U.S. patent application number 13/859950 was filed with the patent office on 2014-10-16 for interleaved motor controllers for an electric taxi system.
This patent application is currently assigned to Hamilton Sunstrand Corportation. The applicant listed for this patent is HAMILTON SUNSTRAND CORPORTATION. Invention is credited to Mustansir Kheraluwala, Keith R. Magnus, Adam M. White.
Application Number | 20140306452 13/859950 |
Document ID | / |
Family ID | 50543424 |
Filed Date | 2014-10-16 |
United States Patent
Application |
20140306452 |
Kind Code |
A1 |
White; Adam M. ; et
al. |
October 16, 2014 |
INTERLEAVED MOTOR CONTROLLERS FOR AN ELECTRIC TAXI SYSTEM
Abstract
Embodiments of the disclosure include an electric taxi system
including a generator configured to provide an AC power source and
a main controller configured to generate one or more PWM control
signals. The electric taxi system also includes a plurality of
motor controllers connected in parallel to the generator, wherein
each of the plurality of motor controllers receives one of the one
or more PWM control signals. The electric taxi system further
includes a plurality of motors, wherein each of the plurality of
motors are coupled to one of the plurality of motor
controllers.
Inventors: |
White; Adam M.; (Belvidere,
IL) ; Kheraluwala; Mustansir; (Lake Zurich, IL)
; Magnus; Keith R.; (Belvidere, IL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
HAMILTON SUNSTRAND CORPORTATION |
Windsor Locks |
CT |
US |
|
|
Assignee: |
Hamilton Sunstrand
Corportation
Windsor Locks
CT
|
Family ID: |
50543424 |
Appl. No.: |
13/859950 |
Filed: |
April 10, 2013 |
Current U.S.
Class: |
290/45 |
Current CPC
Class: |
Y02T 50/823 20130101;
Y02T 50/80 20130101; H02M 5/458 20130101; B64C 25/405 20130101;
B60L 50/12 20190201; H02P 5/74 20130101; B60L 50/13 20190201 |
Class at
Publication: |
290/45 |
International
Class: |
B60L 11/06 20060101
B60L011/06; B60L 11/08 20060101 B60L011/08 |
Claims
1. An electric taxi system comprising: a generator configured to
provide an AC power source; a main controller configured to
generate one or more pulse width modulated (PWM) control signals; a
plurality of motor controllers connected in parallel to the
generator, wherein each of the plurality of motor controllers
receives one of the one or more PWM control signals; and a
plurality of motors, wherein each of the plurality of motors are
coupled to one of the plurality of motor controllers.
2. The electric taxi system of claim 1, wherein each of the one or
more PWM control signals generated by the main controller is a
rectangular pulse waveform.
3. The electric taxi system of claim 2, wherein the rectangular
pulse waveform of each PWM control signal is offset from the
rectangular pulse waveform of the other one or more PWM control
signals.
4. The electric taxi system of claim 3, wherein an amount of the
offset of the rectangular pulse waveform of one PWM control signal
from the other one or more PWM control signals is based on a number
of the plurality of motor controllers present in the electric taxi
system.
5. The electric taxi system of claim 1, further comprising a
landing gear that is coupled to one of the plurality of motor
controllers through a transmission.
6. The electric taxi system of claim 1, wherein each of the
plurality of motor controllers includes an AC/AC converter.
7. An electric taxi system comprising: an AC power source; a main
controller configured to generate a pulse width modulated (PWM)
control signal; a plurality of motor controllers connected in
parallel to the AC power source, wherein each of the plurality of
motor controllers receives the PWM control signal and wherein the
PWM control signal received by each of the motor controllers is
offset from the PWM control signals received by the other motor
controllers; and a plurality of motors, wherein each of the
plurality of motors are coupled to one of the plurality of motor
controllers.
8. The electric taxi system of claim 7, wherein the PWM control
signal generated by the main controller is a rectangular pulse
waveform.
9. The electric taxi system of claim 8, wherein an amount of the
offset based on a number of the plurality of motor controllers
present in the electric taxi system.
10. The electric taxi system of claim 7, further comprising a
landing gear that is coupled to one of the plurality of motor
controllers through a transmission.
11. The electric taxi system of claim 7, wherein each of the
plurality of motor controllers includes an AC/AC converter.
12. An electric taxi system comprising: a generator configured to
provide an AC power source; a main controller configured to
generate one or more identical pulse width modulated (PWM) control
signals; a plurality of motor controllers connected in parallel to
the generator, wherein each of the plurality of motor controllers
receives one of the one or more identical PWM control signals and
wherein each of the one or more identical PWM control signals is
offset from the other of the one or more identical PWM control
signals; and a plurality of motors, wherein each of the plurality
of motors are coupled to one of the plurality of motor
controllers.
13. The electric taxi system of claim 12, wherein each of the one
or more identical PWM control signals generated by the main
controller is a rectangular pulse waveform.
14. The electric taxi system of claim 12, wherein an amount of the
offset of the one or more identical PWM control signal is based on
a number of the plurality of motor controllers present in the
electric taxi system.
Description
BACKGROUND OF THE INVENTION
[0001] The present disclosure relates to taxiing systems, and more
specifically, to interleaved motor controllers for an electric
taxiing system.
[0002] Taxiing systems are used to control the movement of an
aircraft on the ground under its own power. An airplane uses
taxiways to taxi from one place on an airport to another; for
example, when moving from a terminal to the runway.
[0003] Traditional taxiing systems use thrust from propellers or
jet engines to propel the aircraft forward. Reverse thrust for
backing up can be generated by thrust reversers, or reversible
pitch propellers. However, most aircraft are not designed to back
up on their own power and must be pushed back by using an aircraft
tug.
[0004] Currently there is interest in the use of electric
propulsion for taxiing systems in order to realize fuel savings. At
the low power settings typically used during taxiing, combustion
aircraft engines operate at a low efficiency. Accordingly, electric
taxiing may significantly reduce aircraft fuel burn during taxiing
and while waiting in queue to take off adds to the time on the
ground.
BRIEF DESCRIPTION OF THE INVENTION
[0005] According to one embodiment, an electric taxi system
including a generator configured to provide an ac power source and
a main controller configured to generate one or more PWM control
signals. The electric taxi system also includes a plurality of
motor controllers connected in parallel to the generator, wherein
each of the plurality of motor controllers receives one of the one
or more PWM control signals. The electric taxi system further
includes a plurality of motors, wherein each of the plurality of
motors are coupled to one of the plurality of motor
controllers.
[0006] Accordingly to another embodiment, an electric taxi system
includes an AC power source and a main controller configured to
generate PWM control signals. The electric taxi system also
includes a plurality of motor controllers connected in parallel to
the AC power source, wherein each of the plurality of motor
controllers receives PWM control signals and wherein the control
signals received by each of the motor controllers are time delayed
from the control signals received by the other motor controllers.
The electric taxi system further includes a plurality of motors,
wherein each of the plurality of motors are coupled to one of the
plurality of motor controllers.
[0007] Accordingly to a further embodiment, an electric taxi system
includes a generator configured to provide an AC power source and a
main controller configured to generate one or more control signals.
The electric taxi system also includes a plurality of motor
controllers connected in parallel to the generator, wherein each of
the plurality of motor controllers receives PWM control signals and
wherein each of the one or more control signals is time delayed
from the other of the one or more control signals. The electric
taxi system further includes a plurality of motors, wherein each of
the plurality of motors are coupled to one of the plurality of
motor controllers. The PWM control signals for each of the
plurality of motor controllers will have identical waveforms,
albeit time delayed for each motor controller, when each of the
motors is providing equal torque and speed (i.e. the aircraft is
taxiing and not turning). During turning of the aircraft, when
unequal torques and speeds are delivered by each motor, the PWM
control signal waveforms for each motor controller will differ,
however the center of the PWM pulses for each of the motor
controllers will remain time delayed with respect to the center of
the PWM pulses for the other motor controllers.
[0008] Additional features and advantages are realized through the
techniques of the present invention. Other embodiments and aspects
of the invention are described in detail herein and are considered
a part of the claimed invention. For a better understanding of the
invention with the advantages and the features, refer to the
description and to the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The subject matter which is regarded as the invention is
particularly pointed out and distinctly claimed in the claims at
the conclusion of the specification. The foregoing and other
features, and advantages of the invention are apparent from the
following detailed description taken in conjunction with the
accompanying drawings in which:
[0010] FIG. 1 is a block diagram of an electric taxi system in
accordance with an embodiment of the disclosure;
[0011] FIG. 2 is a block diagram of a portion of an electric taxi
system in accordance with an embodiment of the disclosure;
[0012] FIG. 3 is a block diagram illustrating a main controller of
an electric taxi system in accordance with an embodiment of the
disclosure;
[0013] FIG. 4 is a block diagram of a portion of an electric taxi
system in accordance with an embodiment of the disclosure;
[0014] FIG. 5 is block diagram of a portion of an electric taxi
system in accordance with an embodiment of the disclosure; and
[0015] FIG. 6 is block diagram of a portion of an electric taxi
system in accordance with an embodiment of the disclosure.
DETAILED DESCRIPTION OF THE INVENTION
[0016] Referring now to FIG. 1, an electric taxi system 100 in
accordance with an embodiment of the disclosure is shown. As
illustrated the electric taxi system 100 includes a generator 102,
a main controller 104, a plurality of motor controllers 106 and a
plurality of motors 108. In one embodiment, each of the plurality
of motors 108 is an electric motor that is coupled to the aircraft
landing gear 110 by a gearbox (not shown).
[0017] In one embodiment, the generator 102 is configured to supply
AC power, at for example approximately 115 volts, to each of the
plurality of motor controllers 106, which are each connected to the
generator 102 in parallel. The multiple motor controllers 106
appear as parallel loads to the generator 102. Each of the
plurality of motor controllers 106 is also configured to receive a
control signal from the main controller 104. In one embodiment, the
main controller 104 may be a digital signal processing (DSP)
circuit, a field-programmable gate array (FPGA), an application
specific integrated circuits (ASICs) or the like.
[0018] The PWM control signals provided by the main controller 104
are used by the motor controllers 106 to control the operation of
the motors 108. In one embodiment, the PWM control signals provided
by the main controller 104 to the motor controllers 106 are
rectangular pulse waveforms, which has a pulse width that is
modulated to control the speed of the motor 108. In one embodiment,
the PWM control signals provided by the main controller 104 to the
motor controllers 106 are interleaved, or delayed.
[0019] In one embodiment, the electric taxi system 100 includes
four electric motors 108 that each has an associated motor
controller 106. The main controller 104 may provide a PWM control
signal to a first motor controller 106 in the form of a rectangular
pulse waveform having a frequency of 10 kHz and a 100 microsecond
period. The main controller 104 may provide a second PWM control
signal to a second motor controller 106 in the form of a
rectangular pulse waveform having a frequency of 10 kHz and a 100
microsecond period with the center of the second set of PWM pulses
having a 25 microsecond delay relative to the first PWM control
signal. The main controller 104 may provide a third PWM control
signal to a third motor controller 106 in the form of a rectangular
pulse waveform having a frequency of 10 kHz and a 100 microsecond
period with the center of the third set of PWM pulses having a 50
microsecond delay relative to the first PWM control signal. The
main controller 104 may provide a fourth set of PWM control signals
to a fourth motor controller 106 in the form of a rectangular pulse
waveforms having a frequency of 10 kHz and a 100 microsecond period
with the center of the fourth set of PWM pulses having a 75
microsecond delay relative to the first PWM control signal.
[0020] In another embodiment, the electric taxi system 100 may
include two electric motors 108 that each has an associated motor
controller 106. The main controller 104 may provide a PWM control
signal to a first motor controller 106 in the form of a rectangular
pulse waveform having a frequency of 10 kHz and a 100 microsecond
period. The main controller 104 may provide a second PWM control
signal to a second motor controller 106 in the form of a
rectangular pulse waveform having a frequency of 10 kHz and a 100
microsecond period with the center of the second set of PWM pulses
having a 50 microsecond delay relative to the first PWM control
signal. In other embodiments, the electric taxi system 100 may
include any number of electric motors 108 that each has an
associated motor controller 106.
[0021] In one embodiment, the main controller 104 is configured to
generate multiple sets of PWM control signals that are each
transmitted to the motor controllers 106. In another embodiment,
each of the sets of PWM control signals includes a control signal
for each solid state switch in the motor controller.
[0022] As a result of interleaving of the PWM control signals
provided to the motor controllers 106, there is reduced distortion
applied to the electric system of the aircraft, compared to a
non-interleaved system. In addition, this reduction in distortion
allows for a reduction in the filtering components needed, which
results in a reduction of the weight of the electrical system.
[0023] Referring now to FIG. 2, a block diagram of a portion of an
electric taxi system 200 in accordance with an embodiment of the
disclosure is shown. As illustrated the electric taxi system 200
includes an AC power source 202, a main controller 204, a motor
controller 206 and a motor 208. The AC power source 202 is
configured to supply AC power to each of the motor controller 206
and the main controller 204 is configured to transmit a PWM control
signal to the motor controller 206. The motor 108 is coupled to the
aircraft landing gear 216 by a transmission 214. In one embodiment,
the main controller 204 may be a digital signal processing (DSP)
circuit, a field-programmable gate array (FPGA), an application
specific integrated circuits (ASICs) or the like.
[0024] The motor controller 206 is configured to control the
operation of the motor 208 in response to the PWM control signal
received from the main controller 204. For example, the PWM control
signal may be a pulse width modulated signal that is used to
control the speed of the motor 208. In one embodiment, the motor
controller 206 includes an AC/AC converter 212 that is configured
to receive the AC power from the AC power source 202 and is used to
provide AC power to the motor 208. In this manner, the motor
controller 208 may operate and an AC/AC converter 212 and one or
both of the output voltage and frequency of the AC/AC converter may
be controlled, for example, by the PWM control signal.
[0025] In one embodiment, the PWM control signals generated by the
main controller 208 provided to each of the individual motor
controllers are identical rectangular pulse waveforms that are
offset from each other. In one embodiment, the amount of the offset
of the rectangular pulse waveform of one PWM control signal from
the other one or more PWM control signals is based on a number of
the plurality of motor controllers present in the electric taxi
system. For example, in an electric taxi system that has four
motors and four motor controllers, the PWM control signals may be
offset by twenty-five percent of the period of the pulse waveform.
In another example, in an electric taxi system that has three
motors and three motor controllers, the PWM control signals may be
offset by thirty-three percent of the period of the waveform. In
yet another example, in an electric taxi system that has two motors
and two motor controllers, the PWM control signals may be offset by
fifty percent of the period of the waveform.
[0026] Referring now to FIG. 3, a block diagram illustrating a main
controller 300 of an electric taxi system in accordance with an
embodiment of the disclosure is shown. As illustrated, the main
controller 300 receives a nominal carrier period signal 302 and
generates a carrier waveform via a waveform generator 304. The
waveform is provided to one or more PWM controllers 306, 308 which
are used to generate a set of PWM control signals that are provided
to motor controllers for motor. The main controller 300 also
includes one or more delay elements 310 that can be used to delay
the waveform provided one or more of the PWM controllers. Although,
the main controller 300 illustrated includes only two PWM
controllers 306, 308, it will be clear to one of ordinary skill in
the art that any number of PWM controllers may be used.
[0027] Referring now to FIG. 4, a block diagram of a portion of an
electric taxi system 400 in accordance with an embodiment of the
disclosure is shown. As illustrated, the system 400 includes a
generator 402 and a main controller 404 that are coupled to a pair
of motor controllers 406, 408. The motor controllers 406, 408 each
include active DC/AC motor controllers, an EMI filter 412 and a
passive AC/DC converter. The motor controllers 406, 408 are powered
from a single DC bus provided by the generator 402 and receive sets
of PWM control signals from the main controller 404.
[0028] Referring now to FIG. 5, a block diagram of a portion of an
electric taxi system 500 in accordance with an embodiment of the
disclosure is shown. As illustrated, the system 500 includes a
generator 502 and a main controller 504 that are coupled to a pair
of AC/AC motor controllers 506, 508. The motor controllers 506, 508
receive power from an AC/DC converter 510 and receive sets of PWM
control signals from the main controller 504. The AC/DC converter
510 is coupled to the generator 502 via an EMI filter 512.
[0029] Referring now to FIG. 6, a block diagram of a portion of an
electric taxi system 600 in accordance with an embodiment of the
disclosure is shown. As illustrated, the system 600 includes a
generator 602 and a main controller 604 that are coupled to a pair
of AC/AC motor controllers 606, 608. The motor controllers 606, 608
each include active AC/DC converters, active DC/AC converters, and
an EMI filter 612. The motor controllers 606, 608 are powered from
a single DC bus provided by the generator 602 and receive sets of
PWM control signals from the main controller 604. The commands for
both the AC/DC and DC/AC converters are interleaved.
[0030] While the invention has been described in detail in
connection with only a limited number of embodiments, it should be
readily understood that the invention is not limited to such
disclosed embodiments. Rather, the invention can be modified to
incorporate any number of variations, alterations, substitutions or
equivalent arrangements not heretofore described, but which are
commensurate with the spirit and scope of the invention.
Additionally, while various embodiments of the invention have been
described, it is to be understood that aspects of the invention may
include only some of the described embodiments. Accordingly, the
invention is not to be seen as limited by the foregoing
description, but is only limited by the scope of the appended
claims.
* * * * *