Bi-directional charging and discharging of electric vehicle

Abstract

The invention relates to a method (S1-S5) for bidirectionally charging and discharging an electric vehicle (2) equipped with a power battery system (2A) having a power battery (BAT) and a charging and discharging electronics (ELE) provided for charging and discharging the power battery (BAT), in which method the charging and discharging electronics (ELE) are connected to the power battery (BAT) before the charging and discharging process. Determining (S1) a battery charge / discharge loss cost Wbat (WBAT) and a charge / discharge electronic device-charge / discharge loss cost Wel (WELE) of the power battery system; and preventing (S2B) the discharge of the power battery during the charge / discharge process at least for a duration during which the associated discharge gain [pi] dis (PIDIS) is not greater than the two charge / discharge loss costs (WBAT, WELE) by at least one respective predetermined difference (MBAT, MELE) (S2A, S2C), and during the charge / discharge process, preventing (S2B) the discharge of the power battery for at least one duration during which the associated discharge gain [pi] dis (PIDIS) is not greater than the two charge / discharge loss costs (WBAT, WELE) by at least one respective predetermined difference (S2A, S2C). The battery charge / discharge loss cost is calculated according to formula (I), and the electronic device-charge / discharge loss cost is calculated according to formula (II), where Cbat represents the purchase cost of the power battery, Eraated represents the estimated rated total energy throughput of the power battery, Edis represents the energy throughput during the discharge, Cel represents the purchase cost of the charge / discharge electronic device, and Ebat represents the estimated rated total energy throughput of the power battery. Lrate represents an estimated rated operating life of the charge-discharge electronic device, and tdis represents a duration of the discharge. # imgabs0 #

Description

Technical Field

[0001] The present invention relates to a method for bidirectional charging and discharging of an electric vehicle equipped with a power battery. In this method, the charging and discharging loss cost of the power battery is determined, the discharging income for discharging the power battery is determined, and when the discharging income is not greater than the charging and discharging loss cost of the battery, discharging is blocked at least during the time period of this condition. The present invention also relates to an electric vehicle having a power battery system, the electric vehicle being configured to perform bidirectional charging and discharging of the power battery of the electric vehicle, and the electric vehicle being configured to implement the method. In addition, the present invention relates to a system including an electric vehicle and an external data processing supervisor communicably coupled to the electric vehicle, the system being configured to implement the method. The present invention can be advantageously applied especially to electric vehicles with pure electric drive. Background Art

[0002] US10026134B2 discloses a method for charging and discharging planning of an electric vehicle at a time-of-use price in a local energy network (also referred to as a "microgrid"). The method includes: determining the system structure of the microgrid and the characteristics of each unit; establishing an optimized planning objective function of the microgrid at a time-of-use price considering the depreciation cost of the battery of the electric vehicle; determining the limitations of each allocated generator and each battery of the electric vehicle, and forming an optimized planning model of the microgrid together with the optimized planning objective function of the microgrid; at a time-of-use price, determining the amount, start and end times, start and end state of charge, and other basic calculation data of the electric vehicle using the microgrid; determining the charging and discharging power of the electric vehicle when connected to the microgrid, in such a way that the optimized usage planning model of the microgrid is solved by means of a particle swarm optimization algorithm. The depreciation cost C of the battery of the electric vehicle BAT is calculated according to the following formula:

[0003]

[0004] C REP represents the battery replacement cost, E PUT represents the total energy throughput during the life of the battery, t1 and t2 represent the start and end times of the connection time period on the microgrid, and P represents the charging or discharging power during the connection time period. For multiple electric vehicles, the corresponding sums are formed.

[0005] CN109713696B addresses the daily optimization planning problem of a photovoltaic charging station system for charging electric vehicles, and creates a cycle life model of the power battery based on the empirical data of the battery and using the B-spline curve interpolation function. On this basis, an optimized "one-day-ahead planning" method is proposed, which takes into account the impact of the battery life of electric vehicles on the discharge behavior of users in the V2G mode. The photovoltaic charging station for electric vehicles is located in a residential area and supplies electric energy to the electric vehicle through slow charging. During the peak time of the electricity price, the electric vehicle can sell electricity to the public energy supply network to obtain income. At this time, the V2G discharge loss cost of the power battery, which is connected to the photovoltaic charging station during the peak time of the electricity price, is considered. The V2G discharge loss cost W takes into account the current state of charge and the ambient temperature of the power battery. The V2G discharge loss cost can be calculated by the following formula:

[0006]

[0007] C Z represents the acquisition cost of the power battery, Γ represents the current throughput of the power battery, L represents the battery life, and C R represents the rated capacity of the power battery. The (current) battery life L is a function of the rated life, the current state of charge, and the current ambient temperature.

[0008] The discharge loss cost is compared with the feed-in income paid by the public energy supply network. If the discharge loss cost of the electric vehicle is higher than the feed-in income, then the user of the electric vehicle does not participate in the V2G mode; otherwise, the user participates in the V2G mode and supplies energy to the public energy supply network during the peak time. Summary of the Invention

[0009] The object of the present invention is to at least partially overcome the defects of the prior art, and in particular to provide a particularly simple possibility: considering the battery charge and discharge loss cost when the power battery of an electric vehicle discharges.

[0010] The above object is solved by the features of the independent claims. Preferred embodiments are particularly apparent from the dependent claims.

[0011] The above object is solved by a method for bidirectional charging and discharging of an electric vehicle equipped with a power battery system, the power battery system having a power battery and a charge and discharge electronic device arranged for charging and discharging the power battery (i.e., charging and discharging), in the method

[0012] - determining the battery charge and discharge loss cost W of the power battery system bat and the charge and discharge electronic device - charge and discharge loss cost W ele ; and

[0013] - During charging, prevent the discharge of the power battery for at least the following duration, at which the discharge benefit is not greater than at least one corresponding predetermined difference over the two charge-discharge loss costs;

[0014] Wherein, the battery charge-discharge loss cost is calculated according to the following formula:

[0015]

[0016] And the electronic device - charge-discharge loss cost is calculated according to the following formula:

[0017]

[0018] Wherein, C bat represents the acquisition cost or value of the power battery, E rated represents the estimated (rated) total energy throughput of the power battery over its lifetime, △E dis represents the energy throughput during discharge, C ele represents the acquisition cost or value of the electronic device components (the "charge-discharge electronic device") that are in operation for the charge-discharge (i.e., charging and discharging) process, L rated represents the estimated (rated) operating life of the charge-discharge electronic device, and △t dis represents the duration of discharge. The charge-discharge electronic device includes, for example, battery electronic devices and / or other vehicle components that operate for the charge-discharge process.

[0019] The estimated rated total energy throughput E rated is usually known, for example, determined by the manufacturer. The estimated (rated) operating life L of the charge-discharge electronic device rated is also determined and typically includes the number of operating hours that the charge-discharge electronic device can nominally operate within its lifetime. The (rated) operating life L of the charge-discharge electronic device rated can be expressed, for example, in hours. Typically, from the factory, it is currently approximately 33000 hours in most vehicles.

[0020] The method considers that the power battery and the charge-discharge electronic device form components that independently define the lifetime of the power battery system. Specifically, different loss driving factors for the battery and the electronic device are considered, i.e., for the battery, especially the energy throughput is considered, and for the charge-discharge electronic device, especially the operating duration is considered. Therefore, a more accurate estimate of the charge-discharge loss cost can be advantageously estimated by simple measures, and thus a particularly reliable judgment can be made as to whether the discharge process is worthwhile. Therefore, in the above method, when calculating the battery charge-discharge loss cost, the energy throughput △E for the discharge process is considereddis When calculating the charge-discharge loss cost of the electronic device, the operating duration Δt during the discharge process is taken into account. dis .

[0021] When the discharge benefit is not greater than at least a corresponding predetermined difference from the two charge-discharge loss costs, the power battery is prevented from discharging. This can also be expressed as follows: when and only when one of the two charge-discharge loss costs is less than the discharge benefit plus the corresponding predetermined difference, the discharge of the power battery is prevented; or when the discharge benefit is greater than at least the corresponding predetermined difference from the two charge-discharge loss costs, the power battery is discharged during the charge-discharge process. This can be achieved, for example, such that a discharge phase that would otherwise occur is shortened or even completely prevented.

[0022] The power battery system exists especially as a power battery module and can be installed especially as a unit ("module").

[0023] Bidirectional charge and discharge includes the following possibilities: the power battery of an electric vehicle can be selectively charged or discharged at a charging point. By discharging, the electrical energy extracted from the power battery can be fed, for example, into a public energy supply network (this is also called "vehicle-to-grid", V2G) and / or into a local energy network, such as the energy network of a property (this is also called "vehicle-to-home", V2H). The charge-discharge process here refers to the charge-discharge operation carried out during the connection period of the electric vehicle at the charging point. The charge-discharge process can have at least one charging phase, at least one discharge phase and perhaps also at least one stationary phase without charge and discharge (that is, without charging or discharging). The energy throughput ΔE during discharge dis can be calculated by the following formula in the case of a varying discharge power P between the start time t1 and the end time t2 of the discharge process dis :

[0024]

[0025] The electric vehicle can be a hybrid vehicle, such as a plug-in hybrid vehicle PHEV, or can be a purely electric-driven vehicle BEV. The electric vehicle can be charged and discharged via a charging point, that is, can be charged or discharged, and the charging point is also configured for bidirectional charge and discharge. The charge and discharge can be carried out via a charging cable or inductively. The charging point can be, for example, a public charging station, a wall box or an inductive parking space.

[0026] One extension is that the charge and discharge loss cost is determined before the charge and discharge process. This significantly simplifies the calculation of the charge and discharge loss cost of the battery in particular. Here, the charge and discharge loss cost can be calculated after identifying an upcoming charge and discharge process (e.g., triggered due to a desired charge and discharge process, e.g., by coupling an electric vehicle to a charging point), but can also be determined independently of a specific charge and discharge process.

[0027] The method can be particularly advantageously applied in the following cases: For a charge and discharge process, a charge and discharge plan with at least one discharge stage is drawn up, and the braking vehicle together with the discharge duration for the charge and discharge process is known in advance. If the discharge benefit is lower than the corresponding charge and discharge loss cost, then in one extension the discharge stage is not implemented. If the charge and discharge plan is updated, the method can be similarly applied thereto.

[0028] If the charge and discharge plan is drawn up by a management unit outside the vehicle, such as an energy management system, and the electric vehicle can communicate with this external management unit (e.g., via the charging point when connected to the charging point), then in one extension, the parameters C bat 、E rated 、C ele and L rated can be transmitted to the management unit outside the vehicle, such that the management unit can draw up a charge and discharge plan that takes into account the discharge benefit and the charge and discharge loss cost in addition to the prediction data, and only plans the discharge stage when it is worthwhile. One extension is that the electric vehicle is connected to a charging point and a charge and discharge plan is drawn up, where for at least the following time segment or time period of the connection time period, no discharge can be specified: in this time segment, the discharge benefit is not greater than the charge and discharge loss cost by at least a predetermined difference. The electric vehicle can then charge and discharge according to this charge and discharge plan. In particular, the parameters C bat 、E rated 、C ele and L rated are set to be constant over the duration of the charge and discharge plan.

[0029] The discharge benefit Π dis in particular corresponds to the economic benefit or gain generated by releasing electrical energy during discharge. In the case of V2G, the discharge benefit corresponds, for example, to the feed-in remuneration determined by the operator of the energy supply network. The discharge benefit can be stated, for example, in euros or in euros per kilowatt-hour. The discharge benefit can be constant or fluctuate over the connection time period during which the electric vehicle at the charging point can be used to carry out the charge and discharge process, for example, fluctuate according to the clock time.

[0030] Condition: The discharge benefit Π dis is not greater than the battery charge and discharge loss cost Wbat exceeds by at least a predetermined difference M bat can also be described as Π dis >W bat +M bat . For the difference M bat , M is applicable bat ≥0, so in an extended scenario, M is also bat =0. M bat =0 includes the following cases: When the discharge benefit Π dis is greater than the battery charge-discharge loss cost W bat , discharging is worthwhile for the user. When M bat >0, discharging is only worthwhile for the user when the discharge benefit is significantly greater than the battery charge-discharge loss cost (i.e., the large difference M bat ). Therefore, for example, it can be considered that discharging can extend for a duration until charging to the desired state of charge of the power battery. The above conditions can be similarly applied to an electronic device with a difference M ele -charge-discharge loss cost W ele . In an extended scenario, M bat =M ele , alternatively, M bat ≠M ele .

[0031] A simple example calculation should illustrate the method: An electric vehicle is connected to a charging point and should be charged and discharged during this period with a charge-discharge plan that specifies a discharge duration Δt of 2 hours dis . (C ele / L rated ) is 0.5 euros per hour. The charge-discharge loss cost W of the charge-discharge electronic device ele is then 1 euro for a 2-hour discharge. Ignoring the difference M ele , from the perspective of the charge-discharge electronic device, discharging is only worthwhile and thus permitted during the connection period if the discharge benefit Π dis is greater than 1 euro.

[0032] Regarding the battery charge-discharge loss cost W batt , it should be (C bat / E rated ) = 0.1 euro / kWh. If the energy throughput ΔE dis generated during discharge is 20 kWh, then the battery charge-discharge loss cost W bat = 2 euros. Ignoring the difference M bat , when the discharge benefit Π disWhen it is greater than 2 euros, from the perspective of the power battery, discharging is worthwhile and thus permitted. On the contrary, if the discharging generates an energy throughput ΔE dis of 100 kWh, then the battery charge-discharge loss cost W bat = 10 euros, and when the discharging profit Π dis is greater than 10 euros, discharging is worthwhile and thus permitted during the charge-discharge process.

[0033] One solution is that the rated total energy throughput E rated is adapted or modified by means of at least one influencing parameter that affects the loss, especially the aging, of at least one power battery. Thus, the battery charge-discharge loss cost W bat is more realistically calculated, which is particularly advantageous when the actual use of the power battery significantly deviates from the use characteristics estimated or assumed at the beginning in order to determine the rated total energy throughput E rated .

[0034] One solution is that the rated total energy throughput E rated is adapted in relation to at least one influencing parameter from the following set of influencing parameters:

[0035] - The battery temperature during the charge-discharge process;

[0036] - The battery temperature during parking;

[0037] - The power of the charge-discharge process or the discharging process;

[0038] - Aging over calendar time. The older the power battery, the smaller the trend of E rated can be estimated;

[0039] - The average storage filling degree; and / or

[0040] - The parking time with a high storage filling degree.

[0041] One solution is that the rated operating life L rated of the charge-discharge electronic device is adapted or modified by means of at least one influencing parameter that affects the loss, especially the aging, of the charge-discharge electronic device. Thus, the charge-discharge electronic device - charge-discharge loss cost W ele can be adapted to the actual use characteristics of the electric vehicle, which is particularly advantageous when the actual use of the charge-discharge electronic device significantly deviates from the use characteristics estimated or assumed at the beginning.

[0042] One solution is that the rated operating life L rated is adapted in relation to at least one influencing parameter from the following set of influencing parameters:

[0043] - The number of charge-discharge phases or charge-discharge cycles;

[0044] - The power during the charge-discharge process (i.e., the charging and discharging processes);

[0045] - Aging according to calendar time;

[0046] - The temperature during the charge-discharge process. The higher the temperature during operation on the charge-discharge electronic device, the stronger the aging of the charge-discharge electronic device;

[0047] - The temperature during parking time.

[0048] One solution is that the electric vehicle is connected to a charging point (especially a wall box) of a local energy network (especially a home network) to perform the charge-discharge process, and the "charging point"-charge-discharge loss cost W generated during discharge of the charging point EVSE is calculated according to the following formula:

[0049]

[0050] where C EVSE corresponds to the acquisition cost or value of the charging point or the electronic device of the charging point, L EVSE,rated corresponds to the estimated (rated) operating life of the charging point, especially the electronic device of the charging point, and Δt dis corresponds to the discharge duration. This is similar to the charge-discharge electronic device-charge-discharge loss cost W ele , especially because in the case of the charging point, the life of the electronic device of the charging point is the limiting influencing parameter. The charging point-charge-discharge loss cost W EVSE can be considered, for example, in the following way: Instead of W ele , the sum W SYS = W ele +W EVSE is compared with the discharge revenue Π dis , and if the discharge revenue Π dis is not greater than the charge-discharge system-charge-discharge loss cost W SYS by at least a predetermined margin, then discharging is blocked at least during the time period of this condition during the charge-discharge process. The solution advantageously extends the consideration of the charge-discharge electronic device-charge-discharge loss cost to the losses that also occur at the charging point. This is particularly advantageous when the user of the electric vehicle corresponds to the operator of the local energy network, such as a homeowner. The solution can be implemented similarly to the aspects described above.

[0051] One solution is the acquisition cost C bat , C ele and / or C EVSEand / or rated parameter E rated 、L rated and / or L EVSE,rated are regularly adapted. Thus, the charge and discharge loss costs can be advantageously adapted to the actual usage characteristics without incurring a significantly increased computational expense. In particular, the adaptation can be carried out at predefined intervals in time, especially at the same intervals, such as every hour, or after a number of hours, such as 12 hours, at intervals of days, weeks or months, and in particular is not event-controlled, for example because a charging process is queued. In this case, it is fully utilized that, especially after a period of time since the first use of the power battery system and / or the charging point, the relatively large deviation from the hitherto usage characteristics that also only occurs at a later time does not suddenly affect the charge and discharge loss costs, so that the hitherto effective charge and discharge loss costs always remain effective with high precision.

[0052] One option is that C bat 、C ele and / or C EVSE and / or rated parameter E rated 、L rated and / or L EVSE,rated are adapted by means of an external data processing authority that can be communicatively coupled to the electric vehicle. This has the advantage that the computational power for adapting the above-mentioned parameters does not need to be provided by the electric vehicle. More precisely, an external data processing authority, such as a web server or a cloud computer, which provides high computational power, can be used. This also simplifies the potential adaptation of the rated parameters by means of more complex calculations. Specifically, values or data regarding at least one influencing parameter can be transmitted from the electric vehicle and / or the charging point to the external data processing authority, which then calculates the correspondingly adapted rated parameters. These adapted parameters can be transmitted to the electric vehicle and / or another authority, which can draw up a charge and discharge plan for the electric vehicle, for example the other authority is a charging point and / or an energy management system. In addition, the acquisition costs and / or the rated parameters can be advantageously managed and adapted centrally by means of the external data processing authority, for example by taking into account the changing costs or values etc. on the market of the power battery or the charge and discharge electronics.

[0053] The method can be applied analogously to a plurality of simultaneously considered electric vehicles ("pooling"). When a plurality of electric vehicles are pooled, the sum of the individual electric vehicles defines the loss costs.

[0054] The task is also solved by an electric vehicle having a power battery system, which is configured to charge and discharge the power battery of the electric vehicle bidirectionally, and which is configured to carry out the method as described above. The electric vehicle can be configured similarly to the method, and vice versa, and has the same advantages.

[0055] Furthermore, the task is solved by a system which comprises an electric vehicle as described above and an external data processing supervisor which can be communicatively coupled to the electric vehicle, which is configured to adapt at least one acquisition cost among the acquisition costs and / or at least one rated parameter among the rated parameters, and which is configured to carry out the method as described above. The system can be configured similarly to the electric vehicle and / or the method, and vice versa, and has the same advantages.

[0056] One embodiment is that the system additionally has: a local energy network which comprises a charging point which is configured to charge and discharge the electric vehicle bidirectionally; and at least one renewable energy generation device, wherein the discharge proceeds are determined taking into account the energy fed into the local energy network by the energy generation device and / or the energy subscription / feed-in tariff to / from the public power grid. The following advantage is thus achieved: when the local energy network is equipped with a stationary storage device, the vehicle can also be charged at the energy generation device and perhaps also from the storage device. This allows for a particularly efficient use of electrical energy to supply loads connected to the local energy network, such as the loads of a real estate property such as a single-family house, and allows for feeding into the public energy distribution network.

[0057] The renewable energy generation device can be, for example, a wind power device or a photovoltaic device. Description of the Drawings

[0058] The above-described properties, features and advantages of the invention and the ways and means of how to achieve them become more clearly and distinctly understandable in connection with the following schematic description of embodiments, which are explained in more detail in connection with the drawings.

[0059] Figure 1 Schematic diagram showing a charging infrastructure for charging and discharging an electric vehicle; and

[0060] Figure 2 Showing the possible process for Figure 1 developing a charging and discharging plan with the charging infrastructure. Detailed Description

[0061] Figure 1Shows a schematic diagram of a charging infrastructure 1 for charging and discharging an electric vehicle 2, which is equipped with a power battery system 2A. The power battery system 2A has a power battery BAT and a charge and discharge electronic device ELE as components. The charging infrastructure 1 includes a real estate property, which is a single-family house 3 in this example. This real estate property has a local energy network ("home energy network 4") for supplying current to electrical end loads 5. Additionally, a photovoltaic device 6, a stationary electrical storage device ("fixed memory 7"), and a charging point in the form of a wall box 8 are integrated into the home energy network 4. The fixed memory 7 can be integrated into the photovoltaic device 6 in an extended scenario. The home energy network 4 is connected to a common power grid or energy supply network 10 via a measurement point or grid connection point in the form of a so-called "smart meter" 9, for example.

[0062] The electric vehicle 2 can be connected to the wall box 8 for bidirectional charging and discharging (i.e., selectively charging and discharging), for example via a charging cable. Then, within a certain range of charge and discharge parameters, the electric vehicle can be used as a storage device for the home energy network 4 and accordingly charge and discharge. The wall box 8 and the electric vehicle 2 can exchange data, for example, through standards ISO15118-2 and / or ISO15118-20. In particular, the wall box 8 can receive charge and discharge parameters from the electric vehicle 2, such as battery capacity, stated or estimated departure time, target SoC at the departure time, maximum charge and discharge power, minimum SoC to be adhered to, and so on.

[0063] The home energy network 4 also includes an energy management system ("home energy management system or HEMS 11"), which is configured to control the charge and discharge processes of the fixed memory 7 and the charge and discharge processes of the power battery BAT that serves as a storage device when connected. If possible, the HEMS 11 is connected in data technology to at least one of the load 5, the photovoltaic device 6, the fixed memory 7, and the wall box 8, as indicated by the dashed line. Here, the HEMS 11 can receive the charge and discharge parameters of the electric vehicle from the electric vehicle 2 through the wall box 8 or also directly. In the current exemplary assumption, the smart meter 9 is connected to the wall box 8 in data technology. Then, in one scenario, the HEMS 11 can be connected to the smart meter 9 in data technology via the wall box 8, for example, and the measurement values of the smart meter can be retrieved. As an alternative or supplement, the HEMS 11 can be directly connected to the "smart meter" 9 in data technology. Generally, instead of the smart meter 9, a private measurement device (not shown) belonging to the single-family house 3 can be used, for example, because the measurement point operator does not use a smart meter but a simple electricity meter, or because the measurement point operator cannot or is not willing to share the measurement data of the smart meter 9 with the user.

[0064] The smart meter 9 is additionally coupled to the measurement point operator 12A in terms of data technology, and the smart meter transmits its measurement data to the measurement point operator, for example. The smart meter 9 can additionally be coupled to at least one energy supplier in the energy market 12B in terms of data technology. The energy supplier supplies or provides energy to the home energy network 4 according to certain - perhaps time - varying - tariff information for taking electricity from the energy supply network 10, and also determines the feed - in price for feeding surplus electrical energy from the home energy network 4 into the energy supply network 10. The energy supplier can transmit tariff information and perhaps other electrical information such as environmental information (e.g., information about the CO2 emissions of the relevant energy) to the smart meter 9, and also transmit current electrical information and / or corresponding electrical information forecasts. The energy market 12B can include, for example, other energy suppliers, energy aggregators, energy markets, network system service markets, external market participants, etc. as additional participants. The participants in the electricity market 12 can cooperate with the grid operator and the measurement point operator, for example.

[0065] Currently, the charging infrastructure 1 additionally has an external supervisor 13, such as a cloud computer or a network server, which serves as the so - called "back - end". The external supervisor 13 can be, for example, an IT system maintained or run by the manufacturer of the electric vehicle 2, and can then also be called the "vehicle back - end". The external supervisor 13 can be directly data - technologically coupled to the electric vehicle 2, the wall box 8, the HEMS 11, and / or the user terminal device 14, such as a mobile user terminal device like a smartphone or a tablet, for example, wirelessly coupled.

[0066] The HEMS 11 can formulate a charge - discharge plan (including charging and discharging) for the fixed memory 7 and the electric vehicle 2 up to the predicted departure time of the electric vehicle 2 based on the prediction of the consumption in the home energy network 4, the prediction of the energy generated by the photovoltaic device 6 (e.g., also in the case of using weather forecasts), and the electrical information transmitted by the participants in the energy market 12B, in order to influence the current flowing through the smart meter 9 for optimizing at least one predetermined objective, such as optimizing costs or minimizing CO2 emissions. The charge - discharge plan formulated by the HEMS 11 for the electric vehicle 2 also takes into account the charge - discharge parameters transmitted by the electric vehicle 2 as charge - discharge boundary conditions. The charge - discharge plan for the electric vehicle 2 can be transmitted from the HEMS 11 to the wall box 8, which then implements the charge - discharge plan together with the electric vehicle 2. Alternatively, the charge - discharge plan can be formulated by the electric vehicle 2, the wall box 8, or the external supervisor 13.

[0067] When formulating the charge - discharge plan, the acquisition cost C of the power battery system 2A bat and C ele and the rated parameter Erated and L rated are considered, and optionally the acquisition cost C of the wall box 8 is also considered EVSE and the rated operating life L EVSE,rated . The parameter C bat 、C ele 、E rated and L rated can be transmitted, for example, from the electric vehicle 2 to the HEMS 11 and / or the external supervisor 13, or these parameters can be stored in the external supervisor 13 and transmitted to the HEMS 11, and so on.

[0068] Figure 2 Shows a possible process for formulating a charging and discharging plan by means of the charging infrastructure 1.

[0069] In step S1, before formulating the charging and discharging plan, the acquisition costs C bat 、C ele and perhaps C EVSE as well as the rated parameters E rated 、L rated and perhaps L EVSE,rated are provided to the HEMS 11 (or another component 2, 8, 13 for formulating the charging and discharging plan).

[0070] In step S2, a charging and discharging plan is formulated, which utilizes information related to the predicted connection duration of the electric vehicle 2 on the wall box 8 and the discharge benefit Π per unit time of the parameter, especially the predicted value. The discharge benefit Π per unit time of the parameter dis can vary over the connection duration, for example, because the feed-in remuneration fluctuates over the clock time and the self-generated energy fluctuates over the clock time, for example, due to fluctuating sunlight incidence, etc. dis Here, in step S2A, when the discharge benefit Π

[0071] 、PI_DIS is not at least a predetermined difference M dis 、M_BAT greater than the battery charge and discharge loss cost W bat 、W_BAT (“no”), then the discharge of the power battery BAT is blocked during the charging and discharging process (step S2B); otherwise (“yes”), then proceed to step S2C. The charging and discharging process can have one or more discharge stages in addition to one or more charging stages. bat In step S2C, it is checked whether the discharge benefit Π

[0072] is at least a predetermined difference M dis greater than the charge and discharge electronic device - charge and discharge loss cost W ele 、W_ELE ele, M_ELE. If this is not the case ("No"), then proceed to step S2B and prevent the power battery BAT from discharging during the charge and discharge process. However, if this is the case ("Yes"), then proceed to step S2D and allow the power battery BAT to discharge. This does not mean that the formulated charge and discharge plan must have a discharge phase, but it can have a discharge phase when the conditions of steps S2A and S2C are both satisfied. If the cost for discharging of the wall box 8 should also be considered, then in step S2C, instead of W ele and M ele , W SYS and M SYS .

[0073] Preventing the power battery BAT from discharging during the charge and discharge process can include that the charge and discharge plan has no discharge phase, or the charge and discharge plan is formulated or modified such that two conditions are satisfied.

[0074] After formulating the charge and discharge plan, the electric vehicle 2 can charge and discharge in step S3 by means of this charge and discharge plan.

[0075] In parallel with steps S1 to S3, in step S4, it is checked by the external authority 13 whether the predetermined calculation duration for calculating or determining the battery charge and discharge loss cost W LS or W bat has elapsed. The calculation duration can be, for example, hours, days, weeks or months. However, if this is not yet the case ("No"), then the check continues.

[0076] However, if this is the case ("Yes"), then in step S5, by means of the external authority 13, based on at least one influencing parameter that affects the losses of the power battery system 2A and possibly the losses of the wall box 8, such as based on the number of charge and discharge cycles, the electric power of the charge and discharge cycles, the aging over calendar time, the parking time with a high memory fill level, the average state of charge and / or temperature (e.g., ambient temperature and / or cell temperature), adapt the acquisition cost and / or rated parameters of the power battery system 2A and possibly additionally adapt the acquisition cost and / or rated parameters of the wall box 8.

[0077] At least some of these influencing parameters can be retrieved or called from the electric vehicle 2 by the external authority 13 during the charging and discharging process of the electric vehicle 2, for example, retrieved directly or via the wall box 8 and / or the HEMS 11. At least some of these influencing parameters can additionally or alternatively be retrieved from the electric vehicle 2 outside the charging and discharging process. The charging and discharging loss costs are thus adapted and provided again in step S1. This provision can include: transmitting the charging and discharging loss costs to the electric vehicle 2, the wall box 8, and / or the HEMS 11.

[0078] It goes without saying that the present invention is not limited to the illustrated embodiments.

[0079] Generally speaking, "one" can be understood as one or more, especially in the sense of "at least one" or "one or more", etc., as long as this is not explicitly excluded, for example, by the expression "exactly one", etc.

[0080] The data can also include exactly the illustrated numbers and can also include the usual error ranges, as long as this is not explicitly excluded.

[0081] List of reference numerals

[0082] 1 Charging infrastructure

[0083] 2 Electric vehicle

[0084] 2A Power battery system

[0085] 3 Single-family house

[0086] 4 Home energy network

[0087] 5 End load

[0088] 6 Photovoltaic device

[0089] 7 Fixed memory

[0090] 8 Wall box

[0091] 9 Smart meter

[0092] 10 Energy supply network

[0093] 11 HEMS

[0094] 12A Measurement point operator

[0095] 12B Energy market

[0096] 13 External authority

[0097] 14 User terminal device

[0098] BAT Power Battery

[0099] ELE Charge and Discharge Electronic Device

[0100] Π dis Discharge Revenue

[0101] M Difference

[0102] S1 - S5 Method Steps

[0103] W_BAT Battery Charge and Discharge Loss Cost W bat

[0104] W LS Charge and Discharge System - Charge and Discharge Loss Cost

Claims

1. A method (S1 - S5) for bidirectional charging and discharging of an electric vehicle (2) equipped with a power battery system (2A), where the power battery system (2A) has a power battery (BAT) and a charging and discharging electronic device (ELE) arranged for charging and discharging the power battery (BAT). In the method, - Before the charge and discharge process, determine (S1) the battery charge and discharge loss cost W of the power battery (BAT) bat (W_BAT) and the charge and discharge electronic device - charge and discharge loss cost W of the charge and discharge electronic device (ELE) ele (W_ELE); and - Prevent (S2B) the discharge of the power battery (BAT) for at least the following duration during the charge and discharge process, at which time the assigned discharge benefit Π dis (PI_DIS) is not greater than the two charge and discharge loss costs (W_BAT, W_ELE) by at least a corresponding predetermined difference (M_BAT, M_ELE) (S2A, S2C); Among them, The battery charge-discharge loss cost W bat (W_BAT) is calculated according to the following formula: And the charge-discharge electronic device - charge-discharge loss cost W ele (W_ELE) is calculated according to the following formula: Among them, C bat represents the acquisition cost of the power battery (BAT), E rated represents the estimated total rated energy throughput of the power battery (BAT) over its lifetime, ΔE dis represents the energy throughput during discharge, C ele represents the acquisition cost of the charge and discharge electronic device (ELE), L rated represents the estimated rated operating life of the charge and discharge electronic device (ELE), and Δt dis represents the duration of discharge.

2. The method (S1-S5) according to claim 1, wherein The rated total energy throughput E rated is adapted by means of at least one influencing parameter which influences the losses of the traction battery (BAT).

3. The method (S1-S5) according to claim 2, wherein, The rated total energy throughput E rated is adaptively matched in relation to at least one influencing parameter among the influencing parameters of the following set: - The number of charging and discharging phases; - The battery temperature during the charging and discharging process; - The temperature during parking; - The power of the charging and discharging process; - Aging according to calendar time; - The average storage filling degree; - The parking time with a high storage filling degree.

4. The method (S1 - S5) according to any one of the above - mentioned claims, wherein, The rated operating life L of the charge-discharge electronic device (ELE) rated is adapted by means of at least one influencing parameter that influences the losses of the charge-discharge electronic device (ELE).

5. The method (S1 - S5) according to claim 4, wherein, The rated operating life L of the charge-discharge electronic device (ELE) rated is adapted in relation to at least one influencing parameter among the influencing parameters of the following set: - The number of charging and discharging phases; - The power of the charging and discharging process or the discharging process; - Aging according to calendar time; - The temperature during the charging and discharging process; - The temperature during the parking time.

6. The method (S1-S5) according to any one of the preceding claims, wherein, The electric vehicle (2) is connected to a charging point (8) of a local energy network (4) - in particular a domestic energy network - in order to carry out a charging and discharging process, and the charging point-charging and discharging loss cost W generated during discharging at the charging point (8) EVSE is calculated according to the following formula: where C EVSE corresponds to the acquisition cost of the charging point (8) or the acquisition cost of the electronic device of the charging point, L EVSE,rated corresponds to the estimated rated operating life of the charging point (8), in particular the electronic device of the charging point, and △t dis corresponds to the duration of the discharge, and during the charge-discharge process, the discharge of the power battery (BAT) is blocked (S2B) at least for the following duration, at which time the discharge benefit Π dis (PI_DIS) is not greater than the sum of the charge-discharge electronic device - charge-discharge loss cost W ele (W_ELE) and the charging point - charge-discharge loss cost W EVSE by at least a predetermined difference (S2C).

7. The method (S1-S5) according to any one of claims 2 to 6, wherein, At least one acquisition cost among the respective acquisition costs and / or at least one rated parameter among the respective rated parameters is regularly adapted.

8. The method (S1-S5) according to claim 7, wherein, At least one acquisition cost among the respective acquisition costs and / or at least one rated parameter among the respective rated parameters is adapted by means of an external data processing authority (13) that can be communicatively coupled to the electric vehicle (2).

9. An electric vehicle (2) having a power battery system (2A), the electric vehicle (2) being configured for bidirectional charging and discharging (S3) of the power battery (BAT) of the electric vehicle, and the electric vehicle (2) being configured for implementing the method (S1 - S5) according to any one of the preceding claims.

10. A system (2, 13), the system comprising the electric vehicle (2) according to claim 9 and an external data processing authority (13) that can be communicatively coupled to the electric vehicle (2), the data processing authority being configured for adapting at least one acquisition cost among the respective acquisition costs and / or at least one rated parameter among the respective rated parameters, the system (2, 13) being configured for implementing the method (S1 - S5) according to claim 8.

11. The system (2, 8, 13) according to claim 10 additionally has: a local energy network (4), which includes a charging point (8) configured to charge and discharge an electric vehicle (2) bidirectionally; and at least one renewable energy generation device (6), wherein, Discharge benefit Π dis (PI_DIS) is determined taking into account the energy fed into the local energy network (4) by the energy generation device (6).

Images