DE19855245B4 - Redundant power supply for electrical consumers - Google Patents

Abstract

Redundant power supply for electrical loads in a vehicle electrical system, comprising a generator, which supplies two separate voltage branches, which are each connected to a separate voltage storage and connectable to the electrical loads, wherein between each voltage storage and the associated voltage branch first switching means (14a, 14b ) and between each voltage memory and the consumers second switching means (17a, 17b) lie, both second switching means (17a and 17b) are normally in a conductive state, characterized in that the first and second switching means (14a, 17a), the to a first one (15a) of the two voltage memories (15a, 15b), and / or the first and second switching means (14b, 17b) communicating with a second one (15b) of the two voltage memories (15a, 15b) , Are arranged in a common housing having a female connector directly to a voltage spike Connection is plugged.

Description

The The invention relates to a redundant power supply for electrical Consumers in a vehicle electrical system, especially for electric brakes according to the preamble of claim 1.

State of the art

The Voltage supply in a motor vehicle is usually with the help of a Generators ensured, the one, in more complex on-board networks also two batteries, charges. These batteries are the electrical consumers of the electrical system connected, optionally with additional voltage transformers are present, with the help of an adjustment of the supply voltage is realized to the requirements.

Safety-relevant electrical consumers, for example the electronic control circuit of a brake system, are provided with a redundant power supply. Such a redundant power supply is for example from the EP-B1 0 363 356 known. With this redundant power supply, the safety-relevant consumers are connected to the vehicle battery via a voltage transformer. Parallel to each consumer is a separate backup battery. In addition, a fuse is present, however, which is located in front of the voltage terminal of the consumer, so that in their response, both the power supply from the on-board battery and the power supply from the auxiliary battery is interrupted.

From the DE 35 02 100 C2 a redundant power supply for electrical loads in a vehicle electrical system is known in which, for example, electrically actuated brakes are supplied via two separate voltage branches. The electrical energy is generated by a generator that supplies the two voltage branches. Each of the two voltage branches is assigned its own voltage memory. Between the voltage memories and the two voltage branches with the consumers are switching means, which are normally in a conducting state.

The The object of the invention consists in starting from the known redundant power supply to represent a power supply in which the switching means are combined in a special way.

Advantages of the invention

The inventive redundant Power supply for electrical load has over the prior art the Advantage that it is particularly reliable and also when it occurs an error in one of the supply branches nor a power supply for the Consumers can be maintained, with a favorable arrangement the individual circuit parts is provided.

achieved the advantage is a redundant power supply with the Features of claim 1. For this purpose is or are the electrical consumers over at least two separation modules with one voltage storage connectable, wherein Normally, both separation modules have a conductive connection between both voltage storage and the consumers manufacture. In addition, the two voltage storage units or batteries via one charge separation module each connectable with two separate voltage branches, from one of which is directly related to the generator during the second over a voltage converter is connected to the generator. Both the Charge-breakers as well as the separation modules can in an advantageous manner in a spatially closed arrangement near the battery pole or in a particularly advantageous manner directly as Battery plug can be realized.

Further Advantages of the invention are given by the in the subclaims activities achieved. It is advantageous, for example, that the separation modules used have a shutdown function, if necessary, the connection in the event of a fault, independently interrupts. Furthermore, it is advantageous that the separation modules due to their Diode function a current flow only in the direction of the consumer. Advantageously the separation modules a transistor opens automatically at too high a current load and a diode that only current flow in one direction. The used charge separation modules, between the generator and the Batteries lie, allow an opening the connections, if a short circuit occurs on the generator side. With the help of further switching means can be further suitable separation possibilities in case of error.

If a charge separation module or separation module conducts current in both To allow directions, it can be also realize in an advantageous manner as a transmission gate. In Connection with a vehicle electrical system management system with a control device, receiving the required information and outputting drive signals, can open or Shut down the individual switching means are triggered by control signals from this controller.

drawing

The invention is illustrated in the figures and explained in more detail in the following description tert. In detail shows 1 the essential components of the power supply system, 2 shows an example of the design of a separation module and 3 an example of the assembly of separation module and charging separation module in a common connector. In 4 this connector is shown as a battery connector and 5 shows an embodiment of the plug. In 6 is a possible electrical configuration of the plug shown and 7 shows the circuit of a bidirectional transmission gate, which may be part of a battery connector.

description

In 1 is an embodiment of a redundant voltage or power supply for electrical consumers in a vehicle electrical system shown. The power supply comprises a generator 10 , For example, an alternator connected to a first voltage branch 11 communicates and has a voltage transformer 12 to a second voltage branch 13 leads. To the voltage branch 11 is a charge separation module 14a connected via a voltage storage, or a battery 15a is loadable. To the voltage branch 13 is a second charge separation module 14b connected via the voltage storage, or the battery 15b is loaded. The state of charge monitoring of the batteries 15a . 15b occurs via assigned state of charge monitoring 15c . 15d , which trigger a display Aa or Ab below a minimum charge.

The consumer 16 is via a separation module 17a and optionally a switch 18a from the battery 15a energized. Continues to be the consumer 16 over the separation module 17b and optionally a switch 18b from the battery 15b energized. Via a separation module 17c can be the same consumer 16 additional or additional consumers to the battery 15a be connected, with additional switches, such as the switch 18c can be present.

The charge separation modules 14a . 14b are also referred to below as the first switching means, and the separation modules 17a . 17b as second switching means.

With the in 1 shown power supply is the consumer 16 simultaneously with an energy storage device (battery) 15a and an energy storage (battery) 15b connected. The separation modules 17a and 17b prevent failure of the entire system or a reaction to the other functional energy storage in the event of a fault. The separation modules 17a . 17b and optionally 17c must have a diode function, which allows the flow of current only towards the consumer. Furthermore, the separation modules should 17a . 17b have a shutdown, which triggers in case too high currents. The current at which the tripping is to take place can be adapted to the expected conditions.

In the 2a is the circuit arrangement of a separation module 17a . 17b shown. It includes a transistor 19 , which opens automatically at too high current load, but which can also be controlled externally, for example via a logical element 20 , Furthermore, a diode 21 present, which allows the flow of current only towards the consumer. The diode 21 is the transistor 19 downstream, so that in the case of a short circuit in the region between the diode 21 and the transistor 19 trigger the transistor, that is, can open and thus the voltage memory 15a or 15b saved from destruction. 2 B shows an embodiment with an additional current detection.

The separation modules 17a and 17b following the circuit 2 contained are advantageously arranged spatially separated from each other. Furthermore, additional switches 18a and 18b are used, which trigger in the event of a short circuit between the charge separation module and the separation module and thus secure the charge storage in question. Through the charging separation modules 14a and 14b become the voltage branches 11 and 13 protected if an error occurs in the lines connected downstream of the charging separation modules. This is especially important when it comes to the two charge stores 15a and 15b not the actual electrical system battery, but this in addition to one of the voltage branches 11 or 13 connected.

In a specific embodiment, the charge separation modules are 14a . 14b or the respectively associated separation module 17a . 17b arranged within a common housing, for example in the form of a closed battery connector, which has a socket and is plugged directly onto a battery terminal. 3 respectively. 4 shows corresponding embodiments in which the housing 22 directly on the battery 15a sitting. In this case, the additional switches 18a respectively. 18b of course omitted.

A battery plug with extended function, but the principle of in 3 corresponds to the arrangement shown is in 5 shown. This battery plug 22a is from a housing 22 surround. A recess on the battery connection 23 (Socket) allows secure attachment to the battery.

The battery connector 22a in detail comprises an electrical decoupling 24 with connections 25 and 26 that lead to the electrical system or to the consumers. This electrical decoupling ensures that a fault in the electrical system does not affect the battery-consumer circuit and vice versa. The electrical decoupling can, for example, as a DC / DC converter or in the form of a transmission gate, as in 7 is shown realized. Furthermore, means for current measurement 27 For example, realized as a shunt or means for voltage measurement 28 possible. The control can, for example, with the help of its own intelligent chips 29 carried out, which processes the measuring signals and in the event of an error, the decoupling opens, so for example, the transmission gate switches. In principle, a control via an external electronic processing unit, eg. B. allow the control unit of the vehicle.

One possible circuit design is in 6 shown. It is about the connection 25 the DC / DC converter 30 connected to the electrical system or the generator. To the DC / DC converter 30 are consumers 31 connected. These consumers 31 also stand with the battery 32 in connection, wherein in this connection a device for current measurement 27 is integrated. The device for measuring voltage 28 is parallel to the battery 32 , Such a battery connector can be used in principle in connection with any vehicle battery.

In 7 Finally, an example of an electrical decoupling in the form of a transmission gate is shown. This transmission gate comprises two n-channel field-effect transistors 33 . 34 , which are connected to each other at the drain terminal D. The diodes 35 and 36 each lie between source S and drain D, it would also be possible to design the circuit so that the anodes of the diodes 35 and 36 would be connected to a common source terminal. Switching is achieved by driving the gate electrodes G.

With such a wear-free switch can be in a power supply device after 1 in the event of a fault, realize fast switchovers. It can thus be quickly disconnect from the consumer at a short circuit occurring the corresponding voltage branch. An intelligent monitoring by means of its own microprocessor or by means of a connectable microprocessor can be switched on or off depending on the operating condition and demand, by the detection and evaluation of current and voltage and a state of charge monitoring can be realized. If the state of charge monitoring reveals that one of the two is the consumer 16 assigned batteries has an unacceptable state of charge, a display function a can be triggered. The power supply is then backed up by the other battery.

When Extension of the described function of the charge separation modules and separation modules in the battery connector can still further functions are defined. These functions are:

features:

• - Current measurement
• - Voltage measurement
• - Temperature measurement
• - CAN interface
• - switching function: care safety-critical consumer (secure node) decoupling redundant supply branches Battery backup centrally Reverse polarity protection.

In 8th the circuit arrangement of the intelligent battery terminal is shown. The switches (transmission gates) to the battery (LTM charge isolation module) and to the individual consumers (TM separation module) with the associated control logic or evaluation are identical to those in 1 , they also have the same reference numerals.

Next The function of the current and voltage measurement can also be the battery temperature measurement be integrated into the battery terminal. The transmission of measured data, the switch-on signals of the individual supply branches, the switching state signals or diagnostic register of the individual transmission gates can preferably via the CAN bus to a parent Control unit transmitted become.

Further Switching functions, such as the decoupling of redundant supply branches, central reverse polarity protection and battery fuse (separation in short circuit or crash case / fire hazard) can additionally be realized or covered. The integrated drive and Evaluation logic (current monitoring, Short circuit, Voltage level and voltage direction) controls the individual switches at.

Claims (8)

A redundant power supply for electrical consumers in a vehicle electrical system, comprising a generator which supplies two separate voltage branches, each of which has its own voltage store and can be connected to the electrical consumers, wherein between each voltage store and the associated voltage branch, first switching means ( 14a . 14b ) and between each voltage memory and the consumers second switching means ( 17a . 17b ), both second switching means ( 17a and 17b ) are normally in the conductive state, characterized in that the first and second switching means ( 14a . 17a ), with a first ( 15a ) of the two voltage memories ( 15a . 15b ), and / or the first and second switching means ( 14b . 17b ), with a second ( 15b ) of the two voltage memories ( 15a . 15b ) are arranged in a common housing having a female connector which is directly plugged onto a voltage storage terminal. Redundant power supply for electrical consumers according to claim 1, characterized in that the first switching means ( 14a . 14b ) Charging separation modules, via which the charge of the voltage storage ( 15 . 15b ) and the second switching means ( 17a . 17b ) Separation modules are that separate the subsequent consumers in case of failure. Redundant power supply according to claim 1 or 2, characterized in that the two separate voltage branches from each other via a DC-DC converter ( 12 ) are galvanically decoupled. Redundant power supply according to Claim 2 or Claim 3 in conjunction with Claim 2, characterized in that the voltage memories ( 15a . 15b ) Batteries are, which include own state of charge monitoring, wherein if a state of charge monitoring detects that one of the two batteries assigned to the consumer falls below a minimum state of charge, triggers a display function and outputs a corresponding signal to open the separation modules and / or display. Redundant power supply according to one of the preceding claims, characterized in that the first switching means ( 14a . 14b ) have a diode function, which allows a current flow only in the direction from the generator to the consumers and trigger a shutdown, which triggers at high currents. Redundant power supply according to claim 5, characterized in that the first switching means ( 14a . 14b ) comprise a transistor whose switching path is between the generator and the respectively associated voltage memory and which can be controlled via a logic and in addition a diode is present, which is located between the transistor and the voltage storage. Redundant power supply according to one of the preceding Claims, characterized in that in the housing of the switching means a circuit arrangement is included for electrical decoupling over which the connection between the generator or the electrical system and the consumers separable is, with additional Means for current measurement and voltage measurement between the voltage storage terminal and the Circuit for electrical decoupling are present. Redundant power supply according to claim 7, characterized characterized in that the circuit for electrical decoupling as a DC-DC converter or in the form of a transmission gate is realized, each with two connected in series Field effect transistors and two diodes, their cathodes or anodes with the common drain or source terminal of the field effect transistors keep in touch.