U.S. patent application number 10/468540 was filed with the patent office on 2004-07-08 for device and method for adjusting the speed of a vehicle.
Invention is credited to Bickendorf, Frank, Foelsche, Volkmar, Huelser, Holger, Kallenbach, Rainer.
Application Number | 20040129470 10/468540 |
Document ID | / |
Family ID | 7709568 |
Filed Date | 2004-07-08 |
United States Patent
Application |
20040129470 |
Kind Code |
A1 |
Huelser, Holger ; et
al. |
July 8, 2004 |
Device and method for adjusting the speed of a vehicle
Abstract
A device (1) and a method implementable therewith for regulating
the driving speed of at least one vehicle (3), having an electric
motor/generator (17) connected or connectable to a drive train (7;
7') for at least one wheel (11, 13; 11', 13') as a function of at
least its actual speed and setpoint speed. The device (1) includes
a control unit (31) for controlling the torque of the electric
motor/generator (17), means for driving the electric
motor/generator (17), means (37) for recording the actual speed of
the vehicle (3) and means (39) for preselecting the setpoint speed
of the vehicle (3). The device (1) is characterized in that the
electric motor/generator (17) is usable in generator operation to
generate a braking torque and in engine operation to generate a
driving torque.
Inventors: |
Huelser, Holger; (Graz,
AT) ; Foelsche, Volkmar; (Heilbronn, DE) ;
Bickendorf, Frank; (Ditzingen, DE) ; Kallenbach,
Rainer; (Waiblingen, DE) |
Correspondence
Address: |
KENYON & KENYON
ONE BROADWAY
NEW YORK
NY
10004
US
|
Family ID: |
7709568 |
Appl. No.: |
10/468540 |
Filed: |
February 12, 2004 |
PCT Filed: |
December 10, 2002 |
PCT NO: |
PCT/DE02/04516 |
Current U.S.
Class: |
180/170 ;
180/65.26; 180/65.27; 180/65.28; 180/65.285; 903/947 |
Current CPC
Class: |
B60W 10/06 20130101;
B60W 20/10 20130101; B60W 2520/10 20130101; B60K 31/04 20130101;
B60K 6/26 20130101; B60W 2710/0666 20130101; B60K 31/042 20130101;
Y02T 10/6286 20130101; B60W 10/18 20130101; B60K 6/485 20130101;
Y10S 903/93 20130101; Y02T 10/62 20130101; B60W 10/08 20130101;
Y02T 10/7258 20130101; Y10S 903/907 20130101; Y02T 10/72 20130101;
Y02T 10/6226 20130101; B60W 2720/10 20130101; B60W 20/00
20130101 |
Class at
Publication: |
180/170 ;
180/065.2 |
International
Class: |
B60K 006/00; B60K
031/00 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 18, 2001 |
DE |
101 62 017.9 |
Claims
What is claimed is:
1. A device (1) for regulating the driving speed of a vehicle (3)
having at least one electric motor/generator (17) connected or
connectable to a drive train (7; 7') for at least one wheel (11,
13; 11', 13') as a function of at least its actual speed and
setpoint speed, comprising a control unit (31) for controlling the
torque of the electric motor/generator (17), means for driving the
electric motor/generator (17), means (37) for recording the actual
speed of the vehicle (3), and means (39) for preselecting the
setpoint speed of the vehicle (3), wherein the electric
motor/generator (17) may be used in generator operation to generate
a braking torque as well as in motor operation to generate a
driving torque.
2. The device as recited in claim 1, wherein the electric
motor/generator (17) is connected by electric lines (43, 45) to a
current storage device (47) and at least one electric consumer
(49).
3. The device as recited in one of the preceding claims, wherein
the control unit (31) has at least one electronic control device
(33) which is designed to demand of the electric motor/generator
(17) a positive torque (driving torque) when the actual speed drops
below the setpoint speed in driving operation of the vehicle (3)
and to demand a negative torque (braking torque) when the actual
speed exceeds the setpoint speed.
4. The device as recited in one of the preceding claims, wherein
the electric power consumption by at least one electric consumer
(49) can be increased by the control unit (31).
5. The device as recited in one of the preceding claims, wherein
the torque of an internal combustion engine (15), which is
connected or connectable to a drive train (7; 7') for at least one
wheel (11, 13; 11', 13'), is controllable by the control unit
(31).
6. The device as recited in one of the preceding claims, wherein
the internal combustion engine (15) and the electric
motor/generator (17) are connected or connectable to the same drive
train (7) or to different drive trains (7; 7').
7. The device as recited in one of the preceding claims, wherein
strategies for distributing the torque required to implement the
required setpoint speed of the vehicle (3) between the internal
combustion engine (15) and the at least one electric
motor/generator (17) are stored in the control unit (31).
8. The device as recited in one of the preceding claims, wherein a
brake (29) is provided for the at least one wheel (11; 13; 11';
13'), and the brake (29) is operable by the control unit (31).
9. A drive system (5; 5', 5") for a vehicle (3), comprising at
least one electric motor/generator (17) and, optionally, an
internal combustion engine (15), each being connected or
connectable to at least one drive train (7, 7') for at least one
wheel (11; 13; 11'; 13'), and having a device (1) for regulating
the driving speed of the vehicle (3), in particular as recited in
one of claims 1 through 8.
10. A method of regulating the driving speed of a vehicle (3)
having at least one electric motor/generator (17), as a function of
at least its actual speed and the required setpoint speed, the
actual speed being determined and the setpoint speed being
adjustable, and a comparison of the actual speed with the setpoint
speed being performed, wherein deceleration of the vehicle (3) is
required when the actual speed is greater than the setpoint speed,
and, to do so, the electric motor/generator (17) is operated as a
generator, and when the actual speed is less than the setpoint
speed, the electric motor/generator (17) is operated as a
motor.
11. The method as recited in one of the preceding claims, wherein
in addition at least one brake (29) cooperating with at least one
wheel (11; 13; 11'; 13') of the vehicle (3) is actuated to increase
the braking torque when the actual speed is greater than the
setpoint speed.
12. The method as recited in one of the preceding claims, wherein
for the purpose of decelerating and accelerating the vehicle (3),
the torque of an internal combustion engine (15) of the vehicle (3)
is varied accordingly.
13. The method as recited in one of the preceding claims, wherein
when the electric motor/generator (17) is in motor operation, it is
supplied with current by at least one current storage device (47)
for driving the vehicle (3), and, when the electric motor/generator
(17) is in generator operation, the current it generates is stored
by the at least one current storage device (47) and/or is consumed
by at least one electric consumer (49).
14. The method as recited in one of the preceding claims, wherein
when there is at least one electric consumer (49), the electric
power consumption is increased if the at least one current storage
device (47) cannot store all of the current generated by the
electric motor/generator (17) in generator operation and the
deceleration of the vehicle (3) due to the braking torque of the
electric motor/generator (17) is not sufficient.
15. The method as recited in one of the preceding claims, wherein
short-term and/or relatively minor fluctuations in the driving
torque required to keep the vehicle (3) at a constant speed are
compensated exclusively by the electric motor/generator (17).
16. The method as recited in claim 15, wherein the vehicle is
compensated by regenerative braking when the driving speed is too
high, and when the driving speed is too low, it is compensated by
the electric motor/generator supplying a driving torque.
17. The method as recited in one of the preceding claims 15 and 16,
wherein after a certain period of time (t.sub.max) during which
fluctuations in the driving torque are compensated exclusively by
the electric motor/generator, the torque of the internal combustion
engine is regulated up or down, preferably via an integrator, and
the contribution of the electric motor/generator to the total
driving torque is returned to zero.
18. The method as recited in one of the preceding claims 15 through
17, wherein if the torque supplied by the electric motor/generator
is not sufficient to maintain the required setpoint speed, the
torque of the internal combustion engine or the gear ratio is
adjusted accordingly.
Description
[0001] The present invention relates to a device for regulating the
driving speed of a vehicle according to the preamble of Claim 1 and
a method for regulating the driving speed of a vehicle according to
the preamble of Claim 10.
BACKGROUND INFORMATION
[0002] Devices and methods of the type indicated here are known.
They are also known as ACC systems (adaptive cruise control), speed
governors or cruise control, and they are used to regulate the
speed of vehicles.
[0003] Vehicles are known which also have an electric
motor/generator in the drive train in addition to an internal
combustion engine. Such an electric motor/generator in the drive
train of a motor vehicle is also known as a starter generator, a
crankshaft starter generator or an integrated starter
generator.
[0004] German Patent 199 14 428 C1 describes a device of the type
mentioned here, in which the braking torque of an electric
motor/generator in the drive train is used in combination with an
automatic cruise control and distance regulating system. When the
motor vehicle is driven, the electric motor/generator connected to
the engine is always operated as a generator to decelerate the
engine and thus supply a load torque to the drive train.
ADVANTAGES OF THE INVENTION
[0005] The device according to the present invention having the
features defined in Claim 1 offers the advantage over the related
art that the at least one electric motor/generator provided in the
vehicle may be used in a variety of ways in combination with the
device (cruise control) for regulating the driving speed of the
vehicle, i.e., not only for deceleration but also for acceleration
of the vehicle. According to the present invention, the electric
motor/generator is to be operated either in generator operation or
in engine operation, the particular mode of operation of the cruise
control being set as a function of at least the instantaneous
(actual) speed and a preselectable setpoint speed and at least one
additional parameter, if necessary.
[0006] The device may be used in vehicles having an internal
combustion engine and an electric motor/generator as well as in
vehicles driven exclusively by at least one electric
motor/generator.
[0007] The device includes a control unit for controlling the
torque of the electric motor/generator and means for driving the
electric motor/generator by which a desired torque (driving torque
or braking torque) may be preselected. In addition, means are
provided for determining the actual speed of the vehicle, as well
as means being provided for preselecting the setpoint speed of the
vehicle. The actual speed may be determined in a wide variety of
ways, e.g., by a sensor which detects the rotational speed of a
wheel. Several possibilities are also conceivable for preselecting
the setpoint speed, e.g., an occupant of the vehicle, in particular
the driver, may preselect a desired speed via an operating element.
The means for preselecting the setpoint speed may also include a
device for setting the distance of the vehicle from an object, in
particular a vehicle driving in front (cruise control and distance
regulating system, e.g., an ACC system). According to a third
variant, a setpoint speed is preselected for the control unit via a
data connection, e.g., a satellite connection.
[0008] Advantageous exemplary embodiments of this device are
derived from combinations of the features given in the
subclaims.
[0009] The present invention also relates to a drive system for a
vehicle having at least one electric motor/generator and, if
necessary, an engine having the features of Claim 9.
[0010] The present invention also relates to a method having the
features of Claim 10, wherein at an actual speed higher than the
setpoint speed, the vehicle is required to decelerate and for this
purpose, the electric motor/generator is operated as a generator,
and at an actual speed lower than the setpoint speed, the electric
motor/generator is operated as an engine. If the vehicle also has
an internal combustion engine in addition to the electric
motor/generator, the torque required by a cruise control as a
function of the actual speed and the setpoint speed of the vehicle
is applied optionally by the electric motor/generator or by the
internal combustion engine or by the electric motor/generator and
the internal combustion engine, depending on the design of the
drive system, and this torque is transmitted to at least one wheel
of the vehicle. To this end, strategies for optimally distributing
the required torque optimally between the electric motor/generator
and the internal combustion engine may be stored in the control
unit of the cruise control. If the sum of the torques transmitted
to the at least one wheel is greater than the road resistance
acting on the vehicle, this results in acceleration of the vehicle,
whereas when the sum of these torques is less than the road
resistance, this results in a deceleration (braking) of the
vehicle.
[0011] Alternatively or additionally, to reduce the driving speed
of the vehicle, a braking device assigned to at least one wheel of
the vehicle may also be operated. Therefore, the driving speed may
be reduced even more than would be possible through the internal
combustion engine and the electric motor/generator alone.
[0012] Advantageous embodiment variants of the method are derived
from combinations of the features characterized in the
subclaims.
DRAWINGS
[0013] The present invention is explained in greater detail below
on the basis of the corresponding drawings.
[0014] Figures each shows a basic diagram of a drive system 1
through 3 for a vehicle; and
[0015] FIG. 4 shows two graphs in which the total demand for
driving torque at a constant driving speed (graph I) is plotted as
a function of the altitude profile of the road on which the vehicle
is traveling (graph II).
DESCRIPTION OF THE EXEMPLARY EMBODIMENTS
[0016] Several exemplary embodiments of a device 1 for automatic
regulation of the driving speed of a vehicle, e.g., passenger
vehicles, trucks, buses or the like, are described in greater
detail below with reference to the figures.
[0017] FIG. 1 shows a basic diagram of a first exemplary embodiment
of device 1 for a vehicle 3 (not shown in detail), having a drive
system 5 with a drive train 7. Drive train 7 is used to drive
wheels 11 and 13 mounted on axle 9.
[0018] Drive system 5 has an engine 15, formed here by an internal
combustion engine 16, and an electric motor/generator 17, the rotor
of which (not shown) is in a rotationally fixed connection with
crankshaft 19 of internal combustion engine 16 and also with an
input part 21 of a clutch 23, e.g., a friction clutch. In a first
shift position, clutch 23, which may be operated electrically or
mechanically, for example, allows crankshaft 19 of internal
combustion engine 16 and the rotor of electric motor/generator 17
to rotate without sending a torque (driving or braking torque) to
wheels 11, 13.
[0019] As an alternative to clutch 23, a torque converter may also
be used.
[0020] Furthermore, a transmission 25, e.g., a standard
transmission or an automatic transmission, and a differential 27
are also provided in drive train 7. It remains to be pointed out
that clutch 23, transmission 25 and differential 27 are optional
devices that are not essential for implementing the method
according to the present invention.
[0021] With clutch 23 engaged, both internal combustion engine 16
and electric motor/generator 17 are in a suitable connection with
wheels 11, 13 for transmitting a torque via the rotor of the
electric motor/generator, clutch 23, transmission 25 and
differential 27, so that a driving torque or a braking torque is
transmittable to the wheels. In this embodiment of drive system 5,
internal combustion engine 16 and electric motor/generator 17 are
preferably always used jointly to accelerate or decelerate vehicle
3. It is readily possible for a preselectable torque to be applied
to wheels 11, 13 only via electric motor/generator 17, e.g., when
there is a failure in internal combustion engine 16 or when vehicle
3 (hybrid) is to be driven only by electric power. It is naturally
also possible to use only internal combustion engine 16 to supply a
torque to wheels 11, 13 while electric motor/generator 17 is in an
inactive mode.
[0022] Vehicle 3 also has a brake 29 for braking wheels 11, 13.
Brake 29 may be assigned to only one wheel of vehicle 3, as
indicated in FIG. 1, or to multiple wheels. The design and
functioning of such a brake 29 are known, so they need not be
described in greater detail here.
[0023] Device 1 includes a control unit 31 having at least one
electronic control device 33 via which the torque of internal
combustion engine 16 is controllable, as indicated by a control
arrow 35 shown with broken lines. By varying the torque of internal
combustion engine 16, it is possible to vary the speed of vehicle
3. Electronic control device 33 includes means 37 for determining
the prevailing instantaneous speed of vehicle 3 and means 39 for
preselecting a setpoint speed of vehicle 3. Means 37, 39 are known
per se, so they need not be described in greater detail here.
[0024] Instead of the single electronic control device 33, control
unit 31 may also have a plurality of control devices interconnected
by data links.
[0025] Electric motor/generator 17 may be used either as a
generator or as a motor in operation of vehicle 3. In generator
operation, electric motor/generator 17 may apply a torque to
decelerate (brake) vehicle 3, and in engine operation it may apply
a torque to accelerate (drive) vehicle 3. Electric motor/generator
17 also includes essentially known means for driving whereby a
desired torque may be preselected. This is preferably accomplished
via electronic control device 33, which is indicated by a control
arrow 41, shown as a broken line.
[0026] Electric motor/generator 17 is connected by electric lines
43 and 45 to a current storage device 47, e.g., a battery, and at
least one consumer 49, e.g., a heating or air conditioning system.
In motor operation of electric motor/generator 17, current storage
device 47 supplies power for driving vehicle 3; in generator
operation, current storage device 47 and consumer 49 receive the
current generated.
[0027] The function of device 1: to adjust the speed preselected
via means 39, electronic control device 33 demands a torque from
internal combustion engine 16 and/or electric motor/generator 17.
Therefore strategies for distributing the torque optimally between
engine 16 and motor/generator 17 are preferably stored in
electronic control device 33. If the sum of the torques supplied by
internal combustion engine 16 and electric motor/generator 17 to
wheels 11, 13 is greater than the road resistance acting on vehicle
3, this results in acceleration of vehicle 3. In the other case,
i.e., when the sum of the torques transmitted to wheels 11, 13 from
internal combustion engine 16 and electric motor/generator 17 is
lower than the road resistance, this results in a deceleration of
vehicle 3. When electronic control device 33 wishes to reduce the
speed of vehicle 3 because the prevailing speed of vehicle 3
detected via means 37 is greater than the setpoint speed
preselected via means 39, it is also possible for brake 29 to be
actuated by electronic control device 33, as indicated with a
control arrow 51 shown with a broken line, and to thereby reduce
the speed even more than would be possible simply using internal
combustion engine 16 and electric motor/generator 17.
[0028] It is particularly advantageous if, in the case when vehicle
3 is to be decelerated, electronic control device 33 also increases
the electric power consumption by at least one electric consumer 49
should current storage device 47 be unable to accept all of the
cur-rent generated by electric motor/generator 17, and the
deceleration of vehicle 3 due to the braking torque of electric
motor/generator 17 is not sufficient. The driving of electric
consumer 49 by electronic control device 33 is indicated with a
control arrow 53, shown with a broken line.
[0029] A particularly advantageous embodiment for regulating the
driving speed which is described below may be used in a motor
vehicle having a drive system which includes at least one electric
motor/generator and at least one internal combustion engine, i.e.,
as described with reference to FIG. 1, for example.
[0030] When the cruise control described above is activated, it
attempts to keep the speed of the vehicle constant or essentially
constant, resulting in considerable changes in the driving torque
required when driving over hilly terrain. Therefore, according to
the present invention, the driving torque is to be regulated
largely with the help of the electric motor/generator and with the
most constant possible use of the internal combustion engine. The
engine provides a basic driving torque, which is obtained from the
vehicle dynamics equation. This basic driving torque is set at an
operating point of the engine at which fuel consumption and/or
emissions are as low as possible. Short-term fluctuations in the
required total driving torque are compensated exclusively by the
electric motor/generator. The connection to a CVT transmission or
automatic transmission and a coordinated drive train control
provides another potential for optimization. Therefore, the engine
may be operated at the lowest possible rotational speed and, in the
case of gasoline engines, with as little throttling as possible.
The advantage is that engines (internal combustion engines) are
usually favorable in terms of fuel consumption here and may even be
operated with low emissions, and furthermore, the torque of an
electric motor and thus also the effect to be achieved is usually
greatest at low rotational speeds.
[0031] The method described above is explained in greater detail
below with reference to FIG. 4. Graph I shows torque M.sub.E
supplied by the electric motor/generator, torque M.sub.B supplied
by the internal combustion engine and the desired/necessary total
driving torque M.sub.G composed of the individual torques as a
function of the altitude profile of the road as shown in graph II.
To keep the driving speed constant, if the resulting speed is too
high, it is compensated by regenerative braking (charging the
battery), and if the driving speed is too low, it is compensated by
a positive torque delivered by the electric motor/generator. The
torque of the internal combustion engine is regulated up or down
via an integrator only after lengthy battery charging or
discharging phases (t>T.sub.max) and the percentage of the total
driving torque contributed by the electric motor/generator
approaches zero again accordingly. In other words, the torque of
the engine is constant during the period of time from t.sub.0 to
t.sub.6, and it increases only after time t.sub.6 because at this
point in time, the discharge phase of the battery is greater than
T.sub.max and the torque of the electric motor/generator approaches
zero again. If the additional torque of the electric
motor/generator is not sufficient to maintain the desired target
speed (setpoint speed) of the vehicle, either the torque of the
engine or the gear ratio is adjusted.
[0032] It is readily apparent from FIG. 4 that when the cruise
control is active, the total torque required to keep the vehicle
constantly at a desired speed is consistently divided between the
electric motor/generator and the engine. In the case of a flat
driving surface and driving surfaces having a constant slope, the
desired speed is regulated down with a high precision and a low
activity on the part of the cruise control. Only by dividing the
total driving torque and refraining from changes in the operating
point of the engine as much as possible is it possible to minimize
fuel consumption even when driving over long distances at a
constant speed.
[0033] FIG. 2 shows a basic diagram of the second exemplary
embodiment of device 1. The same parts are labeled with the same
reference numbers, so that reference is made in this regard to the
description of FIG. 1. Therefore, only the differences are
described in greater detail below.
[0034] Vehicle 3 has a drive system 5' having first and second
drive trains 7 and 7', of which drive train 7 is allocated to
wheels 11, 13 of axle 9 (front or rear axle) and the other drive
train 7' is allocated to a wheel 11' of a second axle 9' (rear or
front axle). First drive train 7 includes engine 16, clutch 23,
transmission 25 and differential 27 and is used to drive wheels 11,
13. Second drive train 7' includes electric motor/generator 17,
which is connected in a rotationally fixed manner by its drive part
21 to wheel 11' of the other axle 9' of vehicle 3, so that the
wheel receives a driving torque or a braking torque.
[0035] Broken lines in FIG. 2 indicate that in another variant,
electric motor/generator 17 may additionally also drive at least
one other wheel 13' on axle 9' via a differential 27'. In a third
variant (not shown) of second drive train 7' at least two electric
motors/generators are provided, each being connected to one wheel
11', 13' in a manner capable of transmitting torque. In a fourth
variant (not shown) drive train 7 allocated to axle 9 has a design
identical to that of drive train 7 described with respect to FIG.
1, while at least one additional drive train 7' allocated to axle
9' or only to wheel 11' is designed as described above.
[0036] The method of regulating the driving speed of the exemplary
embodiment described with reference to FIG. 2 corresponds
essentially to the method described with reference to FIG. 1. In
other words, electronic control device 33 may demand of electric
motor/generator 17 and engine 16, independently of one another, a
torque which depends on the actual speed and the setpoint speed of
vehicle 3. Therefore, it is readily possible for wheel 11' or
wheels 11' and 13' of second axle 9' and wheels 11 and 13 of first
axle 9 to receive different torques, which may be advantageous in
certain driving situations.
[0037] The exemplary embodiment according to FIG. 2 differs from
that described with reference to FIG. 1 in particular in that
engine 16 and electric motor/generator 17 may be triggered
independently of one another, and another axle or at least one
wheel per vehicle axle may be driven independently of the other
wheel. It should be pointed out that the drive system shown in FIG.
2 permits four-wheel drive.
[0038] FIG. 3 shows a basic diagram of a third exemplary embodiment
of device 1. Parts that have already been described on the basis of
FIGS. 1 and 2 are labeled with the same reference numbers.
Therefore, reference is made to the description of FIGS. 1 and 2.
The vehicle has a drive system 5" having only one drive train 7
which includes at least one electric motor/generator 17 but no
internal combustion engine. Thus this is a strictly electric
vehicle. Electric motor/generator 17 is connected here directly via
drive part 21 and differential 27 to both wheels 11, 13 of axle 9
in a rotationally fixed manner. As an alternative, it is also
possible to eliminate differential 27 and to connect electric
motor/generator 17 directly to only one wheel 11, 13. In another
variant, a plurality of electric motors/generators is provided,
each driving one wheel of the vehicle, and these wheels may be on
different axles.
[0039] In the exemplary embodiment shown in FIG. 3, neither a
clutch 23 nor a transmission 25 is provided in drive train 7.
However, it is also readily possible for these devices to be
provided in drive train 7.
[0040] In drive system 5" shown in FIG. 3, instead of at least one
battery as current storage device 47, it is also possible to
provide at least one fuel cell, preferably a plurality of fuel
cells, as the source of the current.
[0041] The method implementable by the exemplary embodiment
illustrated in FIG. 3 for regulating the driving speed of vehicle 3
is like the methods described on the basis of FIGS. 1 and 2. Thus,
if electronic control device 33 ascertains that the prevailing
driving speed of vehicle 3 detected via means 37 is lower than the
setpoint speed preselected via means 39, then electronic control
device 33 demands a positive torque from electric motor/generator
17, resulting in acceleration of vehicle 3. If, based on a
comparison of the actual speed and the setpoint speed, electronic
control device 33 demands deceleration of vehicle 3, then a
negative torque is required of electric motor/generator 17 via data
connection 35. Here again, it is advantageous if control device 33
also actuates brake 29 for at least one wheel 11 to decelerate
vehicle 3 even more if the negative torque of electric
motor/generator 17 alone is not sufficient. Finally, it is also
possible here for electronic control device 33 to increase electric
power consumption by at least one electric consumer 49 if current
storage device 47 is unable to consume all the current generated by
electric generator 17 in generator operation and the deceleration
ed through the braking torque of electric generator 17 is not
sufficient.
* * * * *