DE102019117582A1 - PROCEDURE AND SYSTEM FOR THE COORDINATION OF CHARGING PROCEDURES FOR ELECTRIC VEHICLES - Google Patents

Abstract

A method is disclosed for the dynamic coordination of charging processes for a plurality of electric vehicles (14, 14 ') which are to be charged via charging points (13) which are connected to a common transformer (11) via a local network (17). With the help of recorded load data of the transformer (11) and received load profile prognoses for other connected loads, an overload profile of the transformer (11) is determined and regularly recorded and updated. Each time a new electric vehicle (14 ') is connected to a charging point (13) in the local network (17), its charging requirement is received, an adapted overload curve (33) is determined and compared with an overload limit value OTH. If this is not exceeded, the charging requirement is approved and the overload profile (33) is updated, otherwise the charging requirement is refused. In the event of a refusal, measures can be taken to relieve the burden that still allow loading in a timely manner. A corresponding system for charging coordination is also disclosed.

Description

The invention relates to a method for the dynamic coordination of charging processes for a plurality of electric vehicles, and to such a system.

The change in the type of drive for motor vehicles from vehicles with internal combustion engines to electrically powered vehicles places considerable new demands on the energy supply, since the energy storage devices of many electric vehicles have to be charged with considerable charging capacities. Delivery services in particular are pioneers in converting their vehicle fleets to electric vehicles, and they rely on the fact that their vehicles can be charged in a short time and in large numbers at the logistics points of the delivery services. The same applies to future charging stations on motorways to serve individual mobility needs.

A resulting power requirement at these logistics points can quickly overload the existing components of the energy supply network, in particular transformers that adapt a network voltage from a high-voltage network to a local network supplying the logistics points, even if the transformers are significantly above their nominal capacity for a certain time higher power can be loaded without being damaged. The overload threshold on a transformer, from which it is excessively damaged, is not firmly defined, but a function of the level and duration of the overload, but also of the previous load, which is usually empirically determined. A dynamic and continuous recalculation of the overload threshold is therefore necessary in order to be able to fully use the available overload margin of a transformer.

Therefore, the requirement arises to forecast the performance curves resulting from the charging of the electric vehicles and to be able to optimally use an overload margin of the transformers by coordinating the charging processes in order to be able to charge as many electric vehicles as possible in a short time. Of course, this requirement does not depend on the application presented above, but also arises when a large number of electric vehicles have to be charged via a common resource such as a transformer. This can also be the case, for example, in a residential area in which private motor vehicles are used as electric vehicles, the residential area being connected to the electrical supply network via a common local network transformer.

The font EP 2,505,421 B 1 discloses a system for planning a power requirement, in which overload data from a transformer and charging requirement data from electric vehicles are received in a central controller and a charging plan is determined there using an overload margin of the transformer. The disadvantage of this method is that the charging requirements of all vehicles in the charging plan to be created must be available before the method can be carried out.

In practice, there is a requirement to be able to create the site plan dynamically, since the electric vehicles are connected to their charging point for charging at different times and their charging requirements are accordingly known at different times. When connecting the electric vehicle, it should also be possible to reliably determine whether and to what extent the charging requirement of the electric vehicle can be satisfied. In addition, it should be ensured that the power requirements of other loads in the local network can be satisfied.

The invention is based on the object of being able to meet this requirement that exists in practice.

This object is achieved by a method with the features of independent claim 1 and by a system with the features of independent claim 7. The dependent claims describe preferred embodiments.

A method according to the invention for the dynamic coordination of charging processes for a plurality of electric vehicles that are to be charged via charging points that are connected to a common transformer via a local network is characterized by the acquisition of system data including a nominal capacity, an overload evaluation scheme and an overload limit value for the transformer. A load forecast is received for other loads connected to the local network. This also includes the case that data is only received to create a load forecast. Using the overload evaluation scheme and taking into account at least the load profile prognosis for the other loads connected to the transformer, an overload profile of the transformer is determined. The overload profile of the transformer is updated regularly by recording a time profile of a power flowing through the transformer and taking it into account in the update.

Each time a new electric vehicle is connected to a charging point in the local network, a charging requirement of the new electric vehicle is received, the charging requirement being an amount of energy and an end point at which the amount of energy is to be charged into the new electric vehicle includes. Taking into account the additional charging requirement of the new electric vehicle, a possible overload profile of the transformer is determined and a maximum value of the possible overload profile is compared with the overload limit value. If the maximum value of the possible overload profile does not exceed the overload limit value, charging of the new electric vehicle is approved and carried out in accordance with the charging requirement, and the overload profile of the transformer is updated taking into account the additional charging requirement of the new electric vehicle. However, if the maximum value of the possible overload profile exceeds the overload limit value, the charging requirement is rejected and charging of the new electric vehicle is blocked. The approval or rejection of the charging requirement is preferably communicated to the electric vehicle and displayed to a user of the electric vehicle in a suitable form.

The overload evaluation scheme is a means of assessing whether an overload of the transformer leads to an acceptable or an unacceptable load. In principle, transformers are very robust devices that also allow a power flowing through them that considerably exceeds the nominal capacity for a finite period of time without causing immediate damage to the transformer. A reduction in the life of the transformer due to overloading can also be acceptable within certain limits. The overload evaluation scheme can in particular be a computation method which converts a time profile of a power flowing through the transformer up to a point in time t into a characteristic number O (t). This characteristic number can then be compared with a limit value, an exceeding of the limit value by the characteristic number O (t) indicates that the overload of the transformer at time t has exceeded an acceptable level. The overload assessment scheme can be generated from a thermal model of the transformer, which takes into account the heating and cooling behavior of the transformer as a function of the flowing power. A concrete possibility for an overload evaluation scheme is a weighted integration of the power P exceeding the nominal capacity P ₀ over time: $$O\left(t\right)={\displaystyle \underset{-\infty }{\overset{0}{\int }}G\left(\tau \right)\ast \left(P\left(t+\tau \right)-P_0\right)}d\tau$$

Here, g (τ) denotes a weighting function which simulates the thermal inertia of the transformer.

The overload evaluation scheme can also take into account a real temperature measured at the transformer in order to enable a more precise estimate of the overload. In particular, by taking into account the actually measured temperature, a simplified profile of a power flowing through the transformer can be used, for example in that the power profile before the time of the temperature measurement can be disregarded.

In a specific example, the overload evaluation scheme describes a real or virtual temperature. For example, taking into account the measurement of a temperature T (t ₀ ) at time t ₀ , the overload evaluation scheme can be expressed as follows: $$O\left(t\right)=T\left(t_0\right){\displaystyle \underset{t0}{\overset{t}{\int }}G\left(t-\tau \right)\ast \left(P\left(t\right)-P_0\right)}d\tau$$

• in einer ersten Ausführungsform kann ein möglicher Ladebedarf, der unter Einhaltung des Überlastgrenzwerts erfüllt werden kann, bestimmt werden, wobei der mögliche Ladebedarf eine gegenüber dem abgelehnten Ladebedarf eine reduzierte Energiemenge oder einen späteren Endpunkt enthält, und nach Bestätigung des möglichen Ladebedarfs kann das neue Elektrofahrzeug gemäß des möglichen Ladebedarfs geladen werden. Hierdurch ergibt sich eine maximale Ausnutzung der Überlastmarge des Transformators, allerdings werden später eintreffende Elektrofahrzeuge mit einer geringeren Energiemenge versorgt oder eventuell auch gar nicht mehr geladen.

If the charging requirement of the newly connected electric vehicle results in the maximum value of the overload profile exceeding the overload limit value, different strategies can be pursued in advantageous embodiments of the method according to the invention:

• In a first embodiment, a possible charging requirement that can be met while adhering to the overload limit value can be determined, with the possible charging requirement containing a reduced amount of energy compared to the rejected charging requirement or a later end point, and after confirmation of the possible charging requirement, the new electric vehicle can according to of the possible charging requirement. This results in maximum utilization of the overload margin of the transformer, but electric vehicles arriving later are supplied with a smaller amount of energy or may not be charged at all.

In a second embodiment, a power that is transmitted to the other loads connected to the transformer can be limited to a power that is reduced compared to the load profile prognosis, see above that the charging requirements of the new electric vehicle can be met while adhering to the overload limit. In this way, charging of the new electric vehicle can be approved and carried out in accordance with the charging requirement. This results in a prioritization of the charging of the electric vehicles over the operation of other loads on the local network, which are regulated or even switched off completely if the transformer is overloaded.

In a third embodiment, additional power from a generator or a storage device can be fed into the local network so that the charging requirement of the new electric vehicle can be met while adhering to the overload limit value, so that charging of the new electric vehicle can be approved and carried out according to the charging requirement. The storage tank can be recharged at times when the transformer is not overloaded.

In a fourth embodiment, a reduced charging requirement for electric vehicles whose charging requirement has already been approved can be determined such that the charging requirement of the new electric vehicle can be met, and charging of the new electric vehicle according to the charging requirement can be approved and carried out. Charging the electric vehicles. whose charging requirement has already been approved will continue with the specific reduced charging requirement. This can optionally require prior approval of the reduced charging requirement by the affected electric vehicles.

It is also conceivable that a voltage transformation ratio of the transformer is changed with the aim of being able to push the overload index below the overload limit value in the course of a recalculation taking into account the changed voltage ratio.

In a further aspect of the invention, a system is used for the dynamic coordination of charging processes for a plurality of electric vehicles which are to be charged via charging points which are connected to a common transformer via a local network. The system is set up to acquire system data which have a nominal capacity, an overload rating scheme and an overload limit value for the transformer. A load profile forecast for other loads connected to the local network is received and an overload profile of the transformer is determined using the overload evaluation scheme and taking into account at least the load profile forecast for the other loads connected to the transformer. Furthermore, a time profile of a power flowing through the transformer is recorded and the overload profile of the transformer is updated regularly taking into account the power recorded.

Each time a new electric vehicle is connected, the system is set up to receive a charging requirement of the new electric vehicle, including an amount of energy and an end point at which the amount of energy is to be charged into the new electric vehicle, and a possible overload profile by taking into account the additional charging requirement of the new one To determine the electric vehicle, and to compare a maximum value of the possible overload curve with the overload limit value. It is conceivable that the course of a charging curve for the newly connected GFZ or also the courses of charging curves for already connected electric vehicles are varied in order to obtain an overload course with the lowest possible maximum value.

If the maximum value of the possible overload profile does not exceed the overload limit value, charging of the new electric vehicle is approved and carried out in accordance with the charging requirement, and the overload profile of the transformer is updated taking into account the additional charging requirement of the new electric vehicle.

However, if the maximum value of the possible overload profile exceeds the overload limit value, the charging requirement is rejected and charging of the new electric vehicle is blocked.

In an advantageous embodiment, the system additionally has an energy store and / or a generator, which are connected to the local network. In this case, the system is set up to feed additional power from the generator or the storage unit into the local network in the event that a charging requirement is rejected, so that the charging requirement of the new electric vehicle can be met while adhering to the overload limit. The charging of the new electric vehicle is then approved and carried out according to the charging requirement.

• 1 eine Infrastruktur mit einer Mehrzahl von Ladepunkten, die über ein lokales Netz an einen gemeinsamen Transformator angeschlossen sind, und in der das erfindungsgemäße Verfahren ausgeführt werden kann,
• 2 ein Flussdiagramm für das erfindungsgemäße Verfahren, und
• 3 beispielhafte zeitliche Verläufe einer Überlast und einer über den Transformator fließenden Leistung zeigen.

The invention is described in more detail below with the aid of figures, of which

• 1 an infrastructure with a plurality of charging points that are connected to a common transformer via a local network and in which the method according to the invention can be carried out,
• 2 a flow chart for the method according to the invention, and
• 3 show exemplary time profiles of an overload and a power flowing through the transformer.

1 shows an infrastructure in which the method according to the invention can advantageously be carried out. A local network 17th is through a transformer 11 with an energy distribution network (EVN) 10 connected. Via the local network 17th become both consumers 12 , for example a commercial enterprise or a private household, is supplied with electrical energy. It is not excluded that the consumer 12 not only draws energy from the local grid, it can also feed energy into the local grid. Furthermore to the local network 17th are a plurality of charging points 13th connected, about the electric vehicles 14th , 14 ' can be loaded. Optionally, a memory can also be used 16 be connected to the local network and exchange energy with it, that is to say draw energy from the network for a first period in order to store it 16 to load and in a second period of time in the memory 16 feed charged energy back into the grid. The charging point 13th and the electric vehicles 14th can also belong to a commercial enterprise, for example a logistics company, or also be independent private households or other independently or jointly operated units. The charging points 13th , the consumer 12 and the memory 16 are via a communication link 18th with one system 15th to coordinate the charging processes via the charging points 13th connected. The communication link 18th can be a physical line connection, for example a copper cable or a glass fiber line, or a radio connection.

Via the communication link 18th becomes the system 15th notified that a new electric vehicle 14 ' to a charging point 13th should be connected. In this context, the system 15th also communicated what charging needs the newly connected electric vehicle 14 ' has, in particular within which period of time the electric vehicle needs how much energy. This information can be divided into a minimum energy and a desired energy for the affected electric vehicle 14 ' . Furthermore, the information can also be divided into a desired time and a latest time at which the charging process is to be completed. The system 15th then decides whether to charge the newly connected electric vehicle 14th Stroke can be carried out according to the communicated demand data and shares the result of this decision with the affected charging point 13th with, which starts the charging process in the event of a positive decision. Alternatively or additionally, this information can also be sent directly to the affected electric vehicle instead of the charging point 14 ' be transmitted.

The system 15th can also share information with memory if necessary 16 and / or the consumer 12 exchange; in particular, it can use the exchanged information to extract or feed these two components from or into the local network 17th influence. This influence is used in particular to determine a charging requirement of the connected vehicles 14th , 14 ' to satisfy without the transformer 11 to overload.

The system can do this 15th additional information directly with the transformer 11 exchange, in particular data about the temporal course of the power flow through the transformer 11 the system 15th be communicated. It is also conceivable that the system 15th about that with the transformer 11 exchanged information the transformer 11 can actively control, for example can influence a transformation ratio of the transformer.

The charging points 13th share the system 15th Information about the charging curves of the electric vehicles connected to them 14th With. It is also conceivable that the system 15th the charging progress of the connected electric vehicles 14th about their charging point 13th actively regulates.

With the information exchanged, the system 15th be able to control the power flow through the transformer 11 to be monitored and at least actively controlled if necessary in such a way that the charging requirements of as many electric vehicles as possible can be satisfied without the transformer 11 to overload it in an unacceptable manner.

2 shows a flowchart showing a possible implementation of the method according to the invention. In a first step 21st system data are recorded that are specific to the transformer that connects the local network with the higher-level energy distribution network. The recorded data can have a nominal capacity, an overload evaluation scheme and a limit value for an overload. The nominal capacity and the limit value can be recorded as an explicit variable or implicitly in the context of the overload evaluation scheme. Acquiring here means that the corresponding data are made known to the system executing the method.

Furthermore, in the first step 21st receive a load profile forecast for loads connected to the local network. The load consumption forecast can be part of a consumption plan for the load, or it can be obtained from empirical values, for example from load profiles from past periods of time. However, other methods for determining a load consumption forecast should not be excluded here.

In a second step 22nd an overload profile of the transformer is determined taking into account the load consumption forecast using the overload evaluation scheme. The overload profile can initially only be obtained from the load consumption forecast, but further load profiles, in particular those from charging processes of electric vehicles connected to charging points of the local network, can also be taken into account at later times.

A third step is then carried out at regular intervals 23 a time profile of a power flowing through the transformer is recorded and the overload profile of the transformer is updated taking into account the power recorded. As a result, deviations in the load profile of the other loads from the load consumption forecast are automatically taken into account as a correction.

In a fourth step 24 it is checked whether a new electric vehicle should be connected to the local network for charging. If this is not the case, the third step is 23 returned. Each time a new electric vehicle is connected to a charging point in the local network, the fifth step is then 25th first receive the charging requirement of the new electric vehicle, the charging requirement comprising at least an amount of energy and an end point at which the amount of energy is to be charged into the electric vehicle to be newly connected.

This information is then used in a sixth step 26th used to determine a possible overload profile that results from taking into account the additional charging requirements of the newly connected electric vehicle. A maximum value of the possible overload profile is determined in a seventh step 27 compared to the overload limit.

If the maximum value of the possible overload profile does not exceed the overload limit value, then in an eighth step 28 the charging of the new electric vehicle to be connected is approved and a charging process is carried out according to the charging requirement. The transformer's overload profile is updated taking into account the additional charging requirements of the newly connected electric vehicle.

If the maximum value of the possible overload profile exceeds the overload limit value, it is initially not possible to charge the electric vehicle in accordance with its charging requirement. Hence, in a ninth step 29 the charging requirement is rejected and the charging of the new electric vehicle to be connected is blocked.

In embodiments of the method according to the invention, as part of the ninth step 29 further procedural steps are carried out with the aim of still enabling the newly connected electric vehicle to be charged. These method steps are either aimed at reducing power consumption from the local network by other charging points or other loads, or they are aimed at introducing additional power into the local network in a different way than via the transformer. Both approaches are basically suitable for reducing the power flowing through the transformer to such an extent that the charging requirement of the newly connected electric vehicle can still be met without exceeding the overload limit of the transformer. If a sufficient reduction is possible, the charging process is approved according to the charging requirement and the charging process is carried out.

Both following the eighth step 28 as well as following the ninth step 29 becomes the fourth step 24 returned.

3 shows exemplary time profiles of a power P (t) flowing through the transformer, as well as a profile of the characteristic number O (t) of an overload resulting from this power profile. The gradients can be used, for example, in an infrastructure as in 1 shown. In a power curve 31, in a first phase before a point in time t _1, a plurality of electric vehicles are successively connected to the local network, their power requirements are checked and their charging process is approved and carried out. As a result, the power flowing into the local network via the transformer increases gradually in the first phase and exceeds the nominal capacity P _{Nom of} the transformer.

Exceeding the nominal capacity P _Nom initially does not constitute an obstacle to the fact that further electric vehicles can be connected to the local network for charging and charged, since one is based on the power curve 31 resulting course 32 the key figure O (t) increases, but initially remains below the overload limit value OTH.

Only at a point in time t ₁ is a further electric vehicle to be connected to the local network for charging, so that additional charging power linked to the fulfillment of the charging requirement 33 would cause the resulting course 34 the overload index O (t) would exceed the limit value OTH when the charging requirement is met. Therefore, the charging process for this electric vehicle is not started initially.

At a point in time t ₂ , the power flowing through the transformer drops, it being irrelevant whether this reduction is due to targeted intervention, for example feeding in additional power from a storage unit connected to the local network, or a reduction in power drawn from the local network by consumers or is caused by adapting the charging requirements of already connected electric vehicles or takes place without active intervention by a supervisory authority. As a result of the power reduction, the overload index O (t) also falls, so that at a point in time t ₃ it is recognized that even when the The power requirement of the new electric vehicle to be connected 32 the overload index O (t) no longer exceeds the limit value OTH, so that the charging request for the new electric vehicle to be connected is met immediately.

In this way, as many electric vehicles as possible can be guaranteed that their charging requirements can be met quickly, with the transformer's overload margin being optimally exploited. However, it is not necessary to know in advance the times and the charging requirements of the electric vehicles to be connected. Rather, it is possible to react dynamically to the arrival of electric vehicles. The integration of additional energy reserves in a storage system is also made possible efficiently.

List of reference symbols

10

Energy distribution network (EVN)

11

transformer

12th

consumer

13

Charging point

14th

Electric vehicle

14 '

Electric vehicle

15th

system

16

Storage

17th

local network

18th

Communication link

21-29

step

31

Performance history

32

KPI history

33

Additional charging power

34

KPI history

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• EP 2505421 [0005]

Claims (8)

A method for the dynamic coordination of charging processes for a plurality of electric vehicles (14, 14 ') which are to be charged via charging points (13) which are connected to a common transformer (11) via a local network (17), comprising the steps: - Acquisition of system data that have a nominal capacity, an overload evaluation scheme and an overload limit value OTH for the transformer (11), - Receipt of a load profile forecast for other loads connected to the local network (17), - Determination of an overload profile of the transformer (11) using the overload assessment scheme and taking into account at least the load profile prognosis for the other loads connected to the transformer (11), - Detecting a time profile (31) of a power flowing through the transformer (11) and regularly updating the overload profile (32) of the transformer (11) taking into account the detected power, - each time a new electric vehicle (14 ') is connected to a charging point (13) of the local network (17), + Receipt of a charge requirement of the new electric vehicle (14 '), comprising an amount of energy and an end point at which the amount of energy is to be charged into the new electric vehicle (14'), + Determining a possible overload profile (33) by taking into account the additional charging requirement of the new electric vehicle (14 ') and comparing a maximum value of the possible overload profile (33) with the overload limit value OTH, + if the maximum value of the possible overload profile does not exceed the overload limit value OTH, approve and carry out charging of the new electric vehicle (14 ') according to the charging requirement, as well as updating the overload profile (32) of the transformer (11) taking into account the additional charging requirement of the new electric vehicle ( 14 '), + if the maximum value of the possible overload profile exceeds the overload limit value OTH, rejecting the charging requirement and blocking charging of the new electric vehicle (14 '). Procedure according to Claim 1 , furthermore comprehensive in the case of the refusal of the charging requirement: determination of a possible charging requirement that can be met while adhering to the overload limit value, the possible charging requirement containing a reduced amount of energy compared to the rejected charging requirement or a later end point, and after confirmation of the possible charging requirement, charging the new electric vehicle (14 ') according to the possible charging requirement. Procedure according to Claim 1 , furthermore comprehensive in the case of the refusal of the charging requirement: Limiting a power transmitted to the other loads connected to the transformer (11) to lower power than the load profile forecast, so that the charging requirement of the new electric vehicle (14 ') is met while adhering to the overload limit value OTH and approving and performing charging of the new electric vehicle (14 ') according to the charging needs. Procedure according to Claim 1 , further comprising in the case of the refusal of the charging requirement: feeding an additional power from a generator or a storage (16) into the local network (17) so that the charging requirement of the new electric vehicle (14 ') can be met while adhering to the overload limit value, and approving and performing charging of the new electric vehicle (14 ') according to the charging demand. Procedure according to Claim 1 , furthermore comprehensive in the case of the rejection of the charging requirement: determination of such a reduced charging requirement for electric vehicles (14) whose charging requirement has already been approved so that the charging requirement of the new electric vehicle (14 ') can be met, optionally requesting and waiting for a confirmation thereof, and Charging the new electric vehicle (14 ') according to the charging requirement, as well as charging the electric vehicles. whose charging requirement has already been approved, with the specific reduced charging requirement. Method according to one of the preceding claims, further comprising each time an electric vehicle is disconnected from its charging point (13): - Check whether the charging requirement of the separated electric vehicle has been met, and - Updating the overload profile (32) of the transformer (11), taking into account the unfulfilled charging requirement. System (15) for the dynamic coordination of charging processes for a plurality of electric vehicles which are to be charged via charging point (13) which are connected to a common transformer (11) via a local network (17), the system (15) is set up for this purpose: - to record system data which have a nominal capacity, an overload evaluation scheme and an overload limit value OTH for the transformer (11), - to receive a load profile forecast for other loads connected to the local network (17), - an overload profile (31) of the transformer (11) using the overload assessment scheme and taking into account at least the load profile prognosis for the other loads connected to the transformer (11), to record a time profile of a power flowing through the transformer (11) and to regularly update the overload profile (32) of the transformer (11) taking into account the recorded power, - each time a new electric vehicle (14 ') is connected, + a charging requirement of the new electric vehicle (14 '), comprising an amount of energy and an end point at which the amount of energy is to be charged into the new electric vehicle (14') to receive + a possible overload profile (33) by taking into account the additional charging requirements of the new electric vehicle (14 ') and to compare a maximum value of the possible overload profile (32) with the overload limit value OTH, + if the maximum value of the possible overload profile (33) does not exceed the overload limit value OTH, approve charging of the new electric vehicle (14') according to the charging requirement and perform, as well as the overload curve (32) of the transformer (11) taking into account the additional To update the charging requirement of the new electric vehicle (14 '), + if the maximum value of the possible overload profile (33) exceeds the overload limit value OTH, to reject the charging requirement and to block charging of the new electric vehicle (14'). System (15) Claim 5 , further comprising a memory (16) and / or a generator, which are connected to the local network (17), the system (15) being set up to provide additional power from the generator and / or in the event that the charging requirement is rejected to feed the memory (16) into the local network (17) so that the charging requirement of the new electric vehicle (14 ') can be met while adhering to the overload limit value OTH, and to approve the charging of the new electric vehicle (14') according to the charging requirement and perform.

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