DE102016211035A1 - Device for charging an energy store - Google Patents

Abstract

The present invention relates to a method for controlling a charging device for charging a battery of a vehicle. In this method, the driver of the vehicle activates the charging device in a first step A, in a second step B at time t0 the charging device starts charging the battery, in a third step C the charging device determines a movement profile BP of the driver, on the basis of which the charging device controls the charging current IL.

Description

The present invention relates to a device for charging an energy storage device for electrically operated vehicles (electric or hybrid vehicles).

State of the art

Electric vehicles (electric vehicles) or plug-in hybrid vehicles (hybrid vehicles) usually have an electrical energy storage, such as a traction battery (battery), which provides the electrical energy for the drive. If this electrical energy store is completely or partially discharged, then the electric vehicle has to control a charging station, at which the energy store can be recharged. So far, it is customary for this purpose that the electric vehicle is connected to the charging station by means of a cable connection at such a charging station. Regular charging is often done using charging plans that determine when the battery is charged.

For example, the shows JP 2010 093 999 the update of a loading plan due to changed conditions. Such a change of a framework condition can be caused by a traffic jam, for example.

The US 2008 319 596 discloses a charging plan for a hybrid vehicle based on the route being run after the load plan has been completed.

In the JP 2004 098 726 A a load plan is created based on just the next entered destination. However, a cost optimization is not made.

The DE 10 2008 053 141 A describes the determination of the cost-optimal loading time based on the information about the next planned journey start of a single trip. For example, so the cheap night current can be exploited.

In the JP 2008 249 503 A the route to a charging station and the charging costs at this charging station are determined. Furthermore, a loading plan for reaching the charging station along a selected route is determined. This document assumes a single destination, the charging station. A cost analysis is carried out exclusively on the costs of the relevant charging stations and the information, if they are available.

The battery is usually connected by the user / driver of a vehicle for charging to a charger. Most electric vehicle users have no background in electromobility. Such users often connect the battery to a charger at each available opportunity and fully charge it. To the Standbzw. To shorten the waiting time when charging the battery, the battery is charged in a short time with high current densities - one speaks in this context of "fast charging" or "fast charging".

Battery fast charging seems ideal at first glance to reduce waiting time. The time advantage that results from charging with high current densities in a short time compared to slow charge, however, is realized at the expense of a not fully charged battery and a very high load of the energy storage.

Comparatively low charging times - usually between approx. 30 minutes and 1 hour for 80% SOC - are offset by a 20% reduction in the amount of traction current or range and a higher level of wear. The faster cells are charged, the less electricity and chemical energy they absorb. Due to the high current levels, charging leads to increasing internal resistance in the cells and, as a result, to a strong generation of heat. The increased resistance in turn accelerates the heating. Even with great cooling power, this coil can be dampened by more heat and resistance for just a few minutes. Then the power must be shut down. This is done via the charging characteristic in the controller of the charger. The charging process is only as long as safe as controls and various emergency devices work.

The thermal energy generated during heavy current charging triggers the formation of dendrites, which are irreversible because they close the pores of the electrodes and thus reduce their functionality. During charging, metallic lithium accumulates in the form of porous and needle-shaped metal deposits on the negative electrode, which can lead to local short circuits in the battery or at too high a temperature to explosive reactions with the electrolyte. In addition, the fast charge also degrades the charging efficiency: the ratio between the current drawn from the grid and the energy actually present in the battery.

In the prior art, a fast charge when reaching a level of 80% SOC (SOC: State of Charge) - the remaining available capacity of the battery in relation to the nominal value of the capacity is automatically canceled to protect the battery from the risk of Overheating, which means that fast full charge on 100% capacity is not possible: a fast charge (20% SOC to 80% SOC) provides only 60% of the capacity of a battery, assuming that modern battery management systems Prevent discharge of vehicle memory to below 20% SOC from the outset for safety reasons.

A fast charge (20% SOC to 80% SOC) and a subsequent slow charge (80% SOC to 100% SOC) do not offer a convincing time advantage over a slow charge (20% SOC to 100% SOC) right from the start. The load of the last 20% SOC is estimated to take three to four times longer than the first 80% SOC, which minimizes the advantage over slow loading. Even against this background, the irreversible thermal stress to which a battery is repeatedly exposed by rapid charging, not justified, unless costs (for example in the form of a prematurely "Batteries") are irrelevant.

There is therefore a need for an intelligent charging method that charges the battery both as quickly as possible but does not expose the battery to unnecessary stress.

Disclosure of the invention

The inventive method with the characterizing part of claim 1 has the advantages that the battery is charged only as fast as necessary, and therefore is not exposed to unnecessary and excessive stress.

According to the invention, a method is provided for controlling a charging device for charging a battery of a vehicle, in which the driver of the vehicle activates the charging device in a first step A, in a second step B the charging device starts charging the battery, in a third step C the charging device determines a movement profile BP of the driver and the charging device controls the charging current IL as a function of the movement profile of the driver.

This method for charging the battery of the vehicle has the advantage that by means of the charging device by knowing and forecasting the movement profile of the driver, the time for the onward journey can be derived. This allows the charger to adjust / reduce the charge current accordingly so that the battery does not reach the desired (e.g., maximum) state of charge prior to the earliest possible continuation of the ride. The life of the battery increases advantageously without the driver having to limit or schedule the charging process. Furthermore, the energy costs are lower, since with lower currents, the efficiency of the charging process is better.

The measures mentioned in the dependent claims advantageous refinements of the method specified in the independent claim are possible.

Advantageously, the movement profile of the driver is determined by means of a position determining device. After the driver has activated the loading device in the first method step A and has left the vehicle, the loading device determines the position of the driver by communication with the position determining device and can thus determine how far the driver has moved away from the vehicle and how long he has to travel needed the distance. This results in minimum periods for moving away from and moving to the vehicle, the sum of the charging device are available to charge the battery.

Furthermore, it is advantageous that the charging device informs the driver at the time t1 that the battery will have reached a predetermined charging target at the time t2 when the driver starts the return journey to the vehicle at the time t1. Here, t2> t1> t0, where t2 is the time at which the driver reaches the vehicle or returns to it. Thus, the driver knows that the battery has reached the specified charging target when he makes his way back - so he does not have to wait unnecessarily with the onward journey or, for example, in the restaurant or gas station.

Furthermore, it is advantageous that the charging device controls the charging current IL in such a way that the charging current IL between the times t1 and t2 is, on average, less than or equal to the average charging current between the times t0 and t1. After time t1, that is, after the information has been communicated to the driver that the battery will have reached the predetermined charging target when the driver makes the return journey at time t1, the charge current is not reduced until the driver returns to the vehicle at time t2 , The battery is charged as fast as possible over the entire time (t0 to t2). If the driver does not make the return trip at time t1, the charging current is reduced until the driver returns to the vehicle at time t2. Up to the delivery of the information to the driver at time t1 is thus charged with higher charging current, as between t1 and t2 - thus the battery is spared accordingly.

Furthermore, it is advantageous that the positioning device uses GPS, Gallileo, GLONASS, Bluetooth, NFC or similar positioning devices. For example, GPS (Global Positioning System) is based on satellites that constantly radiate their current position and time with coded radio signals. From the signal transit times, special GPS receivers can then calculate their own position and speed, with an accuracy of often better than 10 meters is possible. If the positioning device has GPS, it is thus advantageously possible to determine the position of the driver to within 10 meters. Thus, the charger can even better determine the amount of time that the driver normally requires (normal walking speed) to return to the vehicle and adjust accordingly the charging process of the battery or the charging current.

Advantageously, the position determination device uses surrounding WLan networks for position determination. Based on the evaluation of the identification of the WLan networks and their signal strength and together with an Internet connection, the charging device is thus able to determine the distance to the vehicle, the driver is staying. Thus, the charging device can advantageously calculate or estimate the minimum possible charging period and regulate the charging current accordingly.

Furthermore, it is advantageous that the position-determining device is a GPS receiver or a smartphone that has the abovementioned capabilities (GPS, Gallileo, GLONASS, Bluetooth, NFC, etc.). Alternatively, portable devices (so-called handsets) would also be conceivable, which also have the abovementioned capabilities (GPS, Gallileo, GLONASS, Bluetooth, NFC, etc.). The GPS receiver can for example be advantageously integrated in the car key of the driver and communicate with the charging device. Alternatively or additionally, the key or a key fob can also be equipped with Bluetooth or NFC, the signals of which can be received by stationary devices and the location of the driver can be determined by way of this. Alternatively, the driver's smartphone serves as a position determining device. As a rule, smartphones (mobile phones) today have Internet connectivity and are GPS-enabled. Thus, the driver can have his position determined by the smartphone and confirm the loader. Alternatively, the smartphone can connect to existing WLAN networks without being GPS-capable and thus also confirm the driver's position based on the localization of the WLAN networks to the charging device. Accordingly, the charging device can advantageously calculate or estimate the minimum possible charging period and adapt the charging current accordingly.

In addition to the position of the driver, the loading device can also advantageously determine or predict the movement profile of the driver with the aid of calendar entries of the driver. So the smartphone can use more information to calculate the time of the return of the driver to the car better or estimate. If the smartphone contains calendar entries of the driver in which, for example, appointments are registered at the current location, a period can be calculated based on the start, the duration and the end, which is available to the charging device to charge the battery accordingly. Furthermore, it is also possible to determine from knowledge of traffic information and the thus estimated estimated travel time when the driver would have to continue at the latest in order to reach his destination on time and the battery is charged by the charging device correspondingly advantageously by adjusting the charging current.

Furthermore, it is advantageous that the system determines the movement profile of the driver with the aid of order and / or payment transactions of the driver. Instead of a (more or less) deterministic prediction (for example, by reading the calendar including appointment entries in the smartphone), the loader can learn from repetitive behavior patterns of the driver, which is to be expected until the start of the journey. Thus, e.g. about time, place and amount of ordering and / or payment transactions, the typical behavior of the driver are learned (dwell time, etc.) and estimated time periods from leaving the vehicle until the return to the vehicle and ultimately beneficial to the charging current through the charger on be regulated on the basis of the determined durations.

Advantageously, in a fourth step D, the charging device suspends the charging process when the battery has reached the charging target or an SOC sufficient to reach the next destination. If the battery merely needs to be charged in order to reach the nearest destination and no fully charged battery is required, the charging target (desired SOC of the battery or state of charge of the battery) can also be adapted depending on the next destination. The information required for this purpose can advantageously be provided by a smartphone or navigation device and transmitted to the charging device.

Advantageously, the charging device proposes to the driver the charging target of the battery, which the driver can subsequently correct. Thus, the driver can determine for himself whether that is from the Charger calculated or predicted charge target is correct or contrary to his calendar entries or otherwise the loader available information but has different destinations for the less or more battery charge is needed.

Further features and advantages of embodiments of the invention will become apparent from the following description with reference to the accompanying drawings.

Brief description of the drawings

Show it:

1 FIG. 3 is a schematic diagram of the different steps relating to the method of operating a charging device; FIG.

2 : another schematic representation of a cross section

3 : a schematic representation of a vehicle with the charging device according to the invention

The drawings shown in the figures are not necessarily drawn to scale for the sake of clarity. Like reference numerals generally designate like or equivalent components.

1 shows a schematic representation of a method for operating a charging device 10 such as for charging a battery 11 (Traction battery) in a vehicle 12 , preferably electric vehicle or hybrid vehicle can be used. In a first step A, the loading device 10 by the driver 13 activated. For example, the driver parks 13 the vehicle 12 in a parking lot or a rest area and leaves the car / vehicle 13 to go to a restaurant. By activating the charging device 10 the driver intends 13 the battery 11 of the vehicle 12 to load. Then the driver moves 13 from the vehicle 12 path. In a second step B, the loading device begins 10 the charging process of the battery 11 at a time t0. In a third step C determines the charging device 10 a movement profile BP of the driver 13 , by means of which the loading device 10 controls the charging current IL. The movement profile BP of the driver 13 is using a positioning device 14 determined. Through the communication with the positioning device 14 it is possible to predict the time for the onward journey through the charging device and the charging current to be adjusted accordingly, so that the battery 11 does not reach the desired (eg maximum) state of charge before the earliest possible continuation of the journey. The position determination device 14 uses GPS for positioning. Using GPS, Gallileo, Glonass, Bluetooth, NFC and similar systems, the position of the driver can be determined to within 10 meters. It is also possible that the position determining device 14 WLan networks used for position determination. By communicating with appropriate servers is the charging device 10 able to determine with which WLAN network the positioning device 14 has connected and at what distance to the vehicle 12 the driver 13 currently has to reside or stop. As a position determining device 14 A GPS-enabled smartphone or, for example, a GPS receiver is possible, each with the charging device 10 communicate. For example, the GPS receiver may be in the car key of the driver 13 be integrated and with the charger 10 For example, communicate via Bluetooth, NFC, etc. Alternatively, the smartphone communicates with the charging device 10 and transmits the location of the driver 13 , The smartphone of the driver 13 thus monitors the driver's movement profile BP 13 , causing the charging device 10 is able to predict the start of the onward journey. Furthermore, the loader reduces 10 the charging current of the type that the battery 11 not reached the desired state of charge before the earliest possible start of the journey. An example will illustrate the concept below.

For example, the driver activates 13 loading the vehicle 12 according to the method of the invention. The loading device 10 starts, the battery 11 initially with the maximum charging current IL_max to load - this is eg 2% SOC / minute. The remaining capacity C_start is 20% SOC and the charging target is a capacity C_stop of 80% SOC.

Then the driver goes to a restaurant 400 meters away. The loading device 10 communicates with the driver's smartphone 13 and determines the location when leaving the vehicle 12 and the current location of the driver 13 , From this information, the charging device calculates 10 that the driver 13 It takes at least 6 minutes to get back to the car. The loading device 10 calculates the current charging current I_akt based on the current capacity C_akt I_act = min (IL_max, IL_max T / t C_stop - C_akt / C_80% - C_20%) for C_akt <C_stop and t> 0 where I_akt the current charging current, IL_max the maximum charging current, C_stop the desired capacity or the charging target of the battery 11 at the completion of the charging process, C_akt the current capacity of the battery 11 , T is the period of time to charge the battery constantly with IL_max from capacity C_20% with 20% SOC to capacity C_80% with 80% SOC, and t is the amount of time the driver is likely to need to return to the vehicle.

The charger charges the battery up to 68% SOC at the maximum charging current. From this point on, with the maximum charge current, it would take another 6 minutes to complete the battery 11 to charge to the desired charging target of a capacity C_stop of 80% SOC. Since the driver in this example a total of 35 minutes, so still another 11 minutes outside the vehicle or in the restaurant noticed, reduces the charging device 10 the charging current.

In addition to the position of the driver 13 The smartphone can still use more information at the time of the return to the vehicle 12 predict. For this purpose, calendar entries, for example stored in a smartphone, are used. Among other things, these contain dates at the current location and show both the beginning, the duration and the end. Thus, by communicating with the smartphone, the loader is able to better predict the movement profile of the driver by reading the calendar entries and its earliest possible return to the vehicle 12 estimate.

Alternatively - in contrast to a (more or less) deterministic prediction, the loader can 10 learn from certain behavioral patterns of the driver and thus predict the time to the next trip. For example, during order and payment transactions, the time of the place and amount of the order or payment process can be recorded and from it forecasts for the return of the driver to the vehicle 12 be predicted. In addition, the charging device 10 also adjust the battery charging target depending on information coming from the smartphone. These include, for example, calendar entries and the knowledge that there may not be a charging station or charging facility at the destination. Alternatively, for example, an appointment can be entered in the calendar, which takes place in a place where although a charging station is present, but the appointment takes too short to the battery 11 enough to load it enough for the trip home.

The driver 13 is from one of the handsets 14 pointed out when the break can end and to the vehicle 12 can run back. For example, charging begins at time t0. The loader knows the location of the driver and calculates its return time to the vehicle. At time t1, the charging device (which may also be implemented as a networked system having the server) informs the driver that he can return to the vehicle. This information is delivered at time t1 only if the driver requires, with immediate return to the vehicle at average return speed, enough for the battery to have reached the predetermined charging target at the return time t2. Between times t0 and t1, the charging device charges the battery at a higher charge current than between times t1 and t2.

The driver also gets the charging target planned for the charging process from the vehicle 12 or one of the handsets 14 suggested and can correct this if necessary.

2 shows a further schematic representation of the method according to the invention for operating a charging device 10 , Same elements in terms of 1 are provided with the same reference numerals and are not explained in detail. In a fourth step D, the charging device interrupts 10 Charging when the battery 11 has reached the SOC, which is sufficient to the next destination of the vehicle 12 to reach.

3 shows a schematic representation of a system 16 consisting of vehicle 12 with the charging device according to the invention 10 , a battery 11 , the server 15 the driver 13 and one of the handsets 14 , Same elements in terms of 1 and 2 are provided with the same reference numerals and are not explained in detail.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been 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.

Cited patent literature

• JP 2010093999 [0003]
• US 2008319596 [0004]
• JP 2004098726A [0005]
• DE 102008053141 A [0006]
• JP 2008249503 A [0007]

Claims (12)

Method for operating a charging device ( 10 ) for charging a battery ( 11 ) of a vehicle ( 12 ), characterized in that - the driver ( 13 ) in a first step (A) the loading device ( 10 ) activated; In a second step (B) at time t0 the charging device ( 10 ) the charging process of the battery ( 11 ) begins; In a third step (C) the loading device ( 10 ) a movement profile (BP) of the driver ( 13 ), by means of which the loading device ( 10 ) controls the charging current IL. Method according to claim 1, characterized in that the loading device ( 10 ) the movement profile of the driver ( 13 ) by means of a position determining device ( 14 ). Method according to one of the preceding claims, characterized in that the loading device ( 10 ) the driver ( 13 ) at time t1, where t1 is greater than t0, informs that the battery ( 11 ) at time t2 with t2 greater than t1 at which the driver ( 13 ) to the vehicle ( 12 ), has reached a predetermined loading target when the driver ( 13 ) at time t1 the way back to the vehicle ( 12 ). Method according to one of the preceding claims, characterized in that the loading device ( 10 ) controls the charging current IL such that the charging current IL between the times t1 and t2 is, on average, less than or equal to the average charging current between the times t0 and t1. Method according to one of the preceding claims, characterized in that the position-determining device ( 14 ) GPS, Gallileo, GLONASS, Bluetooth, NFC or similar positioning methods. Method according to one of the preceding claims, characterized in that the position-determining device ( 14 ) surrounding WLan networks used for position determination. Method according to one of the preceding claims, characterized in that the position-determining device ( 14 ) is a smartphone or an alternative portable handset. Method according to one of the preceding claims, characterized in that the loading device ( 10 ) the movement profile of the driver ( 13 ) with the help of calendar entries of the driver ( 13 ). Method according to one of the preceding claims, characterized in that the loading device ( 10 ) the movement profile of the driver ( 13 ) by means of order and / or payment processes of the driver ( 13 ). Method according to one of the preceding claims, characterized in that - the loading device ( 10 ) in a fourth step (D) interrupts the charging process when the battery ( 11 ) has reached the charging target or has reached an SOC sufficient to reach the next travel destination of the vehicle ( 12 ) to reach. Method according to one of the preceding claims, characterized in that the loading device ( 10 ) the loading destination based on the route planning or calendar entries of the driver ( 13 ). Method according to one of the preceding claims, characterized in that the loading device ( 10 ) proposes the loading target and the driver ( 13 ) can correct the loading target.

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