English:
[0001] The present disclosure generally relates to an energy storage system and method employing second-life electric vehicle batteries, and more particularly to an integrated battery energy storage system, which includes a plurality of electric vehicle battery packs coupled in a series/parallel arrangement.
[0002] Reducing the cost of energy storage systems (ESS) is an important objective for electricity ratepayers and policymakers. A primary metric to measure ESS cost is the levelized cost of storage (LCOS), defined as the total lifetime cost of the ESS, including capital costs to construct as well as costs to operate, divided by the cumulative delivered electricity that the system has stored.
[0003] Repurposing electrochemical batteries from electric vehicles (EV) for a second use or second-life stationary storage application can significantly reduce the LCOS of ESS compared to using new batteries. Deploying EV batteries in stationary storage applications is the highest and best use of batteries when the batteries are no longer suitable for use in EVs. Larger scale ESS requires a large number of batteries to be deployed in series and parallel electrical configurations to deliver energy at high voltage and current levels. Whether electrically connected in front of or behind a customer’s meter, an ESS must efficiently integrate and manage batteries over time and charge/discharge cycles to be effective.
[0004] It would be desirable to have a system that utilizes a plurality of electric vehicle (EV) batteries in second-life stationary storage applications within an overall energy storage system (ESS).
[0005] In accordance with an aspect, an integrated battery energy storage system is disclosed, the integrated battery energy system comprising: a plurality of electric vehicle battery packs coupled in a series/parallel arrangement, the series/parallel arrangement including a plurality of series strings of electric vehicle battery packs, each of the plurality of series strings of electric vehicle battery packs includes at least two of the plurality of electric vehicle battery packs coupled in series; and wherein the plurality of series strings of electric vehicle battery packs are connected in parallel.
[0006] In accordance with another aspect, an integrated battery energy storage system is disclosed, the integrated battery energy storage system comprising: a plurality of electric vehicle battery packs configured to store energy; an enclosure configured to enable outdoor deployment of the energy storage assembly; a plurality of removable exterior enclosure panels configured to facilitate ease of installation and removal of the plurality of electrical vehicle battery packs from the enclosure; a plurality of DC-to-DC converters configured to balancing a voltage or energy storage capacity of series connected electric vehicle battery packs; environmental controls within the enclosure configured to extend the usable lifetime of the plurality electric vehicle battery packs within the enclosure; a racking system for the plurality of electric vehicle battery packs, the racking system 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 pack battery management system without alteration from an original manufacturer’s design and intended function.
[0007] In accordance with an aspect, a method is disclosed for integrating electric vehicle battery packs into an integrated battery energy storage system, the method comprising: coupling a plurality of electric vehicle battery packs in a series/parallel arrangement, the series/parallel arrangement including a plurality of series strings of electric vehicle battery packs, each of the plurality of series strings of electric vehicle battery packs includes at least two of the plurality of electric vehicle battery packs coupled in series; and connecting the plurality of series strings of electric vehicle battery packs in parallel.
[0008] Figure 1 is a block diagram illustrating the utility as part of an energy storage system in accordance with an exemplary embodiment.
[0010] Figure 3 illustrates a battery pack controller (BPC) and smart combiner (SC) in accordance with an exemplary embodiment.
[0012] For simplicity and illustrative purposes, the principles of the embodiments are described by referring mainly to examples thereof. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the embodiments. It will be apparent however, to one of ordinary skill in the art, that the embodiments may be practiced without limitation to these specific details. In some instances, well known methods and structures have not been described in detail so as not to unnecessarily obscure the embodiments.
[0013] In accordance with an aspect, an EV pack storage system (EPS) employs the EV battery packs as an integrated functional unit or building block wherein a plurality of EV battery packs are rather easily aggregated to behave as a larger battery within an ESS. The batteries can be racked in a specialized environmentally controlled enclosure in the original pack casing in which the batteries were mounted in the EV. The specialized environmentally controlled enclosure functions as an integrated EV pack storage unit and the EPS functions as a sub-system building block within the overall ESS. The EV battery packs within the EPS may be electrically connected in series as well as in parallel. Each series string is protected with an overcurrent device. The EPS enclosure is designed for easy installation, removal and replacement of EV battery packs. Each battery pack and string may be monitored with a proprietary battery pack controller (BPC). The BPC helps ensure proper operating parameters and monitors the health of each EV battery pack. The battery pack controller (BPC) can monitor the health of each EV battery pack by interfacing with the EV pack integrated battery management system (BMS). The BPC manages a smart combiner (SC) to actively balance the second-life batteries in order to effectively utilize the charge and discharge cycle of individual packs adjusting for variance in each pack’s capacity. The environment of the EPS enclosure is managed to maintain suitable operating temperatures, and for hazard detection. The EPS operates within a larger ESS that also includes an inverter Power Conversion System (PCS) and Supervisory Control and Data Acquisition (SCADA). Multiple EPS can operate in integrated fashion together within an ESS. The ESS can be configured as DC-coupled, or AC-coupled to the inverter. The EPS can be charged from on-site generation such as solar or wind, or from electricity provided by the AC power system. The EPS within the ESS can be deployed in front of the meter (IFM) directly interconnected to the grid or deployed behind the meter (BTM) to offset a customer’s load and demand.
[0014] In accordance with an exemplary embodiment, an integrated system is disclosed for deploying a plurality of second-life electric vehicle (EV) battery packs within an energy storage system (ESS).
[0015] In the present disclosure, herein referred to as the EV pack storage system (EPS), is an integrated functional building block wherein a number of EV battery packs are easily aggregated to behave as a larger battery within an overall ESS. The EPS composition and function includes; (1 ) the EV battery packs are utilized, both mechanically and electrically, as they were in the original first-life vehicle application, incorporating the battery pack’s battery management system (BMS) as well as a similar digital serial data link format and protocol; (2) the EV battery packs are electrically configured in a parallel arrangement and often in series. EV battery packs may not have been originally designed for use in series connection but this limitation is overcome with a unique design for mounting, communicating and interconnecting; (3) a number of EV battery packs are integrated into an environmentally controlled and monitored cabinet or enclosure which is not considered an occupiable space according to building or fire code definitions, and where a single enclosure, or multiple enclosures, can be integrated in the ESS; (4) a battery pack controller (BPC) is deployed as part of the EPS to integrate the communications and controls necessary for the batteries to work together and operate in coordination as a unified functional block; and (5) a smart circuit combiner provides electrical balancing and overcurrent protection for all EV battery packs within the EPS.
[0016] Figure 1 is a block diagram illustrating the utility of the disclosure in a preferred embodiment as part of a grid-tied energy storage system. In accordance with an exemplary embodiment, the EV pack storage system (EPS) 100 can be implemented as part of an overall energy storage system (ESS). All heavy lines 600 with arrowheads indicate power connections and possible power flow directions. All dashed lines 500 indicate bidirectional digital data bus connections.
[0017] EPS 100 includes a plurality of EV battery packs, designated in Figure 1 as blocks 1 , N-1 and N to indicate any number N of identical EV battery packs. EV battery pack 1 contains batteries 1.1 and Battery Management System (BMS) 1.2. The EV battery pack batteries 1.1 through N.1 are connected in series at nominal voltages, which are multiples of a single pack’s nominal voltage. A number N of EV battery packs are connected in a series/parallel configuration or otherwise aggregated within smart combiner 130 to electrically behave as a larger battery within the overall energy storage system. A smart combiner 130 is connected to a bidirectional DCDC (DC-to-DC) converter 603. A DCDC converter 603 can provide an optimum voltage match between the aggregate EV battery packs and the Inverter Power Conversion System (PCS) 605 to provide an optimum voltage match as the maximum power point of solar PV generation 606 changes with temperature and load. A smart combiner (SC) 130 can be used to actively balance the second-life batteries in order to effectively utilize the charge and discharge cycle of individual packs adjusting for variance in each pack’s capacity.
[0018] When the overall system is delivering energy stored in the EV battery packs, for example, to a power grid 610, DC power flows from the EV battery packs, through smart combiner 130 and through DCDC converter 603. DC power is then converted to AC power by PCS 605 to supply energy to the power grid 610. Power from solar photovoltaic generation 606, when available, for example, can also flows through PCS 605, which functions as a DC to AC power converter to discharge power into power grid 610. In this configuration, the total power into power grid 610 can be, for example, a combination of battery sourced power and solar photovoltaic sourced power.
[0019] In accordance with an exemplary embodiment, when the overall system is delivering energy to charge EV battery packs 1 through N, PCS 605 functions as an AC to DC power converter by sourcing AC power from power grid 610 and converting it to DC power. This DC power flows through DCDC converter 603, through smart combiner 130 and into all EV battery packs 1 through N. Power from solar photovoltaic generation 606, when available, can either be used to reduce the power required from power grid 610 to charge EV battery packs 1 through N or if the power from available solar power generation 606 is greater than the power required to charge these EV battery packs, then the excess power can be delivered to power grid 610. Some system variants will not include solar PV onsite generation 606 and therefore DCDC converter 603 may not be required.
[0020] In accordance with an exemplary embodiment, a battery management system (BMS) 1.2 monitors every cell in the EV battery pack 1 , primarily to check for mismatched, undercharged or overcharged cells in a series string. By monitoring and rebalancing mismatched cells, the usable lifetime of the EV battery pack can be enhanced, and battery cell and pack safe operating parameters can be ensured to avoid hazardous conditions. A Battery Pack Controller (BPC) 140 communicates with individual EV battery packs 1 through N over a digital data bus. Supervisory Control and Data Acquisition (SCADA) 501 communicates with BPC 140 to ascertain the state of charge, state of health and overall availability of the aggregate EV battery packs. In accordance with an exemplary embodiment, SCADA 501 receives top level commands from power system manager 503 via internet 502 to control the operation of the overall energy storage system.
[0021] SCADA 501 can also communicate with a cabinet control system 150. Within EPS 100, the cabinet control system 150 can communicate with thermal management block 151 and the hazard protection block 152. Thermal management block 151 provides air conditioning, dehumidification, venting, and air circulation as required to maintain an optimum environment for EV battery packs 1 through N. The hazard detection block 152 monitors the environment inside the EPS 100 enclosure for smoke and over/under temperature conditions.
[0022] Figure 2 is a modified single-line electrical diagram of an energy storage system in accordance with an exemplary embodiment and illustrates the power flow. This disclosure and description does not limit, however, the scope of the disclosure to systems with the number of elements and/or components described herein.
[0023] As illustrated in Figure 2, the energy storage system, for example, has four EV pack storage assemblies (EPS) 100, 200, 300 and 400. Each EPS 100, 200, 300, 400, can be identical. However, each EPS may not be identical and modifications of one or more the EPSs 100, 200, 300, 400 may occur. In accordance with an exemplary embodiment, the EPS 100 contains 24 EV battery packs (EVBP) designated 1-24. Within each EVBP are a number of series or series parallel connected battery modules shown as 1.1 in EVBP 1 through 24.1 in EVBP 24. There is also a normally an open contactor, which may be configured as one or more series connected contactors designated, 1.3 in EVBP 1 through 24.3 in EVBP 24. EVBP 1-24 may also contain other power circuits, such as but not limited to precharge resistors and contactors. In this exemplary system, EVBP 1 through 24 are connected in a 2S12P circuit arrangement where EVBP pairs are connected in series and where 12 of these series strings are connected in parallel. The series strings 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 through 23/24 are connected through fuses 101 through 112, respectively, in smart combiner 130. Fuses 101 through 112 provide a second tier of overcurrent protection to protect the EV batteries 1.1 through 24.1 from over-currents under abnormal conditions. Fuses 101 through 112 can also prevent contactors 1 .3 through 24.3 from breaking currents outside safe contactor limits. Contactors 1 .3 through 24.3 can provide the first tier of overcurrent protection, for currents less than fuse 101 through 112 ratings, as well as other circuit isolation and connection control functions. The output of smart combiner (SC) 130 is connected to switch 161 , which connects or isolates the power circuits of EPS 100 from the other energy storage system components. Fuse 162 protects the ampacity of conductors and the break capability of switch 161 . In accordance with an exemplary embodiment, circuit breakers or other overcurrent devices and systems may be substituted for fuses in Figure 2.
[0024] In this system example, EPS 100 and 200 are connected to DCDC converter 603. EPS 300 and 400 are connected to DCDC converter 604. DCDC converter 603 can provide an optimum voltage match between parallel connected EPS 100 and EPS 200 and the inverter power conversion system (PCS) 605 to provide an optimum voltage match as the maximum power point of solar PV generation 606 changes with temperature and irradiance. Both DCDC converters 603 and 604 are capable of bidirectional power transfer, to either charge or discharge EV battery packs. PCS 605 is also bidirectional with respect to power flow.
[0025] When the overall system, for example, is delivering energy stored in EPS 100, 200, 300 and 400 batteries to power grid 610 and/or local loads 607, DC power flows from EPS 100 and 200 through DCDC converter 603 and in parallel from EPS 300 and 400 through DCDC power converter 604. DC power can then be converted to AC power by PCS 605. AC power then flows through distribution transformer 608, where the voltage can be raised to more efficient distribution voltage levels and through revenue meter 609 before connection to power grid 610. Power from solar photovoltaic generation 606, when available and utilized, also flows through PCS 605 and PCS 605 functions as a DC to AC power converter to source power into power grid 610 and/or local loads 607. The total power into power grid 610 can be the sum of battery sourced power plus solar photovoltaic sourced power minus the power used by local loads 607. Local loads may also be supported without a connection to power grid 610 in which case PCS 605 works in a “stand alone” AC voltage regulation mode.
[0026] When the overall energy storage system is delivering energy to charge EV battery packs in EPS 100, 200, 300 and 400, PCS 605 functions as an AC to DC power converter by sourcing AC power from power grid 610 and converting AC to DC power. In accordance with an exemplary embodiment, the DC power flows through DCDC converters 603 and 604 to charge EV battery packs in EPS 100, 200, 300 and 400. Power from solar photovoltaic generation 606, when available, for example, can either be used to reduce the power required from the power grid 610 to charge EV battery packs, or if the power available from solar power generation 606 is greater than the power required to charge these EV battery packs and supply local “behind the meter” loads 607, then the excess power can be delivered to power grid 610.
[0027] In accordance with an alternate embodiment as shown in Figure 2, the energy storage system can include one or more of the following: PCS 605, DCDC converter 603, transformer 608 and power meter 609, as part of the integrated EPS 100.
[0028] Figure 3 is a detailed drawing of the battery pack controller 140 and smart combiner 130 as shown in Figure 1 . Reference designator 1 indicates a plurality of EV battery packs (EVBP) with EVBP 1 on top. Reference designator 2 indicates a plurality EVBP with EVBP 2 on top. EVBP 1 and 2 are electrically connected in series as the first series pair in this EPS embodiment. Each series pair within the EPS communicates with one EV BMS interface board (EVIB) within in the BPC. In this first, top level case, BMS 1.2 and BMS 2.2 communicate with EVIB 141 over digital data buses 504 and 505, respectively. The communication protocol is a controller area network bus (CAN bus) as used in the original manufacturer’s electric vehicle application. All other EVBP series pairs within the EPS communicate in a similar way. Control circuit 142 aggregates the data from all EVIB within BPC 140 and provides a Modbus digital communication link 507 to a system controller external to the EPS and Modbus link 506 to smart combiner 130. In accordance with an exemplary embodiment, the Modbus digital communication link 507 communicates with the overall energy system SCADA (element 501 in Figure 1) to report the health, availability and state of charge of the “composite” battery configured from the series/parallel connection of all EV battery packs. Modbus data link 506 connects control circuit 142 to control circuit 138 to actively control the balancing of each EV battery pack in a series string.
[0029] In accordance with an exemplary embodiment, the balancing of each EV battery pack in a series string, for example, can be achieved by monitoring the voltage, current and temperature of each EV battery pack and then transferring energy from the higher voltage of the two packs in a series string to the lower voltage pack. For example, if EVBP 1 has a higher voltage than EVBP 2, then semiconductor switch 132 is closed, current flows from battery 1.1 through inductor 137, semiconductor switch 132 is opened and the current through inductor 137 flows through diode 135 and into battery 2.1 completing one energy transfer cycle. This energy transfer cycle is repeated at high frequencies for an amount of time proportional to the desired energy transfer. If EVBP 2 has a higher voltage than EVBP 1 , then semiconductor switch 134 is closed, current flows from battery 2.1 through inductor 137, semiconductor switch 134 is opened and the current through inductor 137 flows through diode 133 and into battery 1.1 completing one energy transfer cycle.
[0030] Figure 3 illustrates a method of balancing batteries in a series battery string but does not limit the disclosure to any one battery balancing method or number of EVBPs in a series string. In accordance with an exemplary embodiment, the energy storage system includes the interconnections and inter-functionality of the battery pack controller 140, EV battery pack battery management systems, 1 .2 and 2.2 in this example, smart combiner 130 and overall system controller via data link 507. Fuses 131 and 136 can be used to provide fault isolation between EVBP 1 and 2 series string and the parallel circuits of all series strings +BLIS 601 and -BUS 602. In accordance with an exemplary embodiment, all other series strings, for example, can be protected in a similar manner.
[0031] In accordance with an exemplary embodiment, the energy storage system can include each of the elements shown in Figure 1 within EV pack storage system (EPS) box 100 plus a weatherproof enclosure and a racking system for the EV battery packs. Figure 4 illustrates an embodiment of the enclosure, which can include fixed and removable exterior insulated panels 60. The enclosure 50 can be designed, for example, as a cabinet where the battery system and system controls are accessible from outside the enclosure, and the enclosure or cabinet is not an occupiable space as defined in building or fire codes. In accordance with an exemplary embodiment, the enclosure 50 is an outdoor rated enclosure that enables outdoor deployment of the energy storage assembly.
[0032] In accordance with an exemplary embodiment, the racking system 40 can be fabricated from structural steel and configured to hold EV battery packs 1 through 24. Each pack in the present build of the EV pack storage system (EPS), for example, can weighs in excess of 600 pounds. The side panels 60 of the enclosure 50 can be removed, for example, to allow forklift access to rather easily install and remove EV battery packs 1 through 24. In addition, the racking system 40 is designed to allow air flow between the EV battery packs. For example, each EV battery pack can be electrically isolated from the racking system 40 by a standoff 30. The EV battery packs, for example, can be cooled and heated by a thermal management system 151 under the direction of cabinet control system 150. The thermal management system 151 may include cooling, dehumidification, and other environmental controls as a means for extending the useful lifetime of the EV battery packs. A hazard detection system 152 can provide alarms to cabinet control system 150 when smoke, gasses or temperature conditions outside of an operational range are detected.
[0033] The smart combiner 130 and battery pack controller 140 functions are described in connection with the Figure 1 narrative. The smart combiner 130, the battery pack controller 140, the cabinet control system 150, the thermal management system 151 and the hazard detection system 152 are not shown to scale or with specific physical features. In one or more of the smart combiner 130, the battery pack controller 140, the cabinet control system 150, the thermal management system 151 and the hazard detection system 152 can be mounted to the EPS enclosure. In accordance with an exemplary embodiment, the fixed and removable exterior panels 60 of the enclosure 50 may be thermally insulated.
[0034] Techniques consistent with the present disclosure provide, among other features, an energy storage system and method employing second-life electric vehicle batteries. While various exemplary embodiments of the disclosed system and method have been described above it should be understood that they have been presented for purposes of example only, not limitations. It is not exhaustive and does not limit the disclosure to the precise form disclosed. Modifications and variations are possible in light of the above teachings or may be acquired from practicing of the disclosure, without departing from the breadth or scope.

中文:
[0001]本公开总体上涉及采用二次寿命电动车辆电池的能量储存系统和方法,并且更具体地,涉及包括以串联/并联布置联接的多个电动车辆电池组的集成电池能量储存系统。
[0002]降低能量储存系统(ESS)的成本是电费纳税人和决策者的重要目标。衡量ESS成本的主要指标是平准化储存成本(LCOS),LCOS被定义为包括建设资金成本和运营成本的ESS的全寿命成本除以系统已储存的累计输送电力。
[0003]与使用新电池相比,将电动车辆(EV)的电化学电池重新用于二次使用或二次寿命固定储存应用可以显著降低ESS的LCOS。当电池不再适合在EV中使用时,在固定储存应用中部署EV电池是电池的最高和最佳用途。更大规模的ESS需要大量的电池以串联和并联的电气配置部署,以输送高电压和高电流水平的能量。无论是电气连接在客户电表的前方还是后方,ESS都必须随着时间的推移和充电/放电循环有效地集成并管理电池以使其有效工作。
[0004]将期望的是,拥有在整个能量储存系统(ESS)内在二次寿命固定储存应用中利用多个电动车辆(EV)电池的系统。
[0005]按照一方面,公开了一种集成电池能量储存系统,所述集成电池能量系统包括:以串联/并联布置联接的多个电动车辆电池组,所述串联/并联布置包括所述电动车辆电池组的多个串联串,所述电动车辆电池组的多个串联串中的每一个包括串联联接的多个电动车辆电池组中的至少两个;以及其中,所述电动车辆电池组的多个串联串并联连接。
[0006]按照另一方面,公开了一种集成电池能量储存系统,所述集成电池能量储存系统包括:多个电动车辆电池组,所述多个电动车辆电池组被配置为储存能量;外壳,所述外壳被配置为使得所述能量储存组件能够在室外部署;多个可拆卸外部外壳板,所述多个可拆卸外部外壳板被配置为有助于安装和从所述外壳拆卸所述多个电动车辆电池组;多个DC-DC转换器,所述多个DC-DC转换器被配置为平衡串联连接的电动车辆电池组的电压或能量储存容量;所述外壳内的环境控制件,所述环境控制件被配置为延长所述外壳内所述多个电动车辆电池组的可使用寿命;用于所述多个电动车辆电池组的机架系统,所述机架系统被配置为在所述多个电动车辆电池组之间提供电隔离和热隔离;以及电动车辆电池组控制器,所述电动车辆电池组控制器被配置为使用电动车辆组电池管理系统,而不改变原始制造商的设计和预期功能。
[0007]按照一方面,公开了一种用于将电动车辆电池组集成到集成电池能量储存系统中的方法,所述方法包括:以串联/并联布置联接多个电动车辆电池组,所述串联/并联布置包括所述电动车辆电池组的多个串联串,所述电动车辆电池组的多个串联串中的每一个包括串联联接的多个电动车辆电池组中的至少两个;以及将所述电动车辆电池组的多个串联串并联连接。
[0008]图1是图示了按照示例性实施例的作为能量储存系统的一部分的实体的框图。
[0010]图3图示了按照示例性实施例的电池组控制器(BPC)和智能组合器(SC)。
[0012]为了简单和例示的目的,主要通过参照实施例的示例来描述实施例的原理。在以下的描述中,阐述了众多具体细节,以便提供对实施例的彻底理解。然而,对于本领域中的普通技术人员而言将清楚的是,可以在没有限制这些具体细节的情况下实践实施例。在某些情形下,没有详细描述熟知的方法和结构,以免不必要地混淆实施例。
[0013]按照一方面,EV组储存系统(EPS)采用EV电池组作为集成功能单元或构建块,其中,多个EV电池组被相当容易地集中以充当ESS内的较大电池。电池可以被放置在使得电池安装在EV中的原始包装壳体中的专用的受环境控制的外壳中。专用的受环境控制的外壳用作集成EV组储存单元,并且EPS用作整个ESS内的子系统构建块。EPS内的EV电池组可以串联以及并联地电连接。每个串联串都由过电流设备保护。EPS外壳被设计用于方便EV电池组的安装、拆卸和更换。可以用专有的电池组控制器(BPC)监视每个电池组和串。BPC有助于确保正确的操作参数,并且监视每个EV电池组的健康状况。电池组控制器(BPC)可以通过与EV组集成电池管理系统(BMS)接合来监视每个EV电池组的健康状况。BPC管理智能组合器(SC)来主动平衡二次寿命电池,以便有效地利用各个组的充电放电循环,从而针对每个组的容量差异进行调节。管理EPS外壳的环境,以保持合适的操作温度并且便于进行危险检测。EPS在还包括逆变器功率转换系统(PCS)以及监控和数据采集(SCADA)的较大ESS内操作。多个EPS可以在ESS中以集成的方式一起操作。ESS可以被配置为与逆变器DC联接或AC联接。EPS可以通过现场发电(诸如太阳能或风能)被充电,或者可以通过AC电力系统提供的电力被充电。ESS内的EPS可以部署在与电网互连的电表(IFM)正前方,或者部署在电表(BTM)后方,以补偿客户的负载和需求。
[0014]按照示例性实施例,公开了用于在能量储存系统(ESS)内部署多个二次寿命电动车辆(EV)电池组的集成系统。
[0015]在本公开中,本文中所谓的EV组储存系统(EPS)是集成功能构建块,其中,多个EV电池组被容易地集中,以在整个ESS内充当更大的电池。EPS的组成和功能包括:(1)在机械和电气两方面利用EV电池组,就像它们在最初的一次寿命车辆应用中一样,包含电池组的电池管理系统(BMS)以及类似的数字串行数据链格式和协议;(2)EV电池组以并联布置并且通常按串联进行电气配置。EV电池组最初可能不是为了串联连接使用而设计的,但用于安装、通信和互连的独特设计克服了该限制;(3)多个EV电池组被集成在受环境控制和监视的机柜或外壳中,根据建筑或消防法规定义,该机柜或外壳不被视为可占用空间,并且其中单个外壳或多个外壳可以被集成在ESS中;(4)电池组控制器(BPC)被部署为EPS的一部分以集成通信件和控制件,通信件和控制件是电池作为统一功能块一起工作和协调操作所必需的;以及(5)智能电路组合器为EPS内的所有EV电池组提供电气平衡和过电流保护。
[0016]图1是图示了利用优选实施例中的本公开作为并网能量储存系统的一部分的框图。按照示例性实施例,EV组储存系统(EPS)100可以被实现为整体能量储存系统(ESS)的一部分。所有带箭头的粗线600都指示电力连接和可能的电力流动方向。所有虚线500都指示双向数字数据总线连接。
[0017]EPS100包括多个EV电池组,该多个电池组在图1中被指定为块1、N-1和N,以指示任意数量的(N个)相同EV电池组。EV电池组1包含电池1.1和电池管理系统(BMS)1.2。EV电池组的电池1.1至N.1以标称电压串联连接,该标称电压是单个组的标称电压的倍数。N个EV电池组以串联/并联配置连接,或者以其他方式集中在智能组合器130内,以在电气上充当整个能量储存系统内的较大电池。智能组合器130连接到双向DCDC(DC-DC)转换器603。在太阳能PV发电606的最大功率点随着温度和负载变化时,DCDC转换器603可以提供集合的EV电池组与逆变器功率转换系统(PCS)605之间的最佳电压匹配,以提供最佳的电压匹配。智能组合器(SC)130可以用于主动平衡二次寿命电池,以便有效地利用各个组的充电放电循环,从而针对每个组的容量差异进行调节。
[0018]当整个系统在将储存在EV电池组中的能量输送到例如电网610时,DC电力从EV电池组流过智能组合器130和DCDC转换器603。然后,DC电力被PCS 605转换成AC电力,以向电网610供应能量。例如,来自太阳能光伏发电606的电力在可用时也可以流过PCS 605,该PCS用作DC-AC功率转换器以将电力放电到电网610中。在该配置中,进入电网610的总电力可以是例如电池引入电力与太阳能光伏引入电力的组合。
[0019]按照示例性实施例,当整个系统在输送能量以对EV电池组1至N进行充电时,PCS605通过从电网610引入AC电力并且将其转换成DC电力来用作AC-DC功率转换器。该DC电力流过DCDC转换器603,流过智能组合器130进入所有EV电池组1至N。来自太阳能光伏发电606的电力在可用时可以要么用于减少来自电网610的用于对EV电池组1至N进行充电所需的电力,要么如果来自可用太阳能发电606的电力大于对这些EV电池组进行充电所需的电力,则多余的电力可以输送到电网610。一些系统变型将不包括太阳能PV现场发电606,因此可能不需要DCDC转换器603。
[0020]按照示例性实施例,电池管理系统(BMS)1.2监视EV电池组1中的每个电芯,主要是为了检查串联串中的不匹配、充电不足或充电过度的电芯。通过监视和重新平衡不匹配的电芯,可以增强EV电池组的可使用寿命,并且可以确保电池电芯和电池组安全操作参数以避免危险状况。电池组控制器(BPC)140通过数字数据总线与各个EV电池组1至N通信。监控和数据采集(SCADA)501与BPC 140通信,以确认集合EV电池组的充电状态、健康状态和总体可用性。按照示例性实施例,SCADA501经由互联网502从电力系统管理器503接收顶级命令,以控制整个能量储存系统的操作。
[0021]SCADA 501还可以与机柜控制系统150通信。在EPS100内,机柜控制系统150可以与热管理块151和危险保护块152通信。热管理块151按需提供空气调节、除湿、通风和空气循环,以维持EV电池组1至N的最佳环境。危险检测块152监视EPS100外壳内部的环境中的烟雾和温度过高/不足的状况。
[0022]图2是按照示例性实施例的能量储存系统的修改的单线电气图,并且图示了电力流。然而,本公开和描述没有将本公开的范围限制于具有本文中描述的多个元件和/或组件的系统。
[0023]如图2中图示的,能量储存系统例如具有四个EV组储存组件(EPS)100、200、300和400。每个EPS100、200、300、400可以是相同的。然而,每个EPS可能不相同,并且可以对EPS100、200、300、400中的一个或多个进行修改。按照示例性实施例,EPS100包含标示为1-24的24个EV电池组(EVBP)。在每个EVBP内是被示出为EVBP 1中的1.1至EVBP 24中的24.1的多个串联或串并联连接的电池模块。还存在常开接触器,其可以被配置为标示为EVBP 1中的1.3至EVBP 24中的24.3的一个或多个串联连接的接触器。EVBP 1-24还可以包含其他电源电路,诸如但不限于对电阻器和接触器进行预充电。在该示例性系统中,EVBP 1至24以其中EVBP对串联连接并且其中这些串联串中的12个并联连接的2S12P电路布置连接。串联串对是1/2、3/4、5/6、7/8、9/10、11/12、13/14、15/16、17/18、19/20、21/22和23/24。12个串联串1/2至23/24中的每一个在智能组合器130中分别通过熔丝101至112连接。熔丝101至112提供第二层过电流保护,以在异常状况下保护EV电池1.1至24.1免受过电流的影响。熔丝101至112还可以防止接触器1.3至24.3断开超出安全接触器极限的电流。接触器1.3至24.3可以提供针对小于熔丝101至112标称值的电流的第一层过电流保护以及其他电路隔离和连接控制功能。智能组合器(SC)130的输出端连接到开关161,该开关将EPS100的电源电路与其它能量储存系统组件连接或隔离。熔丝162保护导体的载流量和开关161的断路能力。按照示例性实施例,断路器或其他过电流设备和系统可以被替换为图2中的熔丝。
[0024]在该系统示例中,EPS100和200连接到DCDC转换器603。EPS 300和400连接到DCDC转换器604。DCDC转换器603可以提供并联连接的EPS100和EPS200与逆变器功率转换系统(PCS)605之间的最佳电压匹配,从而随着太阳能PV发电606的最大功率点随温度和照度变化而提供最佳的电压匹配。DCDC转换器603和604二者能够进行双向电力输送,以对EV电池组进行充电或放电。PCS 605对于电力流也是双向的。
[0025]当整个系统例如在将储存在EPS100、200、300和400电池中的能量输送到电网610和/或本地负载607时,DC电力从EPS100和200流过DCDC转换器603,并且并行地从EPS 300和400流过DCDC功率转换器604。然后,DC电力可以被PCS 605转换成AC电力。然后,AC电力流过配电变压器608(在该处电压可以被升高至更有效的配电电压电平),并且流过计费表609,之后连接到电网610。来自太阳能光伏发电606的电力在可用并且被利用时还流过PCS 605,并且PCS 605用作DC-AC功率转换器,以将电力引入到电网610和/或本地负载607中。进入电网610的总电力可以是电池引入电力加上太阳能光伏引入电力之和减去本地负载607所使用的电力。也可以在没有连接到电网610的情况下支撑本地负载,在这种情况下,PCS 605以“孤立”的AC电压调节模式工作。
[0026]当整个能量储存系统在输送能量以对EPS100、200、300和400中的EV电池组进行充电时,PCS 605通过从电网610引入AC电力并且将AC转换成DC电力来用作AC-DC功率转换器。按照示例性实施例,DC电力流过DCDC转换器603和604,以对EPS100、200、300和400中的EV电池组进行充电。来自太阳能光伏发电606的电力例如在可用时可以要么用于减少来自电网610的用于对EV电池组进行充电所需的电力,要么如果来自太阳能发电606的可用电力大于对这些EV电池组进行充电所需的电力以及供应本地的“仪表后方”负载607所需的电力,则多余的电力可以被输送到电网610。
[0027]按照如图2中所示的替代实施例,能量储存系统可以包括以下中的一个或多个作为集成EPS100的一部分:PCS 605、DCDC转换器603、变压器608和功率计609。
[0028]图3是如图1中所示的电池组控制器140和智能组合器130的详细图。附图标记1指示多个EV电池组(EVBP),其中EVBP 1在顶部。附图标记2指示多个EVBP,其中EVBP 2在顶部。在该EPS实施例中,EVBP 1和2作为第一串联对串联电连接。EPS中的每个串联对与BPC中的一个EV BMS接口板(EVIB)通信。在这第一个顶层的情况下,BMS1.2和BMS2.2分别通过数字数据总线504和505与EVIB 141通信。通信协议是原始制造商的电动车辆应用中使用的控制器局域网总线(CAN总线)。EPS内的所有其他EVBP串联对以类似的方式通信。控制电路142集中来自BPC 140内的所有EVIB的数据,并且提供通向EPS外部的系统控制器的Modbus数字通信链路507和通向智能组合器130的Modbus链路506。根据示例性实施例,Modbus数字通信链路507与整体能量系统SCADA(图1中的元件501)通信,以报告由所有EV电池组的串联/并联连接配置的“复合”电池的健康状况、可用性和充电状态。Modbus数据链路506将控制电路142连接到控制电路138,以主动地控制串联串中每个EV电池组的平衡。
[0029]按照示例性实施例,通过监视每个EV电池组的电压、电流和温度,然后将能量从串联串中的两个组中的较高电压组转移到较低电压组,可以实现例如串联串中每个EV电池组的平衡。例如,如果EVBP 1具有比EVBP 2更高的电压,则半导体开关132闭合,电流从电池1.1流过电感器137,半导体开关132断开,并且通过电感器137的电流流过二极管135并进入电池2.1,从而完成一个能量转移循环。该能量转移循环以高频率重复与所期望的能量转移成正比的时间量。如果EVBP 2具有比EVBP 1更高的电压,则半导体开关134闭合,电流从电池2.1流过电感器137,半导体开关134断开,并且通过电感器137的电流流过二极管133进入电池1.1,从而完成一个能量转移循环。
[0030]图3图示了平衡串联电池串中的电池的方法,但没有将本公开限制于任一种电池平衡方法或限制串联串中的EVBP的数量。按照示例性实施例,能量储存系统包括电池组控制器140、EV电池组电池管理系统(在该示例中为1.2和2.2)、智能组合器130和整个系统控制器经由数据链路507的互连和交互功能。熔丝131和136可以用于提供EVBP 1和2串联串与所有串联串的+总线601和-总线602的并联电路之间的故障隔离。按照示例性实施例,例如,可以以类似的方式保护所有其他串联串。
[0031]按照示例性实施例,能量储存系统可以包括图1中示出的EV组储存系统(EPS)箱100内的元件中的每一个加上用于EV电池组的防风雨外壳和机架系统。图4图示了外壳的实施例,外壳可以包括固定的和可拆卸的外部绝缘板60。外壳50可以被设计为例如机柜,其中可从外壳外部触及电池系统和系统控制件,并且外壳或机柜不是建筑或消防规范中定义的可占用空间。按照示例性实施例,外壳50是使得能够在室外部署能量储存组件的室外标称外壳。
[0032]按照示例性实施例,机架系统40可以由结构钢制成并且被配置为保持EV电池组1至24。例如,在EV组储存系统(EPS)的目前构建中,每个组的重量可以超过600磅。外壳50的侧板60可以被拆卸,例如,以使叉车能够进入从而相当容易地安装和拆卸EV电池组1至24。另外,机架系统40被设计为使空气能够在EV电池组之间流动。例如,每个EV电池组可以通过支架30与机架系统40电隔离。例如,可以在机柜控制系统150的指导下由热管理系统151冷却和加热EV电池组。热管理系统151可以包括冷却、除湿和其他环境控制作为延长EV电池组的使用寿命的手段。当检测到操作范围之外的烟雾、气体或温度状况时,危险检测系统152可以向机柜控制系统150提供警报。
[0033]结合图1的叙述描述了智能组合器130和电池组控制器140的功能。智能组合器130、电池组控制器140、机柜控制系统150、热管理系统151和危险检测系统152没有按比例示出或者不具有特定的物理特征。在智能组合器130中的一个或多个中,电池组控制器140、机柜控制系统150、热管理系统151和危险检测系统152可以安装到EPS外壳。按照示例性实施例,外壳50的固定且可拆卸的外板60可以是热绝缘的。
[0034]与本公开一致的技术提供了除其他特征之外特别采用二次寿命电动车辆电池的能量储存系统和方法。虽然以上已描述所公开系统和方法的的各种示例性实施例,但应该理解,它们只是出于示例的目的而呈现,而非限制。这不是排他性的,并且没有将本公开限制于所公开的精确形式。鉴于以上教导可以进行修改和变化,或者在不脱离本公开的广度或范围的情况下,可以通过实践本公开来获取。