U.S. patent application number 15/101735 was filed with the patent office on 2017-01-05 for compressor system for a rail vehicle and method for operating the compressor system with safe emergency operation.
The applicant listed for this patent is KNORR-BREMSE SYSTEME FUR SCHIENENFAHRZEUGE GMBH. Invention is credited to Gert ASSMANN, Thomas KIPP.
Application Number | 20170002804 15/101735 |
Document ID | / |
Family ID | 52014055 |
Filed Date | 2017-01-05 |
United States Patent
Application |
20170002804 |
Kind Code |
A1 |
KIPP; Thomas ; et
al. |
January 5, 2017 |
COMPRESSOR SYSTEM FOR A RAIL VEHICLE AND METHOD FOR OPERATING THE
COMPRESSOR SYSTEM WITH SAFE EMERGENCY OPERATION
Abstract
A rail vehicle compressor system and method for controlling the
same use a compressor driven by an electrical machine via a drive
shaft, to produce compressed air for at least one compressed air
tank, wherein the electrical machine can be activated at least
indirectly via a control device for operating the electrical
machine at at least one nominal speed between a maximum speed and a
minimum speed, wherein at least one pressure sensor determines the
pressure for the control device and is disposed in a
compressed-air-carrying line downstream of the compressor. A final
control element continuously influences the speed of the electrical
machine and can be activated via the control device, and wherein a
pressure switch for monitoring the pressure in the at least one
compressed air tank and for influencing at least the speed of the
electrical machine is disposed in the compressed-air-carrying line
downstream of the compressor.
Inventors: |
KIPP; Thomas; (Munchen,
DE) ; ASSMANN; Gert; (Munchen, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
KNORR-BREMSE SYSTEME FUR SCHIENENFAHRZEUGE GMBH |
Munich |
|
DE |
|
|
Family ID: |
52014055 |
Appl. No.: |
15/101735 |
Filed: |
December 2, 2014 |
PCT Filed: |
December 2, 2014 |
PCT NO: |
PCT/EP2014/076166 |
371 Date: |
June 3, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F04B 49/06 20130101;
B61L 25/021 20130101; B61L 25/025 20130101; B61L 2205/04 20130101;
F04B 49/20 20130101; F04B 49/08 20130101; B61D 27/00 20130101; F04B
41/02 20130101; F04B 2205/05 20130101; F04B 2203/0209 20130101;
F04B 35/04 20130101 |
International
Class: |
F04B 49/08 20060101
F04B049/08; B61D 27/00 20060101 B61D027/00; F04B 49/20 20060101
F04B049/20; F04B 41/02 20060101 F04B041/02; F04B 49/06 20060101
F04B049/06; B61L 25/02 20060101 B61L025/02; F04B 35/04 20060101
F04B035/04 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 5, 2013 |
DE |
10 2013 113 557.9 |
Claims
1. A compressor system for a rail vehicle, the compressor system
comprising: at least on compressed-air vessel; an electric machine;
a drive shaft; a compressor which is driven by the electric machine
via the drive shaft and which generates compressed air for the at
least one compressed-air vessel; a regulation device which at least
indirectly controls the electric machine for operation of the
electric machine at at least a rated rotational speed between a
maximum rotational speed and a minimum rotational speed; a
compressed air-conducting line arranged downstream of the
compressor and including at least one pressure sensor for
determining the pressure for the regulation device; an electric
supply; and an actuator arranged between the electrical supply and
the electric machine, wherein the actuator continuously manipulates
the rotational speed of the electric machine and is controlled by
the regulation device; and a pressure switch arranged in the
compressed air-conducting line downstream of the compressor for
monitoring pressure in the at least one compressed-air vessel and
for manipulation of at least the rotational speed of the electric
machine.
2. The compressor system of claim 1, wherein the pressure switch is
operatively connected to the regulation device to indirectly
manipulate the rotational speed of the electric machine.
3. The compressor system of claim 1, further comprising an
isolating switch connected downstream of the actuator for
separating the regulation device and the actuator from the electric
machine.
4. The compressor system of claim 3, wherein the pressure switch is
connected to the isolating switch via an interposed control logic
unit.
5. The compressor system of claim 1, wherein the regulation device
at least indirectly controls a cooler unit which is arranged
downstream of the compressor and which has a cooler fan, wherein a
rotational speed of the cooler fan is continuously adjustable by
the regulation device.
6. The compressor system of claim 2 wherein the compressor is
operated with a variable rotational speed which assumes any
intermediate value between the maximum rotational speed and the
minimum rotational speed, wherein the pressure switch monitors the
pressure in the at least one compressed-air vessel and indirectly
manipulates at least the rotational speed of the electric
machine.
7. The compressor system of claim 6, wherein, when the minimum
pressure in the at least one compressed-air vessel is reached, the
control logic unit receives from the pressure switch a signal for
triggering the isolating switch and separating of the regulation
device and the actuator from the electric machine, wherein the
compressor is operated, via the isolating switch, with the rated
rotational speed until the deactivation pressure is reached.
8. The compressor system of claim 6, wherein, when the minimum
pressure in the at least one compressed-air vessel is reached, the
regulation device receives from the pressure switch a signal for
triggering the actuator to operate the compressor at at least the
rated rotational speed until the deactivation pressure is
reached.
9. The compressor system of claim 6, wherein, after the pressure of
the at least one compressed-air vessel has fallen to the minimum
pressure at least twice, the electric machine is operated with
intermittent alternation between at least the rotational speed when
the pressure falls to the minimum pressure and deactivation of the
compressor when the deactivation pressure is reached.
10. A method for controlling a compressor system for a rail
vehicle, the method comprising: driving a compressor by an electric
machine via a drive shaft to generate compressed air for the at
least one compressed-air vessel; at least indirectly controlling,
using a regulation device, the electric machine to operate at at
least a rated rotational speed between a maximum rotational speed
and a minimum rotational speed; determining pressure for the
regulation device using at least one pressure sensor located in a
compressed air-conducting line arranged downstream of the
compressor; continuously manipulating the rotational speed of the
electric machine using an actuator arranged between an electrical
supply and the electric machine, wherein the actuator continuously
manipulates the rotational speed of the electric machine and is
controlled by the regulation device; and monitoring pressure in the
at least one compressed-air vessel using a pressure switch arranged
in the compressed air-conducting line downstream of the compressor
and using the monitored pressure to control manipulation of at
least the rotational speed of the electric machine.
11. The method of claim 10 wherein the pressure switch is
operatively connected to the regulation device to indirectly
manipulate the rotational speed of the electric machine.
12. The method of claim 10, wherein an isolating switch is
connected downstream of the actuator to separate the regulation
device and the actuator from the electric machine.
13. The method of claim 12, wherein the pressure switch is
connected to the isolating switch via an interposed control logic
unit.
14. The method of claim 10, wherein the regulation device at least
indirectly controls a cooler unit which is arranged downstream of
the compressor and which has a cooler fan, wherein a rotational
speed of the cooler fan is continuously adjustable by the
regulation device.
15. The method of claim 11 wherein the compressor is operated with
a variable rotational speed which assumes any intermediate value
between the maximum rotational speed and the minimum rotational
speed, wherein the pressure switch monitors the pressure in the at
least one compressed-air vessel and indirectly manipulates at least
the rotational speed of the electric machine.
16. The method of claim 15, wherein, when the minimum pressure in
the at least one compressed-air vessel is reached, the control
logic unit receives from the pressure switch a signal for
triggering the isolating switch and separating of the regulation
device and the actuator from the electric machine, wherein the
compressor is operated, via the isolating switch, with the rated
rotational speed until the deactivation pressure is reached.
17. The method of claim 15, wherein, when the minimum pressure in
the at least one compressed-air vessel is reached, the regulation
device receives from the pressure switch a signal for triggering
the actuator to operate the compressor at at least the rated
rotational speed until the deactivation pressure is reached.
18. The method of claim 15, wherein, after the pressure of the at
least one compressed-air vessel has fallen to the minimum pressure
at least twice, the electric machine is operated with intermittent
alternation between at least the rotational speed when the pressure
falls to the minimum pressure and deactivation of the compressor
when the deactivation pressure is reached.
Description
PRIORITY CLAIM
[0001] This patent application is a U.S. National Phase of
International Patent Application No. PCT/EP2014/076166, filed 2
Dec. 2014, which claims priority to German Patent Application No.
10 2013 113 557.9, filed 5 Dec. 2013 the disclosure of which are
incorporated herein by reference in their entirety.
FIELD
[0002] The disclosed embodiments relate to a compressor system for
a rail vehicle, comprising a compressor which is driven by an
electric machine via a drive shaft and which serves for generating
compressed air for at least one compressed-air vessel, wherein the
electric machine can be controlled at least indirectly using a
regulation device for operation of the electric machine at at least
a rated rotational speed between a maximum rotational speed and a
minimum rotational speed, wherein furthermore, in a compressed
air-conducting line arranged downstream of the compressor, there is
arranged at least one pressure sensor for determining the pressure
for the regulation device. The disclosed embodiments relate to a
method for controlling the compressor system according to at least
one of the disclosed embodiments.
BACKGROUND
[0003] Compressors in rail vehicles are subject to a variety of, in
part, conflicting demands, such as for example a high delivery
output, adequate activation duration, low sound emissions, low
energy consumption, a small structural space, and low purchase and
life-cycle costs. Here, the compressor must satisfy extremely
different demand profiles depending on the operating state of the
rail vehicle. The typical problem in designing a compressor is that
of finding the best comprise between these demands which is
acceptable in all operating states of the rail vehicle. In general,
electrically driven compressors are used in rail vehicles. The
operation of the compressors takes the form of on/off operation
with a constant rotational speed, the so-called rated rotational
speed, between the lower activation pressure and the upper
deactivation pressure. The compressor is dimensioned such that a
predefined filling time is attained and a minimum activation
duration during operation is not undershot.
[0004] From the generally known prior art, it emerges that, between
the different operating states of the rail vehicle, there is no
difference in the operation of the compressor. Here, the fan of the
cooling system is subject to the same operating regime as the
compressor, as the fan is generally directly jointly driven by the
compressor.
[0005] It is also known that a more complex construction and more
complex operation of the compressor system in relation to regular
operation and in relation to the regular construction necessitate
additional, in particular electronic components which may exhibit
additional probability of failure or at least additional
susceptibility to failure. In other words, the incorporation of
additional electronics components in the compressor system also
introduces into the compressor system the additional probability of
failure of the individual electronics components. The probability
of faults and the risk of failure of the compressor system are thus
increased. Since the compressor system supplies compressed air to
the brake system, a failure of the compressor system generally has
the effect of bringing the rail vehicle to a standstill.
SUMMARY
[0006] It is therefore the object of the present disclosed
embodiments to optimize a compressor system and a method for
operating the compressor system such that more energy-efficient
operation of the compressor system, with a reduction in sound
emissions, is possible without an increase in the probability of
faults and risk of failure of the compressor system.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] Disclosed embodiments are explained more specifically below
with reference to the accompanying drawings, in which:
[0008] FIG. 1 shows a block circuit diagram of the compressor
system according to the disclosed embodiment,
[0009] FIG. 2 shows a block circuit diagram of the compressor
system according to at least one disclosed embodiment, and
[0010] FIG. 3 shows two related diagrams, wherein a rotational
speed of the compressor is plotted versus time in the upper
diagram, and a pressure of the compressor is plotted versus time in
the lower diagram.
DETAILED DESCRIPTION
[0011] According to at least one disclosed embodiment, an actuator
for the continuous manipulation of the rotational speed of the
electric machine is arranged between an electrical supply and the
electric machine, wherein the actuator can be controlled by way of
the regulation device, and wherein, in the compressed
air-conducting line arranged downstream of the compressor, there is
arranged a pressure switch for monitoring of the pressure in the at
least one compressed-air vessel and for manipulation of at least
the rotational speed of the electric machine.
[0012] In other words, the actuator is situated upstream of the
electric machine in the power flow, and is thus positioned ahead of
the electric machine. The actuator permits operation of the
electric machine at different rotational speeds. Frequency
converters or inverters are particularly suitable for this purpose.
In a manner dependent on frequency, the rotational speed of the
electric machine and thus the operation of the compressor are
adapted. However, the additional electronic components for
regulating the rotational speed, in particular the additional
sensors, cables and the actuator, give rise to an increase in the
probability of faults and risk of failure of the compressor
system.
[0013] Using the pressure switch for monitoring the pressure in the
at least one compressed-air vessel, the reliability of a compressor
system of the type is increased, and the possibility of reliable
emergency running operation is realized. Specifically, in the event
of a drop in pressure, the pressure switch can indirectly
manipulate at least the rotational speed of the electric machine.
Using a signal from the pressure switch to the effect that a
certain lower pressure in the at least one compressed-air vessel
has been undershot, the compressor can be activated, and in
particular the rotational speed of the compressor can be increased,
to increase the pressure in the at least one compressed-air vessel
up to a certain upper pressure. Thus, the pressure switch
manipulates at least the rotational speed of the compressor only
when the pressure reaches either the minimum pressure or the upper
deactivation pressure. When the minimum pressure is reached, the
rotational speed is increased, wherein, when the upper deactivation
pressure is reached, it is at least the case that the rotational
speed is reduced, or the compressor is deactivated. In other words,
in the event of a fault in the compressor system which leads to the
minimum pressure in the at least one compressed-air vessel being
reached, regular operation of the compressor is resumed such that
the compressor is operated at rated rotational speed.
[0014] In at least one disclosed embodiment, the pressure switch is
operatively connected to the regulation device for the purposes of
indirect manipulation of the rotational speed of the electric
machine. In other words, the pressure switch transmits the
generated signals to the regulation device, wherein the latter, may
be by way of an integrated control algorithm, adapts the rotational
speed of the electric machine to the received signal.
[0015] In at least one disclosed embodiment, an isolating switch
for separating the regulation device and the actuator from the
electric machine is connected downstream of the actuator. In this
case, the isolating switch is in particular arranged between the
electrical supply and the electric machine, and thus constitutes a
bridge both between the actuator and the electric machine and
between the electrical supply and the electric machine.
[0016] Furthermore, the pressure switch may be connected to the
isolating switch via an interposed control logic unit. The
isolating switch is consequently independent of the regulation
device and can be operated by way of the control logic unit, which
receives signals from the pressure switch.
[0017] In accordance with at least one embodiment provided that the
regulation device at least indirectly controls a cooler unit which
is arranged downstream of the compressor and which has a cooler
fan, wherein a rotational speed of the cooler fan can be
continuously adjusted by the regulation device. For this purpose,
an actuator may be integrated in the cooler unit. It is
alternatively also conceivable for the actuator to be at least
positioned upstream of the cooler unit. It is likewise conceivable
for an actuator to have two control outputs, such that both the
electric machine and the cooler fan are controlled by way of a
common actuator.
[0018] With regard to the method, the compressor is operated with a
variable rotational speed which assumes any intermediate value
between the maximum rotational speed and the minimum rotational
speed, wherein the pressure switch monitors the pressure in the at
least one compressed-air vessel and indirectly manipulates at least
the rotational speed of the electric machine. By virtue of the fact
that the cooling unit is not connected either directly or
indirectly to the compressor, separate control of the cooling unit
and thus separate adjustment of the rotational speed of the cooler
fan are performed. It is advantageously also possible for the
compressor and the cooler fan to be deactivated.
[0019] In a further exemplary embodiment, when the minimum pressure
in the at least one compressed-air vessel is reached, the
regulation device receives from the pressure switch a signal for
triggering the actuator to operate the compressor at at least the
rated rotational speed until the deactivation pressure is reached.
In this way, it is possible in particular to counteract faulty
sensors and/or cables. Specifically, the regulation device controls
the actuator in accordance with the output of the pressure
switch.
[0020] In a further exemplary embodiment, when the minimum pressure
in the at least one compressed-air vessel is reached, the control
logic unit receives from the pressure switch a signal for
triggering the isolating switch and separating the regulation
device and the actuator from the electric machine, wherein the
compressor is operated, via the isolating switch, with the rated
rotational speed until the deactivation pressure is reached.
Depending on the position of the isolating switch, it is also
possible to generate a rotational speed higher than the rated
rotational speed for the electric machine. For this purpose, the
isolating switch connects the electric machine directly to the
electrical supply. Therefore, the regulation device cannot have any
influence on the electric machine and thus on the rotational speed
of the compressor. In this way, it is possible in particular for a
failure or a fault of the regulation device as a whole, together
with all associated sensors and the actuator, to be
counteracted.
[0021] In accordance with at least one embodiment provided that,
after the pressure of the at least one compressed-air vessel has
fallen to the minimum pressure at least twice, the electric machine
is operated with intermittent alternation between at least the
rated rotational speed when the pressure falls to the minimum
pressure and deactivation of the compressor when the deactivation
pressure is reached. In other words, the rotational speed of the
electric machine and thus the rotational speed of the compressor
are varied no further, to maintain a relatively constant pressure
in the at least one compressed-air vessel. It is however also
conceivable for the compressor to be operated not with the rated
rotational speed but with a maximum rotational speed to permit
faster filling of the at least one compressed-air vessel.
[0022] As per FIG. 1, a compressor system for a rail vehicle has an
electric machine 1 which, via a drive shaft 2, drives a compressor
3 for generating compressed air. The compressed air generated by
the compressor 3 is conducted via a compressed air-conducting line
6 to a cooler unit 9 which has a cooler fan 14. A pressure sensor 7
and a temperature sensor 13b are arranged downstream of the cooler
unit 9 in the compressed air-conducting line 6. Furthermore, the
compressed air-conducting line 6 issues into a pre-separator 11,
downstream of which there is connected an air treatment system 12.
The dried compressed air, which has been purified of particles, is
then fed into a compressed-air vessel 4. Furthermore, in the
compressed-air conducting line 6, there is arranged a pressure
switch 16 for the monitoring of the pressure in the compressed-air
vessel 4 and for the indirect manipulation of the rotational speed
of the electric machine 1 and of the cooler fan 14.
[0023] A temperature sensor 13a, which is arranged at the
compressor 3, and the temperature sensor 13b and the pressure
sensor 7 all transmit the measured temperatures and the measured
pressure to the regulation device 5. Furthermore, via a signal
input 10, the regulation device 5 also receives signals from other
sensors--not illustrated here--or from a train management system.
Furthermore, the regulation device 5 is suitable for both
controlling the rotational speed of the cooler unit 9 and
transmitting signals to an actuator 8. The actuator 8, which is in
the form of a frequency converter, sets the rotational speed of the
electric machine 1 and thus the rotational speed of the compressor
3. Furthermore, the actuator 8 has two outlets and thus also sets
the rotational speed of the cooler fan 14 by way of the regulation
device 5. In this case, the actuator 8 is, for the continuous
manipulation of the rotational speed of the electric machine 1,
arranged between an electrical supply 15 and the electric machine
1. In this case, when a minimum pressure e in the compressed-air
vessel 4 is reached, the regulation device 5 receives from the
pressure switch 16 a signal for triggering the actuator 8 to
operate the compressor 3 at the rated rotational speed n until a
deactivation pressure d is reached.
[0024] In FIG. 2, an isolating switch 17 for separating the
regulation device 5 and the actuator 8 from the electric machine 1
is connected downstream of the actuator 8. The pressure switch 16
is connected to the isolating switch 17 via an interposed control
logic unit 18. In this case, when a minimum pressure e in the
compressed-air vessel 4 is reached, the control logic unit 18
receives from the pressure switch 16 a signal for triggering the
isolating switch 17 and separating the regulation device 5 and the
actuator 8 from the electric machine 1. The compressor 3 is then
operated, via the isolating switch 17, at the rated rotational
speed n until a deactivation pressure d is reached.
[0025] FIG. 3 graphically illustrates the above-described process
in the event of a pressure drop in the compressed-air vessel 4
being measured by way of the pressure switch 16. In a region a, the
compressor 3 is operated at a rotational speed between a minimum
rotational speed i and the rated rotational speed n, wherein the
pressure in the compressed-air vessel 4 is kept in a certain range.
Thus, in the region a, the compressor 3 is in regulated operation.
The rotational speed is variable and dependent on the
situation.
[0026] In a region b, the pressure in the compressed-air vessel 4
and the rotational speed of the compressor 3 spontaneously drop. In
other words, in the region b, a fault has occurred during regulated
operation, which fault has led to a measured pressure drop.
[0027] When the pressure in the compressed-air vessel 4 reaches the
minimum pressure e, the pressure switch 16 reacts and, in a region
c, increases the rotational speed of the electric machine 1 and
thus the rotational speed of the compressor 3 to the rated
rotational speed n indirectly, either via the isolating switch 17
or via the actuator 8. Consequently, in the region c, the reaction
of the pressure switch 16 occurs for the switchover of operation
from regulated operation to non-regulated operation. There are two
states of non-regulated operation. These are firstly the operation
of the compressor 3 at the rated rotational speed n, and secondly
the deactivation of the compressor 3. The cooler fan 14 (not
illustrated here) is also operated analogously to the operation of
the compressor 3.
[0028] After a deactivation pressure d has been reached in the
compressed-air vessel 4, the compressor 3 is deactivated and is
operated once again at a rotational speed between the minimum
rotational speed i and the rated rotational speed n, such that the
pressure in the compressed-air vessel 4 is kept in a certain
range.
[0029] The disclosed embodiments are not restricted to the
embodiments described above. Rather, modifications thereto are also
possible which are also encompassed by the scope of protection of
the following claims. For example, it is also possible for the
compressor 3 to provide a feed to a multiplicity of compressed-air
vessels 4. It may also be provided that, when the minimum pressure
e in the compressed-air vessel 4 is reached, the rotational speed
of the electric machine 1 and thus the rotational speed of the
compressor 3 are increased to a maximum rotational speed m rather
than just the rated rotational speed n.
LIST OF REFERENCE SIGNS
[0030] 1 Electric machine [0031] 2 Drive shaft [0032] 3 Compressor
[0033] 4 Compressed-air vessel [0034] 5 Regulation device [0035] 6
Compressed air-conducting line [0036] 7 Pressure sensor [0037] 8
Actuator [0038] 9 Cooler unit [0039] 10 Signal input [0040] 11
Pre-separator [0041] 12 Air treatment system [0042] 13a, 13b
Temperature sensor [0043] 14 Cooler fan [0044] 15 Electrical supply
[0045] 16 Pressure switch [0046] 17 Isolating switch [0047] 18
Control logic unit [0048] a, b, c Region [0049] d Deactivation
pressure [0050] e Minimum pressure [0051] i Minimum rotational
speed [0052] m Maximum rotational speed [0053] n Rated rotational
speed
* * * * *