DE10112217B4 - Method and device for detecting a variable proportional to the output current of a generator having an electrical machine - Google Patents

Abstract

method for detecting an output current of a generator (30) having electrical machine proportional size, wherein the machine over a supply line (21) an electrical system (20) with several points of consumption (23, 24, 25, 26, 27) supplied with electrical energy and on the 3-phase system (30.1, 30.2, 30.3) is operated and in which the voltage drop in a section (3) containing electrical components (4, 7) by means of a further processing output signal (10, 40) generating Evaluation stage (9, 9.1, 9.2) is determined, characterized that the voltage drop taking into account resistances of the Components (4, 7), of line resistance (5) and mass (1) at least one of the phases (30.1, 30.2, 30.3) is determined and the voltage measurement in the web section (3) takes place and therefrom by means of the evaluation stage (9) indicates an increasing or decreasing tendency of the Phase current (6) of the generator (30) is closed.

Description

Technical area

Of the current values assuming different values at different times Generator current is for the creation of torque curves in motor vehicles or for determining the charge balance of an energy store such as the car battery is a crucial size. Next the current value of the generator current goes into the determination of Charging a car battery also the outside temperature, which is also Fluctuations may be subject to what may happen about inaccurate statements can lead to the charge balance of the car battery. The generator output current stops also a time-varying input for the creation of the charge balance a car battery that over plausible estimates enters into the moment models and this as well as the charge balance a battery with strong uncertainties in terms of informative value the results obtained.

State of the art

DE 37 28 673 C2 has an arrangement for detecting the size of an electrical load in a motor vehicle to the object. The arrangement comprises a load line leading first line and a likewise current-carrying second line. The lines run within a fuse unit of the vehicle, wherein the first line has a portion which is perpendicular to the second line and the portion is surrounded by a magnetic core provided with a magnetoelectric transducer. A gap is formed in the magnetic core, the magnetoelectric transducer comprising a magnetoelectric conversion element inserted into the gap. The second electrical line includes a first fuse element, whereas the first electrical line includes a second fuse element within the fuse unit. With this arrangement, the detection of the load current in the fuse unit should be done with high accuracy.

DE 199 30 017 A1 refers to a device for generating voltage in a motor vehicle. The motor vehicle includes a generator driven by the vehicle engine with a field winding and a stator with two galvanically separated windings. From these windings two different high operating voltages (12 volts, 42 volts) are derived. The two windings are in the same slots of the stator, wherein the second operating voltage (42 volts) is controlled by controlling the current in the field winding and the first operating voltage (12 volts) by a pulse width modulation of actively controlled rectifiers in the form of field effect transistors. The current flow angle of the field effect transistors is controlled within a period of the AC voltage generated by the stator winding in dependence on the angular position of the rotor of the generator so that the current flow angle is approximately in phase with the AC voltage generated by the stator winding and a cos φ is near 1 ,

for lack of quickly available, meaningful Values for the generator current was this, depending on the requirement, determined For this purpose, suitable maps are taken, in which replacement sizes are given are. Suitable replacement sizes for Calculation of the generator output current are for example the duty cycle a field amplifier and with regard to the charge balance of a vehicle battery the temperature model. However, since in the maps no values for the current Value of the generator output current are stored, one is forced to this from the replacement sizes of to calculate suitable maps or to estimate plausibly.

Estimated values is liable per se a higher Uncertainty factor, so that the meaningfulness the esteemed Sizes with significant uncertainties may be involved. Also quite plausible estimated Sizes, go they as input variables in calculation algorithms one, can lead to inaccurate results.

Become from the substitute quantities stored in the maps, however, values for a calculable from the substitute sizes Value for Calculating the generator output current often requires traversing Numerous reference levels and access to a variety of Maps. So too is for the calculation of a torque trend tendency a considerable calculation effort of need, especially in terms of its timing very can behave critically. This may result in a considerable period of time necessary for the calculation. Further are the processors of a car electronics by the derived from substitute sizes Calculation of the current values for The generator output current charged not insignificant. The finally calculated End value for the generator output current according to the usual Method using reference variables from maps is under circumstances on receipt of the final value according to this Calculation routine already outdated, so that resources and time for the Determining one finally no longer current value were used.

This Condition is highest unsatisfactory.

Object of the present invention is Therefore, to provide a method and a device by means of which a proportional to the output current of a generator having electrical machine size can be determined as soon as possible while avoiding substitute variables.

Advantages of the invention

With the proposed method according to the invention and the proposed device can be the voltage drop in one or more phases of the generator determine in which for example, a diode or other electrical device may be included. In addition to the voltage drop across an electrical A component such as a diode or a transistor may also have the voltage drop across it Railway resistance as well as a discrete electrical resistance be detected. Although this is also a substitute size, namely the determined voltage value to determine the value for the generator current available, however let yourself out of this in a simple design and without access to awkward too containing manipulative sizes Maps the current value of the generator output current especially determine in a timely manner.

With this solution The organizational effort can be reduced and the time-consuming Access to stored in maps spare sizes can be avoided. The load The hardware components are significantly degraded, leaving resources to determine or calculate other relevant quantities in the Automotive electronics for other purposes available stand.

With the solution according to the invention for Detecting a voltage drop in one with a phase of electrical Machine coupled phase is available an electrical size, the directly with the height of the generator output current, so that the generator output current can be determined on the basis of the measurement in one phase.

Everyone determined voltage can be assign a defined stream. By the timely measurement and a sequence of short-term successive measurements In addition, a statement about a falling trend or rising trend of generator output current to be hit. This leaves forecasts in terms of a still developing charge balance and looming Momententendenz an energy storage in the vehicle electrical system too.

The Accuracy of measuring the voltage drop in one or more Phases of the generator can be achieved by suitable selection of components, a before the beginning of the voltage measurement made adjustment by means of a Calibration measurement to determine the offset can be further improved. Of the determined generator output current, or a determined therefrom Size (for Example performance or moment) can be processed further for example, as a numerical value, as a voltage level, as a PWM signal a control unit available for further processing be put.

drawing

Based the drawing, the invention will be explained in more detail below.

It shows:

1 a schematic representation of the device according to the invention,

2 the integration of the inventively proposed device in the supply of a vehicle electrical system.

variants

The representation according to 1 is a schematic representation of the device according to the invention can be seen.

According to the solution proposed according to the invention, the voltage drop in a web section 3 between a phase 2 an electric machine and the earth 1 determined. In railway section 3 can electrical components 4 be included, such as diodes, transistors or discrete resistors 7 , In addition, flows into the determination of the voltage drop in the selected path section 3 the line resistance inherent in the track section 5 one. The determined voltage drop in the web section 3 becomes the input side of an evaluation stage 9 given up. The evaluation stage 9 includes an evaluation part 9.1 as well as an output part 9.2 , On the input side are the evaluation part 9.1 the evaluation stage 9 inputs 11 . 12 and 13 assigned, so that by means of the evaluation part 9.1 the evaluation stage 9 three phases of an electrical machine could be measured in parallel. In the illustration according to 1 is at the entrance 11 of the evaluation part 9.1 the evaluation stage 9 only one phase 2 connected to an electrical machine. At the entrances 12 and 13 The other phases of the electric machine can be connected.

From the context of current and voltage can be by means of the in the railway section 3 measured voltage drop directly on the in the railway section 3 flowing current, ie the phase current 6 draw conclusions. This size for the output current of an electric machine can take time can be determined without the need to access Verweisstufen and stored in maps substitute variables for determining the output current of an electric machine would be necessary.

In above the evaluation part 9.1 located output part 9.2 the evaluation stage 9 is determined from the determined value for the phase current 6 a further processable output value 10 generated. This is to a not shown here control unit 39 transfer. In the output part 9.2 the evaluation stage 9 a conversion of the determined value for the phase current takes place 6 into a processable variable such as power or moment. This further processable output value is suitably embodied, for example, as a numerical value, voltage level, PWM signal of an external location, for example in the form of a control unit 39 (see. 2 ) for further processing.

In addition to the in the railway section 3 recorded components diode 4 and resistance 7 In this course, other electrical components that can be used in 1 not shown, be included, which cause a voltage drop to be detected.

From the illustration according to 2 the integration of the inventively proposed device in the supply of a motor vehicle electrical system is apparent.

Via an electric machine that can be operated on the 3-phase system 30 is by means of a supply line 21 a wiring system 20 a motor vehicle supplied with electrical energy. In the electrical system of a motor vehicle, the most diverse consumption points can be provided. From a crossing point of the line system of the electrical system 20 branches a ground connection 22 from. Consumers are resistors 25 as well as inductors 26 in question, which if necessary via switch 24 with the line system of the electrical system 20 which is via the supply line 21 from the generator 30 is fed, can be supplied. For reasons of simplification, the consumption points are 25 . 26 . 27 respectively. 23 each symbolically occupied, where it is the resistance 25 For example, it can be a heated rear window. With reference number 27 is a lighting system symbolized. reference numeral 26 is representative of a high-voltage ignition and the schematically reproduced capacitors 23 for other parts of a vehicle electrical system.

The lighting system 27 - shown here only schematically - is a separate switch 28 associated, for example, can be coupled with an acoustic signal to indicate when the ignition is switched off on the still in operation lighting.

In a housing 29 is the generator operated on the 3-phase system RST 30 assigned. The first phase (R) is with 30.1 referred to, the second phase 30.2 of the generator 30 is occupied with S, while the third phase 30.3 of the generator 30 is occupied by T. The generator is a diode array 31 associated, wherein the diodes can be designed as controllable diodes, so that the diode array can be operated in terms of an inverter. In addition, the use of an active and a passive rectifier bridge are possible. The housing 29 which is the generator 30 is by means of a ground line 22 connected to the vehicle mass. At the ground connection 22 opposite housing end branches the supply line 21 to supply the electrical system 20 with electrical energy.

In the left part of a regulator circuit 33 is the in 1 already mentioned evaluation stage 9 , an evaluation part 9.1 and an output part 9.2 containing, integrated. From the regulator circuit 33 includes, is the evaluation stage 9 a diode branch 34 and a parallel connected in this integrated transistor, which is connected to the housing ground. At the entrance side 36 is the entrance 11 that with the phase 30.3 the three-phase machine 30 , ie the generator is connected. The phase 30.3 corresponds to the in 1 with reference number 2 identified phase of the three-phase machine 30 , When occupying the on the input side 36 of the regulator circuit 33 or the evaluation level 9 located further inputs 12 and 13 (see illustration according to 1 ) were also the remaining phases 30.2 and 30.1 measure the electric three-phase machine in the sense of a voltage drop, so that the respective in the phases 30.1 . 30.2 and 30.3 flowing phase currents 6 in the evaluation part 9.1 the evaluation stage 9 can be determined. In the output part 9.2 the evaluation stage is a conversion of the determined current for the one phase 30.3 or the several phases 30.1 . 30.2 . 30.3 the electric machine 30 , In the output part 9.2 In addition, a conversion of the values of the determined current into variables such as power or torque can take place, which in a suitable form on the output side 37 of the regulator circuit 33 via a signal line to an external control unit 39 can be transmitted. The output signals 10 . 40 on the output side 37 of the regulator circuit 33 can be in an appropriate form, be it as a numerical value, be it as a voltage level, be it as a pulse width modulated signal or otherwise the external controller 39 be made available for further processing.

Be the adjusting voltage waste at one of the phases 30.1 . 30.2 or 30.3 or the phase 2 (see illustration in 1 ) determined one after the other at discrete times, can be determined by the real-time evaluation stage 9 or the evaluation part 9.1 a tendency of the determined generator output current, ie the phase current 6 in the respective phase 30.1 . 30.2 and 30.3 the electric machine 30 derived. This makes it possible to make a statement about a falling generator output current development or about an increasing generator output current tendency. The accuracy of the output side 37 to the input side of the external control circuit 39 transmitted values for the generator output current can be increased by appropriate selection of the components as well as by an adjustment taking place before the beginning of the measurement for the determination of the offset or by an upstream calibration measurement.

The regulator circuit 33 is parallel to the diode branch 34 an on or decoupled inductance 32 connected in parallel. At the connection points or input terminals on the input side 36 of the regulator circuit 33 this can be parallel to the diode branch 34 couple or uncouple.

At the exit side 37 of the regulator circuit 33 stand the determined values 10 . 40 in one or more phases 30.1 . 30.2 . 30.3 the electric machine 30 determined values for the generator output current. In a suitable form, ie as a numerical value, voltage level, pulse width modulated signal, the output values to the input side of an external control device 39 transmitted. The control unit 39 in turn provides feedback control signals 41 via the directional data line to the output side of the regulator circuit 33 back, so that the regulator circuit 33 a control by the external control device 39 is subject.

With the method proposed according to the invention and the inventively proposed measurement of the generator current in such web sections 3 between phase 2 . 30.1 . 30.2 respectively. 30.3 a generator 30 and mass 1 , which electrical components 4 . 5 . 7 As well as combinations of electrical components, taking into account the line resistance can be carried out in real time measurement of the voltage drop, in a simple manner in the web section 3 prevailing phase current 6 is convertible. On the output side of a regulator circuit 33 Consequently, current values are always available above the respective value of the current generator output current without requiring access to substitute variables stored in characteristic diagrams, such as models or temperature profiles, for example to create or forecast charge balances of a motor vehicle battery. By eliminating stored in maps spare sizes can also be brought about a relief of the memory area of a vehicle electronics on-board. The determination of the output-side generator current is largely without access to Verweisstufen or without time-consuming access operations stored in maps and still to be processed substitute variables for determining the generator-side output current.

1

Dimensions

2

phase

3

web section

4

electrical module

5

line resistance

6

phase current

7

discreet resistance

8th

combination Conduit / component

9

evaluation stage

9.1

evaluation section

9.2

output part

10

processable output value

11

entrance evaluation stage

12

Another entrance

13

Another entrance

20

board network

21

supply line

22

earth terminal

23

capacitor

24

switch

25

resistance

26

inductance

27

Another consumer

28

switch

29

casing

30

3-phase generator

30.1

1. Phase R

30.2

Second Phase S

30.3

Third Phase T

31

diode array

31.1-31.6

Single diode

32

parallel inductance

33

Regulator circuit

34

diode branch

35

transistor

36

input side

37

output side

38

interface

39

control unit

40

identified values

41

reported back control signals

Claims (8)

Method for detecting an output current of a generator ( 30 electric machine of proportional size, the machine having a supply line ( 21 ) one Electrical system ( 20 ) with several points of consumption ( 23 . 24 . 25 . 26 . 27 ) supplied with electrical energy and the 3-phase system ( 30.1 . 30.2 . 30.3 ) and in which the voltage drop in an electrical component ( 4 . 7 ) containing section ( 3 ) by means of a further processable output signal ( 10 . 40 ) generating evaluation stage ( 9 . 9.1 . 9.2 ), characterized in that the voltage drop taking into account resistances of the components ( 4 . 7 ), of line resistance ( 5 ) and mass ( 1 ) on at least one of the phases ( 30.1 . 30.2 . 30.3 ) and the voltage measurement in the web section ( 3 ) and from it by means of the evaluation stage ( 9 ) to an increasing or decreasing tendency of the phase current ( 6 ) of the generator ( 30 ) is closed. Method according to claim 1, characterized in that the voltage drop in one or more phases ( 30.1 . 30.2 . 30.3 ) of the generator ( 30 ) is determined. Process according to claim 1, characterized in that from the determined voltage drop in the web section ( 3 ) in the evaluation stage ( 9 ) a value for the phase current ( 6 ), which in an output part ( 9.2 ) of the evaluation stage ( 9 ) is processed. Method according to Claim 1, characterized in that further processed output signals ( 10 . 40 ) of the evaluation stage ( 9 ) a control device ( 39 ) are provided as numerical value, voltage level or pulse width modulated signal for further processing. Device adapted for carrying out the method according to one of Claims 1 to 4, for detecting an output current to a generator ( 30 electric machine of proportional size, the machine having a supply line ( 21 ) an electrical system ( 20 ) with several points of consumption ( 23 . 24 . 25 . 26 . 27 ) and the 3-phase system ( 30.1 . 30.2 . 30.3 ) and with a regulator circuit ( 33 ), which has an evaluation level ( 9 ) with evaluation part ( 9.1 ) and output part ( 9.2 ), characterized in that the regulator circuit ( 33 ) on the input side ( 36 ) with mass ( 1 ) and at least one of the phases ( 2 ; 30.1 . 30.2 . 30.3 ) is connected to the electrical machine, wherein the device is arranged to reduce the voltage drop taking into account line resistance ( 5 ) and mass ( 1 ) at least one phase ( 2 ; 30.1 . 30.2 . 30.3 ) of the electrical machine and from it by means of the evaluation stage ( 9 ) to an increasing or decreasing tendency of the phase current ( 6 ) of the generator ( 30 ) close. Device according to claim 5, characterized in that the control circuit ( 33 ) at least one of the following elements is connected in parallel: an inductance ( 32 ), a diode ( 34 ), a transistor ( 35 ). Apparatus according to claim 5, characterized in that the evaluation part ( 9.1 ) several inputs ( 11 . 12 . 13 ) for connecting the phases ( 2 ; 30.1 . 30.2 . 30.3 ) contains. Device according to claim 5, characterized in that the control circuit ( 33 ) to the control unit ( 39 ) further processed signals ( 10 . 40 ) and from this control signals ( 41 ) received.