery pack and provide flexibility in maintaining and upgrading the system.

[0109] The methods and systems described herein may be embodied at least in part in the form of computer-implemented processes and apparatus for practicing these processes. The disclosed methods may also be embodied at least in part in the form of a tangible, non-transitory, machine-readable storage medium encoded with computer program code. The medium may include, for example, RAM, ROM, CD-ROM, DVD-ROM, BD-ROM, hard drive, flash memory, or any other non-transitory, machine-readable storage medium, or any combination of these media, wherein when the computer program code is loaded into and executed by a computer, the computer becomes an apparatus for practicing the methods. The methods may also be embodied at least in part in the form of a computer, with the computer program code being loaded into and / or executed by the computer, such that the computer becomes an apparatus for practicing the methods. When implemented on a general-purpose processor, the computer program code segments configure the processor to create specific logic circuits. The methods may optionally be implemented at least in part in a digital signal processor formed by an application-specific integrated circuit for executing the methods. The computer or control unit may be operated remotely using a cloud-based system.

[0110] Although the subject matter has been described in terms of exemplary embodiments, it is not limited thereto. Rather, the appended claims should be construed broadly to encompass other variations and embodiments that may be made by those skilled in the art.

Claims

1. An electric energy storage system comprising: Multiple battery packs connected in parallel; one or more battery power management units (BPMUs), each BPMU coupled to the one or more battery packs and configured to monitor and control the one or more battery packs; one or more power converters, each power converter coupled to at least one battery pack and configured to convert direct current (DC) from the at least one battery pack to alternating current (AC) or vice versa; as well as A controller that uses multi-source input intelligence technology (MIST) and includes one or more processors and at least one tangible, non-transitory, machine-readable medium encoded with one or more programs configured to perform the following steps: Read data including state of health (SOH) and state of charge (SOC) from each battery pack; Connect the corresponding battery pack to the corresponding power converter; Receive power commands from the upper-level energy management system (EMS); calculating a corresponding power ratio of each battery pack based on the SOH and the SOC of each battery pack and the power command from the EMS; as well as discharging from or charging to the plurality of battery packs based on the power ratio of each battery pack, The controller is configured to calculate the corresponding power ratio (P i ): and P i =min(P iMax ,P T *a i ) (2), Among them, SOH i and SOC i are the SOH and SOC of each battery pack, P T is the power command from the EMS, P iMax is the maximum capacity of each battery pack, and a i is a multiplier representing the dispatch share of each battery group.

2. The system according to claim 1, wherein: The plurality of battery packs are heterogeneous battery packs selected from new batteries, second-used electric vehicle (EV) batteries, or a combination thereof.

3. The system of claim 1 , wherein each battery pack includes an inverter and an internal battery management unit (BMU). 4 . The system of claim 3 , wherein the controller is configured to read the data from the inverter and the BMU of each battery pack and monitor the inverter and the BMU of each battery pack. 5 . The system of claim 1 , further comprising a plurality of automatic circuit breakers, each circuit breaker being configured to connect or disconnect a corresponding battery pack and a corresponding power converter.

6. The system according to claim 1, wherein: The controller is configured to discharge power from the plurality of battery packs to a grid, or to charge power from the grid to the plurality of battery packs. 7 . The system of claim 1 , wherein the controller is configured to send a signal with instructions for discharging or charging to each converter and / or each battery pack based on the corresponding power ratio of each battery pack.

8. The system of claim 1, wherein the controller is configured to send feedback to the EMS if the power command exceeds a maximum limit of the system.

9. A controller for an electrical energy storage system, the controller utilizing multi-source input intelligence technology (MIST) and comprising one or more processors and at least one tangible, non-transitory, machine-readable medium encoded with one or more programs configured to: reading data including state of health (SOH) and state of charge (SOC) from each of the plurality of battery packs connected in parallel through one or more battery power management units (BPMUs) for monitoring and controlling the plurality of battery packs; connecting the respective battery packs to respective power converters coupled to at least one of the battery packs and configured to convert direct current (DC) from the respective battery packs to alternating current (AC) or vice versa; Receive power commands from the upper-level energy management system (EMS); calculating a corresponding power ratio of each battery pack based on the SOH and the SOC of each battery pack and the power command from the EMS; as well as discharging from or charging to the plurality of battery packs based on the power ratio of each battery pack, The controller is configured to calculate the corresponding power ratio (P i ): and P i =min(P iMax ,P T *a i ) (2), Among them, SOH i and SOC i are the SOH and SOC of each battery pack, P T is the power command from the EMS, P iMax is the maximum capacity of each battery pack, and a i is a multiplier representing the dispatch share of each battery group.

10. The controller according to claim 9, wherein: The plurality of battery packs are heterogeneous battery packs selected from new batteries, second-used electric vehicle (EV) batteries, or a combination thereof.

11. The controller according to claim 9, wherein: The controller is configured to discharge power from the plurality of battery packs to a grid or a load, or to charge power from the grid to the plurality of battery packs. 12 . The controller of claim 9 , wherein the controller is configured to send a signal with an instruction for discharging or charging to each converter and / or each battery pack based on the corresponding power ratio of each battery pack.

13. The controller of claim 9, wherein the controller is configured to send feedback to the EMS if the power command exceeds a maximum limit of the system.

14. A method for operating an electrical energy storage system via a controller therein, comprising: reading data including state of health (SOH) and state of charge (SOC) from each of a plurality of battery packs connected in parallel; connecting the respective battery packs to respective power converters coupled to at least one of the battery packs and configured to convert direct current (DC) from the respective battery packs to alternating current (AC) or vice versa; Receive power commands from the upper-level energy management system (EMS); calculating a corresponding power ratio of each battery pack based on the SOH and the SOC of each battery pack and the power command from the EMS; as well as discharging from the plurality of battery packs to a grid or charging from the grid to the plurality of battery packs based on the power ratio of each battery pack, The corresponding power ratio of each battery pack is calculated according to equations (1) and (2): and P i =min(P iMax ,P T *a i ) (2), Among them, SOH i and SOC i are the SOH and SOC of each battery pack, P T is the power command from the EMS, P iMax is the maximum capacity of each battery pack, and a i is a multiplier representing the dispatch share of each battery group.

15. The method according to claim 14, wherein The plurality of battery packs are heterogeneous battery packs selected from new batteries, second-used electric vehicle (EV) batteries, or a combination thereof.

16. The method according to claim 14, further comprising: Instructions are sent from the controller to each converter and / or each battery pack to discharge or charge based on the respective power ratio of each battery pack.

17. The method according to claim 14, further comprising: If the power command exceeds a maximum limit of the system, feedback is sent from the controller to the EMS.

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