WO2011047952A1

WO2011047952A1 - Monitoring device for an electrical high voltage network of a vehicle

Info

Publication number: WO2011047952A1
Application number: PCT/EP2010/064725
Authority: WO
Inventors: Christian Dengler; Christian Kuschnarew
Original assignee: Continental Automotive Gmbh
Priority date: 2009-10-22
Filing date: 2010-10-04
Publication date: 2011-04-28
Also published as: DE102009050223A1

Abstract

The invention relates to a monitoring device for an electrical high voltage network of a vehicle comprising a conductor loop (16) running through at least one component (12, 14) of the high voltage network, a switch (S12, S14) arranged on the course of the conductor loop (16) for each component (12, 14) which switch is opened in the case of an error at the respective component (12, 14) in order to interrupt the conductor loop (16) and a monitoring unit (18) connected to the conductor loop (16) which outputs an error case signal (f1-f3) in case of interruption of the conductor loop (16). In order to improve the monitoring device in respect of the information thus obtained, according to the invention the switch (S12, S14) is designed as an electrically actuated switch and the monitoring unit (18) furthermore is designed to diagnose the functionality of the electrically actuated switch (S12, S14) and/or the functionality of the conductor loop (16) and/or an error.

Description

description

Monitoring device for a high voltage electrical network of a vehicle

The present invention relates generally to electrical supply systems in vehicles and in particular a surveil ^¬ monitoring device for an electrical high-voltage system of a vehicle according to the preamble of claim 1.

Such a monitoring device is known from the prior art as HVIL device. HVIL stands for "hazardous voltage interlock loop", sometimes also "high voltage interlock loop".

In vehicles with an electric drive device, ie z. B. in electric vehicles or so-called hybrid vehicles (eg., With an internal combustion engine and at least one

Electric motor), an electric supply system provided for the electric drive is usually operated with a relatively high voltage of typically a few 100 V (eg about 400 V). Advantageously, with such a "high voltage" electrical line losses are reduced. The problem, however, is the considerable risk potential of such a high voltage. Therefore, any high-voltage power ^¬ source should be separated from the high-voltage network of the vehicle and discharge any optionally locally stored electrical energy before a person (eg. As a workshop technician) can come into contact with an otherwise live part of the high-voltage network. This can be accomplished in a simple manner with the aid of a generic monitoring device. As soon as a person undertakes an access attempt in the area of one of the components of the high-voltage network (eg a cover screwing on a high-voltage battery solves), this represents a "failure", which opens a switch located in the component to interrupt a running through the components conductor loop. With a monitoring unit connected to the conductor loop, any such error case can thus be easily detected. A subsequent signal outputted from the monitoring unit Def ^¬ lerfallsignal can be used to take appropriate security measures then, in particular z. B. for a separation of the high voltage source (eg traction battery in an electric or hybrid vehicle) from the high voltage network.

In HVIL systems known from the prior art, the switches arranged in the high-voltage components are designed as "mechanical switches" in the broadest sense. For example, a switch used in DE 10 2008 022 982 A1 consists of a plug connection which is forcibly disconnected in the event of an access attempt to the relevant high-voltage component (high-voltage cable connection). A disadvantage of known monitoring devices of this kind is that when detecting an error case no closer information about its cause or nature can be obtained. It is an object of the present invention to provide a moni ^¬ monitoring device of the type mentioned with regard to the so ascertainable information to improve.

This object is achieved according to the invention by a monitoring device according to claim 1. The dependent ones

Claims relate to advantageous developments of the invention.

The monitoring device according to the invention is characterized in that the switch as electrically controllable Switch is formed, and that the monitoring unit is further adapted to diagnose the operability of the electrically controllable switch and / or the functionality of the conductor loop and / or a fault.

Thus a number of Diagnosemög ^¬ possibilities are given in a simple manner, as will be discussed in below. Such diagnoses can z. B. during commissioning and / or performed during normal monitoring operation.

High-voltage networks of the type of interest here generally have a plurality of components for which monitoring of the type according to the invention is expedient. Accordingly, it is most preferred if one of several components of the

High voltage network extending conductor loop is provided, and a plurality, each arranged in the course of the conductor loop in the components switches are provided which are opened in case of failure of the respective component to interrupt the conductor loop. In this case, we ^¬ nigstens one of the switches is then constructed as an electrically controllable switch. In particular, of course, several, and preferably all of the switches can be designed as electrically controllable switch.

The switches can z. B. be designed as transistors. According to one embodiment, z. B. provided that the (at least one) electrically controllable switch is a Tran ^¬ sistor of the self-locking type. This has z. B. the advantage that in case of failure of the transistor holding in its conductive state holding this transistor automatically enters a blocking state, so that (due to the interruption of the conductor loop) the Überwa- unit detects a fault ("fail safe" behavior).

In one embodiment, it is provided that the (at least one) electrically controllable switch can be actuated via a further switch which is arranged in the same component and is sensitive to the error. This additional switch can be connected in series and z. B. structurally combined with the electrically controllable switch and can in particular a mechanical switch or z. B. be a Hall sensor. An additional Ansteuerpfad for driving the electrically controllable switch, regardless of the switching state and the operability of the mechanical switch, is advantageous.

In one embodiment, it is provided that, at the beginning of a monitoring operation, first the functionality of the at least one electrically controllable switch is checked by the monitoring unit for its brief activation. If a plurality of electrically controllable switches are provided, then in particular all these switches can be tested for their functionality at the beginning of the monitoring operation. Each switch can be checked by being electrically energized to its open state for a short time, and monitoring the conductor loop to detect a corresponding break in the conductor loop. A lack of functionality of the switch is evident from the fact that the corresponding interruption of the conductor loop is omitted. In one embodiment, it is provided that the conductor loop runs through a plurality of components of the high-voltage network and a plurality of the switches are designed as electrically controllable switches and is tested in an error case by sequential control of these switches on which component the conductor loop has been interrupted. In case of error, the conductor loop is interrupted. Now, if detected for sequential control of all switches that these Un ^¬ interruption when controlling a particular switch

(Forced closing switch) is canceled, so this allows the conclusion on the cause of the fault triggering component.

There are many possibilities for the electrical control of the switches.

In an embodiment, it is provided that the activation of the (at least one) electrically controllable switch can be effected by means of a control command transmitted via an electronic communication bus of the vehicle. In practice, the components of the electrical high-voltage network are often already connected to an electronic communication bus (eg, CAN bus) for other reasons, so that the activation of the switch via this communication bus does not entail any significant additional expenditure.

Alternatively or additionally, however, it can also be provided that the actuation of the (at least one) electrically controllable switch can be effected by means of (at least) one electrical line leading to the relevant component. The electrical line may be provided specifically for this purpose. In practice, however, mostly anyway electrical leads to the components of the high voltage network, so that under circumstances, and very advantageous, such an already existing (for a different purpose) existing line can be used for this purpose. In particular, this come for. B. lines into consideration, which is used for electrical supply provided in the region of the relevant high-voltage component electrical device, which is normally supplied continuously, however can also be switched off for a short time without any problems. This is z. B. often in sensors, in particular z. B. temperature sensors or pressure sensors possible. The (short-term) shutdown of the supply can then be used to control the switch.

The invention will be further described by means of embodiments with reference to the accompanying drawings. They show:

Fig. 1 is a block diagram illustrating a trained in a conventional manner monitoring device for a high voltage electrical network of a motor vehicle, and

Fig. 2 is a representation corresponding to FIG. 1 of a trained in accordance with the invention system.

In Fig. 1, an electronic control unit 10 is shown, which z. B. for controlling the operation of an electric motor 12 and / or a (not shown) internal combustion engine of a hybrid vehicle is used.

The way the engine control, z. Example by means of energization of the electric motor 12 via a controlled from the controller 10 to ^¬ inverter, is incidental in the context of the present invention and in view of the relevant state of the art, no further explanation. It is essential in the invention that the vehicle includes an electrical high-voltage network with associated high voltage components, of which in the example shown, the electric motor 12, such a high-voltage component is ^¬ represents (z. B. having about 400 V operated). Further, not shown components of the high voltage network are z. For example, the high-voltage electric source ^(¬ traction battery), possible other electrical machines such as the electric motor 12, these associated electrical converters, electrical connectors (for carrying a high voltage cable) etc.

In Fig. 1, the simplicity of illustration is shown only one such additional component 14 of the high voltage ^¬ network.

Due to the danger emanating from these components 12 and 14, a so-called HVIL monitoring device is provided, comprising

a conductor loop 16 running through the components 12 and 14 of the high-voltage network, respectively, mechanical switches S12 and S14 respectively arranged in the course of the conductor loop 16 in the components 12 and 14, which open in the event of a fault on the respective component (12 or 14) (see dashed arrows in Fig. 1) to interrupt the conductor loop 16, and

- a device connected to the conductor loop 16 ^¬ monitoring unit 18 for monitoring of the conductor loop 16, and for outputting error event signals fl, f2 and f3 in case of interruption of the conductor loop sixteenth

In the illustrated embodiment, the conductor loop 16 is connected ^¬ extends from a port 20 of the surveil ^¬ monitoring unit 18, which is also connected to an electrical supply potential Ubat (z. B. 14 V) is connected via a first resistor Rl, further via the high voltage components 14 and 12, to a terminal 22 of the monitoring unit 18, which terminal 22 is connected via a second resistor R2 to an electrical ground GND (0 V).

About the terminal 20, the monitoring unit 18 is electrically powered.

Due to the arrangement of the resistors Rl and R2, a

Monitoring the conductor loop 16 (in terms of their interruption) in a simple manner by monitoring the potential at the terminal 22: If the conductor loop 16 is not interrupted, ie all switches S12, S14 are closed, this potential has a value of R2 / (Rl + R2) x Ubat, whereas when the conductor loop 16 is interrupted, this potential drops to the value GND (electrical ground). Advantageously, the connection of the circuit shown allows ^¬ loop 16 also has a detection of a short circuit somewhere in the loop conductor 16 to the supply potential Ubat out. In this case, the potential at port 22 on Ubat increases.

In one embodiment, it is provided that the resistance values of R1 and R2 are chosen to be equal. In this case, the potential at port 22 is normally 0.5 x Ubat. It can then z. For example, this potential may be monitored by the monitoring unit 18 to determine if an upper threshold of e.g. B. 2/3 x Ubat exceeded or below threshold of z. B. 1/3 x Ubat is exceeded. At least in the latter case, the monitoring unit 18 outputs fault signals fl, f2 and f3 to a driver unit 24, a driver unit 26 and a discharge unit 28.

In normal operation, the driver unit 24 provides for the control (eg PWM control) of switching elements of a DC / AC converter for providing phase currents for the electric motor 12 designed as a multi-phase three-phase motor.

The driver unit 26 provides drive signals for a

DC / DC converter ready, by means of which a transfer of electrical energy between the high-voltage network and a low-voltage network (voltage Ubat) is accomplished.

The discharge unit 28 is normally inactive.

However, if the fault signals fl to f3 are output to these units, the driver units 24 and 26 are deactivated, that is, in particular the electric motor 12 "abge ^¬ switches", and the discharge unit 28 is activated, which via terminals 30 and 32, a decoupling of the (not shown) traction battery from the high-voltage network and a rapid, but controlled discharge of a DC link capacitor of the high voltage network is effected. By these measures, the normally high-voltage lines of the high-voltage network after a short time are safe.

The switches S12 and S14 are designed as mechanical switches in the broadest sense. Each access attempt on the relevant high voltage component 12 or 14 provides an "event of a fault" and leads to a separation of the two depending ^¬ weiligen switch contacts. With regard to the design of the switches S12 and S14, the arrangement shown in Fig. 1 of conventional type.

Finally, in Fig. 1 also housed in the control unit 10 temperature measuring unit 34 can be seen, over two electrical lines with a temperature sensor 36 (temperature-dependent resistor) is connected.

A disadvantage of the system shown in Fig. 1 is that no further Informa ^¬ functions can be determined by the monitoring unit 18, apart from the existence of an error case (Interr ^¬ calculation of the conductor loop 16).

Hereinafter, with reference to FIG. 2, a modified

Monitoring system described which advantageously provides the determination of further information, especially in the event of an error. In this description, the same reference numerals are used for equivalent components. In this case, essentially only the differences from the exemplary embodiment described above are discussed and, moreover, reference is hereby explicitly made to the description of the preceding exemplary embodiment.

An electronic control unit 10 shown in FIG. 2 has substantially the same structure and the same function as the control unit already described above with reference to FIG. 1. However, the monitoring unit 18 has further described below, extended diagnostic options. An essential difference to the already described above

Embodiment is that the switches S12 and S14 as electrically controllable switch (here: self-locking FETs) are formed. The electrical control of the switches S12 and S14 can be effected by the control unit 10, with corresponding control signals (here: gate control signals) arranged on the respective one of the components 12 and 14, respectively Error case sensitive further switch S12 'or S14' are performed.

If an access attempt z. B. is taken to the component 12, the switch S12 is thus not immediately brought into its open state, but first directly the z. B. designed as a mechanical switch or as a Hall sensor further switch S12 'in its opening state ge ^¬ introduced, whereupon the associated electrically controllable switch S12 is brought into electrical manner in its opening state, and thus the conductor loop 16 interrupts. In an analogous manner, the combination (here: series connection) of the two switches S14 and S14 'in the other component 14 also works.

The provision of the electronically controllable switches S12 and S14 and their combination with conventional mechanical switches is not a significant additional effort, but opens up very advantageous diagnostic options. Corresponding diagnoses can z. B. in a specially provided for this purpose

"Diagnostic mode" of the monitoring unit, or even during the actual monitoring operation to be performed. In ^¬ sbesondere diagnoses of interest can be carried out immediately after the occurrence of a "fault situation."

At the beginning of an actual monitoring operation, first the functionality of all the switches arranged in the course of the conductor loop 16, in this case the switches S12 and S14, is checked by their short-term activation with a control signal which brings them into the open state.

For driving the switch S14 leading to the respective component 14 electrical line L14 is provided. Via this line L14, this can open the switch S14 test-by-test Signal are transmitted from the controller 10, whereupon the monitoring unit 18 will detect an interruption of the conductor loop 16 when the switch S14 is functioning. If the switch S14 is defective, the interruption will be suspended. In this way, a short circuit between the line sections of the conductor loop 16 extending within the component 14 to the switch S14 can also be advantageously broken. Based on the electric motor 12, an alternative embodiment of the electrical controllability of the relevant switch is shown by way of example in FIG. 2. The activation of the

Switch S12 is also effected by means of a leading to the respective component, so the electric motor 12 electrical line. However, it is one of the two supply lines, which run between the temperature measuring unit 34 and the temperature sensor 36 and thus are anyway available for the temperature measurement. Switching off the temperature measurement for a short time is unproblematic and is advantageously used here for the test-wise opening of the switch S12.

By a sequential control of all switches S12, S14 before an actual monitoring operation thus the functionality of all switches can be checked.

As an alternative to triggering the switches by means of a drive line leading to the respective component, as illustrated in FIG. 2 for the switches S12 and S14, it is also possible to control the relevant switch by means of an electronic communication bus (eg.

CAN bus) of the vehicle transmitted control command to ^¬ act. The simplicity of the illustration of FIG. 2 sake for each of the switches S12 and S14 are respectively provided more Ans ^¬ expensive paths that a forced control of these switches S12 and S14 are also in "bypass" of the series-mechanical switch S12 'and S14' allow, omitted. In fact, in the system illustrated in FIG. 2, therefore, for each of the switches which can interrupt the conductor loop 16, here the switches S12 and S14, further lines between the control unit 10 and the control terminal (here: gate terminal) of the relevant switch S12 or S14 before ^¬ seen. About this further Ansteuerpfade can switch S12 and S14 independent of the switching state of the mechanical switch S12 'or S14' forcibly close. Thus, another advantage of the system is that, in the event of a fault, there are also diagnostic options with regard to the type of error. So z. Be determined as to which component of the high-voltage network, the conductor loop 16 was un ^¬ interrupted. This can be checked in a simple manner by sequential activation of the relevant switches, here S12 and S14, via the "further drive path". In order for a kicking on ^¬ error can be advantageously located. If the electrical controllability of the switches S12 and S14 is not realized via electrical control lines as shown, but by means of a controllability via an electronic communication bus for data transmission (eg CAN bus), then additional control lines for the "other" can be provided Ansteuerpfade "be waived.

Although in the embodiment described above, the monitoring according to the invention at several components (symbolized by the components 12 and 14) is performed, the invention is in principle applicable to a single component of a high voltage network. However, the application is preferred for a plurality of components, wherein at least a part and In particular, all in the course of the conductor loop arranged in these components switch of the described, electrically controllable type can be. Although in the above described embodiment in the figures, the monitoring unit 18 and that these surveil ^¬ monitoring unit 18 containing control unit 10 is shown separately from the components 12, 14 of the high-voltage network, it shall not be excluded that the monitoring unit (or even is more in the exemplary embodiment be written ^¬ circuit components, in particular a control device) are integrated in one of the components of the high voltage network or structurally summarized with such a component.

In summary, this with Fig. 2 illustrated over ^¬ wachungskonzept with negligible overhead very advantageous diagnostic options. The electrical conductor loop 16 can be passed through all the relevant high-voltage components, which are at the potential risk of becoming a

Touch of high voltage can come. If the loop 16 is opened or short-circuited (eg to ground or a positive supply potential such as Ubat), appropriate protective measures are taken. In this way, a touch-safe state is achieved in a given time

(Voltage <60 V). The purpose for the electrical controllability modified switch can, for. B. as a self-locking

MOSFET switching transistors are formed and coupled in the manner described with based on a mechanical principle switches, as they are known per se from the field of HVIL monitoring devices. If a relevant high-voltage component is not connected to an electronic communication bus, there is often the possibility of an electrical controllability means of a switched power supply to an anyway (another purpose serving) device within the component in question to realize.

Claims

Monitoring device for a high voltage electrical network of a vehicle, comprising

a conductor loop (16) running through at least one component (12, 14) of the high-voltage network,

- One for each component (12, 14) in the course of Lei ^¬ terschleife (16) arranged switch (S12, S14), which is opened in case of failure at the respective component (12, 14) to the conductor loop (16) interrupt, and

- connected one to the conductor loop (16) surveil ^¬ monitoring unit (18) for monitoring the conductor loop (16), and outputting an error event signal (fl-f3) in case of interruption of the conductor loop (16), characterized in that the switch (S12 , S14) is designed as an electrically controllable switch, and that the monitoring unit (18) is further adapted to the operability of the electrically controllable switch (S12, S14) and / or the operability of the conductor loop (16) and / or a Feh ^¬ lerfall to diagnose.

Monitoring device according to claim 1, wherein the electrically controllable switch (S12, S14) is a transistor of the self-locking type.

3. Monitoring device according to claim 2, wherein the

electrically controllable switch (S12, S14) arranged over one in the same components, in the event of a fault sensitive further switch (S12 ', S14') can be controlled.

Monitoring device according to claim 3, wherein the further switch (S12 ', S14') is a mechanical switch or a Hall sensor.

Monitoring device according to one of the preceding claims, wherein at the beginning of a monitoring operation, first the operability of the electrically controllable ^¬ ble switch (S12, S14) is checked by its short-term Ansuerung of the monitoring unit (18).

Monitoring device according to one of the preceding claims, wherein the conductor loop (16) extends through a plurality of components (12, 14) of the high-voltage network and a plurality of the switches (S12, S14) are designed as electrically controllable switches and in an error case by sequential activation of these switches (S12 , S14), on which component (12, 14) the conductor loop (16) has been interrupted.

Monitoring device according to one of the preceding claims, wherein the control of the electrically ans ^¬ expensive switch (S12, S14) by means of a transmitted via an electronic communication bus of the vehicle ^¬ drive command is effected.

Monitoring device according to one of the preceding claims, wherein the control of the electrically ans ^¬ expensive switch (S12, S14) by means of a respective component (12, 14) leading electrical line (L14) is effected.