DE112014007057T5 - Energy storage system based on battery packs - Google Patents

Abstract

The present invention relates to an energy storage system comprising a master BMS, at least two battery packs each having a corresponding slave BMS, a DC bus connected to each battery pack for charging the respective battery pack, and a communication bus for connecting each battery pack to one corresponding master BMS corresponding internal communication interface for transmitting information of each battery pack to the master BMS, wherein the master BMS receives the battery variables of each battery pack from the corresponding slave BMS via the communication bus, the master BMS based on one in a master Control of the master BMS stored algorithm calculates the state of each battery pack, wherein the master BMS makes a decision on the behavior of each battery pack, and wherein the master BMS the battery pack with the power electronics module of the master BMS for charging or discharging the battery pack - or out chaltet.

Description

Technical area

The invention relates to the field of energy storage, in particular to an energy storage system comprising battery packs.

State of the art

As one of the solutions for reducing greenhouse gas emissions from vehicles, electric vehicles are gaining in popularity in view of their improved energy efficiency. The power supplies for the electric vehicles are the rechargeable chemical energy sources, including battery packs. As a result, more and more battery packs for use in electric vehicles are being introduced to the electric vehicle market. The battery packs are removed and replaced after use by the electric vehicles. One current solution is typically that EV dealers / service centers dispose of used battery packs at a refurbishment facility where battery cells in the used battery packs are screened, sorted, tested and finally reconfigured for their second use in stationary applications. Thereafter, the battery cells in the used battery packs are installed in a housing and managed by a battery management system (abbreviated to BMS).

However, the processes of screening, sorting, testing and reconfiguring the secondary battery packs are both expensive and time consuming. Also, technically, only battery packs having nearly identical characteristics (eg, chemical properties, capacity, and even shapes) can be reused in the same system, making it difficult and expensive to reconfigure and reuse different types of used battery packs.

There is a need to solve the above problems.

task

The object of the invention is to provide an open architecture for reusing various types of used battery packs.

In this new architecture, the used battery packs can be used at the battery pack level, so that screening, sorting, testing and reconfiguring efforts can be spared. Batteries supplied by different manufacturers and having different characteristic parameters (eg, chemical properties, energy capacity, etc.) can be integrated together and reused.

According to a first aspect of the invention, there is provided an energy storage system comprising a master BMS, at least two battery packs each having a corresponding slave BMS, a DC bus connected to each battery pack for charging the respective battery pack, and a communication bus for connecting each battery pack having a corresponding internal communication interface of the master BMS for transmitting information of each battery pack to the master BMS, wherein the master BMS controls the power and voltage outputs of each battery pack via the corresponding slave BMS of the battery pack.

According to one possible embodiment, the power electronics module is designed as an array of DC-DC converters which can control the electrical currents of the corresponding battery packs and can adapt to the variation / difference in the voltages of different battery packs.

According to one possible embodiment, the power electronics module is designed as an array of relays which can connect or disconnect the corresponding battery packs with a charging station or a load.

In one possible embodiment, the master BMS turns the relays on / off to individually control the charging / discharging of each battery pack.

According to a possible embodiment, the charging / discharging operations of all the battery packs are performed sequentially or simultaneously.

According to a possible embodiment, the battery variables comprise one or more of them: a voltage, an electric current, a charging / discharging time, a temperature, the state of charge (SOC) and the state of health (English : Status of Health, abbreviated to SOH).

According to one possible embodiment, the at least two battery packs have different power connections, wherein the energy storage system comprises adapters for the power connections, wherein the at least two battery packs have different communication protocols, and wherein the energy storage system comprises a gateway for connecting communication buses of all battery packs.

According to a possible embodiment, the adapters are designed as sockets suitable for the different power connections.

According to one possible embodiment, the battery pack is a secondary battery pack, which is referred to as a unit in an electric bicycle, in an electric motorcycle, in an HEV (Hybrid Electric Vehicle, abbreviated HEV) or in an EV (Electric Vehicle, abbreviated EV) is used.

• – einen ersten Schritt S1, bei dem jedes Batteriepack über den DC-Bus und den Kommunikationsbus mit dem Master-BMS verbunden wird, um physikalische Verbindungen damit herzustellen;
• – einen zweiten Schritt S2, bei dem das Energiespeichersystem eingeschaltet wird, um eine Kommunikation zwischen den Batteriepacks und dem Master-BMS herzustellen, während eine Energieverbindung deaktiviert ist;
• – einen dritten Schritt S3, bei dem das Master-BMS mit dem Slave-BMS jedes Batteriepacks kommuniziert und Informationen über den Zustand jedes Batteriepacks erhält;
• – einen vierten Schritt S4, bei dem das Master-BMS den Zustand jedes Batteriepacks berechnet und eine Entscheidung über das Verhalten jedes Batteriepacks trifft; und
• – einen fünften Schritt S5, bei dem das Master-BMS, basierend auf seiner getroffenen Entscheidung, die Relais einschaltet oder ausschaltet, um das Aufladen/Entladen jedes Batteriepacks individuell zu steuern.

According to a second aspect of the invention, there is provided an operating method of the above-described energy storage system, comprising:

• A first step S1, in which each battery pack is connected to the master BMS via the DC bus and the communication bus to make physical connections therewith;
• A second step S2, wherein the energy storage system is turned on to establish communication between the battery packs and the master BMS while a power connection is disabled;
• A third step S3 in which the master BMS communicates with the slave BMS of each battery pack and obtains information about the state of each battery pack;
• A fourth step S4 in which the master BMS calculates the state of each battery pack and makes a decision on the behavior of each battery pack; and
• A fifth step S5, at which the master BMS, based on its decision, turns on or off the relays to individually control the charging / discharging of each battery pack.

• – dass das Master-BMS Steuerbefehle für ausgewählte Batteriepacks generiert und diese Steuerbefehle an die mit den ausgewählten Batteriepacks korrespondierenden Slave-BMSs sendet, und
• – dass die Slave-BMSs ihre korrespondierenden Batteriepacks steuern, um diese Batteriepacks jeweils aufzuladen oder zu entladen.

According to a possible embodiment, the method further comprises the following steps:

• That the master BMS generates control commands for selected battery packs and sends these control commands to the slave BMSs corresponding to the selected battery packs, and
• - That the slave BMSs control their corresponding battery packs to charge or discharge these battery packs.

With an energy storage system according to the invention, used battery packs can be used at the battery pack level so that efforts to screen, sort, test and reconfigure the used battery packs can be spared. Batteries supplied by different manufacturers and having different characteristic parameters (eg, chemical properties, energy capacity, etc.) can be integrated together and reused.

drawings

Further features, aspects and advantages will be explained in more detail by means of embodiments of the invention in combination with the attached figures. Show it:

1 FIG. 3 is a block diagram of an energy storage system based on battery packs according to the invention; FIG.

2 and 3 : first and second embodiment of the energy storage system according to the invention; and

4 a flowchart of an operating method of the energy storage system according to the invention.

embodiments

Specific embodiments of the invention will be described in more detail in combination with the drawings and embodiments. The embodiments herein are merely illustrative of the principle of the invention without limiting the scope of the invention.

An energy storage system according to the present invention seeks to reuse battery packs, especially secondary battery packs used in electric bicycles, electric motorcycles, hybrid electric vehicles or electric vehicles, prior to disposal, and the system aims to simplify the process and reduce the cost thereof Reuse of secondary battery packs. The secondary battery packs may be manufactured by different manufacturers or may include different chemical components or have different characteristic parameters, the parameters being a nominal voltage, a charging voltage, an energy capacity, a maximum allowable charge current, a maximum allowable discharge current, a maximum continuous charge current, a maximum continuous discharge current and a maximum temperature, etc., but not limited thereto.

For example, the battery pack in the invention may be a lithium iron phosphate battery pack, a cobalt-based Li-ion battery pack, or any other battery pack.

The energy storage system according to the invention essentially comprises a master battery management system (hereinafter also referred to as master BMS) and one or more battery packs that are controlled by the master BMS. Each battery pack includes a battery and a slave Battery management system (hereinafter also referred to as slave BMS), which corresponds to the battery pack and controls it. For each battery pack, its slave BMS acts as a standalone master BMS of the individual battery pack before that battery pack is removed and integrated as a secondary battery pack into the energy storage system of the present invention.

Therefore, if the energy storage system includes various types of battery packs, these battery packs may include secondary battery packs manufactured by different manufacturers or containing different chemical components or having different characteristic parameters.

1 shows a block diagram of an energy storage system 1000 on the basis of battery packs according to the invention, which will be described in detail below.

It should be noted that in the energy storage system 1000 three battery packs 200 . 300 and 400 are shown, wherein the number of battery packs in the energy storage system 1000 but not limited to three. Instead, in the energy storage system 1000 one, two, four or more battery packs may be provided. Like from the 1 As can be seen, the three battery packs 200 . 300 and 400 batteries 210 . 310 and 410 and respectively corresponding slave BMSs 220 . 320 and 420 ,

In the in the 1 shown energy storage system according to the invention 1000 are a master BMS 100 , a DC bus 600 (shown in a thick solid line) and a communication bus 700 (shown in a thin solid line).

The master BMS 100 is for controlling all battery packs 200 . 300 and 400 educated. The DC bus 600 is with terminals of all battery packs 200 . 300 and 400 connected. The DC bus 600 is for connection to a charging station for establishing a power connection of the battery packs 200 . 300 and 400 with the charging station for charging the battery packs or is for connecting to a target vehicle for establishing a power connection of the battery packs 200 . 300 and 400 formed with the target vehicle on which the energy storage system 1000 for driving the target vehicle is mounted.

The communication bus 700 is for connecting the communication interfaces (in 2 ) of the master BMS 100 with communication interfaces of the battery packs 200 . 300 and 400 trained so that the master BMS 100 Battery variables of the battery packs 200 . 300 and 400 receive and control commands to the slave BMSs of the battery packs 200 . 300 and 400 can send.

In general, different battery packs may be manufactured by different manufacturers and have different power connections and different communication ports of the communication interfaces.

When the battery packs 200 . 300 and 400 have the different power connections, an adapter 800 be provided to each power port of the battery packs 200 . 300 and 400 with the DC bus 600 connect to. In one embodiment, the adapter 800 as one for the different power connections of the battery packs 200 . 300 and 300 be designed suitable outlet. When the battery packs 200 . 300 and 400 have different communication protocols, they can not communicate directly with each other. This can be a communication gateway 900 in the communication bus 700 to convert the various communication protocols into a communication protocol that is acceptable for all battery packs. In this case, this is the master BMS 100 over the adapters 800 and the gateway 900 with all battery packs 200 . 300 and 400 connected.

It is understood, however, that the adapters 800 and the communication gateway 900 not always necessary and therefore optional. Ideally, the adapters and the gateway can be spared if both power and communication ports are identical and the communication protocols are identical. For example, all battery packs are made by the same manufacturer.

In 2 and 3 In each case, a first and a second embodiment of the detail structure of the master BMS 100 shown.

The master BMS 100 essentially comprises a master controller 110 , a power electronics module (the adapter 800 and the gateway 900 ), internal communication interfaces 122 . 123 and 124 as well as an external communication interface 130 ,

The master control 110 It is designed to store various algorithms and to perform computational operations in receiving the battery variables of the battery packs.

The power electronics module is for controlling the behavior of all battery packs 200 . 300 and 400 formed, for example, to connect / disconnect each battery pack to / from the DC bus 600 , In the in the 2 shown first embodiment of the energy storage system 1000 the power electronics module is essentially an array of DC-DC converters 142 . 143 and 144 for the battery packs 200 . 300 and 400 which are capable of controlling the electrical currents of each battery pack and of adapting to the variation / difference in the voltages of different battery packs to meet the charging and discharging requirements. In the in the 3 shown second embodiment of the energy storage system 1000 the power electronics module is essentially an array of relays 152 . 153 and 154 for the battery packs 200 . 300 and 400 formed each battery pack with the dc bus 600 connect or disconnect each battery pack from the DC bus 600 The relays are particularly suitable for adapting to variation / difference in the voltages of different battery packs. As well as from the 2 and 3 It can be seen, the DC-DC converter 142 . 143 and 144 or the relays 152 . 153 and 154 their own battery packs 200 . 300 and 400 control independently and therefore the batteries can 210 . 310 and 410 the battery pack 200 . 300 and 400 independently of each other in succession or in sequence or simultaneously depending on the DC-DC converters 142 . 143 and 144 in the first embodiment or depending on the relays 152 . 153 and 154 be charged or discharged in the second embodiment.

The internal communication interfaces 122 . 123 and 124 are each communicating with corresponding communication interfaces of the battery packs 200 . 300 and 400 trained and the external communication interface 130 is to communicate with a high-level controller of the entire energy storage system 1000 educated.

For the energy storage system, the battery packs act as a large battery pack. The master BMS reports the state of individual battery pack to the energy storage system and receives commands from the energy storage system to control the behavior of the individual battery packs.

As described above, each battery pack with its own slave BMS may optionally further include an interface module for interfacing with an interface module of the master BMS 100 , a switch, and a thermal management system, and each Slav BMS may further comprise: a monitoring module for monitoring and measuring battery variables of the corresponding battery pack, a charge / discharge module for charging / discharging the battery pack, a slave controller for receiving the control command from the master BMS 100 and charging or discharging the battery pack in accordance with the control command while a power connection is established, and a data memory for storing the measured battery variables.

Each Slawe-BMS has a specific control strategy for its own battery pack manufactured by different manufacturers and is designed to be adapted to different chemical properties and different energy levels, each Slav BMS itself being developed by different manufacturers.

In the energy storage system according to the invention 1000 collects the master BMS 100 Information from the Slav BMS 220 . 320 and 420 via the battery variables measured by the monitoring module of the Slawe-BMS, such as SOC, SOH, a voltage, an electrical current, etc., calculated by means of the master control 110 the condition of the batteries 210 . 310 and 410 based on in the master control 110 stored appropriate algorithms makes a decision on the behavior of the battery packs 200 . 300 and 400 , and switches using the DC-DC converters 142 . 143 and 144 or by means of the relays 152 . 153 and 154 the battery packs 200 . 300 and 400 on or off to charge or discharge the selected battery packs.

An operating method of the energy storage system 100 will now be referring to 4 described.

In a first step S1 of the operating method are the battery packs 200 . 300 and 400 with the DC bus 600 and the communication bus 700 connected so that physical connections are made.

In particular, in the first step S1, terminals of each battery pack are connected to the DC bus 600 connected and communication interfaces of the battery packs 200 . 300 and 400 are each with the corresponding communication interface 122 . 123 and 124 of the master BMS 100 connected.

In a second step S2, the energy storage system is switched on and then a communication is established while the power connection is still deactivated.

In a third step S3, the master BMS communicates 100 with the slave BMSs 220 . 320 and 420 the battery pack 200 . 300 and 400 and receives information from the slave BMSs 220 . 320 and 420 about the condition of the battery packs.

Specifically, in the third step S3, the monitoring module of the slave BMS monitors the battery pack battery variables in real time, periodically, or in accordance with a command from the controller, but the monitored battery variables do not include a voltage, an electric current, a charge / discharge time, and a temperature are limited to it.

The monitored battery variables can be stored in their own memory and then over the communication bus 700 be transferred to the master BMS under the command of the master BMS. Alternatively, the monitored battery variables can be actively transmitted to the master BMS.

In a fourth step S4, the master BMS calculates 100 by means of the master control 110 The state of each battery pack based on the battery variables of the battery pack and makes a decision on the behavior of each battery pack.

In this step, the battery variables are used to calculate the state of the battery pack. For example, the voltage and the electric current may be used to represent an output of the battery pack at that time, and the charge / discharge time, the temperature and characteristic parameters of the battery pack may be used to calculate the SOC and SOH based on a specific algorithm to calculate. Preferably, different algorithms can be selected at different temperatures.

Based on the generated state and the monitored battery variables, the master BMS decides the behavior of each battery pack, for example, charging the battery pack or discharging that battery pack.

In a fifth step S5, based on its decision, the master BMS turns the relays on or off to individually control the charging / discharging of the battery packs.

When the relay is turned on, a power connection is established and the slave controller of the slave BMS can receive the command from the master BMS and perform the charge / discharge operation on the battery pack.

The energy storage system described above is an open architecture in which all slave BMSs are connected via the DC bus and the communication bus to the master BMS, which receive commands from the master BMS and act accordingly. Additional slave BMS can be easily added or removed from the master BMS.

With an energy storage system according to the invention, used battery packs can be used at the battery pack level so that efforts to screen, sort, test and reconfigure the used battery packs can be spared. Batteries supplied by different manufacturers and having different characteristic parameters, e.g. B. chemical properties, energy capacity, etc., can be combined and reused.

The system is used to control the charging and discharging of various battery packs in the same system. So the purpose of the invention is that the different battery packs can work well in the same system. The present invention is not limited to the management of secondary battery packs but could also be used in combination with new battery packs.

It should be noted that various developments and substitutions that may be made by one skilled in the art without departing from the technical principle of the invention should be considered to fall within the scope of the invention ,

LIST OF REFERENCE NUMBERS

1000

Energy storage system

100

Master BMS

110

Master control

122, 123, 124

internal communication interface

130

external communication interface

142, 143, 144

DC-DC converter

152, 153, 154

relay

200, 300, 400

battery Pack

210, 310, 410

battery

220, 320, 420

Slave BMS

600

DC bus

700

communication

Claims (11)

An energy storage system, comprising: a master BMS, at least two battery packs each having a corresponding slave BMS, a DC bus connected to each battery pack for charging the respective battery pack, and a communication bus for connecting each battery pack to one corresponding internal communication interface of the master BMS for transmitting information of each battery pack to the master BMS, wherein the master BMS controls the power and voltage outputs of each battery pack via the corresponding slave BMS of the battery pack. Energy storage system according to claim 1, wherein the power electronics module is formed as an array of DC-DC converter, which can control the electric currents of the corresponding battery packs and adapt to variation / difference of the voltages of different battery packs. The energy storage system of claim 1, wherein the power electronics module is configured as an array of relays that can connect or disconnect the corresponding battery packs to or from a charging station or load. The energy storage system of claim 3, wherein the master BMS turns the relays on / off to individually control the charging / discharging of each battery pack. An energy storage system according to any one of claims 1 to 4, wherein the charging / discharging operations of all battery packs are performed sequentially or simultaneously. An energy storage system according to any one of claims 1 to 5, wherein the battery variables include one or more thereof: a voltage, an electric current, a charge / discharge time, a temperature, SOC, and SOH. Energy storage system according to one of claims 1 to 6, wherein the at least two battery packs have different power connections, wherein the energy storage system comprises adapters for the power connections, wherein the at least two battery packs have different communication protocols, and wherein the energy storage system comprises a gateway for connecting communication buses of all battery packs. Energy storage system according to claim 7, wherein the adapters are designed as suitable for the different power outlets sockets. An energy storage system according to any one of claims 1 to 8, wherein the battery pack is a secondary battery pack used as a unit in an electric bicycle, an electric motorcycle, an HEV or an EV. Operating method of an energy storage system according to one of claims 1 to 9, comprising: A first step S1, in which each battery pack is connected to the master BMS via the DC bus and the communication bus to make physical connections therewith; A second step S2, wherein the energy storage system is turned on to establish communication between the battery packs and the master BMS while a power connection is disabled; A third step S3 in which the master BMS communicates with the slave BMS of each battery pack and obtains information about the state of each battery pack; A fourth step S4 in which the master BMS calculates the state of each battery pack and makes a decision on the behavior of each battery pack; and A fifth step S5, at which the master BMS, based on its decision, turns on or off the relays to individually control the charging / discharging of each battery pack. Operating method according to claim 11, further comprising the following steps: That the master BMS generates control commands for selected battery packs and sends these control commands to the slave BMSs corresponding to the selected battery packs, and - That the slave BMSs control their corresponding battery packs to charge or discharge these battery packs.

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