NL2028818B1

NL2028818B1 - A detachable energy storage system

Info

Publication number: NL2028818B1
Application number: NL2028818A
Authority: NL
Inventors: Adrianus Theodorus Ploegmakers Christianus
Original assignee: Electric Construction Equipment B V
Priority date: 2021-07-23
Filing date: 2021-07-23
Publication date: 2023-01-30
Also published as: NL2028818B3

Abstract

A detachable energy unit for operating in either a standalone mode or in an installed mode, wherein said energy unit comprises: at least one or more modules arranged to discharge energy in the form of electrical energy in a discharging cycle, and a Control Unit, CU, connected to said at least one or more modules, wherein said CU operates in a slave mode when said energy unit is in said installed mode and in a master mode, when said energy unit is in said standalone mode. The energy unit may be, for example, a battery or a hydrogen fuel cell. A vehicle comprising such a detachable energy unit is also presented herein.

Description

Title

A detachable energy storage system

Technical Field

The present disclosure generally relates to the field of modular energy storage systems, and in more particular to detachable battery systems that can be scaled in modular manner.

Background

Most battery systems currently available for vehicles are not suitable for use outside the vehicle as an independent source of energy. Specifically, charging and discharging of electrical energy can only take place when the battery is a part of a vehicle. This is partially also due to a presence of a so-called Battery management system that ensures safe operation — including charging and discharging, of a battery within the vehicle. In addition, these types of batteries are only built into a vehicle as a 'master’, the battery is a separate system that is the only battery built into the vehicle.

Fig. 1 shows an image of a typical battery system for a vehicle 1, in this case a 'pack’, consisting of battery modules 10 which is made up of separate cells. As can be seen, the battery management unit 11 is connected to several cell monitor units and there is a single, central, battery management unit. As soon as the battery is removed from the vehicle, it cannot be used independently due to the lack of this battery management unit.

A disadvantage of such an arrangement is that a vehicle can comprise only one pack and is therefore not scalable or replaceable in a modular manner.

Additionally, the batteries cannot serve as a source of electrical energy when it is removed from the vehicle.

Summary

In a first aspect according to the present disclosure, there is presented a detachable energy unit for operating in either a standalone mode or in an installed mode, wherein said energy unit comprises: - at least one or more modules arranged to discharge energy in the form of electrical energy in a discharging cycle; - a Control Unit, CU, connected to said at least one or more modules, wherein said CU operates in a slave mode when said energy unit is in said installed mode and in a master mode, when said energy unit is in said standalone mode.

The primary aspect of the invention according to the present disclosure is an energy unit that can operate independently in a standalone mode as well as in an installed mode, for example when installed in a vehicle. The skilled person understands that the term energy unit refers to a source of energy.

Such an energy unit is, for example, a Hydrogen Fuel Cell or a battery pack comprising a plurality of battery modules. Fuel Cell Electric Vehicles, FCEVs, employ a Hydrogen Fuel Cell and use a propulsion system similar to that of electric vehicles, where energy stored as hydrogen is converted to electricity by the fuel cell.

Unlike conventional internal combustion engine vehicles, these vehicles produce no harmful tailpipe emissions.

The most common type of fuel cell for vehicle applications is the polymer electrolyte membrane, PEM, fuel cell. In a PEM fuel cell, an electrolyte membrane is sandwiched between a positive electrode, cathode, and a negative electrode, anode.

Hydrogen is introduced to the anode, and oxygen from the air is introduced to the cathode. The hydrogen molecules break apart into protons and electrons due to an electrochemical reaction in the fuel cell catalyst. The energy unit according to the present disclosure may be, for example, such a PEM fuel cell.

Such a fuel cell could in the installed mode draw hydrogen from the tank inside a vehicle and in the standalone mode, draw hydrogen from an external tank,

thereby by providing electrical power even when a source of electrical power is not readily available.

Alternately, the energy unit is a battery pack. As noted earlier, a commercially available battery pack in a vehicle has a disadvantage that the vehicle can comprise of only one pack, is not scalable, and hence cannot be replaced in a modular manner. Furthermore, such a commercially available battery pack cannot operate independently outside of the vehicle in which it is pre-installed.

To overcome these disadvantages, it was the insight of the inventors, to include a Control Unit, CU, according to the present disclosure within the energy unit.

The CU is arranged to determine whether the energy unit is installed within a vehicle or is currently placed outside of a vehicle. The skilled person understands that such a

CU may be implemented in the form of an electronic circuit, for example as a processor or a controller, connected to the corresponding sensors that help to determine whether the battery pack is in the vehicle or outside.

It is further noted that , in said installed mode, the CU is arranged to operate as a slave controller to a master controller external to said energy unit. As highlighted earlier, this enables the smooth operation of the energy unit inside the vehicle and especially when a plurality of energy units are employed in a modular manner.

According to an exemplary embodiment, in said installed mode, the energy unit is installed in a vehicle, and in said standalone mode, the energy unit is removed from said vehicle.

According to an example, the detachable energy unit is a Hydrogen Fuel

Cell arranged to be connected a source of stored Hydrogen.

According to an exemplary embodiment, the detachable energy unit is battery pack, wherein the at least one or more modules are battery modules, that are arranged to store electrical energy in a charging cycle, further wherein said Control

Unit, CU is a Battery Control Unit, BCU.

Further, the inventors found it advantageous to consider that when the

BCU determines that battery pack is in the vehicle, the battery pack operates in an installed mode, and when the battery pack is located outside, it operates in a standalone mode. This allows portability of the stored energy and allows for use of appliances off grid. For example, in the standalone mode, a tool or an electrical appliance may be connected to the battery pack.

The skilled person understands that in order to achieve this, both the electrical appliance and the battery pack need to have suitable connectors that allow the transfer of electrical energy.

Additionally, the BCU operates in a master mode during standalone operation and in a slave mode during installed operation. Normally, commercially available electric vehicles have a master controller, that controls the charging and discharging functionalities of the battery. Therefore, when the battery pack is installed within a vehicle, the BCU operates as a slave towards the master controller located in the vehicle, external to the battery pack. The BCU, when it detects standalone operation, operates in a master mode, thereby allowing charging and discharging functionalities. This, therefore, allows utilizing the stored energy of the battery even when it is outside the vehicle.

Especially, when operating in the standalone mode, it is essential to ensure safe operation, of both the battery as well as any electrical device that it is connected to. In order to do so, the BCU may comprise of additional elements, either in the form of hardware components or a computer program or a combination of hardware components and a computer program that is arranged to monitor the safe operation of the battery pack. This may be implemented, for example, by monitoring the voltage at an output of the battery pack and ensuring that it does not exceed a threshold value. Alternately, safety may be ensured by monitoring the current at the output of the battery pack and ensuring that it does not exceed a threshold value.

The inventors also consider it advantageous that the battery pack may be charged external to the vehicle. Safety during charging, when operating in the standalone mode could also be ensured in a similar manner as described above by 5 means of the BCU.

Additionally, it was also the insight of the inventors that the battery pack be scalable in a modular manner when installed within the vehicle. This has a unique advantage of extending the range of a normal vehicle. During such an operation, there are multiple battery packs, each with its own BCU that are all acting as a slave towards the master controller located in the vehicle external to the battery packs. However, one of the slave BCUs may act as a primary BCU and assign a secondary status, by means of an indicator or a flag, to the other BCUs. In this manner, the discharge and charging of the plurality of battery packs can happen in a coordinated manner.

In an example, the detachable energy unit further comprises a

Combined Charging System, CCS, controller arranged to control the charging of said battery modules.

According to an exemplary embodiment, the energy unit further comprises at least one input means and at least one output means. The skilled person understands that it may be beneficial to employ standard connectors as the input and output means. An example of a standard connector, when the energy unit is a battery pack, is an IEC 62196 Type 2 connector. This may alternately be also referred to as

GB/T as disclosed in the GuoBiao standard 20234.2-2015. By employing standard connectors, universal usage can be ensured. Furthermore, by employing standard connectors, modularity of the battery packs can be enhanced.

The skilled person understands that standard connectors may also be employed when the energy unit is a Hydrogen Fuel Cell, allowing the easy transport of Hydrogen, from a storage tank, to the fuel cell. Correspondingly, standard connectors may also be employed in order to transfer the electrical power so generated to any electrical load that is connected to the fuel cell. In an installed mode,

the electrical load is a motor of the vehicle, and in a stand lone mode, the electrical load is an external electrical appliance.

According to an example, in said standalone mode, the CU is arranged to provide an electrical output via said at least one output means. This electrical power output may be provided via the standard connector as previously disclosed. Such a provision allows the usage of electrical appliances even in remote locations where a conventional source of electrical energy such as a wall outlet is not available.

A further embodiment according to the present disclosure, further comprises a processor arranged to determine whether an external load is connected to said at least one output means and wherein said CU is arranged to discharge said stored electrical energy via said at least one output means upon said determination.

Such a processor may be arranged to detect an electrical load connected to the output by measuring an impedance or by measure the current flow, or in an increase in current flow or any other method known to the skilled person.

In a further embodiment, the detachable energy unit further comprises a Combined Charging System, CCS, controller arranged to control the charging of said battery modules via said at least one input means. Such a CCS controller is, for example, commercially available, and is responsible for efficient charging and discharging of stored electrical energy when used in a vehicle. By utilising such a CCS controller, the architecture of the CU can be simplified and certain tasks, such as efficient energy management can be assigned to the CCS controller. The skilled person understands that the usage of a CCS is particularly relevant when the energy unit is a battery pack.

Furthermore, the skilled person understands that the Electrical energy storage system comprised of batteries may be replaced by other suitable energy storage systems such as, for example, Hydrogen Fuel Cells. In such a case, modularity can be improved by combining multiple fuel cells in order to obtain the same characteristics as that disclosed previously herein.

According to a second aspect of the present disclosure, there is presented a vehicle comprising a detachable energy unit as disclosed previously.

The above and other aspects of the disclosure will be apparent from and elucidated with reference to the examples described hereinafter.

Brief Description of the drawings

Fig. 1 illustrates an exemplary architecture of an electric vehicle according to the prior art.

Fig. 2 schematically illustrates a battery pack according to the present disclosure.

Fig. 3 schematically illustrates an exemplary embodiment of a plurality of battery packs according to the present disclosure operating in an installed mode.

Fig. 4 schematically illustrates a method according to the present disclosure.

Fig. 5 schematically illustrates a method according to the present disclosure.

Fig. 6 schematically illustrates a method according to the present disclosure.

Fig. 7 schematically illustrates a method according to the present disclosure.

Fig. 8 schematically illustrates a method according to the present disclosure.

Detailed Description

It is noted that in the description of the figures, same reference numerals refer to the same or similar components performing a same or an essentially similar function.

Additionally, although the figures only illustrate and describe the usage of battery packs as the energy unit, it is clearly understood from the description and the previous sections that the energy unit could also be, for example a Hydrogen Fuel

Cell.

The skilled person is aware of the architecture as shown in Fig. 1, only the blocks relevant to the present disclosure are described in detail. In particular, the vehicle 1 comprises a plurality of battery modules 10 each with its own cell monitor unit. This serves the purpose of monitoring the charge levels within each respective battery module. The plurality of battery modules are connected to a common bus, CAN which in turn communicates with external components. Furthermore, the vehicle comprises a battery management unit 11 external to the battery pack. This battery management unit 11 is responsible for the effective charging and discharging of the stored electrical energy in the individual battery modules 10.

From this figure, it is evident that upon removing a battery pack from the vehicle, the battery management unit, is no longer connected to the battery pack and additionally, neither are the charging connectors. This results in two things. Firstly, since the connectors are no longer connected to the battery pack, there is no way to charge or discharge the battery, and secondly, even if a way to discharge the battery was identified, due to the absence of the BMU, a safe operation of such a battery in a standalone mode cannot be ensured.

Fig. 2 schematically illustrates a battery pack 20 according to the present disclosure.

The Battery module 21 is a collection of cells and are the actual storage point of electrical energy.

The Vehicle Interface Box, VIB, 23 provides a single interface for communication between the battery system and the vehicle. This allows you to control up to ten battery systems within one system. Furthermore, the VIB 23 ensures an efficient electrical connection between the battery systems and allows you to connect auxiliary units.

In addition, the related Battery Thermal Management System, eBTM, 22 acts as a central temperature control module, optimizing the battery performance and lifetime. The EBTM also ensures a safe operation of the battery.

The BCU 24 is the additional battery management system according to the present disclosure in order to ensure that a plurality of battery packs can be employed in a modular manner within a single vehicle. Furthermore, as noted earlier, the BCU 24 also functions as a master Battery management system, as soon as it is detected that the battery pack has been removed from the vehicle.

The Combined Charging System, CCS, controller 25 forms the interface between an input to the battery pack and a source of electrical energy arranged to charge the battery. Through this, we are able to control the charging rate and ensure safe operation of the charging process.

The power supply provides the low voltage energy to the different subsystems.

The unit 20 as illustrated in Figure 2 can be understood as basic building block according to the present disclosure comprising of a battery pack, a BCU and the relevant connectors as may be required according to a particular embodiment. For example, as illustrated in Fig. 2, the embodiment comprises a standard GB/T connector 27 for transferring the electrical power. This may either be used as a common interface for connecting multiple battery packs or for providing the output, either to the motors in the vehicle in an installed mode or to a suitable electrical load in a standalone mode.

Fig. 3 schematically illustrates an exemplary embodiment 30 of a plurality of battery packs according to the present disclosure operating in an installed mode. As shown, the embodiment of Fig.3 utilises 2 battery packs 20 identical to the embodiment as illustrated in Fig. 2. Using the GB/T connector 27, they connect to the common Voltage Control Unit, VCU, 31 that acts a master to both the battery packs.

The master VCU 31 then ensures the safe charging and discharging of each of the individual battery packs.

The battery packs may also be connected to other devices in order to discharge the stored electrical energy. As illustrated in Figure 3, they can be, for example, an inverter and/or converter and/or other devices that require an electrical power to operate such as an on-board charge or air conditioning unit.

Fig. 4 schematically illustrates a method according to the present disclosure. Specifically, in Fig.4, the BCU is able to determine whether the battery has been installed in a vehicle safely. Initially, the BCU is in an Idle mode, which means that the battery is not yet installed in a vehicle. Once it ensures that the connectors are locked and that there is a voltage drop over the contactors, it can determine that battery has been safely installed. Additionally, it may also check for multiple batteries being connected and that the total voltage drop does not exceed a threshold value.

Fig. 5 schematically illustrates a method according to the present disclosure. Specifically, figure 5 illustrates an algorithm to determine different modes of operation of a system according to the present disclosure. After performing some initial checks, the BCU is able to determine the mode based on the presence or absence of the GB/T and the CCS connector plugs.

Fig. 6 schematically illustrates a method according to the present disclosure. The algorithm as illustrated in Fig. 6 is a safety loop and ensures the safe operation of the battery packs in an installed mode.

Fig. 7 schematically illustrates an alternate embodiment for a safety loop according to the present disclosure. Specifically, the algorithm according to Figure 7 discloses a safety loop that may be used in the energy system according to the present disclosure in order to ensure safe operation in an installed mode.

Fig. 8 schematically illustrates a method according to the present disclosure.

Although the invention has been illustrated by several layouts showing specific embodiments, it will be appreciated that control circuitry shown in one embodiment may be equally applied in another embodiment, or that specific control circuitry may be omitted from a particular embodiment. Controllers, such as controllers for charging and discharging of an electrical battery for the purpose of the present disclosure, other than shown and discussed above, are known and available in practice.

Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measured cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope thereof.

Claims

CONCLUSIONS

1. A detachable energy unit to operate in a stand-alone mode or in an installed mode, where the energy unit comprises: - at least one or more modules arranged to dissipate energy in the form of electrical energy in a discharge cycle; - a control unit, CU, connected to the at least one or more modules, the CU operating in a slave mode when the power unit is in installed mode and in a master mode when the power unit is in stand-alone mode.

2. The detachable power unit, wherein in said installed mode the power unit is installed in a vehicle, and in said stand-alone mode, the power unit is removed from said vehicle.

A detachable power unit according to any one of claims 1 to 2, wherein the detachable power unit is a hydrogen fuel cell adapted to be connected to a source of stored hydrogen.

The detachable power unit according to any one of claims 1 to 2, wherein the detachable power unit is a battery pack, the at least one or more modules being battery modules arranged to store electrical energy in a charging cycle, further where said Control Unit, CU is a Battery Control Unit, BCU.

The detachable power unit of claim 4, further comprising a combined charging system, CCS, controller configured to control charging of the battery modules.

A detachable power unit according to any one of the preceding claims, further comprising at least one input means and at least one output means.

The detachable power unit of claim 6, wherein in the standalone mode the CU is arranged to provide an electrical output signal through the at least one output means.

The detachable power unit of claim 7, further comprising a processor configured to determine whether an external load is connected to the at least one output means and wherein the CU is configured to discharge the stored electrical energy through the at least one output means. means of output. at said determination.

9. Vehicle provided with a detachable energy unit according to one of claims 1-8.