Multifunctional energy-storing charging system

Abstract

The present invention presents a multifunctional energy-storing charging system (10, 20, 300) which comprises an AC / DC inverter (13, 304), a DC electric energy storage (14, 305), a DC / DC inverter (15, 306), and a charging point (18, 307) for an electric vehicle, wherein the AC / DC inverter (13, 304) and / or the DC electric energy storage (14, 305) acts as an interface to a power distribution grid (12, 303), to other electric loading and to local electricity production (16, 308, 309, 310). DC electric energy can be transmitted between the AC / DC inverter (13, 304) and the DC electric energy storage (14, 305), and also between the DC electric energy storage (14, 305) and the DC / DC inverter (15, 306). One terminal of the DC / DC inverter (15, 306) is connected to the charging point (18, 306) for an electric vehicle. The multifunctional energy-storing charging system (10, 20, 300) is controlled so that it operates, in terms of transmission of electric energy, either unidirectionally or bidirectionally between the network elements using AC electric energy and the DC electric energy storage (14, 305), irrespective of whether the electric vehicle (17, 311) is connected to the charging point (18, 307) for an electric vehicle to be charged, or not.

Description

[0001] MULTIFUNCTIONAL ENERGY-STORING CHARGING SYSTEM

[0002] Field of the invention

[0003] The present invention relates to an electric energy storage device, a relating charging station for an electric automobile, and a smart control method for the system to enable transmission of electricity in many different directions between a power distribution grid, an internal network, and a vehicle to be charged.

[0004] Background of the invention

[0005] For the needs of distribution of power for electric traffic, that is, electric automobiles, various charging concepts are available, which can be electrically divided into two classes: AC ( / .e. alternating current) and DC ( / .e. direct current) charging devices, according to the electric current used for energy transmission between the charging device and the automobile. AC charging devices are typically charging devices providing lower power, about 3 to 22 kW, being connected to the power grid and distributing electricity in the form of alternating current to an internal charging device (AC / DC) of an automobile and to a battery downstream. DC charging devices, in turn, are typically more powerful than AC chargers, converting electricity from alternating current to direct current (AC / DC) in the charging device itself, whereby the electric energy is transmitted in the form of direct current to the vehicle on the basis of the charging control of the vehicle (and the charging device).

[0006] As product concepts, charging devices can be classified by, for example, the maximum power provided by them, the method of installation, or transportability, and also the structural layout of the components of the devices. The embodiment of the device is also influenced by the implementation of energy transmission between the charging device and the vehicle: by cable or inductively, and unidirectionally or bidirectionally. The charging device may be available publicly or as a private device, and this affects the techniques of identifying the vehicle as well as the technical aspects of payment, including the connections needed. The right to use or the cost of the energy to the user may be free, or based on time, energy consumption or charging power. Further, there are many types of device acquisition model: ownership, rental, based on service model, or based on other operating agreement.

[0007] A typical concept of prior art, suitable for charging cars at commercial and traffic stations, is DC charging, whereby a vehicle can be charged with a maximum power of 150 to 300 kW. In such an implementation, the connection to the power grid and the AC / DC conversion is often done in a separate power unit which is placed e.g. at the edge of the charging field, and the units of operation are then arranged in connection with the respective charging points. Technically, the components / functions of the charging device are divided into separate units which are manufactured and installed separately.

[0008] In an example of prior art, higher-power AC electricity of a power grid is converted to a lower voltage in an MV substation, after which a power rectification unit converts the AC to DC, for example to a voltage of 950 V, for a number of parallel charging points.

[0009] In the present situation it can be seen that the number of electric vehicles is going to increase significantly in the future. Moreover, viewed by vehicle category, more and more different vehicle types switch to electricity, such as heavy-duty vehicles, public transport vehicles, and also off-road machinery, and furthermore, also many light vehicles (such as scooters) are increasingly electric. Also, increased charging powers must be taken into account in the present energy system and in its future design. This increases the costs of building charging infrastructure. As a result, there is a need to provide the devices with a higher utilization rate, or e.g. multifunctional features. The present invention tackles this very problem.

[0010] In the present electrified world, the demand on single consumer points may also be more significant than before (in terms of consumption capacity), and the range of consumption of electricity, from minimum to peak consumption, may also be broad. At locations of power consumption, the increase and range of power consumption involve a need to optimize the purchase of electricity and, on the other hand, to level out consumption peaks. An example of this is the transition in heating of buildings from fossil fuels to electricity, as well as the transition of industrial processes to utilize electric energy. All these share the common need for possibilities to optimize the utilization and costs of electricity at the consumption point.

[0011] Due to the green transition, an increasing share of electricity production is dependent on weather conditions and the time of year (wind and sunshine). On the other hand, in terms of power grid capacity, it would be optimal to have at least approximately equal amounts of production and consumption in the power grid. Because the range increases both in production and consumption of electricity, there is also a need for more adjustability in electricity transmission networks. This is a current problem in prior art.

[0012] In prior art, charging systems for electric automobiles have been largely developed against the background of unidirectional energy transmission so that charging energy is only transmitted to a battery of a vehicle when the vehicle is connected to a charging point; the charging point is unused for the rest of the time.

[0013] Charging points presently in use for electric vehicles contain a power unit consisting of power modules (for example, 150, 200, 350, or 720 kW), charging points, or so-called satellites, connected to them (for example, 180 kW / 360 kW) for distributing the energy produced by the power unit to vehicles via actual charging cables which are connected to the respective vehicles. The charging systems also comprise data channels needed for communication, that is, intelligence, for controlling the actual charging process (e.g. dynamic load management). That is to say, these conventional charging station concepts do not have any battery capacity needed for energy storage; that is, due to their functional implementation, they cannot be used as an energy storage. Consequently, these conventional charging stations cannot provide their owner and the environment with added value greater than the charging function at times when no vehicle (with a battery) is connected to the charging system. This is an obvious problem of prior art.

[0014] WO 2023 / 057970 describes an electricity distribution device where batteries of an electric vehicle can be charged on one hand, but the system also makes it possible to transmit electricity in the other direction, that is, in the direction of the power grid, thanks to the Back-to-Meter functionality (BTMF). A large number of electric vehicles can be charged simultaneously in the charging module of the system (EVCF). The system also comprises a battery-swapping function (BSF) where the batteries can be removed from the vehicles when empty, be connected to a charging device for rapid charging, after which the fully charged batteries can be re-installed in the same or another vehicle. In the product according to the document, at least two of said three functionalities (BSF, EVCF, BTMF) can be utilized in connection with each other.

[0015] However, the previously mentioned problems are still present, and these will be tackled by the present invention.

[0016] Summary of the invention

[0017] The idea of the new method to be presented is to utilize, for example, battery modules functioning as a bidirectional energy storage (a so-called DC / DC battery bank) instead of a power unit used in implementations of charging systems of prior art. The method is particularly useful because the battery bank replacing a power unit and connected directly to charging points, i.e. so-called satellite devices, is capable of producing high added value to its owner and to the environment even when no electric vehicles with their batteries are connected to the charging station.

[0018] The new method makes it possible to utilize the battery bank acting as an energy storage in three directions simultaneously. The method of implementation enables, at the same time, use in a reserve market, optimization of consumption in an internal network (infrastructure in an environment, such as a real estate or factory), and stepless charging of an electric vehicle. Naturally, the bidirectional operation requires management of the device assembly, that is, intelligence of the solution and profiling of the use of the device. Said management is implemented by means of a control unit utilizing various internal and external data sources.

[0019] The control unit may be a separate physical element, or it may be implemented by software in another element of the system. Furthermore, the functionality of the management may be implemented in only one device or distributed over a number of different devices.

[0020] In an embodiment of the invention, the control unit or distributed control is arranged to control an AC / DC inverter, a DC electric energy storage and a DC / DC inverter. In another embodiment of the invention, the control unit or distributed control is arranged to control a charging point for a vehicle, in addition to the above-mentioned elements.

[0021] In an embodiment of the invention, a charging point / connection for a vehicle is arranged to be controlled by a control unit, to communicate with a vehicle connected to be charged, to transmit output DC electric energy from a DC / DC inverter to the vehicle, and to act as a user interface for users of the charging point / connection for a vehicle. The user interface may be implemented in the device itself, as a network service, or as a mobile application, but is not limited to these.

[0022] Another significant advantage of utilizing a battery bank is that it can be used (parallel use) to provide a charging capacity higher than the power capacity of the grid connection available. Similarly, the method supports optimization of consumption, i.e. loads, and changing capacity needs in the environment, that is, for example a real estate or a factory.

[0023] Battery banks can also be connected together to increase the capacity. In the big picture, these can be utilized in any part of a power network, from the production end down to internal networks of consumers.

[0024] The device assembly is controlled and managed by a control unit. By means of the control logic of the controller, the operational use of the device assembly is optimized from selected approaches according to desired and weighted, i.e. custom-tailored use profiles. The use of the device assembly can be controlled proactively by forecasting the required charging capacity. An example of this is the power capacity to be reserved in advance for charging of vehicles present, setting its own requirements. Discharging and charging of the energy storage of the battery bank is controlled, in turn, by prices on the electricity market and, with respect to the balancing of the power grid, by the reserve markets.

[0025] Compared to a conventional charging device, the multifunctional charging device according to the invention has the following characteristics. An AC / DC power unit is replaced with DC / DC battery modules. The battery bank can be utilized in three directions simultaneously:

[0026] 1) Via an AC / DC inverter to a transmission network to balance various consumption needs (so-called reserve market).

[0027] 2) Further, the AC / DC inverter can be used for the needs of an internal network, to enable higher power output than a mains connection can provide in an internal network, to optimize the price of other power consumption or so-called peak consumption.

[0028] 3) The energy needed for charging an electric vehicle can be drawn steplessly from the battery pack.

[0029] Furthermore, a centralized device control is needed for the battery bank, to obtain the following information, among other things: a) the market price for electricity, b) network frequency data, c) data on the consumption of the electricity connection, d) state of charge and voltage of the battery, e) data relating to the need to recharge a vehicle, but not limiting to the points from a) to e), f) also needs relating to charging of these batteries, g) control data of the AC / DC inverter, and / or h) control data of the DC / DC inverter relating to the batteries and the vehicle charging devices.

[0030] The device controller can optimize the use of the device assembly, and said optimization can be based on the following factors:

[0031] A) vehicle charging rate,

[0032] B) purchase prize of energy for recharging a vehicle, C) minimization of other energy costs in an internal network,

[0033] D) increasing of maximum power output in an internal network,

[0034] E) minimization of grid connection used (tariffs),

[0035] F) maximization of benefits from adjusting the transmission network, and / or

[0036] G) trading in electricity at spot prices (arbitrage).

[0037] According to a first aspect, the present invention presents a multifunctional energy-storing charging system. The multifunctional energy-storing charging system comprises:

[0038] - an AC / DC inverter,

[0039] - a DC electric energy storage,

[0040] - a DC / DC inverter,

[0041] - a charging point for an electric vehicle, wherein

[0042] - the AC / DC inverter and / or the DC electric energy storage is used as an interface to a power distribution grid, to other electric loads and to local electricity production,

[0043] - DC electric energy can be transferred between the AC / DC inverter and the DC electric energy storage,

[0044] - DC electric energy can be transferred between the DC electric energy storage and the DC / DC inverter,

[0045] - one terminal of the DC / DC inverter is connected to a charging point for an electric vehicle, and

[0046] - an electric vehicle can be connected to the charging point for an electric vehicle, and

[0047] - the multifunctional energy-storing charging system is configured to be controlled so that the multifunctional energy-storing charging system operates, in terms of transmission of electric energy, either unidirectionally or bidirectionally between network elements using AC electric energy and the DC electric energy storage, irrespective of whether an electric vehicle is connected to a charging point for an electric vehicle for charging, or not.

[0048] In an embodiment of the invention, the multifunctional energy-storing charging system further comprises a control logic, which may be implemented in the form of a control unit, or the control logic may be distributed over a number of locations within the multifunctional energy-storing charging system. In an embodiment of the invention, the control unit is configured to control at least one of the following: the AC / DC inverter, the DC electric energy storage, the DC / DC inverter, and the charging point for an electric vehicle.

[0049] In an embodiment of the invention, the DC / DC inverter is arranged to convert the direct voltage and direct current from the output of the DC electric energy storage to a level suitable for the electric vehicle, under control by the control unit.

[0050] In an embodiment of the invention, the charging point for an electric vehicle is arranged to be controlled by the control unit, to communicate with the electric vehicle connected to be charged, to transmit the output DC electric energy from the DC / DC inverter to the electric vehicle, and to act as an interface for users of the charging point for an electric vehicle.

[0051] In an embodiment of the invention, the control logic is arranged, according to the devices connected and the measurement data obtained from them, to prioritize the operations to be carried out in the multifunctional energy-storing charging system, based on at least one of the following: situations of use of devices, needs for re-charging the DC electric energy storage and an electric vehicle, state of internal and external networks, and / or other external data sources.

[0052] In an embodiment of the invention, the control logic is arranged to derive part of the charging power needed by the electric vehicle from the DC electric energy storage, and part from the power distribution grid, or to derive the charging power needed by it merely from the DC electric energy storage, or merely from the power distribution grid.

[0053] In an embodiment of the invention, the control logic is arranged, in a situation of higher consumption demand in the local internal network, to direct electric energy from the DC electric energy storage via the AC / DC inverter inversely to the local internal network. In an embodiment of the invention, the control logic is arranged, if necessary, to direct surplus electric energy from the DC electric energy storage to the power distribution grid via the AC / DC inverter.

[0054] In an embodiment of the invention, information about the electric loading conditions, the conditions on the electricity market, and forecast data relating to these is received in the input of the control unit, and the control unit is arranged to set up a priority list for various electric energy consumption points to be applied in the near future.

[0055] In an embodiment of the invention, the control unit is connected to a cloud service comprising external data sources and / or databases, comprising spot prices on the electricity market, weather forecasts, advance information on the state of the power distribution grid, and / or advance information on future power needs relating to charging or the state of the power distribution grid.

[0056] In an embodiment of the invention, the priority list is set up on the basis of total output and / or the desired charging time of an electric vehicle and / or the purchase price of electricity, and the priority list can be set to vary as a function of time.

[0057] In an embodiment of the invention, the AC / DC inverter acts as an interface to the power distribution grid, to other AC electric loading of the consumption point, and to local electricity production.

[0058] In an embodiment of the invention, the DC electric energy storage acts as an interface to other DC electric loading of the consumption point.

[0059] According to a second aspect, the present invention presents a method for using a multifunctional energy-storing charging system. The method comprises the following steps:

[0060] - providing the multifunctional energy-storing charging system with an AC / DC inverter, a DC electric energy storage, a DC / DC inverter, and a charging point for an electric vehicle, wherein - the AC / DC inverter and / or the DC electric energy storage is used as an interface to a power distribution grid, to other electric loads and to local electricity production,

[0061] - DC electric energy can be transferred between the AC / DC inverter and the DC electric energy storage,

[0062] - DC electric energy can be transferred between the DC electric energy storage and the DC / DC inverter,

[0063] - connecting one terminal of the DC / DC inverter to the charging point for an electric vehicle, and

[0064] - an electric vehicle can be connected to the charging point for an electric vehicle, and

[0065] - controlling the multifunctional energy-storing charging system so that the multifunctional energy-storing charging system operates, in terms of transmission of electric energy, either unidirectionally or bidirectionally between network elements using AC electric energy and the DC electric energy storage, irrespective of whether an electric vehicle is connected to the charging point for an electric vehicle for charging, or not.

[0066] Brief description of the drawings

[0067] Fig. 1 shows an example of the modular structure of a multifunctional charging device according to the invention, on an upper level,

[0068] Fig. 2 shows an example of a multifunctional charging device according to the invention, wherein external data can be introduced in the system via a cloud service, and

[0069] Fig. 3 shows yet another alternative embodiment of the invention, including several points of electricity consumption in addition to energy for charging an electric vehicle.

[0070] Detailed description of the invention

[0071] The need for storing electricity is increasing in general, and this need will be particularly acute in the foreseeable future. Also, the connecting of charging devices and electric vehicles to the energy system has increased the need for energy storage and balancing of consumption. For balancing of electricity consumption, energy storages could be connected to the same consumption point as the production site, the transmission network or the charging devices. For energy storages, the concept Battery energy storage system, or BESS, is used, and such an energy storage operates on the principle of storing electric energy in electrochemical form in batteries.

[0072] Even a single battery may be considered an electricity storage, but to speak of a complete or at least more useful system, the battery needs other components around it. A physically complete device comprises not only batteries but also elements of power electronics for controlling the recharging and discharging of the batteries, together with control software.

[0073] In the present invention, we can speak of an electricity storage, an energy storage, a battery, or a battery pack (that is, an assembly of several different batteries), but the idea of the invention is, broadly defined, that an energy storage can be used which is reversible, that is, converting the type of energy back and forth between two states. In an example, the energy storage may be a heat storage, from which thermal energy can be converted to electric energy by means of a steam turbine. Naturally, the energy storage may be a purely electric energy storage consisting of one or more batteries, that is, chemical electric energy storages. The energy storage may also consist of a combination of several energy storages of different types.

[0074] The electricity storages may have a modular structure, which means that different components can be added one by one; in other words, the electricity storage is composed of components. In this way, it is easier to meet the end user’s needs and to tailor solutions for a larger number of uses. The modular design also makes it possible to scale up the system by adding modules purchased later on. If the power output or the number of batteries is increased, for example, caused by an increased occupancy level or extension of a building, components can be added to provide the device with more targeted benefits.

[0075] In electricity storages, energy is stored as direct current, i.e. DC voltage, in batteries. However, devices used for normal operation and connected to a power grid are driven by alternating current (AC). Consequently, the alternating current available from a grid has to be converted to direct current, to be stored in batteries. On the other hand, for discharging electricity from a battery pack back to devices connected as a load to the device, the direct current of the batteries has to be converted to alternating current. These conversions can be implemented by components of power electronics, such as rectifiers and inverted rectifiers. An inverted rectifier, or a component converting direct current to alternating current, is often called by the term inverter as well.

[0076] To include an electric storage in the reserve market of a transmission system operator (for example, Fingrid in Finland), the power electronics must be capable of creating a frequency of its own and to independently control its power input. Some devices are not capable of this, but they only trace the frequency already existing in the network and connect to it by following and supplying a voltage at the same frequency.

[0077] In the reserve market, Fingrid does not transmit control signals for all control products, but most electricity storages acting on the reserve market must be capable of automatically changing their operation on the basis of the frequency of the grid connected to them. It must also be possible to create a frequency specific to an inverter, if the electricity storage is used for creating micro network of its own. This means a situation in which a load or an entire real estate downstream of the electricity storage is completely separated from the power distribution grid. This may be the case, for example, in the event of a complete blackout, or if no power grid is available for the target, for example because of a long connection distance.

[0078] For an electricity storage to be capable of designing and seamlessly implementing the consumption of electricity in a real estate, it must also be capable of measuring the energy consumption in the real estate and possible self-generation of electricity. In these cases, the implementation may be a connection to existing electric meters or providing a separate measuring solution as a part of the electricity storage assembly. In relation to the self-generation of electricity, the present invention provides different embodiments as to how and where such a device or device assembly for generating electric energy can be implemented in practice. In an embodiment of the invention, such a device or system can be connected directly to an AC / DC inverter or an internal network, or a combination of these. On the other hand, an electric energy generating device may be an arrangement implemented as a separate device or a system, that is, a combination of several devices. In an example, the electricity generating device or system (or part of it) may be directly connected to an electric energy storage.

[0079] The present invention relates to a multifunctional charging device and an electricity storage arrangement, for example for charging of electric vehicles, which enables a more flexible way than the prior art to introduce a charging device in different types of applications, provides the device with more uses, and enables smaller energy losses and helps to implement the green transition in a way that is more efficient and economical than existing solutions.

[0080] In the following, the technical structure of a multifunctional charging device and electronic storage arrangement will be described on an upper level with reference to Fig. 1. This constitutes an example of the invention.

[0081] In this example, the technical structure of the device consists of five main functions, or main elements. These main functions can be implemented by functional modules which will be described in the following paragraphs.

[0082] The first main functionality consists of an AC / DC inverter, or a bidirectional converter 13 which connects the device to a power distribution grid (AC) 12 and converts alternating current to direct current when the device is powered, and converts direct current to alternating current when energy is discharged in the direction of the internal network 16 of the consumption point and the power distribution grid 12. The amount and direction of the current can be controlled by a control unit 11.

[0083] The second main functionality consists of a bidirectionally used DC energy storage 14 which may be implemented by a battery pack. In an example of the invention, the voltage level of the battery pack may be high voltage, but it is also possible to use a low voltage battery pack. In this context, high voltage can be defined so that an alternating voltage exceeding 50 V or a direct voltage exceeding 120 V is defined to be high voltage, and correspondingly, an alternating or direct voltage lower than these limits is defined to be low voltage. The DC energy storage 14 also receives its control signal from the control unit 11. Technically, the DC energy storage 14 is arranged between the DC connection of the AC / DC inverter 13 and the second DC connection of the DC / DC inverter, or converter, 15 (to be introduced in the next paragraph).

[0084] The third main functionality of the present example consists of the DC / DC inverter or converter 15 for converting the electric energy ( / .e. voltage and current) obtained from the DC energy storage 14 and the AC / DC inverter 13 to a level suitable for an electric vehicle 17. This conversion is controlled by the control unit 11.

[0085] The fourth main functionality is the use point for a charging device ( / .e. a charging point for a vehicle) 18, whose functions include communication with the electric vehicle 17 to be charged and with the control unit 11 , and transmission of DC charging current from the DC / DC inverter 15 to the vehicle 17, and acting as a user interface for users of the charging point 18, for example, for identification and displaying of status data (including e.g. the charging rate, i.e. battery capacity, of the electric vehicle 17 in percent between O and 100 %).

[0086] The fifth main functionality is the control unit 11 , already introduced in several instances above, for controlling the functions of the multifunctional charging device. In practice, the control unit 11 may be a computer, a server, or a controller which is capable of processing data, storing it in a memory unit where necessary, and outputting control signals to desired elements of the system. The control signals may be implemented by cable connections or in a wireless manner. The control unit 11 is connected to the internal functions of the device and to several external systems and / or to measurement data, and these can be used by the control unit 11 to prioritize operations to be carried out by the device according to the situation of use, charging needs, the state of internal and external networks, and / or other external data sources, among other things.

[0087] Although a single controller or control unit 11 is mentioned in several instances in the description, this control functionality may be logically distributed over a number of different elements or locations within the system. Consequently, control signals may be received by components of the system from two or more different control units or controllers. In an example, some components can be controlled by a separate control unit 11 , and some other components can be controlled, for example, by a remote control signal obtained from a cloud. The cloud service will be described in more detail in connection with the following figures.

[0088] The system may further include an internal or external converter (not shown in the figure).

[0089] Via its functionalities, the present invention solves the following issues and problems.

[0090] When applying the device according to the invention, the capacity of an electricity connection can be varied, in a way, dynamically; in other words, the capacity needed does not have to be equal to the capacity of the grid connection 12. The present invention also enables charging of a vehicle 17 significantly more efficiently than via a local grid connection, because the power capacity of both the grid connection 12 and the DC energy storage 14 can be used for a charging session. With this device arrangement, it is possible to achieve charging power several times the connection power. An example of this is the 200 A fuse size for the power distribution grid 12, thus outputting a maximum power slightly higher than 200 kW, whereas a heavy-duty vehicle would be capable of taking in a charging curve peak power of 600 kW. Thus, the DC energy storage 14 can be utilized for the missing power of about 400 kW to obtain the optimal or shortest possible charging time for charging the vehicle 17. This provides a significant advantage when using the device according to the invention. Balancing electricity with respect to the internal network 16 is also possible when applying the present invention. In addition to such a multifunctional charging device, the internal network 16 may also include other electricity consumption points using the same grid connection. For a large charging power, a situation may arise where the whole capacity of the grid connection would be needed for charging. For temporary power consumption peaks in the internal network which exceed the capacity of the grid connection, the multifunctional charging device provides a possibility of supplying a charging session with power from the DC energy storage 14 so that the total capacity of the grid connection is not exceeded, in spite of the other consumption points. One such particular use situation is the power demand of the internal network 16 when the other consumption points exceed the connection capacity even if a charging session were not going on. Thus, the multifunctional charging device can supply the internal network 16 with power from its DC energy storage 14, controlled by the control unit 11, enabling the same power scaling for consumption points not directly connected to the charging device. In this latter situation, the power is converted to alternating current for the internal network 16 by means of a module 13, while power losses are minimized in the internal power optimization of the device by operating directly with the direct current.

[0091] The present invention also makes it possible to participate in the load adjustment market. In addition to the operation of charging a vehicle 17 and optimization of the power demand of the consumption point 16, the charging device can contribute to balancing load variations caused by production and consumption in the external grid (that is, the power distribution grid 12), and meeting possible power demands by, for example, remote control.

[0092] With respect to a reserve market, the device according to the invention makes it possible to support demand flexibility. The device according to the invention can participate in the maintenance of an energy balance in the transmission grid by timing sessions of consumption and grid feed-in under control by the control unit 11. In such situations, the significance of priorities given to the device is noteworthy. In a multi-use situation, the device supports consumption points according to the priority list defined for it. Priorities can also be changed dynamically, if / when considered necessary. The present invention also solves the problem of complexity, that is, multiple components which are widely used in the technical implementation of charging devices of prior art, by simplifying, that is, reducing the number of such components in the arrangement. By this device arrangement according to the invention, unnecessary AC / DC conversions are avoided, whereby fewer components, or modules, are needed in the device assembly. At the same time, the total efficiency of the device is improved, reducing the heat load (that is, thermal losses caused by the modules) and the required capacity of the grid connection.

[0093] Multifunctional charging according to the present invention also supports the green transition and helps with the balancing needs of the green transition, as well as enables full-time use of a significant investment, unlike charging devices of prior art, in which utilization rates remain low and the device is completely passive at times outside charging sessions. On economic grounds, the multifunctional charging device according to the invention reduces costs relating to the purchase and use of the charging device, helping to expedite the transition to electric traffic, and to maintain the costs of electricity connections needed for charging devices at a reasonable level. This is achieved by the described optimization of the technical structure of the device according to the invention (that is, by using fewer components and reducing losses compared with devices of prior art), and by enabling the utilization of the device for more functions than present “single purpose” charging devices. In terms of income streams, such a multifunctional charging device according to the invention deploys - unlike energy sale by charging devices of prior art - a number of services by which profits can be made from the operation of the device, even irrespective of charging sessions. Such a device can be considered to be available and in use 24 / 7 in points where charging sessions are not going on all the time or not even regularly. Such an approach supports the transition to electric traffic when the construction of infrastructure does not require a critical mass for charging sessions and for the number of vehicles using the charging device.

[0094] The multifunctional charging device can also be connected to a grid connection having a capacity lower than the charging capacity. This has positive impact on the following: The costs of the electricity connection normally remain lower than for a full-capacity grid connection, and clearly more locations can be found, and faster, for this type of a charging device than for a charging device which requires a grid connection of higher capacity or an increase in the capacity of the grid connection. This latter alternative very often has to be approved and implemented in cooperation with the grid companies and may involve unexpected problems of scheduling the introduction of the charging device.

[0095] Figure 2 shows an example of a multifunctional charging device 20 according to the invention, wherein external data can be introduced in the system via a cloud service.

[0096] In the device arrangement example shown herein, modules 11 to 18, that is, a control unit 11 , a power distribution grid (AC) 12, an AC / DC inverter 13, a DC electric energy storage 14, a DC / DC inverter 15, other electric loading at the consumption point and local production 16, a chargeable electric vehicle 17, and a charging point 18 for the vehicle, are quite similar to the elements already presented in connection with Fig. 1 , with corresponding functionalities and connections with respect to the actual transmission of electric energy as well as the control signals, i.e. data flows, relating to the operation of the device.

[0097] An addition in this embodiment is a cloud service 21 which is arranged in bidirectional communication with the control unit 11 and behind which various external data sources 22 can be accessed by the device, to be processed by the control unit 11. The cloud service 21 may also be arranged in a data connection with parameters of the power distribution grid (AC) 12. Said external data sources 22 may be in the form of a data base or data bases, for example, or they may be in the form of single stored data records which can be transmitted in a message from the external data source to the cloud service 21. Such external data sources or data bases 22 may comprise, for example, spot prices on the electricity market, weather forecasts on e.g. local or national level, advance information on future power needs, or advance information on the state of the power distribution grid 12. The block chart of Fig. 2 for a multifunctional charging device 20, wherein the device is controlled by centralized device control, may be implemented as a physical hardware solution, as a software solution, or as a combination of these two. The device controls can be concentrated in a single device implementation or, alternatively, the device controls can be implemented as a combination of several partial (device) controls. In Fig. 2, electric energy flows are illustrated in blue and data flows in red colour.

[0098] In an example of the invention, a centralized AC / DC conversion is made which is power controlled in two directions, wherein energy in the electric storage can also be re-charged or discharged in the direction of the internal network 16 and the power distribution grid 12. The charging can be controlled at a high or low control frequency, depending on the purpose. Exemplary purposes may include flexibility of consumption in the same electricity connection, optimization of tariffs, trading in electricity at spot prices to an external grid, or balancing of the electricity grid by frequency control. Furthermore, the same control unit 11 can be used for management of the DC electric energy storage 14, the state of the device and the control of charging, and it is also possible to take into account information from external data sources 22 when making decisions on prioritization regarding the use of the charging device (when defining the priority for different uses).

[0099] Centralized device control is used for controlling the charging of a vehicle 17 on the basis of information obtained from the vehicle by directing energy from the DC electric energy storage 14 via the DC / DC converter 15 to the charging of the vehicle 17. The centralized device control prioritizes the functions of the device according to the priorities of the user or the party responsible for the control of the device. These priorities may vary at different times. Prioritization can be implemented on the basis of, for example, total return, time of charging a vehicle, or purchase price of electricity. The device may also be used a reserve power supply, in which case the DC electric energy storage 14 (having a given stored energy capacity at all times) is used on the basis of an energy reserve. The prioritization may also be based on other factors, that is, some other parameters or a desired purpose. Consequently, the control unit 11 collects internal status and measurement data of the device according to the invention, from several internal and / or external sources, where necessary. In this way, the device assembly comprising the multifunctional charging device and the vehicle 17 connected to it becomes part of a smart energy concept which takes not only internal needs but also external needs into account.

[0100] In terms of environmental efficiency, the multifunctional device according to the invention reduces average emissions caused by electricity production, by means of balancing out consumption peaks in the power grid and storing energy. When consumption peaks in the power grid are balanced either by controlling the consumption or by providing the power distribution grid 12 with adjustment power from the DC electric energy storage 14, it is possible to avoid the deployment of reserve production (that is, auxiliary power sources) in the energy system. Typically, such production of electricity by auxiliary power sources is more expensive and causes higher levels of emissions than production of electricity on the average (that is, in a normal situation). Replacing or reducing the use of such auxiliary power sources decreases the emission factors of the whole energy system. This a significant ecological advantage.

[0101] In conclusion, it can be seen that the multifunctional charging device according to the invention performs functions in three physical directions (charging direction, internal network, external / distribution grid) from the centralized device implementation, whereas charging devices of prior art are only capable of taking into account the demand in the direction of the vehicle during the charging session, and remain inactive the rest of the time.

[0102] Figure 3 shows yet another example of a multifunctional charging device 300. Some of the functional components and elements to be presented correspond to the components shown in the preceding Figs. 1 and 2, but some functional units of a new type are included. Transmission of electric energy between the components is illustrated with broken line arrows. Transmission of control signals and data between the components, in turn, is illustrated by solid line arrows.

[0103] In this embodiment, the components of the system according to the invention include a power distribution grid 303, an electric energy storage 305, a system controller 302, and a vehicle charging point (which may also be called a satellite) 307. Auxiliary components and elements include external data available in a cloud service 301, an AC / DC inverter (or a bidirectional converter) 304, a DC / DC inverter 306, an electric vehicle 311 to be charged, other consumption of AC electric energy at a consumption point 308, possible self-generation of electricity 309, as well as other uses of DC electricity at a consumption point 310. The electric energy storage 305 is thus an energy storage for direct current (DC).

[0104] Figure 3 shows (with broken lines) all the connections between the elements where transmission of electric energy can take place. From AC to DC, the chain includes the power distribution grid 303, the AC / DC inverter 304, the electric energy storage (direct current storage) 305, the DC / DC inverter 306, and the satellite 307, to which the electric vehicle 311 can be connected for normal charging or rapid charging. In addition, the system may be supplied, as an input, with possible self-generation of electricity 309 which may be, for example, a solar panel (or panel system) connected to the consumption point. In view of the logic of the system, the DC consumption points 310 are paralleled with the DC electric energy needed by the electric vehicle 311. The AC consumption points 308 are naturally connected to the AC terminal of the arrangement, as shown in Fig. 3. The controller 302, or the control unit, controls the elements 303 to 307 (these controls are shown by solid lines in the figure). Furthermore, the controller 302 may also control the operation of the DC electricity consumption points 310. The controller 302 may be provided with access to external data and other necessary parameters via the cloud service 301. External data sources of many types can be stored in the cloud, such as weather forecasts, prices on the electricity market, including forecast spot prices in the near future, advance information on future power needs (relating to charging or the state of the power distribution grid), advance information on the state of the power distribution grid 303, etc. Data stored in the cloud 301 can be updated at predetermined times or, for example, at regular intervals (such as, for example, once an hour). This data can be used for smart control of the system according to the invention so that it is possible, for example, to optimize the purchase price of electric energy taken from the grid, and / or, on the other hand, to compensate for possible peaks in electricity consumption. Thus, the controller 302 is arranged to smartly control the electric energy flows in the system to achieve the advantages listed elsewhere in this description (or at least one of them).

[0105] In an embodiment of the invention, the self-generation of electricity 309 can also be connected to the controller 302 so that the self-generation of electricity can be controlled via the control logic and, on the other hand, the production parameters of the self-generation of electricity can be made accessible to the control logic, where necessary.

[0106] In an embodiment of the invention, the controller 302 or control logic can be connected to all the elements of the system shown in the figures, but the control signal can be selected to be sent to only the desired elements at different times. Also, data transmission from the elements to the controller 302 or the control logic can be implemented from all the elements or, for example, only some of the elements used, when looking at a specific moment of operation. In this way, the transmission of control signals and data can be arranged, in principle, bidirectionally (that is, the control signal from the controller and, where necessary, measured data or used system parameter to the controller) between the controller 302 and any other element in the system, in an example of the invention.

[0107] In the following, features and advantages of different embodiments of the invention with respect to prior art will be described in more detail.

[0108] The present invention enables multifunctional use of the charging device, which further enables increasing the capacity utilization rate of the charging device from use only during a charging session to a level close to 100 percent.

[0109] Consequently, the invention also has the advantage of being capable of providing added value by increasing the operating time from merely the charging session to periods when no electric vehicle is connected to the charging point for a vehicle to be charged.

[0110] The present invention contributes to the implementation of the green transition. In this context, the described vehicle charging device which, by its charging function as such, has a consuming effect and causes a need for balancing the power grid, is capable of compensating for more than the consumption effect of the charging device would be as such; in other words, the device can be made to compensate for effects caused in the power grid, even more than the device consumes. In this way, the described multifunctional charging device, by balancing its own effect in the power grid, is capable of reducing emissions caused by electricity production, for example by replacing reserve power plants using fossil fuels with so-called clean electricity.

[0111] In the device according to the present invention, it is also possible to reduce the number of components which, in turn, reduces the risk of failure, costs, and power losses.

[0112] Furthermore, modular AC / DC conversion, which is responsible for power control in charging devices of prior art, is replaced by battery modules in the present invention.

[0113] Moreover, the invention avoids power losses between the DC electric energy storage and the charger ( / .e. charging device) by removing AC / DC and DC / AC conversions.

[0114] In the invention, device management is centralized, because the control unit can be configured as a centralized control element for the whole assembly.

[0115] By means of the invention, it is possible to reduce operative costs of grid connections (including power and capacity costs), which creates a new way of earning by compensations from balancing in the internal and external networks and by participating in the electricity market (trading and balancing).

[0116] The present invention also enables bidirectional use of the battery pack via two inverters in two different directions. From the same terminals of the battery pack, power can be drawn in two directions by connecting power from the battery pack, the charging direction, and the grid connection according to a separately determined priority (order of importance list).

[0117] The scope of protection of the present invention is defined by the appended claims.

Claims

Claims1. Multifunctional energy storing charging system (10, 20, 300), comprising:- an AC / DC inverter (13, 304),- a DC electric energy storage (14, 305),- a DC / DC inverter (15, 306),- a charging point (18, 307) for an electric vehicle, wherein- the AC / DC inverter (13, 304) and / or the DC electric energy storage (14, 305) acts as an interface to a power distribution grid (12, 303), to other electric loading and to local electricity production (16, 308, 309, 310),- DC electric energy can be transmitted between the AC / DC inverter (13, 304) and the DC electric energy storage (14, 305),- DC electric energy can be transmitted between the DC electric energy storage (14, 305) and the DC / DC inverter (15, 306),- one terminal of the DC / DC inverter (15, 306) is connected to the charging point (18, 306) for an electric vehicle, and- an electric vehicle (17, 311) can be connected to the charging point (18, 307) for an electric vehicle, characterized in that- the multifunctional energy-storing charging system (10, 20, 300) is arranged to be controllable so that the multifunctional energy-storing charging system (10, 20, 300) operates, in terms of transmission of electric energy, either unidirectionally or bidirectionally between network elements consuming AC electric energy and the DC electric energy storage (14, 305), irrespective of whether the electric vehicle (17, 311 ) is connected to the charging point (18, 307) for an electric vehicle to be charged, or not, and the DC electric energy storage (14, 305) is used as an interface to other DC electric loads (310) of the consumption point, wherein the other electric loads (310) comprise at least one other battery, and wherein two or more charging points (18, 30) for an electric vehicle are connected to the DC electric energy storage (14, 305) via a DC / DC inverter (15, 306) for each charging point (18, 307).

2. The multifunctional energy-storing charging system according to claim 1 , characterized in that the multifunctional energy-storing charging system (10, 20, 300) further comprises a control logic, which may be implemented in the form of a control unit (11 , 302), or the control logic may be distributed over several locations within the multifunctional energy-storing charging system (10, 20, 300).

3. The multifunctional energy-storing charging system according to claim 2, characterized in that the control unit (11 , 302) is configured to control at least one of the following: the AC / DC inverter (13, 304), the DC electric energy storage (14, 305), the DC / DC inverter (15, 306), and the charging point (18, 307) for an electric vehicle.

4. The multifunctional energy-storing charging system according to claim 2, characterized in that the DC / DC inverter (15, 306) is arranged to convert the direct voltage and direct current provided from the output of the DC electric energy storage (14, 305) to a level suitable for the electric vehicle (17, 311 ), under control by the control unit (11 , 302).

5. The multifunctional energy-storing charging system according to claim 2, characterized in that the charging point (18, 307) for an electric vehicle is arranged to be controlled by the control unit (11 , 302), to communicate with the electric vehicle (17, 311) connected to be charged, to transmit the output DC electric energy obtained from the DC / DC inverter (15, 306) to the electric vehicle (17, 311 ), and to act as an interface for users of the charging point (18, 307) for an electric vehicle.

6. The multifunctional energy-storing charging system according to claim 2, characterized in that the control logic is arranged, based on the devices connected and the measurement data obtained from them, to prioritize operations to be carried out in the multifunctional energy-storing charging system (10, 20, 300) according to at least one of the following: operating conditions of the devices, needs to recharge the DC electric energy storage (14, 305) and the electric vehicle (17, 311), state of internal and external networks, and / or other external data sources (22).

7. The multifunctional energy-storing charging system according to claim 2, characterized in that the control logic is arranged to obtain part of the charging power needed by the electric vehicle (17, 311) from the DC electric energy storage (14, 305) and part from the power distribution grid (12, 303).

8. The multifunctional energy-storing charging system according to claim 2, characterized in that in a situation of higher consumption demand in the local internal network, the control logic is arranged to direct electric energy from the DC electric energy storage (14, 305) via the AC / DC inverter (13, 304) inversely to the local internal network (16).

9. The multifunctional energy-storing charging system according to claim 2, characterized in that if necessary, the control logic is arranged to direct surplus electric energy from the DC electric energy storage (14, 305) to the power distribution grid (12, 303) via the AC / DC inverter (13, 304).

10. The multifunctional energy-storing charging system according to claim 2, characterized in that the control unit (11 , 302) obtains information about the electric loading conditions, the conditions on the electricity market, and forecast data relating to these, and the control unit (11 , 302) is arranged to set up a priority list for various electric energy consumption points.

11. The multifunctional energy-storing charging system according to claim 2, characterized in that the control unit (11 , 302) is connected to a cloud service (21, 301) comprising external data sources and / or databases (22), comprising spot prices on the electricity market, weather forecasts, advance information on the state of the power distribution grid (12, 303), and / or advance information on future needs relating to charging or on power needs relating to the state of the power distribution grid (12, 303).

12. The multifunctional energy-storing charging system according to claim 10, characterized in that the priority list is set up on the basis of total output and / or the desired charging time of an electric vehicle (17, 311 ) and / or purchase price of electricity, and the priority list can be set to vary as a function of time.

13. The multifunctional energy-storing charging system according to claim 1 , characterized in that the AC / DC inverter (13, 304) acts as an interface to the power distribution grid (12, 303), to other AC electric loading (16, 308) of the consumption point, and to local electricity production (16, 309).

14. A method for using a multifunctional energy-storing charging system (10, 20, 300), the method comprising the following steps:- providing the multifunctional energy-storing charging system (10, 20, 300) with an AC / DC inverter (13, 304), a DC electric energy storage (14, 305), a DC / DC inverter (15, 306), and a charging point (18, 307) for an electric vehicle, wherein- the AC / DC inverter (13, 304) and / or the DC electric energy storage (14, 305) acts as an interface to a power distribution grid (12, 303), to other electric loading and to local electricity production (16, 308, 309, 310),- DC electric energy can be transmitted between the AC / DC inverter (13, 304) and the DC electric energy storage (14, 305),- DC electric energy can be transmitted between the DC electric energy storage (14, 305) and the DC / DC inverter (15, 306),- one terminal of the DC / DC inverter (15, 306) is connected to the charging point (18, 306) for an electric vehicle, and- an electric vehicle (17, 311) can be connected to the charging point (18, 307) for an electric vehicle, characterized in that- controlling the multifunctional energy-storing charging system (10, 20, 300) so that the multifunctional energy-storing charging system (10, 20, 300) operates, in terms of transmission of electric energy, either unidirectionally or bidirectionally between the network elements using AC electric energy and the DC electric energy storage (14, 305), irrespective of whether the electric vehicle (17, 311) is connected to the charging point (17, 311) for an electric vehicle for charging, or not, and that- the DC electric energy storage (14, 305) acts as an interface to other DC electric loading (310) of the consumption point, wherein the other electric loading (310) comprises at least one other battery, and wherein- two or more charging points (18, 307) for an electric vehicle are connected to the DC electric energy storage (14, 305) via a DC / DC inverter (15, 306) corresponding to each charging point (18, 307).

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