DE102020209241A1 - Method for operating a charging device and charging device - Google Patents

Abstract

The invention relates to a charging device (1) and a method for operating a charging device (1) for charging a battery of a vehicle, comprising: - separating an electrical connection between a vehicle-side connection (2) of the charging device (1) and a mains-side connection (3 ) the charging device (1), - determining the functionality of a fault current sensor (8) of the charging device (1), - enabling the establishment of the electrical connection if the functionality is determined.

Description

The invention relates to a method for operating a charging device for charging a battery of a vehicle and such a charging device.

Known from the prior art is the DE 10 2018 219 296 A1 , which discloses a device for charging a battery of an electrically powered motor vehicle, this device having a first plug element with AC contacts for connection to a household electricity network, a second plug element with DC contacts for supplying a charging DC voltage to the battery of the motor vehicle and one between the AC contacts and the DC contacts switched voltage converter for converting an AC voltage provided by the domestic electricity network into the charging DC voltage. Furthermore, this publication discloses that a residual current circuit breaker can be present, which separates the AC contacts from the voltage converter in the event of a fault.

Further known is the US 2012/0286729 A1 which discloses an apparatus for electric power supply of a vehicle, wherein an overcurrent protection circuit prevents excessive current flow to the electric vehicle. This document also discloses that test signals for a ground fault detector can be generated. Also disclosed is a test signal for the overcurrent protection circuit. However, this publication discloses an AC charger whose vehicle-side connection is an AC connection.

To charge electric or hybrid vehicles, an AC power pack in the form of a charging wall box or a charging cable is usually connected to the vehicle. In the vehicle, an on-board charger then converts the AC voltage into the DC voltage required for charging the drive battery and adjusts the voltage level according to the state of charge. The maximum possible charging power is dependent on both the AC power pack and the on-board charger.

The disadvantage is that the on-board charger is only required for AC charging, which is carried out when the vehicle is stationary. When the vehicle is driving, the on-board charger has no function and is only carried along.

External DC chargers, which allow the vehicle battery to be charged without a charger on board the vehicle, are currently mostly chargers with a high charging capacity. A high level of operational reliability combined with a compact and inexpensive design is desirable for such a charging device.

The technical problem thus arises of creating a method for operating a charging device and a charging device for charging a battery of a vehicle which provide improved operational safety while at the same time having a compact and inexpensive design of the charging device.

The technical problem is solved by the subject matter having the characteristics of the independent claims. Further advantageous configurations of the invention result from the dependent claims.

A method for operating a charging device for charging a battery, in particular a traction battery, of a vehicle, in particular an electrically driven or drivable motor vehicle, is proposed. Such a vehicle can be an electric vehicle, which only stores the energy required for the drive in a battery, an electric vehicle with a range extender, a hybrid vehicle and/or a plug-in hybrid vehicle.

The charging device is particularly suitable for enabling the battery to be charged without using a charger arranged on the vehicle, in particular a so-called on-board charger, e.g. from an AC voltage network such as a household electricity network or a different AC voltage source. To charge the battery, the charging device can be connected to the AC voltage source mentioned and to a charging connection of the vehicle. For this purpose, a connection of the charging device on the vehicle side can be connected to a vehicle connection, ie a connection of the vehicle. A mains-side connection of the charging device can also be connected to a mains connection, that is to say a connection to the supply network or the supply voltage source. The vehicle connection can in particular be a direct current connection. Thus, the connection of the charging device on the vehicle side can also be a DC connection. Thus, the charging device is a DC charging device. The mains-side connection of the charging device can be an AC connection. However, the line-side connection can also be a DC connection.

The method includes disconnecting an electrical connection between the vehicle-side connection of the charging device and the mains-side connection of the charging device. This connection can, as mentioned in the introduction DE 10 2018 219 296 A1 , are produced via connector elements.

The electrical connection is separated in particular in a state in which the connection of the charging device on the vehicle side is connected to the vehicle connection and the connection of the charging device on the mains side is connected to the mains connection.

The disconnection can take place in particular by a means for disconnecting and establishing the electrical connection, with this means being comprised by the charging device. The means can in particular include a switching element, more particularly an isolating switching element. The means can also comprise a control device for generating switching signals for disconnection or production. The means for separating and establishing can, for example, separate or establish at least one connecting line for connecting the vehicle-side and network-side connection. Disconnecting ensures that no electrical energy can be transferred from the mains connection to the vehicle connection via the charging device.

The method also includes determining the functionality of a residual current sensor of the charging device. Through this determination, a functionality of the residual current sensor can be established. A lack of functionality of the fault current sensor can also be determined. The charging device may include the residual current sensor. This can detect a fault current and, if a fault current is detected, generate a fault current signal. This can be provided at an error current signal output of the error current sensor. Furthermore, the fault current sensor can also include a circuit breaker function. For example, the fault current sensor can be arranged and/or designed in such a way that it disconnects the electrical connection between the vehicle-side connection of the charging device and the mains-side connection of the charging device if a fault current is detected. For this purpose, the explained at least one connecting line can be separated. However, the leakage current sensor is different from the means for separating and making.

The method also includes enabling the establishment of the electrical connection between the connection of the charging device on the vehicle side and the connection of the charging device on the mains side if the functionality is determined.

In this case, this release does not necessarily include the establishment of the electrical connection mentioned. Rather, the charging device is put into a released state by the release, with the electrical connection being able or being established only in this released state. In a non-released state, the electrical connection cannot or will not be established. This can mean, for example, that in the released state, but not in the non-released state, a switching signal generated by a control device, for example, for establishing the electrical connection is actually used to control the corresponding means for establishing it.

This advantageously results in improved operational reliability of the charging device, since it is ensured that the electrical connection for charging via the charging device is only established when the residual current sensor is functional.

In a further embodiment, the method additionally comprises determining the functionality of a resettable flip-flop means of the charging device, a reset input of the flip-flop means being connected to the error current signal output of the error current sensor. The residual current signal output of the residual current sensor can denote a signal output at which, in the event of a fault, a residual current signal is provided and can be tapped off. In particular, an error current signal can therefore be transmitted from the error current sensor to the reset input of the flip-flop means and reset a set state.

Here, the loading device can be in the non-released state in the reset state of the toggle means and in the released state in the set state of the toggle means.

Furthermore, the release for establishing the electrical connection only takes place if the operability of the resettable flip-flop means is also determined. The release does not take place if this functionality is not determined.

The use of a flip-flop means and enabling the establishment of the electrical connection only when this flip-flop means is functional further increases operational reliability in an advantageous manner. Thus, the use of the toggle means enables the establishment of the released state of the loader to require setting of the toggle means, which setting can only be carried out under certain conditions, which in turn enables this setting to be carried out only under reliable conditions gene to perform. This is particularly advantageous when an error current signal is generated by the error current sensor and this has led to the flip-flop means being reset. Thereafter, the flip-flop means can be set and thus the released state can only be established when the residual current sensor is functional (again).

In a further embodiment, in order to test the functionality of the resettable flip-flop means, a set input of the resettable flip-flop means is supplied with a set signal for setting the output signal of the flip-flop means to a predetermined enable signal. In this case, the charging device can be in the released state when the flip-flop means generates the release signal as an output signal. In particular, the enable signal is therefore generated in the set state. The predetermined enable signal can in particular have a predetermined signal level, for example a signal level which represents a logical one. For example, it is possible for an output signal of the flip-flop to have a first level, for example a high level, or a further level, for example a low level, with the levels being different from one another. In this case, the first or the further level can represent a logical one.

Furthermore, the actual output signal of the resettable flip-flop means is detected after the application of the set signal and compared with the predetermined enable signal. For example, the signal levels of these signals can be compared for this purpose. Furthermore, the operability of the resettable flip-flop means is determined if the output signal is equal to the predetermined enable signal. In other words, it is analyzed whether a behavior of the resettable flip-flop means corresponds to the desired behavior.

In the case of an operable flip-flop means, applying the set signal to the set input can lead to the provision of an output signal having the first level. However, if it is detected that the actual output signal does not have the first level, then a lack of functionality of the resettable flip-flop means is determined. However, if it is detected that the level of the output signal corresponds to the first level, then an operable flip-flop means is determined.

Alternatively, to check the functionality of the resettable flip-flop means in the event of an error detected by the fault current sensor, the output signal of the resettable flip-flop means is recorded and compared to a predetermined blocking signal of the flip-flop means, with the functionality of the resettable flip-flop means being determined if the output signal is equal to the predetermined blocking signal . In this case, the charging device can be in the non-released state, which can also be referred to as the blocked state, when the flip-flop means generates the blocking signal as the output signal. In particular, the blocking signal is generated in the reset state of the flip-flop means. In particular, the predetermined blocking signal can have a predetermined signal level that differs from the signal level of the enable signal, for example a signal level that represents a logical zero.

If the fault current sensor detects a fault, it generates a fault current signal which is transmitted from the fault current signal output of the fault current sensor to the reset input of the flip-flop means, which then generates the blocking signal after successful resetting. If this blocking signal is then detected, the functionality can be determined. If the resetting is not successful and the blocking signal is therefore not generated either, then a lack of functionality of the flip-flop means can be detected.

This results in an advantageous manner in a simple and reliable check of the functionality of the resettable flip-flop means and thus in a simple and reliable production of the improved operational safety.

In a further embodiment, a fault current is generated to check the functionality of the fault current sensor. Alternatively, a test signal for testing the functionality can be applied to a test connection of the residual current sensor. In the latter case, it is possible for the residual current sensor to have a corresponding test signal input connection, with the residual current sensor checking its functionality if a corresponding input signal is present at this connection.

It is also checked whether the residual current sensor generates a residual current signal, with the functionality of the residual current sensor being determined if the residual current sensor generates the residual current signal. This results in an advantageous manner in a simple and reliable check of the functionality of the fault current sensor.

In a further embodiment, the release for establishing the electrical connection takes place by setting an output signal of the resettable flip-flop means to the release signal explained. This can be done by setting the resettable flip-flop means, in particular by applying a set signal to a set input. As explained above, the electrical connection between the terminals of the charging device can only be established in this released state, which is given when the output signal of the resettable flip-flop corresponds to the release signal.

Furthermore, a non-released state can be produced, that is to say the non-release for establishing the electrical connection, by setting the output signal of the resettable flip-flop means to the blocking signal explained. This can be done by resetting the flip-flop means, in particular by applying a corresponding signal to the reset input. The level of the enable signal can correspond to the level of the output signal which is set in the case of an operable flip-flop when the set input is supplied with a set signal. The level of the blocking signal can correspond to the signal level of the output signal of the flip-flop means, which occurs when the flip-flop means is operational when a reset signal, for example the error current signal, is applied to the reset input.

In order to establish the electrical connection, in addition to the enable signal generated by the flip-flop means, it may also be necessary to generate a switching signal for establishing the electrical connection. In particular, a switching element of the charging device can only be put into a state in which the electrical connection between the terminals of the charging device is established via the switching element if both the enable signal generated by the flip-flop means and the corresponding switching signal for establishing the electrical connection are generated. Correspondingly, the electrical connection between the terminals can be separated via a switching element if, although the release signal is generated by the flip-flop means, a switching signal for the separation is generated. The electrical connection is also separated if a switching signal for establishing the electrical connection is generated, but the flip-flop means generates the blocking signal. It is conceivable that the resultant drive signal for driving the means for making or separating is the output signal of an AND gate whose input signals are the output signal of the flip-flop means and the switching signal.

This advantageously results in a simple implementation of the release for establishing the electrical connection, as a result of which the improved operational reliability can advantageously be provided in a simple manner.

In a further embodiment, the functional capability of the residual current sensor is determined whenever an energy supply to the charging device is established, in particular when an energy supply to a control device of the charging device is established. In particular, it is possible for the residual current sensor to function exclusively or only when the power supply mentioned is established. This can mean that the operability is not determined or is blocked after the energy supply of the charging device has been completely established, in particular for a predetermined period of time after the start of the establishment, preferably until the next time the energy supply is established. This can also mean that the operability is not determined if the charging device is not supplied with energy, in particular for a predetermined period of time.

In particular, the start of the establishment of the power supply can generate a trigger signal, with the functionality of the fault current sensor being determined when the trigger signal has been generated.

This advantageously results in a further improvement in operational reliability, since the functionality is checked each time the charging device is restarted, thereby reducing the probability of states with non-functionality occurring, without a user interaction being necessary.

The charging device can be supplied with energy, for example, when the mains-side connection of the charging device is connected to a mains connection and/or when the vehicle-side connection of the charging device is connected to a vehicle connection.

In a further embodiment, a control device controls the disconnection of the electrical connection between the connection of the charging device on the vehicle side and the connection of the charging device on the mains side. Alternatively or cumulatively, the control device carries out the determination of the operability of the residual current sensor and/or the determination of the operability of the resettable flip-flop means. In particular, a set signal can be generated by the control device and transmitted to the set input of the flip-flop means. Furthermore, the output signal of the resettable flip-flop means can be detected by the control device and compared with a predetermined output signal. Furthermore, an error detected by the fault current sensor can be detected by the control device the. For this purpose, the residual current output signal of the residual current sensor can be detected by the control device.

Furthermore, a fault current can be generated by the control device or a device for generating the fault current can be controlled accordingly. The control device can also apply a test signal to a test connection of the residual current sensor.

In this case, the control device can be in the form of a microcontroller or an integrated circuit or can include one or more.

Furthermore, the functional capability of the residual current sensor can be determined, in particular only when an energy supply is established for the control device of the charging device. In this case, the control device can be connected to the mains-side connection and/or to the vehicle-side connection of the charging device, for example via suitable power converters and/or voltage regulators.

This advantageously results in a reliable implementation of the method according to the invention.

A charging device for charging a battery of a vehicle is also proposed. This includes a vehicle-side connection, a network-side connection, means for separating and establishing an electrical connection between the vehicle-side and the network-side connection and at least one residual current sensor in the electrical connection between the vehicle-side and network-side connection.

Furthermore, the charging device is configured in such a way that a method for operating a charging device according to one of the embodiments described in this disclosure can be carried out with the charging device.

This advantageously results in a device for carrying out a corresponding method with the technical advantages already mentioned.

The charging device can additionally include at least one rectifier and/or at least one voltage controller. Furthermore, the charging device can include fuses.

The charging device can in particular be a transformerless charging device. This can mean that no transformer, in particular no transformer for galvanic isolation between the two connections, is arranged in the electrical connection between the vehicle-side connection and the network-side connection.

Furthermore--as explained above--the loading device can comprise a control device which carries out or controls one, several, but not all, or all steps of the method.

In a further embodiment, the charging device comprises a resettable flip-flop means whose reset input is connected to a fault current signal output of the fault current sensor. Furthermore, the resettable flip-flop means can be used to provide an enable signal for establishing the electrical connection between the connection on the vehicle side and the connection on the mains side as an output signal. The resettable flip-flop means can be designed in particular as an electronic circuit. This electronic circuit can be different from an electronic circuit of the control device, in particular it can be constructed differently from it. In other words, the control device and the flip-flop means can have different components or units.

However, it is also conceivable for the resettable flip-flop means to be in the form of software means. In this case the controller can provide the operation of the resettable flip-flop means.

Advantageously, the presence of the resettable toggle means, as discussed above, allows for an improvement in the operational reliability of the loading device.

In a further embodiment, the means for separating and establishing an electrical connection and/or the resettable flip-flop means is/are designed at least partially as software means. In the first case, a control device can provide the functionality of the means for separating and/or establishing the electrical connection or at least some of the functions of this means and in particular can generate a (resulting) control signal for the means only under certain conditions. This advantageously results in a charging device that takes up little installation space and manufacturing costs, since no separate electronic circuits are required to provide the means for separating and producing and/or the resettable flip-flop means.

• 1 ein schematisches Blockschaltbild einer erfindungsgemäßen Ladevorrichtung gemäß einer ersten Ausführungsform,
• 2 ein schematisches Flussdiagramm eines erfindungsgemäßen Verfahrens,
• 3 ein schematisches Blockschaltbild eines Teils einer erfindungsgemäßen Ladevorrichtung in einer weiteren Ausführungsform und
• 4 ein schematisches Blockschaltbild einer erfindungsgemäßen Ladevorrichtung in einer weiteren Ausführungsform.

The invention is explained in more detail using exemplary embodiments. The figures show:

• 1 a schematic block diagram of a charging device according to the invention according to a first embodiment,
• 2 a schematic flow chart of a method according to the invention,
• 3 a schematic block diagram of a part of a charging device according to the invention in a further embodiment and
• 4 a schematic block diagram of a charging device according to the invention in a further embodiment.

In the following, the same reference symbols designate elements with the same or similar technical features.

1 shows a schematic block diagram of a charging device 1 according to the invention. It is shown that the charging device 1 has a connection 2 on the vehicle side and a connection 3 on the mains side. These are used to connect the charging device 1 to a vehicle connection of a vehicle, not shown, or to connect the charging device 1 to a mains connection of an energy source, not shown, for example an energy supply network. In particular, connecting lines 19 and a protective conductor 18 of the charging device 1 can be connected to the mains connection and vehicle connection. This protective conductor 18 is represented by a dashed line, which is connected to corresponding protective conductor connections of the connection 2, 3 on the vehicle side and on the mains side. Connection lines 19, which are connected to corresponding connection line connections of the connection 2, 3 on the vehicle side and on the network side, are represented by solid lines.

It is also shown that the charging device 1 comprises a control device 4 designed as a microcontroller.

The charging device 1 also includes an interference suppression filter 5, a first rectifier 6, a voltage controller 7 and a fault current sensor 8, these elements being arranged in an electrical connection between the vehicle-side and the mains-side connection 2, 3.

A fault current signal is generated by the fault current sensor 8 when a fault current is detected. This can be the case, for example, if a difference between the currents flowing in the connecting lines 19 is greater than a predetermined threshold value. For example, this threshold may be 6 mA in the DC portion of charger 1 and 30 mA in the AC portion of charger 1.

It is also shown that the charging device 1 comprises a first switching element 9, which is designed in particular as a switching element, and a further switching element 10, which is also designed as a switching element. The first isolating switching element 9 is arranged in an electrical connection between the line-side connection 3 and the first rectifier 6 . It is shown that the interference suppression filter 5 is also arranged in this electrical connection, with the first switching element 9 in turn being arranged in the electrical connection of the interference suppression filter 5 to the first rectifier 6 . Thus, AC terminals of the first rectifier 6 are connected to the noise filter 5 via the first switching element 9 . DC connections of the first rectifier 6 are connected to the voltage regulator 7, in particular input connections of this voltage regulator 7, with output connections of the voltage regulator 7 being connected to the connection 2 on the vehicle side via the fault current sensor 8. The further switching element 10 is arranged in the electrical connection between the fault current sensor 8 and the connection 2 on the vehicle side. Fuses 11 are also shown, which are arranged in the electrical connection between the residual current sensor 8 and the vehicle-side connection 2 and in the electrical connection between the mains connection 3 and the interference suppression filter 5 .

The first switching element 9 is thus arranged in an AC voltage section of the charging device 1 and the further switching element 10 is arranged in a DC voltage section of the charging device 1 .

The charging device 1 also includes a further rectifier 12 whose AC voltage connections are connected to the mains connection 3 , in particular via a fuse 11 . This additional rectifier 12 is used to provide a DC supply voltage for the control device 4.

It is shown that the control device 4 includes a first switching signal output 13a for providing a switch-on or switch-off signal for the first switching element 9 . It is also shown that the control device 4 includes a second signal output 13b for providing a setting signal for a resettable flip-flop 14, this second signal output 13b being connected to a set input of this flip-flop 14 in terms of signals. The control device 4 also includes a third signal output 13c for providing a test signal for the fault current sensor 8, this third signal output 13c being connected to a test signal input of the fault current sensor 8. The control device 4 also includes a fourth signal output 13d for providing a switch-on or switch-off signal for the further switching element 10.

The control device also includes a first signal input 15a, which is connected to a signal output of the flip-flop 14. The control device 4 also includes a second signal input 15b which is connected to a fault current signal output of the fault current sensor 8 .

The charging device also includes a first AND gate 16, with a first input of AND gate 16 being connected to the first signal output 13a of control device 4 and a further signal input of first AND gate 16 being connected to the signal output of flip-flop 14. The charging device 1 also includes a further AND gate 17, a first signal input of the further AND gate 17 being connected to the fourth signal output 13d of the control device 4 and a further signal input of the further AND gate 17 being connected to the signal output of the flip-flop 14.

in the in 1 In the illustrated embodiment of the charging device 1, the flip-flop 14 can be set by providing a set signal at the second signal output 13b of the control device 4, with an output signal representing a logical one being generated by the flip-flop 14 in the set state. This output signal corresponds to an enable signal.

Due to the connection to the AND gates 16, 17, it is only possible in this set state to establish (and disconnect) the electrical connection between the network-side and the vehicle-side connection 3, 2 of the charging device by moving the switching elements 9, 10 into a closed ( or open) state. For this purpose, the control device 4 can, for example, provide corresponding switching signals at the first and fourth signal output 13a, 13d. If, for example, a switching signal representing a logical one is provided at these signal outputs 13a, 13d, then a signal representing a logical one is present at the signal outputs of the AND gates 16, 17, even if flip-flop 14 is also set state is. This output signal of the AND gates 16, 17 can then be a resultant control signal for putting the switching elements 9, 10 into the closed state, as a result of which the electrical connection between the vehicle-side and the mains-side connection 2, 3 is established.

If the flip-flop 14 is in the set state and the control device 4 generates a switching signal at the first and the fourth signal output 13a, 13d which represents a logical zero, this correspondingly causes the switching elements 9, 10 to be set to the open state.

If flip-flop 14 is reset, ie if it is in the reset state, it generates an output signal at the signal output which represents a logical zero. This output signal corresponds to a blocking signal. In this case, both the first and the further switching element 9, 10 due to the AND gates 16, 17, which then also each generate an output signal which represents a logical zero, placed in the open state, whereby the electrical connection between the vehicle-side and the mains-side connection 2, 3 is separated. When the flip-flop 14 is in the reset state, the arrangement of the AND gates 16, 17 means that no control signal can be generated to establish the electrical connection via the switching elements 9, 10, regardless of which switching signals the control device 4 sends at the first or fourth signal output 13a , 13d provides.

At the in 1 illustrated embodiment, the control device 4 is supplied with energy via the further rectifier 12 when the electrical connection between the charging device 1 and an external energy source is established via the mains-side connection 3 . This can 2 The methods shown are always carried out when such a production of the energy supply takes place.

Alternatively, it is of course also possible to use the method for operating the charging device 1 according to FIG 2 always (only) to be carried out when the control device 4 is supplied with energy by establishing an electrical connection between the control device 4 and a vehicle energy source via the vehicle-side connection 2 .

It is conceivable that a vehicle identifier, for example in the form of a vehicle address, can be queried and stored via a communication interface (not shown), which can in particular be part of the vehicle-side connection 2, for example in a storage device (not shown) of the charging device 1. If a fault current signal of the fault current -Sensor 8 detected, the vehicle identifier can be assigned an incorrect state, with this information is also stored.

The vehicle identifier can then be queried again when the charging device 1 is connected to this vehicle again, in which case a renewed querying of the vehicle identifier can be detected. It can also be checked whether an incorrect status is assigned to this vehicle identifier. If this is the case, the release for establishing an electrical connection cannot be made respectively. If no faulty state is assigned to the vehicle identification or if this is unknown, the release can take place.

It is of course possible for the assignment of an incorrect status to the vehicle identifier to be reset by suitable reset options, as a result of which the vehicle identifier is then no longer assigned an incorrect status.

This makes it possible in an advantageous manner that a vehicle, during the charging process of which a fault current was detected, cannot be reconnected to an external energy source, which increases operational reliability.

It is further possible that the in 2 The method shown is also carried out when a corresponding start signal is generated, for example by a user actuating a corresponding input device, for example in the form of a reset button on/in the charging device 1.

The functioning of the in 1 The loading device 1 shown is illustrated using the schematic flow chart shown in 2 is shown, explained, with this flowchart showing a method according to the invention for operating the in 1 illustrated loading device 1 represents.

In a first step S1 of the method, the electrical connection T is disconnected between the vehicle-side and the mains-side connection 2, 3 of the charging device 1 (see 1 ) by the control device 4 providing corresponding switching signals at the first and fourth signal output 13a, 13d. Furthermore, in the first step S1, the flip-flop 14 is put into a set state in that the control device 4 provides a corresponding set signal at the second signal output 13b. This can be done before the switching signals are provided.

In a first test step PS1, it is checked whether the output signal provided at the signal output of flip-flop 14 corresponds to a predetermined output signal, in particular an output signal representing a logical one, ie the enable signal. For this purpose, the control device 4 can determine the signal level present at the first signal input 15a and compare it with a predetermined signal level. If the signal level does not correspond to the predetermined signal level, a flip-flop error signal FS14 is generated and the method is terminated.

If the signal level corresponds to the predetermined signal level of the enable signal, the functionality of the residual current sensor 8 is checked by the control device 4 providing B a corresponding test signal at the third signal output 13c, which is transmitted to a test input of the residual current sensor 8 and a test process triggers.

In a further test step PS2 it is then checked whether a residual current signal is present at the residual current signal output of the residual current sensor 8 . For this purpose, the control device 4 can determine a signal level of the signal present at the second signal input 15b and compare it with a predetermined signal level. In particular, it can be determined whether the signal level represents a logical one.

If no error current signal is generated by the error current sensor, then an error current sensor error signal FS8 is generated and the method ends. However, if an error current signal from the error current sensor 8 is detected, the functionality of the error current sensor 8 can be determined.

In this case, the flip-flop 14 is reset R, and in a further test step PS3 it is checked whether the flip-flop 14 generates an output signal which corresponds to a predetermined blocking signal. This can be done by determining a signal level of the signal present at the first signal input 15a of the control device 4 and comparing it with a predetermined locking signal level, which in particular can represent a logical zero.

If the flip-flop 14 does not generate the blocking signal after the residual current signal has been generated by the residual current sensor 8, a flip-flop error signal FS14 is generated and the method is ended.

However, if the flip-flop 14 generates the predetermined blocking signal, the control device 4 terminates BE the provision of the test signal at the third signal output 13c and then sets the flip-flop 14 again by providing B a corresponding setting signal at the second signal output 13b of the control device 4 the release for establishing the electrical connection between the vehicle-side and the mains-side connection 2, 3 of the charging device 1 is effected.

If it is therefore detected that flip-flop 14 generates the blocking signal, a release for establishing the electrical connection between the vehicle-side and the network-side occurs Connection of the charging device 1 by the flip-flop 14 being placed in the set state, in particular by the control device 4 providing a corresponding setting signal at the second signal output 13b.

3 shows a schematic block diagram of a part of a charging device according to the invention 1. In 3 Various possible arrangements of the residual current sensor 8 are represented by dashed lines, which are alternatives to the one shown in 1 shown arrangement can be selected. In one to the in 1 In the first alternative arrangement shown, the residual current sensor 8 is arranged in the electrical connection between the first rectifier 6 and the voltage controller 7 . In other words, DC connections of the first rectifier 6 are connected to the voltage controller 7, in particular its input connections, via the fault current sensor 8.

In a second alternative, the residual current sensor 8 is arranged between the first switching element 9 and AC connections of the first rectifier 6 . In other words, output terminals of the first switching element 9 can be connected to the AC terminals of the first rectifier 6 via the leakage current sensor 8 .

In a third alternative, the residual current sensor 8 can be arranged in the electrical connection between the interference suppression filter 5 and the first switching element 9 . In other words, the interference suppression filter 5 can be connected to the input terminals of the first switching element 9 via the leakage current sensor 8 .

In a fourth alternative, the residual current sensor 8 is arranged in the electrical connection between the mains-side connection 3 and the interference suppression filter 5 . In other words, the line-side connection 3 is connected to the interference suppression filter 5 via the residual current sensor 8 .

through the in 1 The illustrated arrangement of the residual current sensor 8 in the electrical connection between the voltage regulator 7 and the vehicle-side connection 2 results in an advantageous manner in that energy stored by capacities, not shown, of the charging device 1 cannot delay the triggering time of the residual current sensor, or only minimally, particularly since fault currents do not first charge these capacitances, not shown, and the difference discussed above can be detected later than desired.

In the 3 The illustrated arrangement of the fault current sensor 8 according to the second, the third, the fourth and the fifth alternative can therefore require that the time at which the fault current signal is generated is determined as a function of the capacity of the charging device 1 .

The arrangement of the fault current sensor 8 according to the fifth alternative results in a technically advantageous manner in that all elements of the charging device 1 and also a vehicle connected to the charging device 1 are protected in the event of a fault current.

4 shows a schematic block diagram of a charging device 1 according to the invention in a further embodiment. In contrast to the in 1 illustrated embodiment, the functionality of the in 1 shown flip-flop 14 and in 1 AND gates 16, 17 shown are provided by software means, the functions provided by these software means being executed by the control device 4. In this case, the control device 4 does not require a signal output 13b to provide a setting signal and a signal input 15a to tap the output signal of the flip-flop 14.

Reference List

1

loading device

2

vehicle connection

3

mains connection

4

control device

5

noise filter

6

first rectifier

7

voltage regulator

8th

residual current sensor

9

first switching element

10

another switching element

11

fuses

12

another rectifier

13, ..., 13d

signal outputs

14

resettable flip-flop

15a, 15b

signal inputs

16

first AND gate

17

another AND gate

18

protective conductor

19

connection conductor

T

Separate

B

Provide

BE

End

PS1, PS2, PS3

test step

FS14

Flip-flop mean error signal

FS8

Residual current sensor error signal

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited 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

• DE 102018219296 A1 [0002, 0011]
• US 2012/0286729 A1 [0003]

Claims (10)

Method for operating a charging device (1) for charging a battery of a vehicle, comprising: - Disconnecting an electrical connection between a vehicle-side connection (2) of the charging device (1) and a mains-side connection (3) of the charging device (1), - Determining a functionality of a fault current sensor (8) of the charging device (1), - Release to establish the electrical connection if the functionality is determined. procedure after claim 1 , characterized in that the method additionally comprises determining an operability of a resettable flip-flop means (14), the reset input of which is connected to an error signal output of the error current sensor (8), the release for establishing the electrical connection taking place, albeit additionally the operability of the resettable toggle means (14) is determined. procedure after claim 2 , characterized in that to test the functionality of the resettable flip-flop means (14), a set input of the resettable flip-flop means (14) is supplied with a set signal for setting an output signal of the flip-flop means (14) to a predetermined enable signal, the output signal of the resettable flip-flop means (14 ) is detected and compared with the predetermined enable signal, the operability of the resettable flip-flop means (14) being determined if the output signal is equal to the predetermined enable signal or that in the event of a fault current sensor (8) detected error, the output signal of the resettable flip-flop means ( 14) is detected and compared to a predetermined disable signal, the operability of the resettable flip-flop means (14) being determined if the output signal is equal to the predetermined disable signal. Method according to one of the preceding claims, characterized in that to check the functionality of the fault current sensor (8) a fault current is generated or a test connection of the fault current sensor (8) is supplied with a test signal, it being checked whether this generates a fault current signal , The functionality of the fault current sensor (8) is determined if the fault current sensor (8) generates the fault current signal. Method according to one of the preceding claims, characterized in that the enabling for establishing the electrical connection takes place by setting an output signal of a resettable flip-flop means (14) to a predetermined enabling signal. Method according to one of the preceding claims, characterized in that the functional capability of the residual current sensor (8) is determined when an energy supply to the charging device (1) is established. Method according to one of the preceding claims, characterized in that a control device (4) controls the disconnection of the electrical connection between the vehicle-side connection (2) of the charging device (1) and the mains-side connection (3) of the charging device (1) and/or the Determining the operability of the fault current sensor (8) and / or determining the operability of the resettable flip-flop means (14). Charging device for charging a battery of a vehicle, comprising a vehicle-side connection (2), a network-side connection (3), means for disconnecting and establishing an electrical connection between the vehicle-side and network-side connection (2, 3) and at least one residual current sensor (8 ) in the electrical connection between the vehicle-side and network-side connection (2, 3), wherein the charging device (1) is configured to carry out the following steps: - Disconnecting an electrical connection between the vehicle-side connection (2) of the charging device (1) and the mains-side connection (3) of the charging device (1), - Determining a functionality of the residual current sensor (8), - Release to establish the electrical connection if the functionality is determined. charger after claim 8 , characterized in that the charging device (1) comprises a resettable flip-flop means (14), the reset input of which is connected to an error signal output of the residual current sensor (8) and through which a release signal for the establishment of the electrical connection between the vehicle-side and network-side Connection (2, 3) can be provided as an output signal. Loading device according to one of Claims 8 or 9 , characterized in that the means for separating and establishing an electrical connection and/or the resettable flip-flop means (14) are designed as software means.

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