DE102022214277A1 - Hybrid energy storage system - Google Patents

Abstract

The invention relates to a hybrid energy storage system (1) for storing and providing electrical energy, comprising a stationary storage unit (2) which is designed to store and deliver electrical energy, a plurality of charging points (LP1-LP5), each of which is designed to charge and/or discharge an electric vehicle (EV1-EV5), an energy management system (4) which is designed to control the plurality of charging points (LP1-LP5) via a low-energy output interface (42), and a connection point (6), wherein the energy management system (4) is further designed to provide a predetermined first amount of energy and/or first power at the connection point (6), for which purpose at least one electric vehicle (EV1) connected to a first charging point (LP1) is discharged via the first charging point (LP1), and a second amount of energy or second power thus provided by said electric vehicle (EV1) is supplied to the connection point (6).

Description

The invention relates to a hybrid energy storage system for storing and providing electrical energy, comprising a stationary storage unit which is configured to store and deliver electrical energy, an energy management system which is configured to control a plurality of charging points, and a connection point, wherein the energy management system is further configured to provide a predetermined first amount of energy at the connection point.

With the increasing conversion of energy supply to renewable energy sources such as solar and wind energy, storage is becoming increasingly important due to the natural fluctuations in energy production. While energy consumption can be partially controlled intelligently using smart grids or similar, and certain consumption processes can be shifted to times when renewable energy is naturally available in greater quantities, this approach is only possible to a limited extent.

This makes it all the more important to have options for storing energy and making it available as needed. Storing electrical energy requires considerable capacity due to the low energy density of conventional storage technologies compared to the total electricity consumption. Improving storage options therefore goes hand in hand with better utilization of existing capacities and better planning of the use of these capacities.

The idea of using the batteries of temporarily unused electric vehicles as additional storage capacity is generally known and is currently being widely discussed. However, not least due to the fact that the ownership of such electric vehicles and the operation of a power grid by a supplier or similar usually do not coincide, a variety of problems arise in planning, accessing and providing this additional storage capacity by the electric vehicles. This particularly concerns the control of the integration of the existing battery capacities.

The invention is therefore based on the object of specifying a hybrid energy storage system which should allow the simplest and most efficient integration of battery capacities into a predetermined amount of energy to be provided by the hybrid energy storage system.

The stated object is achieved according to the invention by a hybrid energy storage system for storing and providing electrical energy, comprising a stationary storage unit which is designed to store and deliver electrical energy, a plurality of charging points which are each designed to charge and/or discharge an electric vehicle, an energy management system which is designed to control the plurality of charging points via a low-energy output interface, and a connection point, wherein the energy management system is further designed to provide a predetermined first amount of energy and/or first power at the connection point, for which purpose at least one electric vehicle connected to a first charging point is discharged via the first charging point, and a second amount of energy or second power thus provided by said electric vehicle is supplied to the connection point. Advantageous and partly inventive embodiments are the subject of the subclaims and the following description.

The stationary storage unit preferably comprises a plurality of battery cells and is designed in particular to store and release a significant amount of energy as needed. The energy management system preferably has a central control unit for carrying out the tasks mentioned, which is appropriately equipped and set up for this purpose, for example by means of appropriate processor power, RAM capacity, etc.

The individual charging points form an integral part of the hybrid energy storage system.

A charging point is understood to mean any device, arrangement or infrastructure which, according to its design, is intended and set up to electrically charge a battery of an electric vehicle and/or to extract electrical energy from the battery of an electric vehicle. The hybrid energy storage system is preferably arranged in a spatially delimited area, e.g. on a company or factory site, or in a residential complex or similar. In the former case, the charging points can then be installed in particular in company parking spaces. Preferably, the hybrid energy storage system can be used by its operator, who can in particular be the owner of the property comprising the hybrid energy storage system, to optimize the company's own electricity costs, which are to be paid to an electricity supplier, for example, by reducing a performance price (i.e. a price paid for a service guaranteed by the supplier). In particular, each charging point can be provided by a dedicated charging station, which can be located, for example, in a parking lot or a company parking space or similar, or by an installation in a private household (e.g. in a private parking space in front of/next to a residential building or in a garage if the hybrid energy system is operated by the owner of a residential complex, for example). Each charging point preferably has a low-energy interface, i.e. in particular for communication via a Low-Power Wide-Area Network (LPWA). In particular, a charging point can also be designed for communication via powerline, preferably in accordance with ISO 156118.

An electric vehicle preferably includes any electrically operated motor vehicle (motor vehicle). The electric vehicle is in particular a purely battery-electric motor vehicle, i.e. without an internal combustion engine for hybrid operation. However, the electric vehicle can also be a so-called plug-in hybrid. For this purpose, the electric vehicle has one or more batteries, which in turn can each comprise a plurality of battery cells. An electric vehicle preferably has at least one and particularly preferably exactly one battery management system, which is provided and set up to control the flow of energy into the battery when charging and out of the battery when discharging (e.g. when the electric vehicle is in operation), and in doing so also to ensure, among other things, an even loading or strain on the individual cells of the battery. The electric vehicle can also have a number of control units and in particular a central control unit. The central control unit is preferably designed to control all basic functions of the electric vehicle (drive of the individual wheel motors in electric driving mode, on-board electronics, lighting, temperature control, etc.) and can in particular be provided by a vehicle server (or by the control unit which regulates power output from the battery for driving mode and power consumption during charging).

The connection point is preferably designed as a grid connection point for a general power grid of a grid operator or energy supplier or similar. However, further connections, such as feed-in points or for any consumers and producers, can also be interposed between the connection point and such a grid connection point.

A first amount of energy and/or a first power is now specified, which is to be made available at the connection point. In this case, specifying or providing a first amount of energy includes in particular that the parameter of the provision is the amount of energy (i.e., for example, a total amount in kWh or MWh is specified). Specifying or providing a first power includes in particular that the parameter of the provision is the power (i.e., for example, a power in kW or MW is specified for a certain point in time or similar). The specification can be made externally, for example by a network operator of a power grid connected to the connection point, or it can be determined by the energy management system based on specifications and/or historical data and/or statistical data (which can also be provided by the network operator).

If the first amount of energy or first power can be covered by the stationary storage unit and its capacity or performance data, the first amount of energy or first power can be provided directly by it. However, if the capacity or load capacity of the stationary storage unit is not sufficient to provide the first amount of energy or first power, the energy management system takes measures to provide an additional second amount of energy or second power through a battery of an electric vehicle that is connected to a first charging point that can be controlled by the energy management system. The battery energy or battery power of the electric vehicle in question can be passed on directly to the connection point. For the discharging process of the electric vehicle into the hybrid energy storage system via the first charging point, the electric vehicle, and in particular also the first charging point, is preferably controlled by the energy management system via an LPWA in order to transmit in particular the amount of energy to be discharged or a power profile, whereby the actual discharging process is preferably controlled as autonomously as possible by the first charging point and the electric vehicle (i.e. in particular control of a discharging current by the electric vehicle, and if applicable by the charging point).

Preferably, the energy management system further comprises at least one input interface, the energy management system is designed to receive at least one first piece of information about a particular existing and/or expected load profile at the connection point and/or about an existing and/or expected energy supply to the hybrid energy storage system via said input interface, and the second energy quantity or second Power can also be provided based on the first information. In particular, typical time profiles of energy demand over the day (e.g. as averages of several days or even months or as maximum values of a year or similar) can be transmitted in the first information, as well as an immediate, instantaneous demand for electrical power in a power grid connected to the connection point, so that the energy management system can map the most detailed power profile possible based on the first information and can use this to plan control of discharging processes of the electric vehicles via the associated charging points into the hybrid energy storage system.

The low-energy interface is expediently provided as an LPWA access point (AP), wherein the energy management system is set up to control and/or activate the discharging process of the associated electric vehicle taking place at the first charging point via said LPWA AP, and/or wherein the energy management system is set up to control or activate the discharging process of the associated electric vehicle taking place at the first charging point in such a way that a central control unit of the electric vehicle and preferably all vehicle-side consumers except for a battery management system are put into an inactive state or inactive mode (i.e. in particular deactivated, put into standby mode, switched off or also de-energized), so that on the vehicle side the discharging process into the hybrid energy storage system via the first charging point is controlled, in particular exclusively (from the establishment of a discharge connection between the battery in the electric vehicle and the charging point) by the battery management system. In particular, during the discharging process, all control commands (e.g. specified limit values, target values and/or actual values for energy quantities to be transferred, power, currents and/or voltages for the discharging process) are specified by the battery management of the electric vehicle and transmitted from the electric vehicle to the first charging point via the LPWA.

This allows power losses due to additional consumers in the electric vehicle to be minimized during the discharge process, so that the battery power of the electric vehicle is fully available for the hybrid energy storage system (except for the consumption of the battery management itself).

The energy management system is advantageously set up to control or actuate the first charging point and an electric vehicle connected to the first charging point in such a way that all approvals are granted in the electric vehicle for the discharging process, and then the central control unit of the electric vehicle or all vehicle-side consumers of the electric vehicle except for the battery management system are put into the inactive state for the discharging process. Controlling the first charging point or the electric vehicle by the energy management system includes in particular directly controlling the power transmission during the discharging process, while controlling includes controlling corresponding control units in the first charging point or in the electric vehicle (e.g. the vehicle-side battery management system), which then control the discharging process independently.

Advantageously, the energy management system is further configured to receive the first information about a current and/or expected load profile at the connection point via said input interface, and to receive second information about a current and/or expected energy supply to the hybrid energy storage system, and to determine a peak load gap based on the first information, the second information and a charge level of the stationary storage unit, and to provide the predetermined first energy quantity or first power at the connection point by providing the energy quantity or power corresponding to the peak load gap at least partially by said electric vehicle as said additional energy quantity via the first charging point. The peak load gap can relate to a power or an energy quantity.

Preferably, the energy management system is further configured to use the peak load gap to determine a feed-in price and/or a particularly reduced charging tariff for drawing energy via one of the charging points, and to output said feed-in price or charging tariff to a plurality of users of electric vehicles via a decentralized display system connected to the energy management system. This decentralized display system can in particular include corresponding apps or similar in the on-board displays of electric vehicles and/or other apps in mobile phones of owners of electric vehicles who are authorized to use the charging points (i.e., for example, company employees at charging points at company parking spaces or similar). The decentralized display system can also include a server for an information flow from said apps. The feed-in price can apply in particular to a specific point in time, and in particular can be higher the larger the peak load gap is, and the more closer to the said point in time at which the said peak load gap begins (or from which additional power is to be provided within a peak load gap). The charging tariff for obtaining energy via one of the charging points can be reduced in particular compared to a normal tariff (as valid at the time of determination) on the condition that before charging the electric vehicle in question to a desired state of charge (SOC), a battery of the electric vehicle is first discharged further in order to be able to compensate for the peak load gap using the amount of energy released. Only then (after the end of the peak load gap) is the electric vehicle then charged from a lower SOC than its original one at the agreed (reduced) charging tariff to the desired SOC. Care must be taken to ensure that the energy temporarily provided by the electric vehicle does not result in the battery falling below a specified minimum SOC.

A user can then book a discharge process into the hybrid energy storage system at the feed-in price mentioned above, or book a charging process for a later time at the (discounted) charging tariff, depending on his own planned use of his electric vehicle, and initially provide residual power from his battery for this purpose, so that the price mechanism at the feed-in price or at the discounted charging tariff and by informing a sufficient number of users can ensure that the required amount of energy and power is provided with a sufficiently high degree of probability.

It proves to be further advantageous if the hybrid energy storage system further comprises a central inverter which is connected to the connection point and which is designed to convert a direct current taken from the stationary storage unit and/or a direct current fed into the hybrid energy storage system by an electric vehicle via the first charging point into a corresponding alternating current and to supply it to the connection point.

Preferably, a number of the charging points are each connected to the stationary storage unit and/or the central inverter via a DC bus, and/or to the central inverter and the connection point via an AC bus. In particular, a number of charging points can each comprise a partially autonomous DC-DC converter. With such a partially autonomous DC-DC converter, the discharging process can be controlled locally and without direct intervention by the energy management system (except for specifying the second power or second energy quantity) solely by the relevant charging point and the associated electric vehicle.

The invention further mentions a method for operating the hybrid energy storage system described above, wherein a first amount of energy and/or first power to be provided at a connection point of the hybrid energy storage system is determined, wherein a charge level of a stationary storage unit of the hybrid energy storage system is determined, wherein, depending on the first amount of energy or the first power and the said charge level for providing the first amount of energy or the first power, a second amount of energy is discharged into the hybrid energy storage system from an electric vehicle via a first charging point of the hybrid energy storage system and is supplied to the connection point, and wherein the said discharging process of the electric vehicle at the first charging point is controlled by an energy management system of the hybrid energy storage system via a low-energy output interface.

The method according to the invention shares the advantages of the hybrid energy storage system according to the invention. The advantages specified for the hybrid energy storage system and for its further developments can be transferred to the method accordingly. In particular, for the method in an electric vehicle for discharging the second amount of energy via the first charging point, a central control unit of the electric vehicle and preferably also every other consumer except for a battery management system are put into an inactive state so that the discharging process is controlled on the vehicle side by the battery management system.

• 1 schematisch ein hybrides Energiespeichersystem mit einer stationären Speichereinheit und einer Mehrzahl an Ladepunkten, über welche jeweils Elektrofahrzeuge zusätzliche Energie bzw. Leistung bereitstellen können, und
• 2 schematisch einen Leistungsverlauf, welcher durch das hybride Energiespeichersystem bereitgestellt wird.

An embodiment of the invention is explained in more detail below with reference to drawings. These show schematically:

• 1 schematically shows a hybrid energy storage system with a stationary storage unit and a plurality of charging points, via which electric vehicles can provide additional energy or power, and
• 2 schematically shows a power curve provided by the hybrid energy storage system.

Corresponding parts and sizes are provided with the same reference numerals in all figures.

In 1 A hybrid energy storage system 1 for storing and providing electrical energy is shown schematically in a block diagram. The hybrid energy storage system 1 comprises a stationary storage unit 2, which has a large number of battery cells (not shown separately) and which is set up to store and release a considerable amount of energy as needed, preferably at least 100 kWh, particularly preferably at least 250 kWh. The hybrid energy storage system 1 further comprises an energy management system 4, which has a central control unit 5 and is set up to control the operation of the hybrid energy storage system 1 described below. The hybrid energy storage system also comprises a connection point 6 and a central inverter 8. The stationary storage unit 2 is connected to the central inverter 8 via a DC bus 10 of the hybrid energy storage system 1. The central inverter 8 is in turn connected to the connection point 6, which is designed here as a grid connection point 12 for a general power grid 14 of an energy supplier. However, additional connections, such as feed-in points or for possible consumers, could also be connected between the connection point 6 and the grid connection point 12. The central inverter 8 is designed to convert a direct current received from the DC bus 10 into a corresponding alternating current and to supply this to the connection point 6.

The hybrid energy storage system 1 further comprises a plurality of charging points LP1-LP5, which are connected to the DC bus 10. Each of the charging points LP1-LP5 is individually configured to charge any connected electric vehicle according to the specifications of a respective owner, and further configured to discharge such a connected electric vehicle as required. In 1 In the case shown, corresponding electric vehicles EV1-EV3 are connected to a first charging point LP1 and to two further charging points LP2, LP3. The electric vehicles EV1-EV3 can either be designed as purely battery-electric vehicles, or as plug-in hybrid vehicles with an internal combustion engine in addition to a battery-electric drive train. Other electric vehicles EV4, EV5 are on the roads (not shown in detail) near the charging points LP1-LP5, i.e. within their range. The charging points LP1-LP5 can, for example, be arranged at company parking spaces, with the hybrid energy storage system 1 being operated by the company in question and distributed across its company premises (i.e. in particular the stationary storage unit 2, the energy management system 4 and the DC bus 10 are also arranged on the company premises).

The energy management system 4 further comprises an input interface 16, which in particular has a communication device (such as an antenna, a LAN or WLAN connection or similar) and is set up to receive, on the one hand, from a server 20 of a network operator of the general power grid 14, a first piece of information Info1 with regard to an expected flexibility requirement at the grid connection point 12 and/or with regard to a provided energy supply to a spatially delimited area (such as a company site or similar properties) comprising the hybrid energy storage system 1. In particular, typical time profiles of the demand for energy over the day (for example as averages of several days or even months or also as maximum values of a year or similar) can be transmitted in the first piece of information Info1, as well as an immediate, instantaneous demand for electrical power in the general power grid 14. Furthermore, current values of the energy supply by the energy supplier as well as planned delivery processes for a future period (such as the rest of the day or the next 24 hours or similar) can be transmitted, as provided for in the energy supplier's internal planning.

Preferably, the energy management system 4 can use the first information Info1 to map a power curve that is as detailed as possible and from this can plan the control of discharging processes of the electric vehicles EV1-EV3 via the associated charging points LP1-LP3 into the hybrid energy storage system 1, which is yet to be described.

Furthermore, the input interface 16 is configured to receive a second information Info2 from a server 22 of an energy supplier regarding tariff information for electricity prices in the immediate future (e.g. coming hours).

The hybrid energy storage system 1 is preferably supplied by the grid operator through the connection point 6 with the amount of energy announced in advance after the first information Info1. This amount of energy can be obtained from fossil, nuclear or renewable energy sources (the exact type of energy generation is not important in this case). The hybrid energy storage system 1 can also be connected, in particular, to a three-phase AC bus 26 between the central inverter 8 and the grid connection point 12, provide further, decentralized feed-in points 28, into which additional photovoltaic systems or combined heat and power plants (not shown) feed energy into the AC bus 26. In addition, additional charging points (not shown) can also be connected to the AC bus 26.

The energy management system 4 now uses the first and second information Info1, Info 2, as well as the knowledge of the charge level of the stationary storage unit 2 and the knowledge of the technical restrictions that apply to the stationary storage unit 2 and the grid connection point 12 (e.g. maximum power that the stationary storage unit 2 can deliver or with which the grid connection point 12 can be loaded, etc.) to determine a temporal progression profile for the operation of the hybrid energy storage system 1. Such a temporal progression profile is shown schematically in 2 shown.

In 2 a load profile 30 of a power P is plotted schematically against a time t. The load profile 30 corresponds to the demand in the general power grid 14 at the grid connection point 12. Up to a time T0, the power P requested in the general power grid 14 according to the load profile 30 can be covered by a power P _SE that the stationary storage unit 2 is able to deliver. After the time T0, however, the requested power P in the general power grid 14 exceeds the power P _SE that can be provided by the stationary storage unit 2, resulting in a peak load gap 32 (hatched area).

To cover this peak load gap 32, the additional power P _LP1 is used up to a point in time T1, which is generated by the electric vehicle EV1 at the first charging point LP1 after 1 is fed into the hybrid energy storage system 1. For a short period of time between times T1, T2, the power P demanded (double-hatched area) exceeds the power P _SE + P _LP1 that can initially be provided by the hybrid energy storage system 1, so that a power P _LP2 from another electric vehicle EV2 is now fed in via the corresponding charging point LP2 in order to cover the energy requirement. After time T2, the power P _SE + P _LP1 provided by the stationary storage unit 2 and the electric vehicle EV1 (via the first charging point LP1) is again sufficient to cover the power P demanded.

From a point in time T3, the power P demanded in the general power grid 14 is again less than the power P _SE that can be provided by the stationary storage unit 2. The peak load gap 32 has ended, and the power P _SE that can be provided by the stationary storage unit 2 can now be used to recharge the electric vehicles EV1, EV2, which were temporarily discharged into the DC bus 10 of the hybrid energy storage system via the charging points LP1, LP2 to cover the peak load gap 32. This effectively results in a type of load shift 34 of the peak load gap 32 to a period in which the demand is sufficiently low to be covered by the stationary storage unit 2 alone.

To use the 2 In order to achieve the described coverage of demand, the energy management system 4 calculates, in an advantageous embodiment, a feed-in price 36 for feeding in energy via one of the charging points LP1-LP5 based on the first information Info1 (i.e. in particular based on an expected load profile contained therein) and on the second information Info2 (i.e. in particular based on an intended energy supply by the energy supplier contained therein). The feed-in price 36 can be calculated in particular for a specific point in time in the interval T0 to T3 (after 1 ) and are particularly higher the larger the peak load gap 32 after 2 is, and the closer the time T0 (or the time T1) is at which the said peak load gap 32 begins (or further additional power is to be provided within the peak load gap 32). In particular, instead of the feed-in price 36 or in addition to it, a reduced charging tariff 37 can be determined, which is offered to a user for charging his electric vehicle to a SOC desired by him after the time T3, if the owner in return makes any remaining battery power available to the hybrid energy storage system 1 during the peak load gap 32 (i.e. discharges the electric vehicle in the period T0 to T3 via one of the charging points LP1-LP5 in order to provide additional power to cover the peak load gap 32).

The energy management system 4 is connected to a decentralized display system 38 by means of a corresponding communication device (not shown in detail; the communication device can in particular use the physical infrastructure of the input interface in whole or in part, or even duplicate it). This decentralized display system 38 can in particular include corresponding apps in the on-board displays of the electric vehicles EV4, EV5 as well as other apps in mobile phones 40 of owners of other electric vehicles (not shown). The decentralized display system 38 can also include a server (not shown) for an information flow from the said apps.

The feed-in price 36 is now displayed via the said decentralized display system 38 to a plurality of users (i.e. in particular drivers and/or owners) of electric vehicles EV1-EV5. A user can then book a discharge process into the hybrid energy storage system 1 according to his own planned use of his electric vehicle, so that the price mechanism and the notification of a sufficient number of users can ensure that the required amount of energy and power (P _LP1 and P _LP2 according to 2 ) is provided with a sufficiently high probability. In particular, users of electric vehicles EV2, EV3 whose electric vehicles EV2, EV3 are already connected to a charging point LP2, LP3, but which are not yet in a charging or discharging process (cf. in contrast the electric vehicle EV1 at the first charging point LP1), can also be informed via the app.

In an embodiment that is independent of said decentralized display system 38, the energy management system 4 has a low-energy output interface 42, which is designed here as an LWPA access point (LPWA-AP) 44 and is set up to communicate with the charging points LP1-LP5 and with an electric vehicle EV1-EV3, which is connected to a charging point LP1-LP3, via a corresponding LPWA (as is the case, for example, in an NB-loT network or a LoRaWAN). A discharging process can thus be controlled by the energy management system 4 via the LPWA-AP 44 by first controlling the first charging point LP1 and the electric vehicle EV1, which are also connected to the said LPWA, to prepare the discharging process accordingly. On the part of the electric vehicle 1, this includes the necessary safety checks being carried out in order to be able to issue corresponding approvals. On the side of the first charging point LP1, this means in particular that it is prepared to react to control commands from the electric vehicle 1 with regard to voltage and/or current curves, and in particular is set up to receive a corresponding direct current of not inconsiderable power from the electric vehicle EV1 and, after a DC-DC conversion, to feed it into the hybrid energy storage system 1. For this purpose, the individual charging points LP1-LP5 preferably each comprise a semi-autonomous DC-DC converter DW1-DW5, which can also be controlled via the said LPWA, in particular by an electric vehicle connected to the relevant charging point LP1-LP5, and which are each capable of converting a direct current fed in by an electric vehicle to a predetermined voltage for the DC bus 10, without the need for any further external control.

The first charging point LP1 and the electric vehicle EV1 connected to it are now controlled via the low-energy output interface 42 to establish a connection to each other via the LPWA, via which all control commands (e.g. specified limit values, target values and/or actual values for energy quantities to be transferred, power, currents and/or voltages for the discharging process) are transmitted from the electric vehicle EV1 to the first charging point LP1 during the discharging process. In particular, for efficient discharging, the central control unit of the electric vehicle EV1 is put into an inactive mode (i.e. in particular deactivated, put into standby mode, switched off or even de-energized). The central control unit is designed to control all basic functions of the electric vehicle (drive of the individual wheel motors, on-board electronics, lighting, temperature control, etc.) and can in particular be provided by a vehicle server (or by the control unit that regulates power output from the battery for driving and power consumption during charging). In particular, when discharging, all other consumers on the part of the electric vehicle EV1, with the exception of battery management (not shown), are put into an inactive mode for greater efficiency. The battery management is particularly intended and set up to control the flow of energy into the battery during charging and out of the battery during discharging (e.g. when driving the electric vehicle EV1), and in doing so also to ensure, among other things, an even loading or strain on the individual cells of the battery.

The measures described enable the hybrid energy storage system 1 to respond flexibly to requested peak loads and to feed in the energy provided by the electric vehicles as efficiently as possible, i.e. in particular without unnecessary losses during the discharging process. In addition, the hybrid energy storage system 1 is designed to be as decentralized as possible, which further increases flexibility.

Although the invention has been illustrated and described in detail by the preferred embodiment, the invention is not limited to the disclosed examples and other variations can be derived therefrom by those skilled in the art without departing from the scope of the invention.

List of reference symbols

1

hybrid energy storage system

2

stationary storage unit

4

Energy management system

5

central control unit (of the energy management system)

6

Connection point

8th

central inverter

10

DC bus

12

Grid connection point

14

general power grid

16

Input interface

20

Server (of the network operator)

22

Server (of the energy supplier)

26

AC bus

28

decentralized feed-in points

30

Load profile

32

Peak load gap

34

Load shift

36

Feed-in price

37

(discounted) charging tariff

38

decentralized display system

40

Mobile phone

42

Low energy output interface

44

LPWA Access Point

DW1-DW5

(semi-autonomous) DC-DC converter (DC-DC converter)

EV1-EV5

Electric vehicles

Info1/2

first/second information

LP1

first charging point

LP2-LP5

Charging points

P

(demanded) performance

PLP1/2

(power fed into charging point LP1/2)

PSE

Performance (of the stationary storage device)

t

Time

T0-T3

Timings

Claims (10)

Hybrid energy storage system (1) for storing and providing electrical energy, comprising - a stationary storage unit (2) which is designed to store and deliver electrical energy, - a plurality of charging points (LP1-LP5), each of which is designed to charge and/or discharge an electric vehicle (EV1-EV5), - an energy management system (4) which is designed to control the plurality of charging points (LP1-LP5) via a low-energy output interface (42), and - a connection point (6), wherein the energy management system (4) is further designed to provide a predetermined first amount of energy and/or first power at the connection point (6), for which purpose at least one electric vehicle (EV1) connected to a first charging point (LP1) is discharged via the first charging point (LP1), and a second amount of energy or second power thus provided by said electric vehicle (EV1) is supplied to the connection point (6). Hybrid energy storage system (1) according to Claim 1 , wherein the energy management system (4) further comprises at least one input interface (16), and wherein the energy management system (4) is configured to - receive at least one first item of information (Info1) about a load profile at the connection point (6) and/or about an energy supply to the hybrid energy storage system (1) via said input interface (16), and - also provide the second amount of energy or second power thus provided by said electric vehicle (EV1) on the basis of the first information (Info1). Hybrid energy storage system (1) according to Claim 1 or Claim 2 , wherein the low-energy interface (42) is provided as a low-power wide-area access point (44), wherein the energy management system (4) is set up to control and/or activate the discharging process of the associated electric vehicle (EV1) taking place at the first charging point (LP1) via said low-power wide-area access point (44), and/or wherein the energy management system (4) is set up to control or activate the discharging process of the associated electric vehicle (EV1) taking place at the first charging point (LP1) in such a way that a central control unit of the electric vehicle (EV1) and preferably all vehicle-side consumers except for a battery management of the electric vehicle (EV1) are put into an inactive state so that the discharge process into the hybrid energy storage system (1) via the first charging point (LP1) is controlled by the battery management of the electric vehicle (EV1). Hybrid energy storage system (1) according to Claim 3 , wherein the energy management system (4) is designed to control the first charging point (LP1) and an electric vehicle (EV1) connected to the first charging point (LP1) in such a way that - all releases in the electric vehicle (EV1) are issued for the discharging process, and - then the central control unit of the electric vehicle (EV1) or all vehicle-side consumers of the electric vehicle (EV1) except for said battery management are put into the inactive state for the discharging process. Hybrid energy storage system (1) according to one of the preceding claims, wherein the energy management system (4) is further configured to - receive the first information (Info1) about a present and/or expected load profile at the connection point (6) via said input interface (16), and to receive second information (Info2) about an energy supply and/or a power supply to the hybrid energy storage system (1), - determine a peak load gap (32) based on the first information (Info1), the second information (Info2) and a charge level of the stationary storage unit (2), and - provide the predetermined first amount of energy or first power at the connection point (6) by providing the amount of energy or power corresponding to the peak load gap (32) at least partially by said electric vehicle (EV1) as said additional amount of energy or power via the first charging point (LP1). Hybrid energy storage system (1) according to Claim 5 , wherein the energy management system (4) is further configured to use the peak load gap (32) to determine a feed-in price (36) for feeding in energy via one of the charging points (LP1-LP5) and/or a charging tariff (37) for obtaining energy via one of the charging points (LP1-LP5), and to output said feed-in price (36) or charging tariff (37) to a plurality of users of electric vehicles (EV1-EV5) via a decentralized display system (38) connected to the energy management system (4). Hybrid energy storage system (1) according to one of the preceding claims, which further comprises a central inverter (8) which is connected to the connection point (6) and which is designed to convert a direct current taken from the stationary storage unit (2) and/or a direct current fed into the hybrid energy storage system (1) by an electric vehicle (EV1) via the first charging point (LP1) into a corresponding alternating current and to supply it to the connection point (6). Hybrid energy storage system (1) according to Claim 7 , wherein a number of the charging points (LP1-LP5) - are each connected to the stationary storage unit (2) and/or the central inverter (8) via a DC bus (10), and/or - are each connected to the central inverter (8) and the connection point (6) via an AC bus (26). Hybrid energy storage system (1) according to one of the preceding claims, wherein a number of the charging points (LP1-LP5) each comprise a semi-autonomous DC-DC converter (DW1-DW5). Method for operating a hybrid energy storage system (1) according to one of the preceding claims, wherein a first amount of energy and/or first power to be provided at a connection point (6) of the hybrid energy storage system (1) is determined, wherein a charge level of a stationary storage unit (2) of the hybrid energy storage system (1) is determined, wherein, depending on the first amount of energy or the first power and the said charge level for providing the first amount of energy or first power, a second amount of energy is discharged into the hybrid energy storage system (1) from an electric vehicle (EV1) via a first charging point (LP1) of the hybrid energy storage system (1) and is supplied to the connection point (6), and wherein the said discharge process of the electric vehicle (EV1) at the first charging point (LP1) is controlled by an energy management system (4) of the hybrid energy storage system (1) via a low-energy output interface (42).

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