DE10234088A1 - Influencing polyphase generator load-response function e.g. for vehicle, involves generating function profile control signals depending on system voltage, internal combustion engine operating state, and driving situation - Google Patents

Abstract

The method involves generating control signals (40,40.1-40.4) for the profile of the load response function (1), which is provided to minimize reactions on the engine from the operation of the generator when loads are connected, depending on the voltage Ub) within the on-board electrical system and taking into account the operating state (17,18) of the internal combustion engine and the driving situation.

Description

Technical field

For the control of three-phase generators on internal combustion engines for feeding the vehicle electrical system Motor vehicle and used to charge the vehicle battery can be In addition to standard controllers, multifunction controllers can also be used. In the case of multifunction controllers, in addition to the normal voltage regulation the implementation of special functions is still possible. A special function is the "Load Response Function" (LRF). By a limited rate of increase in the electrical power output of the alternator over the Time, the running and exhaust behavior of an internal combustion engine support in particular, this prevents the connection of electrical consumers in the electrical system of the motor vehicle by the increase in output power of Three-phase generator retroactively on the internal combustion engine Braking torque slump or a "stall" of the internal combustion engine he follows.

State of the art

Today used in motor vehicles Generators give a load signal. In addition, the target voltage of the generator and / or the load response time can be controlled. The corresponding signals can both digitally using a bus system (e.g. via a bit-synchronous interface) as well as in analog form, e.g. transmitted in the form of a pulse width modulation signal become. The target voltage of the vehicle electrical system is on the input side of the generator given up. Furthermore, a signal, which the load response time with which is a ramp-shaped The excitation current is controlled in the three-phase generator, transmitted to the three-phase generator become. By means of these input variables of the three-phase generator can be its electrical power and its drag torque influence at a known speed.

The load response function can control the voltage on the three-phase generator from the outside controlled superimposed become. This has the consequence that the pulse width of the excitation current in the excitation circuit of the three-phase generator from the pulse widths impressed from the outside controlled load response signal is limited. So that is electrical Output power of the three-phase generator at a certain operating point and thus its drag torque caused by the internal combustion engine is limited. As a result, an electrical Load jump no sudden braking torque over the Three-phase generator driving V-belt on the internal combustion engine reacts and at this, especially in the low speed range, a drop in speed causes. A drop in speed can be particularly small Combustion engines with lower displacement occur that due to their comparatively low torque, the power over the Apply speed.

In the above-mentioned, unfavorable operating points one Internal combustion engine is switched on when a strong electrical Load the needed one electrical energy temporarily delivered from the vehicle battery. During this period the load response function ramped up, whereby the excitation current in the excitation circuit of the three-phase generator increases. This continues until the electrical that is fed into the vehicle electrical system Power of the three-phase generator equal to that consumed in the vehicle electrical system electrical power and the target voltage in the vehicle electrical system resumes.

Depending on the operating status of the Internal combustion engine can the ramp, according to which the Load response function is ramped up more or less steeply can be controlled by gradually increasing the pulse width of the load response function. The increasing drag torque according to the ramp slope, what about the Belt drive of the internal combustion engine to the three-phase generator transferred to its drive can, by shifting the ignition angle or an improvement in cylinder filling be corrected.

In three-phase generators that are already in use, the load response function is permanently wired in the generator regulator of the three-phase generator. The circuit is designed in such a way that the load response function is effective up to a speed of approximately 3,000 min ^{−1 of} the generator.

In the case of software control of the Load response function is the load response time, i. H. the ramp slope of the excitation current as a function, for example in a control unit the speed, temperature, and torque of the internal combustion engine stored. The load response time is therefore only dependent on the conditions which the internal combustion engine occupies. The load response function is also in various operating states of the internal combustion engine active. To these operating states counts the Start phase in which the load response function has a flat ramp gradient has, i.e. the excitation current in the excitation circuit of the three-phase generator rises slowly. About that In addition, the load response function during idle and while Acceleration phases of the internal combustion engine activated, wherein the ramp slope of the load response function essentially one maintains constant value.

Out US 5,262,711 A device for regulating the output voltage of a three-phase generator driven by an internal combustion engine is known, according to which a load response function is activated while driving. The excitation current in the excitation circuit of the three-phase generator is continuously increased after switching on an electrical consumer that consumes high electrical power, so that speed drops do not occur in the internal combustion engine. According to this solution, the load response function is linked to a speed evaluation while driving. The excitation current in the excitation circuit of the three-phase generator is increased as a function of the comparison of the measured speed of the internal combustion engine with a speed threshold. Suppression of the activation of the load response function is not provided.

Out DE 196 38 357 A A device for voltage regulation in a separately excited three-phase generator driven by an internal combustion engine is known. According to this solution, the load response function activated while driving is blocked when certain conditions occur. If a drop in speed is detected, the load response function is blocked. This results in a rapid rise in the excitation current in the excitation circuit of the separately excited three-phase generator. This in turn results in a rapid increase in the electrical power output of the externally excited three-phase generator, which counteracts a voltage drop in the vehicle electrical system of a motor vehicle. On the other hand, if the speed of the internal combustion engine is constant or increasing, the load response function remains activated, as a result of which there is no sudden increase in the braking drag torque which the three-phase generator exerts on the internal combustion engine when a consumer consuming high electrical power is switched on.

presentation the invention

The execution of the load response function according to the invention on an externally excited three-phase generator enables consideration the vehicle electrical system voltage and the driving dynamics of the motor vehicle. It is very beneficial if the load response function spans the entire speed range is effective, i.e. no speed restrictions, speed thresholds given are. The control of the load response function, in particular their ramp slope can now depend on the vehicle electrical system voltage occur so that voltage fluctuations within the vehicle electrical system be prevented. Furthermore, the load response function is under Considering the Charged state of the vehicle battery controlled so that excluded is that this is during a transition period with the coverage of what is not yet covered by the three-phase generator when switching on consumers with high electrical output required additional service for that Electrical system is charged. This will result in a gradual unloading an insufficiently charged vehicle battery is prevented. An insufficient state of charge of the vehicle battery, i.e. a creeping Unloading the same is particularly the case for frequent short journeys of the motor vehicle.

Furthermore, can be advantageously achieve the ramp slope of an active load response function become dependent changes from the operating point of the internal combustion engine. Depending on the operating point and change the operating point of the internal combustion engine can either charging the vehicle battery through a steeper ramp the active load response function at favorable engine operating points, i.e. higher Speeds of the internal combustion engine are taken into account, or when changing towards less favorable engine operating points operating conditions the internal combustion engine by a flatter ramp slope caused by the three-phase generator in the event of sudden power output, drag torque retroactive to the internal combustion engine is reduced become. This causes a drop in the speed of the internal combustion engine prevented during idling or at only slightly higher speeds.

In special driving situations, see above especially during Acceleration phases of the motor vehicle - for example when overtaking - can Three-phase generator entirely be switched off. For this purpose, either the absolute pedal position or the change the pedal position can be used by the driver. Almost one detected acceleration phase of the internal combustion engine can the ramp slope of the load response function was kept very flat or the excitation current in the excitation circuit of the three-phase generator reduced to 0 so that the from the alternator to the internal combustion engine retroactive Drag torque is minimized. It is found that the vehicle electrical system voltage is about to drop below a certain preselectable threshold, the switching off of the three-phase generator can be locked, i.e. prevented become. This is particularly advisable if an inadequate one State of charge of the vehicle battery is determined so that a Protection against discharge is given.

With the solution proposed according to the invention, by superimposing the load response pulse width via the voltage regulation, it is possible to switch the generator off completely in certain operating states, for. B. during the starting process of the internal combustion engine. This is possible without a separate input for external voltage regulation, in which the load response pulse width is set to 0 and the excitation current is thus completely prevented. This operating state finds its limit, however, in the fact that this is only permitted when the vehicle battery is sufficiently charged or the vehicle electrical system voltage is above a minimum value.

The active load response function proposed according to the invention on a three-phase generator can also be used outside of specially detected operating conditions such as e.g. the above Acceleration phase of an internal combustion engine act. This does not allow the load jumps jerky, but steered within a flat ramp slope be so that the mechanical components of a belt drive such as. of an open-sided V-belt with which the in motor vehicles three-phase generators used by the internal combustion engine driven, spared and their lifespan is extended.

In an embodiment variant of those proposed according to the invention solution let yourself an external voltage control via implement a load response input. By means of a fixed Excitation current in the excitation circuit of the three-phase generator can be the three-phase generator without constriction through the load response pulse width (i.e. pulse width 100%) a constant Deliver tension. The speed threshold for an active load response function may not be present in this case. It can therefore be about the entire speed range of the internal combustion engine regulated become. In this case, lets the load response pulse width is set such that the limited excitation current, taking into account the battery charge level and the corresponding electrical system voltage in the electrical system established. The on-board electrical system voltage is read in by the engine control unit and compared with a target voltage. The difference between the vehicle electrical system voltage and the target voltage leads to a corresponding specification of the load response pulse width. This variant an external voltage regulation allows an external voltage regulation and is very flexible just about the load response input can be implemented. The actual load response function in this case, of course also be implemented.

drawing

The invention is described below with reference to the drawing described in more detail.

It shows:

1 the components shown in block form and their signal exchange to achieve an active load response function in an overview,

2 the signal flow within the active load response function during the cold start phase of an internal combustion engine,

3 the increment, ie the ramp jumps of the load response function,

4 the signal flow of the load response function during the acceleration phase, ie a speed increase phase of an internal combustion engine,

5 the signal flow for determining a control signal for the three-phase generator,

6 the course of the excitation current in the excitation circuit of the three-phase generator with opposed active and inactive load response functions,

7 the basic structure of a three-phase generator with a voltage control, which is superimposed on a load response function and

8th the representation of a control loop for external voltage regulation by influencing the pulse width of the load response function.

 variants

As shown 1 the components shown in block form and their signal exchange within a load response function can be found.

The function blocks of a load response function shown in block diagram form 1 include a detector routine 2 for the detection of a positive load step on the three-phase generator, also an evaluation unit 3 in which the the load response function 1 driving output signal 40 . 40.1 . 40.2 . 40.3 respectively. 40.4 is generated. By the sequence of the load response function 1 triggering signals (G signal) pulse width values are generated to limit the excitation current in the three-phase generator, so that a ramp-shaped load response function can be represented. The load response function also includes 1 a cold start routine 4 , an idle routine 5 as well as a driving situation detection 6 , The listed function blocks can be designed both hardware and software within a circuit for the load response function and allow active regulation of the excitation circuit of a three-phase generator depending on the voltage of the vehicle electrical system and thus the energy store as well as depending on the driving situation or an operating state of the the internal combustion engine driving the generator.

The evaluation unit 3 in which the the load response function 1 driving output signal 40 . 40.1 . 40.2 . 40.3 respectively. 40.4 is generated is at an input 31 with the on-board electrical system voltage U _b representing signal. In addition, the evaluation unit 3 a load step detection routine 2 upstream, the input side via a signal 7 is applied, which represents the current load of the three-phase generator. The load step routine generates on the output side 2 a signal 10 , via which the activation of the load response function 1 to the evaluation unit 3 is transmitted. There is also a load step detection routine on the output side 2 an output signal, which represents the current generator load of the alternator of the internal combustion engine. The load step detection routine is on the input side 2 not only via a signal representing the current generator load 7 applied, but the load jump detection routine 2 is about a feedback 9 on a branch 41 tapped, the current pulse width of the output signal 40 . 40.1 . 40.2 . 40.3 as well as 40.4 to control the load response function. The signal representing the current electrical system voltage U _b is at the evaluation unit 3 at a corresponding entrance 31 on while the output signal 10 the load step detection routine 2 on the evaluation unit 3 at a corresponding entrance 32 pending. The output signal representing the current generator load of the three-phase generator 11 the load shedding detection routine 2 stands at an entrance 33 the evaluation unit 3 on.

In addition to the input variables, which are the current electrical system voltage U _b and the current generator load 7 indirectly or directly to the input side of the evaluation unit 3 transmit the evaluation unit 3 in addition, signals are supplied which result from operating parameters of the internal combustion engine or from accelerator pedal positions, from which the current operating state of the internal combustion engine and thus the driving situation of the vehicle can be derived.

This is a cold start routine 4 implemented on the input side at an input 16 Both a signal T _mot representing the current temperature of the internal combustion engine and a signal n _mot representing the current speed of the internal combustion engine are applied. At an entrance 14 the cold start routine 4 there is also a signal 13 which indicates the end of the starting phase of the internal combustion engine. The three signals mentioned are on the input side of the cold start routine 4 on. In the cold start routine 4 a bit is set, B _{gen, on} , which represents the switch-on state of the three-phase generator. The B _{gen, on} is at an appropriately configured input 34 the evaluation unit 3 the load response function 1 on. In addition, in the cold start routine 4 an output signal 17 generated, which represents the operating state of the internal combustion engine. This output signal 17 becomes the evaluation unit 3 not directly connected, but indirectly with the interposition of a first electronic switch 19 or a second electronic switch 28 on which in addition to the output signal 17 further output signals, as explained below, are pending.

The parameters n _mot or T _mot representing the operating state of the machine become inputs 15 . 16 an idle detection routine 5 switched on, that of the cold start routine mentioned above 4 is connected in parallel. Within the idle routine 5 becomes an output signal 18 generated, which indicates the idle state of the internal combustion engine. The output signal 18 the idle routine 5 is on the input side of the first electronic switch 19 on just like the output signal 17 the cold start routine 4 as well as a signal 12 , which indicates the activation of an idle control of the internal combustion engine.

The load response function according to the overview in 1 also includes a driving situation detection 6 , The detection of the driving situation 6 is at their entrances 22 . 23 . 24 loaded with signals that allow conclusions to be drawn about the respective driving situation of the vehicle. So is the entrance 22 the detection of the driving situation 6 a signal representing the accelerator pedal position 20 given up. It also says at the entrance 23 the detection of the driving situation 6 a signal 21 which signals a change in the accelerator pedal position. Finally stands at the entrance 24 the detection of the driving situation 6 a signal v _F representing the vehicle speed. Within the driving situation detection 6 the input signals become output signals 25 . 26 . 27 generated. That at the exit of the driving situation detection 6 pending output signal 25 is set if full load operation is detected and shows the activation of the load response function 1 in this operating range of the internal combustion engine. In addition, in the driving situation detection 6 a signal 26 generated, which is set when from the input signals 20 . 21 or v _{F is} recognized that the internal combustion engine is in an acceleration phase caused by an increase in vehicle speed and a change in the signal 21 , which characterizes the accelerator pedal position, can be recognized. Depending on a detected acceleration state of the internal combustion engine due to the change in the signal 21 or v _F , can within the driving situation detection 6 an output signal 27 generated, which is a change in the load response function 1 during an acceleration phase of the internal combustion engine. The output signal 27 becomes the first electronic switch 19 downstream second electronic switch 28 fed on the input side.

According to the overview 1 reproduced active load response function 1 thus takes into account the current on-board electrical system chip voltage U _b , the current generator load 7 of the alternator, the fact whether an idle control 12 the internal combustion engine is switched on or off, a signal 13 , which represents the end of the starting phase of the internal combustion engine and the current engine speed n _mot , the current engine temperature T _{mot of} the internal combustion engine; finally, about driving situation detection 6 the accelerator pedal position 20 , and their change 21 and the prevailing current vehicle speed v _F when generating the load response function 1 output signal driving a three-phase generator 40 . 40.1 . 40.2 . 40.3 respectively. 40.4 considered.

In addition to the sizes, which of the evaluation unit 3 on its input side, either directly, such as the vehicle electrical system voltage U _b , are sent to the evaluation unit 3 preprocessed signals 32 . 33 . 34 . 35 and 36 fed. The signals supplied indirectly are interposed by the load step detection routine 2 , the cold start routine 4 , the idle routine 5 or by interposing a driving situation detection 6 preprocessed. The output signals 17 or 18 of the cold start routine 4 or the idle routine 5 as well as the signal 12 , which signals the activation of the idle control of the internal combustion engine, the first electronic switch 19 given up. This switches the output signal to a first signal path 29 as well as a second signal path 30 , the signal lying on this signal path representing normal operating states of the internal combustion engine.

The output signal of the first electronic switch 19 , which represents the operating state of the internal combustion engine, is a second electronic switch on the input side 28 given up. In addition, the second electronic switch 28 which is the change in the load response function 1 output signal presenting due to an acceleration phase of the internal combustion engine 27 activated on the input side. Furthermore, the second electronic switch 28 optionally with an internal combustion engine at full load and a correspondingly activated load response function 1 representative signal 25 consider. In the second electronic switch 28 Accordingly, the operating state of the internal combustion engine is determined by combining the signals 12 . 17 and 18 at the first electronic switch 19 with the current driving situation 25 or 27, determined in the driving situation detection 6 , merged; from this information at the second electronic switch 28 the amount of change in the pulse width is determined which corresponds to the input 36 the evaluation unit 3 is abandoned. At the entrance 36 the evaluation unit 3 there is therefore information on the change in the pulse width of the load response function 1 depending on the operating state or on the driving situation of the motor vehicle of the internal combustion engine or the motor vehicle.

The evaluation unit 3 generates an output signal 37 , which is a maximum value limiter 39 is abandoned. In addition to the output signal 37 the evaluation unit 3 is the maximum value limiter 39 with a 100% signal (38) of a set value. In the case of an inactive load response function, an output signal is generated using the 100% value 40.1 to control the load response function 1 generated, which runs ramp-free (compare excitation current curve 75 without LRF in the diagram according to 6 ).

As shown 2 the calculation of the load response ramp slope during engine start and thereafter can be found.

From the input signals 13 Displaying the end of the start phase, the current engine speed n _mot and the current engine temperature T _mot are in the cold start routine 4 output signals 17 or B _{gen, one} generated. The alternator is normally switched off during a cold start phase of the internal combustion engine. This is done by the signal 51 , which is a comparative signal link 52 is connected upstream. The signal link 52 is next to the set signal 51 " Upper engine speed limit for generator off "the engine speed n _{mot on the} input side. The output signal of the signal linkage 52 becomes an AND operation 52.1 abandoned on the input side of the signal 13 is supplied, which indicates that the end of the starting phase of the internal combustion engine has been reached. The LTND link 52.1 is a flip-flop 52.2 downstream, which in turn is a delay element 53 is connected downstream. The delay element 53 the period of time during which the alternator should remain switched off can be stamped. After expiry of the delay element 53 pre-settable delay time, the switching on of the three-phase generator causing bit B _{gen, on is} set. The period of time during which the three-phase generator has exceeded the threshold 51 should remain switched off, by changing the delay element 53 adjustable delay time can be varied.

In the start routine 4 z. B. by means of the map 50 a load response ramp slope corresponding to the operating state of the internal combustion engine from the current engine speed nmor and the engine temperature T _mot 17 generated and as an input signal for the in 1 illustrated first electronic switch 28 used.

In an advantageous manner, the delay element 53 according to 2 the delay time is set in such a way that it is approximately 3 s, ie essentially corresponds to the time period in which the internal combustion engine has reached its idling speed of approximately 550 to 700 min ⁻¹ after a start. The start routine 4 , in the 2 regarding the signal processing is reproduced in more detail remains active with regard to controlling an active load response function 1 as long as no engine idling or acceleration request from the driver is recognized. The one in the start routine 4 determined ramp slope of the loade response function 1 always affects the signal 36 " Δ pulse width load response ", as long as no idle control or an acceleration state is detected on the internal combustion engine. If these operating states, ie idle of the internal combustion engine or acceleration, are detected, the respective switches are flipped and the corresponding values of the idle blocks 5 , Driving situation detection 6 , Acceleration, output to the laod response function.

3 shows the signal flow within the idle routine according to the overview in 1 ,

As related to 1 already mentioned are routine 5 , which covers the idle case, at their entrances 15 or 16 also gave up the signals n _mot or T _{mo t} representing the current engine speed and the current engine temperature. Within a characteristic field 54 , are increments that indicate the course of a load response function 1 represent with regard to their ramp slope. This becomes an output signal 18 generated, which characterizes the ramp slope of the load response function for the idle state of the internal combustion engine depending on the input variables n _mot or T _{mo t} .

In 4 is the signal flow within the driving situation detection 6 according to the overview in 1 shown in more detail.

The driving situation detection is on the input side 6 about a signal 20 , which represents the accelerator pedal position, is also acted upon by a signal indicating a change in the accelerator pedal position 21 and immediately with a signal v _F , which represents the driving speed.

In a first signal link 56 become the current through the signal 20 representing accelerator pedal position and a set accelerator pedal position 55 compared. The accelerator pedal position set should roughly correspond to the full load state. The output signal of the first signal link 56 represents the output signal 25 represents, which indicates a high load state of the internal combustion engine. The input signal representing a change in the accelerator pedal position 21 becomes both a comparative signal link 57 "Accelerate" as well as a comparative signal link 58 " Delay "abandoned. Both the signal linkage 57 as well as the signal link 58 are on the input side with set values 59 respectively. 60 acted upon, which represent the accelerator position curve during acceleration, ie positive accelerator pedal gradient or the accelerator pedal position curve during deceleration, ie negative accelerator pedal gradient. The output signal of the first signal link 56 as well as the output signal of the signal linkage acceleration 57 are at a signal merge 61 coded and a flip-flop on the input side 62 given up. On the flip-flop 62 is the output signal of the signal combination 61 at a set entrance. At the reset input of the flip-flop 62 is the output signal of the signal link 58 "Delay". The output signal of the flip-flop 62 represents the output signal 26 , which in turn is the second electronic switch 28 is given up and indicates an acceleration phase of the internal combustion engine.

In addition, the signal representing the accelerator pedal position 20 and the signal v _F representing the current vehicle speed in a characteristic field 54 fed, in which different courses of the load response function 1 are stored for different combinations of accelerator pedal position and vehicle speed. In the case of acceleration detection, the output of the ORing 61 the respective pedal position as input 22 in the map 54 accepted. Along with the one at the entrance 24 given signal v _F becomes an output signal 27 determines which characterizes a change in the pulse width to be set in accordance with the detected acceleration and vehicle speed for the active load response function.

5 shows the signal processing within the evaluation unit 3 the load response function as shown in 1 ,

Becomes an inactive load response function 1 which results from an evaluation of the at the entrance 32 the evaluation unit 3 pending signal is detected, an output signal is detected 40.1 to control the load response function 1 output, which by the evaluation unit 3 downstream fixed value 38 is set to 100%, ie the course of the load response function 1 is in this case, ie when the load response function is inactive 1 , characterized by a rampless course, ie jumps of the excitation current in the three-phase generator to 100% are possible.

At the start of the activation of the load response function 1 is obtained by evaluating the signal representing the last load value of the three-phase generator 33 a control signal 40.2 for the pulse width of the load response function 1 generated, (compare 6 , Position 73 ) at a time when indicated by a positive jump in signal 32 , the connection of another electrical consumer in an electrical system 108 a motor vehicle that has a high electrical power consumption.

From the output signal 36 of the second electronic switch 28 , which is an increment of the pulse width of the load response function 1 displays and from the current electrical system voltage U _b with the interposition of a characteristic curve field in which the curves of the rates of increase of the load response function are present, taking into account the vehicle electrical system voltage at a junction 71 the desired curves depending on the prevailing on-board voltage 78 or 79 (compare 6 ) the load response function 1 determined. When merging signals 71 becomes the ramp slope of the load response function 1 influenced by the current on-board voltage U _b , since the slope of the load response function in the characteristic field depends on this 54 is determined. The output merging 71 becomes a summation point 70 fed. At the summation point 70 the current pulse width of the load response function, represented by the original control signal 40 for the pulse width of the load response function 1 merged with the desired slope of the load response function ramp and a resulting new pulse width of a load response function that takes into account the operating state of the internal combustion engine and vehicle electrical system voltage 1 presented by the modified control signal 40.3 , determined.

The current vehicle electrical system voltage Ub is also compared to a permissible minimum voltage U _min . In addition, the output signal 25 the detection of the driving situation 6 , which shows the full load state of the internal combustion engine and a correspondingly activated load response function 1 displays and the signal B _{gen , on} a signal processing supplied. By comparing the current electrical system voltage Ub with a minimum voltage, an input signal for another electronic switch 72 determined. The further electronic switch 72 is applied via an input via which the generator can be switched off. There is also another electronic switch 72 the current control signal 40 for the pulse width of the load response function 1 on. Through the further electronic switch 72 The three-phase generator of the internal combustion engine is only switched off during an acceleration phase of the internal combustion engine on the basis of the signals present at the inputs if the on-board electrical system voltage Ub is within the on-board electrical system 108 of the vehicle exceeds a minimum voltage value U _min . If the vehicle electrical system voltage is too low, the originally calculated ( 40.1 or 40.2 or 40.3 ) Load response slope 1 , ie their pulse width, switched through.

Is that the further electronic switch 72 given, the switching on of the alternator represent bit B _{gen, on} with the value 0, which according to 2 happens during the starting process of the internal combustion engine, the generator is switched off and is only after the delay element has expired 53 set delay time switched on.

6 shows the course of the excitation current in the excitation circuit of a three-phase generator, the course of which is compared with one another when the load response function is activated or deactivated.

The excitation current I _ERR is plotted over the time axis. When switching on a strong electrical consumer with a high power consumption such as a windscreen heater or a rear window heater within the vehicle electrical system 108 of a motor vehicle, a load jump occurs on the three-phase generator of the internal combustion engine. In the absence of a load response function 1 According to the present figure, the additional power requirement within the electrical system 108 of the motor vehicle jump covered immediately by the generator. When the load response function is active 1 the power requirement of the generator is provided in a ramp. The coverage contribution to the electrical power that the vehicle battery provides is due to the shaded area 74 in the diagram according to 6 shown. The one with reference numerals 75 marked course represents the excitation current I _ERR , which the three-phase generator without limitation by a load response function 1 after the jump in load occurs when an electrical consumer is switched on, the switch-on point 73 having. Accordingly, the three-phase generator now has an abrupt drag torque, which is to be applied by the internal combustion engine.

The one with reference numerals 76 marked course of the excitation current I _ERR can by an activated load response function 1 can be achieved according to the proposed invention. In contrast to the one with reference numerals 75 marked course of the excitation current I _ERR , the excitation current increases after switching on an electrical consumer with high power consumption in the electrical system 108 of the motor vehicle in the form of a ramp, ie there is no sudden load on the three-phase generator. On the one hand, this protects the belt drive that drives the three-phase generator, whether it is an open-flank or a different type of V-belt, and extends its service life, and on the other hand, thanks to the active load response function 1 the drag torque of the three-phase generator, which has a retroactive effect on the internal combustion engine, is significantly reduced or rises more gently, so that speed drops in the internal combustion engine do not occur during idling or in the low partial load range.

When connecting an electrical consumer with a high electrical power consumption at the time of connection 73 the excitation current I _{ERR increases} in increments 80 corresponding to a first ramp slope 78 on. The first ramp climb 78 , ie the excitation current I _ERR is increased in accordance with that in the second electronic switch 28 (compare illustration according to 1 ) first signal 36 , which is the change in the pulse width of the active load response function 1 triggers. If the internal combustion engine is in a range of higher speeds, the activated load-response function can certainly start with a first steep incline 78 can be controlled. Changes, identified by reference numerals 77 However, the operating state of the internal combustion engine can be changed due to the changed driving situation by the active load response function 1 the ramp slope according to that with reference numerals 79 in increments 80 increasing ramp course z. B. be flattened. If the vehicle electrical system voltage drops, for example, the slope of the ramp course could also become steeper, ie increase. By flattening the ramp slope of the load response function 1 For example, the driver's request for acceleration can be supported by, in extreme cases, reducing the excitation current I _ERR to 0, so that a minimal generator drag torque which has an effect on the internal combustion engine occurs during the acceleration phase of an internal combustion engine. Thereafter, when the vehicle electrical system voltage is detected, Ub can occur within the vehicle electrical system 108 the ramp slope in the range of a just permissible minimum voltage U _min 78 or 79 depending on the on-board voltage-dependent characteristic 54 the load response function 1 (compare illustration according to 5 ) are taken into account. Depending on the shift in the operating point of the internal combustion engine, either the better battery charge, ie by a steeper ramp gradient 78 the load response function is taken into account, or a better behavior of the internal combustion engine, ie a minimization of the retroactive drag torque on the internal combustion engine by a flat ramp gradient 79 the load response function (compare position 79 in 6 ).

According to the representation 7 the principle of an external voltage regulation of a three-phase generator is reproduced via the input of a load response function, according to a further embodiment variant of the solution proposed according to the invention (cf. page 5).

An entrance 92 the load response function 1 is with a load response signal 93 applied. On an AND link 94 becomes the load response signal, which at the input 92 the load response function 1 pending with a square wave 91 linked, which in turn by a rectangular generator 90 (constant pulse width signal) is linked. With an AND link 94 resulting link signal 95 influences the excitation current I _ERR in the excitation circuit 96 a three-phase generator 98 that next to the excitation circle 96 a group of runners 97 contains. According to this further embodiment of the solution proposed according to the invention, the three-phase generator can be operated by means of a fixed excitation current 98 generate a constant voltage of, for example, 17 volts without constriction by means of a load response pulse width, ie 100%. The speed threshold for an active load response function 1 is not available, therefore regulation can be made over the entire speed range. The load response pulse width is set in such a way that the link signal 95 limited excitation current I _ERR , the battery state of charge of a motor vehicle battery 105 and the load U _b within the vehicle electrical system 108 of the motor vehicle sets an electrical system voltage.

In 8th An example is shown of how the vehicle electrical system voltage is regulated by means of a control device according to the principle mentioned above.

Within a control unit 104 is based on a battery model 100 , which also includes the battery temperature T _Bat and based on a charging characteristic 101 a car battery 105 , a _target voltage U _{target is} determined. At a negative link, the determined voltage U _{Soll is} compared with the actual voltage U _b within the vehicle electrical system 108 of the vehicle compared. The voltage difference ΔU determined within the evaluation unit 3 the pulse width for a load response function 1 determined and as a control signal 40.4 that of an input terminal 109 (G +) of the three-phase generator 98 switched. At the G + terminal of the three-phase generator 98 is the plus pole 106 the car battery 105 connected, the negative pole 107 to the mass of the electrical system 108 is led.

With the in 7 respectively. 8th The embodiment variant of the solution proposed according to the invention can control the entire voltage control externally and very flexibly via a load response input 92 respectively. A separate input for voltage regulation can therefore be omitted, so that the voltage regulator is on the three-phase generator 98 can be simplified considerably.

1

Load-response function

2

load step detection routine

3

evaluation

4

start routine

5

routine (Neutral)

6

Fahrstituationserkennung

U _b

Board supply voltage

7

generator load

8th

entrance Generator load signal

9

feedback Load response pulse width

10

output Load response pulse width

11

output generator load

12

Idle speed control active

n _mot

rotational speed Internal combustion engine

T _mot

temperature Internal combustion engine

13

The End VKM start phase

14

entrance Start phase signal

15

Entrance n _mot

16

T _mot

17

output VKM operating status

B _{gen, on}

signal Generator ON

18

output Idle routine

19

first electronic switch

20

Accelerator pedal position

21

modification Accelerator pedal position

v _F

Accelerator pedal position

22

entrance Accelerator pedal position signal

23

Receipt change Accelerator pedal position

24

Input signal v _F

25

delay (Load response active)

26

output acceleration phase (Load response active)

27

Output signal change Load response function due to acceleration phase

28

second electronic switch

57

Signal linkage acceleration

29

1. Signal path operating state of internal combustion engine

30

Another Signal path operating state of internal combustion engine

31

Entrance U _b

32

entrance Bit: Load response active

33

entrance Load value pulse width

34

Input bit B _{gen, on}

35

entrance Bit LR (full load) active

36

Receipt change pulse width Load-response function

37

output pulse width Load Response

38

limiter (100%)

39

Maximum value limiter

40

40.1

voltage / driving situation

40.2

dependent control signal

40.3

pulse width Load response function increments operating state

40.4

function

50

curve Load response function increments operating state

51

"Generator off" switch

52

signal combination

52.1

AND operation

52.2

Flip-flop

53

delay

T

Delay Time

54

Of characteristics Gradient increment load response

55

Full load signal

function because of acceleration phase

56

First signal combination

T _Bat

battery temperature

58

Signal link delay

59

Maximalpedalweg accelerator

60

throttle pedal travel = 0 (delay)

61

ORing

62

Flip-flop

70

Signal activation point change loading

71

resulting Rampensteigungs-

72

Another electronic switch

U _min

board network minimum voltage

72

Another electronic switch

I _ERR

excitation current Excitation circuit three-phase generator

t

timeline

73

Connect time electrical consumer

74

contribution margin vehicle battery

75

Excitation current course without LRF

76

Excitation current course with LRF

77

modification VKM operating status

78

First Ramp slope LRF

79

Second Ramp slope LRF

80

Ramp increment

90

square wave generator

91

square wave

92

entrance Load response signal from the control unit

93

Load response signal

94

AND operation

95

Linked signal

96

excitation circuit

97

rotor circuit

98

Alternator

100

battery model

101

Charging characteristic

102

target voltage board network

.DELTA.U

voltage difference

104

control unit

105

Car battery

106

positive pole

107

minuspol

108

board network

B +

generator terminals

G +

109

entrance Generator load response pulse width specification

Claims (18)

Procedure for influencing the load response function ( 1 ) on an externally excited three-phase generator driven by an internal combustion engine ( 98 ) of a pathogen group ( 96 ) and a group of runners ( 97 ) and the load response function ( 1 ) to minimize the effects of the three-phase generator ( 98 ) on the internal combustion engine when switching on electrical consumers within an electrical system ( 108 ), which is an energy storage ( 105 ), characterized in that depending on the voltage U _b within the vehicle electrical system ( 108 ) of a vehicle and taking into account the operating state ( 17 . 18 ) the internal combustion engine and the driving situation, control signals ( 40 . 40.1 . 40.2 . 40.3 . 40.4 ) for the course ( 78 . 79 ) the load response function ( 1 ) to be generated. Method according to claim 1, characterized in that the variables determined as a function of the driving dynamics of the vehicle ( 31 . 32 . 33 . 34 . 35 . 36 ) processing evaluation unit ( 3 ) an output signal dependent on voltage and driving dynamics ( 37 ) to generate a control signal ( 40 . 40.1 . 40.2 . 40.3 . 40.4 ) for the load response function ( 1 ) is produced. A method according to claim 2, characterized in that the output signal ( 37 ) of the evaluation unit ( 3 ) is a signal which is influenced with regard to the pulse width and which _excites the excitation current I _ERR in the excitation circuit ( 96 ) of the three-phase generator ( 98 ) influenced. A method according to claim 2, characterized in that when the load response function is not activated ( 1 ) the evaluation unit ( 3 ) an output signal ( 37 ) generated by an actuator ( 38 . 39 ) into a rampless control signal ( 40.1 ) to control the load response function ( 1 ) is converted. A method according to claim 2, characterized in that at the start (32) of the activation of the load response function ( 1 ) in the evaluation unit ( 3 ) an output signal ( 37 ) taking into account the last load value ( 7 . 33 ) of the three-phase generator ( 98 ) is generated, which the control signal ( 40.2 ) for the load response function ( 1 ) represents. A method according to claim 1, characterized in that the evaluation unit ( 3 ) On the input side, variables that characterize the operating state of the internal combustion engine and the driving dynamics of the vehicle ( 34 . 35 . 36 ) are given up in a cold start routine ( 4 ), an idle routine ( 5 ) and in a driving situation detection ( 6 ) be determined. A method according to claim 6, characterized in that the cold start routine ( 4 ) in entrances ( 14 . 15 . 16 a speed signal n _{mot of} the internal combustion engine, a temperature signal T _mot and a signal indicating the end of the start phase of the internal combustion engine ( 13 ) are supplied, from which an output signal characterizing the operating state of the internal combustion engine ( 17 ) is generated. A method according to claim 6, characterized in that in the cold start routine ( 4 ) the switch-on signal for the three-phase generator ( 98 ) representing bit B _{gen, on} , which is assigned to the evaluation unit ( 3 ) at an entrance ( 34 ) is abandoned. A method according to claim 6, characterized in that in the idle routine ( 5 ) at entrances ( 15 . 16 ) the speed signal n _{mot of} the internal combustion engine and a temperature signal T _{mot of} the internal combustion engine are supplied, from which an idle state ( 18 ) output signal characterizing the internal combustion engine ( 18 ) is generated. Method according to claims 8 and 9, characterized in that a signal indicating the activation of an idle control of the internal combustion engine ( 12 ), the output signal characterizing the operating state of the internal combustion engine ( 17 ) and the signal indicating the idle state ( 18 ) the idle routine ( 5 ) a first electronic switch ( 19 ) be given up. A method according to claim 6, characterized in that from a signal indicating the accelerator pedal position ( 20 ), a signal indicating the change in the accelerator pedal position ( 21 ) and the vehicle speed v _F in a driving situation detection activating the load response function ( 1 ) signal at full load ( 25 ), which the evaluation unit ( 3 ) is fed directly and an activated load response function ( 1 ) signal during the acceleration phase ( 26 ) and a change in the pulse width of the load response function ( 1 ) signal to be shown ( 27 ) are generated, both a second electrical switch ( 28 ) be given up. A method according to claim 11, characterized in that the second electronic switch ( 28 ) from the output signals ( 26 . 27 ) of the driving situation detection ( 6 ) and the output signal of the first electronic switch ( 19 ) depending on the operating status ( 17 ) the internal combustion engine the pulse width of the load response function ( 1 ) changing signals ( 36 ) to the evaluation unit ( 3 ) are transmitted. A method according to claim 11, characterized in that the output signals ( 36 ) of the second electronic switch ( 29 ) and the current electrical system voltage U _b in the evaluation unit ( 3 ) based on an increment ( 54 ) the load response function ( 1 ) containing characteristic curve an adaptation of the course ( 78 . 79 ) of the excitation current I _ERR ( 76 ) through the load response function ( 1 ) he follows. A method according to claim 11, characterized in that the pulse width of the load response function ( 1 ) influencing signal ( 40 ) on an interface ( 70 ) with the result of a merger ( 71 ) of a change in the course ( 78 . 79 ) the load response function ( 1 ) effecting input variables ( 36 ) or Ub and the pulse width of the load response function ( 1 ) influencing control signal ( 40.3 ) is produced. A method according to claim 1, characterized in that the incrementation ( 80 ) change of course ( 78 . 79 ) the load response function in characteristic fields ( 50 . 54 ) are saved. A method according to claim 1, characterized in that depending on an input signal indicating the full load state of the internal combustion engine ( 35 ), a voltage difference ΔU between U _b and U _min within the vehicle electrical system ( 108 ) and from a signal bit B _{gen, on} (generator ON) the three-phase generator ( 98 ) can be switched off during an acceleration phase of the internal combustion engine. Procedure for influencing the load response function ( 1 ) on an externally excited three-phase generator driven by an internal combustion engine ( 98 ) that has a pathogen group ( 96 ) and a group of runners ( 97 ) and the load response function ( 1 ) to minimize the effects of the three-phase generator ( 98 ) on the internal combustion engine when switching on electrical consumers within the vehicle electrical system ( 108 ) is used in which an energy store ( 105 ) is recorded, characterized in that a pulse width modulated signal ( 91 ) of a signal generator ( 90 ) and an input side ( 92 ) Load response signal ( 93 ) to a resulting signal ( 95 ) with which the pathogen winding ( 96 ) of the three-phase generator ( 98 ) as part of the load response function ( 1 ) is controlled and thus a voltage or power control of the three-phase generator ( 98 ) can be realized. A method according to claim 17, characterized in that in a battery model ( 101 ) with charging characteristic ( 101 ) containing control unit ( 104 ) the _target voltage U _target ( 102 ) of the electrical system ( 108 ) is determined and from a resulting voltage difference ΔU within an evaluation unit ( 3 ) the determination of the pulse width of a control signal ( 40.4 ) for the load response function ( 1 ) which is connected to the G + terminal ( 109 ) the excitation circle ( 96 ) of the three-phase generator ( 98 ) is supplied.