EP2646273A2

EP2646273A2 - Charging apparatus for motor vehicles, and charging method

Info

Publication number: EP2646273A2
Application number: EP11763685.2A
Authority: EP
Inventors: Stephan Gase; Jochen Fassnacht
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2010-12-02
Filing date: 2011-09-29
Publication date: 2013-10-09
Also published as: CN103313871B; CN103313871A; WO2012072308A2; DE102010062369A1; WO2012072308A3

Abstract

The present invention discloses a charging apparatus without potential isolation for motor vehicles: having a first switchable isolation apparatus (1) which is designed to open and/or to close at least the conductor (LL), through which current flows, of a charging cable (11) which couples the charging apparatus (15) to a supply system, in order to establish or cancel potential isolation between the vehicle mass and neutral conductors of the charging cable (11); having a second switchable isolation apparatus (2) which is designed to open and/or to close at least one line (LB), which connects a high-voltage vehicle battery (7) to the charging apparatus (15) and/or to an on-board vehicle electrical system (6); and having a monitoring apparatus (3) which is designed to monitor a fault state (F) of the charging apparatus (15) or of the motor vehicle (11) and to transmit a control signal (Sig1, Sig2) to the first and/or the second isolation apparatus (1, 2) depending on the fault state (F), and a charging method.

Description

Description title

Charging device for motor vehicles and charging method

Field of the invention

The invention relates to a loading device for motor vehicles with a

Vehicle high-voltage battery according to the preamble of independent claim 1, as known from DE 603 19 570 T2 and a charging method.

Technical background

In the development of modern motor vehicles plays a reduction of the

Fuel consumption of the motor vehicle is an increasingly important role. One measure to reduce the consumption of a motor vehicle is to combine the internal combustion engine with an electric drive in a hybrid vehicle. The electric drive in hybrid vehicles usually consists of an electric drive, which also as

Generator can be operated, a high-voltage energy storage, from which the electric drive is powered and an electronic control system.

There are three main types of hybrid vehicles. In a so-called mild hybrid, the electric drive mainly supports the internal combustion engine

Performance increase and the braking energy can be partially recovered. As electromotive powers about 6-14 kW are given.

The so-called full hybrid vehicles with an electromotive power of more than 20 kW are able to drive purely by electric motor.

In the hybrid variants mentioned so far, the high-voltage energy storage devices are charged by means of energy recovery using the electric drive operated as a generator. Charging the high-voltage energy storage via an external power source is not provided. To further reduce fuel consumption, the so-called plug-in hybrids offer the possibility of charging the high-voltage energy storage via an external energy source. In this case, the external energy source may be the public power grid, a solar and / or wind turbine or the like.

An alternative to vehicles with conventional internal combustion engines are electric vehicles. Unlike hybrid vehicles, electric vehicles do not have an internal combustion engine that can drive the motor vehicle. Therefore, in these vehicles charging the high-voltage energy storage via an external power source is necessary. The Hochvoltenergiespeicher is today usually as

Vehicle high-voltage battery trained.

To charge the vehicle high-voltage battery of a hybrid or electric vehicle via, for example, a public power grid, a charging device is necessary. Today usual charging devices have a charging electronics with a potential separation.

Usually, in a charging device for motor vehicles, a transformer in addition to the task of voltage adjustment also fulfills the task of potential separation. The

Potential separation in a charging device fulfills three important safety functions:

- Preventing electric shock when touching the plug contacts

unplugged charging plug and active high-voltage circuit;

Preventing saturation of an RCD circuit breaker in the electrical installation, from which the electrical energy for charging the vehicle's high-voltage battery comes from;

- Separation of the neutral conductor and the vehicle ground, creating a

Insulation monitoring in the vehicle during the charging process is possible.

Summary of the invention

The present invention provides according to claim 1, a charging device without

Potential Separation for Motor Vehicles: With a first switchable disconnecting device, which is designed to open and / or close at least the current-carrying conductors of a charging cable, which couples the charging device to a supply network, in order to establish or cancel a potential separation between the vehicle ground and neutral conductor of the charging cable ; with a second switchable disconnecting device, which is designed to at least one line which a vehicle high-voltage battery with the Charging device and / or a vehicle electrical system connects to open and / or close; and with a monitoring device which is designed to monitor a fault condition of the charging device or of the motor vehicle and to transmit to the first and / or the second disconnecting device a control signal as a function of the fault state.

Furthermore, the invention according to claim 7 provides a charging method for charging without electrical isolation for motor vehicles, in particular with an inventive

Charging apparatus, comprising the steps of: monitoring the charging device and the motor vehicle for electrical faults; Generating information about a fault condition of

Charging device and the motor vehicle; Transmitting an actuating signal for opening to a first separating device, which is designed to open and / or close at least the current-carrying conductors of the charging cable, which couples the charging device to a supply network, if the information about the error state indicates an error in the charging device and or indicates the motor vehicle; and / or transmitting an actuating signal for opening to a second disconnecting device, which is designed to open and / or close at least one line which connects a vehicle high-voltage battery to the charging device and / or a vehicle electrical system, if the information about the error state fails displayed in the charging device and / or the motor vehicle.

The realization of the present invention is that the safety functions that a transformer offers in a conventional charging device can be realized by other components in a charging system.

The idea underlying the present invention is now based on dispensing with potential separation in the charging device and realizing the safety functions by means of a suitable electrical circuit. A combination of two separation devices and a monitoring device as disclosed in the present invention is capable of doing the same

Emulate safety functions known by a transformer.

The risk of electric shock at the plug contacts with unplugged charging plug and active high voltage circuit can be prevented by the

Monitoring device, the first separator opens as soon as the charging plug from the Socket is removed. For safety reasons, the monitoring device also opens the first disconnecting device when a loading operation is completed.

With the charging device presented here, saturation of an RCD circuit breaker in the electrical installation, from which the electrical energy for charging the vehicle's high-voltage battery originates, can be reliably detected and eliminated. The

Saturation of the RCD circuit breaker is not a direct safety hazard, but causes a RCD circuit breaker, which usually protects several sockets, from becoming ineffective. An RCCB can saturate if a DC error current flows between one of the conductors and the vehicle ground. To do this with the present

Recognize charging device monitors the monitoring device, the charging device and the motor vehicle to a fault current and / or insulation fault. With the help of the present charging device, this is also possible during a charging process.

If an error is detected by the monitoring device or an insulation resistance that decreases due to humidity and / or dust, the first and second separation devices are opened and not closed again until the insulation resistance reaches a value that poses a risk to people

is excluded. If an insulation fault has been detected, this error can also be displayed to the driver via suitable display devices.

Advantageous embodiments and developments emerge from the others

Subclaims and from the description with reference to the figures of the drawings.

In an alternative embodiment, the first disconnecting device comprises at least one at least three-pole AC contactor for disconnecting the charging device from the supply network, and the second disconnecting device comprises at least one DC-DC contactor, at least two-pole, for disconnecting the vehicle's high-voltage battery from the vehicle

Charger and / or the vehicle electrical system on. The use of contactors makes it possible to reliably and quickly disconnect the power supply of the charging device in the event of a fault and prevents a residual current from flowing when the contactors are open, as is the case, for example, with semiconductor switches.

In a further alternative embodiment, the first separation device is designed to automatically open at least the current-carrying conductor of a charging cable when removing a charging plug of the charging cable from a power outlet. By the automatic opening of all lines, which the plug of the charging cable with the Connecting vehicle electrical system, it can be ensured that the contacts of the plug are potential-free. Touching the contacts is safe for people.

In yet another alternative embodiment, the first separation device is designed to automatically open at least the current-carrying conductor of the charging cable at the end of a charging process. If the lines which connect the motor vehicle to a supply network are automatically disconnected after completion of a charging process, it is prevented that the charging cable has an electrical voltage in the event of a fault, which could pose a risk to persons.

In yet an alternative embodiment, the monitoring device includes a DC fault measurement circuit configured to measure a DC error current that can flow between at least two conductors of the charging cable (11), and the monitoring device (3) is configured to detect a fault

Error direct current of the first and / or the second separation device (1, 2) to transmit a control signal (Sig1, Sig2) for opening. With the help of the DC fault measurement circuit, the charging cable and the charging device can be permanently checked for errors. If a fault current occurs in the charging cable or the charging device, the charging device can be disconnected immediately from the supply network. Thus, the charging cable is de-energized and at the same time a saturation of the RCD switch is prevented.

In a further alternative embodiment, the monitoring device is provided with an insulation monitoring device present in the motor vehicle and the first

Coupling device coupled, wherein the monitoring device is adapted to the first separation device at intervals of up to 15 minutes, preferably at intervals of up to 5 minutes to transmit a control signal to open, and the first and / or the second separation device in response to a result of the

Insulation monitoring device (5) to transmit a control signal for opening and / or closing. If a monitoring of the charging device and of the motor vehicle is carried out cyclically and for this purpose an insulation monitoring device already present in the motor vehicle is used, a dedicated DC fault measuring circuit can be dispensed with. This makes it possible to provide a more cost-effective charging device.

In an alternative embodiment, the two possibilities mentioned above for monitoring the charging device and the motor vehicle are combined. In such an embodiment, the monitoring device is provided with a

DC fault measuring circuit connected for permanent fault monitoring and asks additionally cyclically continues a vehicle-internal insulation monitoring device. This variant offers the greatest possible security, since errors can also be detected if one of the two devices, either the DC fault measuring circuit or the insulation monitoring device, has a defect.

The above embodiments and developments can, if appropriate, combine with each other as desired. Other possible embodiments, developments and

Implementations of the invention also include not explicitly mentioned combinations of features of the invention described above or below with respect to the exemplary embodiments. In particular, the person skilled in the art will also add individual aspects as improvements or additions to the respective basic form of the present invention.

In particular, in an alternative embodiment, additional sensors can be installed in the motor vehicle, which may possibly detect critical external conditions to which the charging device can react accordingly. For example, high humidity and / or a temperature near the dew point may cause the temperature to drop

Cause insulation resistance. To detect this early, for example, moisture sensors, which measure the humidity, or temperature sensors, which detect the ambient temperature of the motor vehicle, provided and

be evaluated.

In yet another alternative embodiment, a charging cable is provided, which connects the charging device to a socket, and which a

Separating device in a plug which is adapted to open the conductors, the neutral conductor, and the ground line of the charging cable, if a fault current between at least one of the conductors and the neutral conductor and / or the ground line flows. Wrd inserted in the plug of the charging cable, a separate RCD circuit breaker, the charging cable itself, even if it is not connected to the motor vehicle is de-energized. This is necessary, for example, when the charging cable is connected to the socket but not to the motor vehicle and the charging cable is damaged, for example by a lawnmower. A shutdown of the RCD circuit breaker can be evaluated in the monitoring device and automatically a shutdown of the first separation device can be initiated. The present invention may be for charging a vehicle high voltage battery to a conventional AC outlet, charging a vehicle high voltage battery to a three phase AC outlet, and charging a vehicle high voltage battery to another Voltage sources are used. When the invention is used for charging a vehicle high-voltage battery to an AC outlet, the first separation device in one embodiment has at least 2 poles, one for the

live conductor and one for the neutral conductor. Wrd the invention, however, used to charge a vehicle high-voltage battery to a three-phase outlet, the first separator in a further embodiment has at least 3 poles, one for each of the three live conductors L1, L2 and L3, and one for the eventually built neutral.

Brief description of the drawings

The present invention will be explained in more detail with reference to the exemplary embodiments given in the schematic figures. It shows:

Fig. 1 is a block diagram of an embodiment of the invention

Loader;

Fig. 2 is a block diagram of an embodiment of the invention

Charging method for loading for motor vehicles; and

Fig. 3 is a schematic representation of a motor vehicle with an alternative

Embodiment of a charging device according to the invention.

In all figures, the same or functionally identical elements and devices - unless otherwise stated - have been given the same reference numerals.

Description of exemplary embodiments

Fig. 1 shows a block diagram of an embodiment of the invention

Loading device for motor vehicles.

In Fig. 1, the reference numeral 15, an embodiment of a charging device according to the invention with a first separator 1, which is mounted in a first conductor LL, and with a second separator 2, which is mounted in a second conductor LB, shown. Both separators 1, 2 are also with a Monitoring device 3 is connected, which detects an error condition F, and the separation devices 1, 2 in response to the detected error state F respectively a control signal Sig1, Sig2 for opening or closing the respective conductor LL, LB sends. The first separation device 1 is designed in an embodiment according to the invention to open at least the current-carrying conductor LL of the charging cable 1 1, which connects the charging device 15 with a conventional AC power source 10, which provides electrical energy for charging the vehicle high-voltage battery 7. By contrast, the second separating device 2 is designed to open at least one current-carrying conductor which connects the vehicle high-voltage battery 7 to the charging device 15 or the vehicle electrical system 6. In an alternative embodiment, the charging device 15 is connected to a three-phase power source instead of an AC power source 10.

The monitoring device 3 monitors the motor vehicle 1 and in particular the charging device 15 for electrical errors by measuring at least one voltage drop between a current-carrying component and / or circuit element and a ground point in a circuit and / or the vehicle. In alternative embodiments, the monitoring device 3 may monitor the motor vehicle 1 and / or the charging device 15 for electrical faults by measuring a voltage drop across a measuring resistor or a current through a shunt resistor or current transformer. If the monitoring device 3 detects an electrical fault in the motor vehicle 1 which impairs the safety of the charging device 15 or of the motor vehicle 1, the monitoring device 3 sends an actuating signal Sig1, Sig2 for opening to the first and / or the second disconnecting device 1, 2 for a current flow interrupt. If the first and second separating device are designed as contactors, alternatively the holding voltage, which causes a closing of the contactors, can be switched off.

Fig. 2 shows a block diagram of an embodiment of the invention

Charging method for loading for motor vehicles.

In a first step S1, the charging device 15 and / or the motor vehicle 1 are monitored for electrical faults. In particular, the charging device 15 and the motor vehicle 1 are monitored for insulation faults, earth fault currents or sinking insulation resistances, which could result in a current flow between at least two of the conductors of the charging cable. In a second step S2, based on the monitoring of the charging device 15 and / or the motor vehicle 1, information about the error state F of

Loading device 15 and / or the motor vehicle 1 generated. In a third step S3, the first disconnecting device 1 or the separating device 9 is transmitted in the plug an actuating signal for opening, if the information on the fault condition F indicates an electrical fault. Thus, the motor vehicle is disconnected from the supply network to which it has been connected to charge the vehicle's high-voltage battery. By disconnecting the motor vehicle from the supply network is also due to the error possibly present saturation of an RCD circuit breaker in the

Supply network eliminated.

In a fourth step S4, the second separating device 2 is sent an actuating signal for opening if the information about the fault state F indicates an electrical fault. This step serves to protect the persons approaching the motor vehicle. By separating the vehicle high-voltage battery from the vehicle electrical system is prevented in the event of an error that body parts and / or other vehicle parts can be under tension. 3 shows a schematic representation of a motor vehicle with an alternative embodiment of the charging device 15 according to the invention.

In Fig. 3 is a motor vehicle 12 with an alternative embodiment of a

Charging device 15 according to the invention, consisting of a first separation device 1 and a second separation device 2, which are both connected to a monitoring device 3 and the vehicle electrical system 6, shown. The first separator 1 is further connected via a charging cable 11 and a plug 8 with separator 9 with a

AC voltage source 10 connected. The second separator 2 is connected to the

Vehicle high-voltage battery 7 coupled. The charging device also has one

DC fault measurement circuit 4, which is connected to the monitoring device 3. The monitoring device 3 can query an error information from the insulation monitoring device 5 present in the motor vehicle and is connected to the control of the existing in the plug 8 of the charging cable 1 1 RCD circuit breaker 9 with this.

In this embodiment, the monitoring device 3 monitors the

Charger with the help of the DC fault measurement circuit 4 and with the help of Insulation monitoring device 5. The monitoring is through the

DC fault measuring circuit 4 permanently active and the DC fault measuring circuit 4 can be queried as often as desired by the monitoring device 3. To the

To be able to monitor charging device with the aid of the insulation monitoring device 5, the monitoring device 3 must open the first disconnecting device 1 and then query error information from the insulation monitoring device 5. If the first separator 1 is not opened, the insulation monitoring device 5 can not work properly, since the neutral conductor and the ground line are then not galvanically separated from each other. The opening of the first separation device 1 happens here at intervals of 5 minutes. If the first separator 1 is opened, the

Error information can be queried and evaluated by insulation monitoring within a few seconds. If no insulation fault is detected, the

Monitoring device 3, the first separation device 1 after e.g. 5 seconds again and the charging of the vehicle's high-voltage battery continues. However, if an insulation fault is detected, if necessary or desired, the second separating device 2 or 9 can also be opened. In alternative embodiments, the interval at which the first separator is opened may be up to 20 minutes, more preferably up to 10 minutes. For safety reasons, the monitoring device also opens the first disconnecting device 1 when a charging operation is completed or when the monitoring device 3 detects that the plug 8 of the charging cable 1 1 has been removed from a socket.

Regardless of the monitoring device 3, the plug 8 of the charging cable 1 1 an RCD circuit breaker 9, which in the case of a fault current in the charging cable 11 the

Ladder and the neutral conductor of the charging cable opens.

Although the present invention has been described above with reference to preferred embodiments, it is not limited thereto, but modifiable in a variety of ways.

Claims

claims

1. Charging device without electrical isolation for motor vehicles: comprising a first switchable disconnecting device (1) which is designed to open at least the current-carrying conductors (LL) of a charging cable (11) which couples the charging device (15) to a supply network and / or to close to establish or cancel a potential separation between the vehicle ground and neutral of the charging cable (11); with a second switchable separating device (2), which is designed to at least one line (LB), which a vehicle high-voltage battery (7) with the

Charging device (15) and / or a vehicle electrical system (6) connects to open and / or close; and with a monitoring device (3), which is adapted to a

Fault condition (F) of the charging device (15) or of the motor vehicle (11) to monitor and the first and / or the second separating device (1,2) in dependence of

Error state (F) to transmit a control signal (Sig1, Sig2).

2. Loading device according to claim 1,

characterized ,

in that the first separating device (1) has at least one at least two-pole

AC contactor for disconnecting the charging device (15) from the supply network; and that the second separating device (2) has at least one at least two-pole

DC contactor for disconnecting the vehicle high voltage battery (7) from the

Charging device (15) and / or the vehicle electrical system (6).

3. Loading device according to one of the preceding claims,

characterized ,

in that the first separating device (1) is designed to at least the

current-carrying conductor of a charging cable (11) when removing a charging plug (8) of the charging cable (11) to open automatically from a socket.

Loading device according to one of the preceding claims,

characterized ,

in that the first separating device (1) is designed to at least the

current-carrying conductor of the charging cable (11) to open automatically at the end of a charging process.

Loading device according to one of the preceding claims,

characterized ,

in that the monitoring device (3) has a DC fault measuring circuit (4) which is designed to measure an error DC current which flows between at least two conductors of the charging cable (11), and in that the monitoring device (3) is designed to detect a fault

Error direct current of the first and / or the second separation device (1,2) each to transmit a control signal (Sig1, Sig2) for opening.

Loading device according to one of the preceding claims,

characterized ,

in that the monitoring device (3) is coupled to an insulation monitoring device (5) present in the motor vehicle (12) and to the first separating device (1), wherein the monitoring device (3) is designed to be the first one

Separating device (1) at intervals of up to 60 minutes, preferably at intervals of up to 5 minutes to transmit an actuating signal (Sig1) for opening, and the first and / or the second separating device (1,2) in response to a result of Insulation monitoring device (5) to transmit a control signal (Sig1, Sig2) for opening and / or closing.

Charging method for charging without electrical isolation for motor vehicles, in particular with a charging device (15) according to one of Claims 1 to 6,

with the steps:

Monitoring the charging device (15) and the motor vehicle (12) for electrical faults; Generating information about a fault condition of the charging device (15) and the motor vehicle (12);

Transmitting an actuating signal (Sig1) for opening to a first separating device (1), which is designed to at least the current - carrying conductor (LL) of the

Charging cable (11) which couples the charging device (15) to a supply network to open and / or close, if the information about the fault condition indicates a fault in the charging device (15) and / or the motor vehicle (12); and / or transmitting an actuating signal (Sig2) for opening to a second separating device (2), which is designed to be at least one line (LB), which a

Vehicle high-voltage battery (7) with the charging device (15) and / or a

Vehicle electrical system (6) connects to open and / or close, if the information about the error state a fault in the charging device (15) and / or

Motor vehicle (12) indicates.

8. Loading method according to claim 7,

characterized ,

in that a control signal (Sig1) for opening is transmitted to the first disconnecting device (1) as soon as a charging plug (8) which connects the charging device (15) to a supply network is disconnected from a socket.

9. Loading method according to one of claims 7 and 8,

characterized ,

in that a control signal (Sig1) for opening is transmitted to the first separating device (1) as soon as a charging process has ended.

10. Loading method according to one of claims 7 to 9,

characterized ,

in that the step of monitoring the charging device (15) and the motor vehicle (12) for electrical faults comprises the step of using a faulted DC current which flows between a conductor and the neutral conductor and / or the vehicle ground

To measure fault current measuring device (4). 11. Loading method according to one of claims 7 to 10,

characterized ,

in that the monitoring of the charging device (15) and the motor vehicle (12) electrical fault has the following steps:

Transmitting an actuating signal (Sig1) for opening to the first separation device (1) at intervals of up to 60 minutes, preferably at intervals of up to 5 minutes;

Polling an error information of an insulation monitoring device (5) while the first separation device (1) is opened;

Transmitting an actuating signal (Sig1) for closing the first separator (1) if the requested error information does not indicate an error; and

Eventually transmit an actuating signal (Sig2) to open to the second

Disconnector (2) if the requested error information indicates an error.