U.S. patent application number 15/836545 was filed with the patent office on 2018-06-14 for control system for hydraulically powered ac generator.
The applicant listed for this patent is Cummins Power Generation IP, Inc.. Invention is credited to James C. Alexander, Eric G. Bollensen, Hans L. Drabek, Nick V. Halstead, Tony Leakey, Robert E. Torney, Gerald R. Williams.
Application Number | 20180163862 15/836545 |
Document ID | / |
Family ID | 55438431 |
Filed Date | 2018-06-14 |
United States Patent
Application |
20180163862 |
Kind Code |
A1 |
Torney; Robert E. ; et
al. |
June 14, 2018 |
CONTROL SYSTEM FOR HYDRAULICALLY POWERED AC GENERATOR
Abstract
Systems and methods for use in controlling a hydraulically
powered AC generator are provided. One control system includes a
valve system. The valve system includes a fixed valve configured to
provide a substantially constant flow rate of the fluid through the
fixed valve to the hydraulically powered AC generator. The valve
system further includes a variable valve configured to provide a
variable flow rate of the fluid through the variable valve to the
hydraulically powered AC generator. The control system further
includes a sensor device configured to measure a speed of movement
of a component of the hydraulically powered AC generator. The
control system further includes a control circuit configured to
control the variable flow rate of the variable valve based on the
speed of movement of the component measured by the sensor
device.
Inventors: |
Torney; Robert E.;
(Minneapolis, MN) ; Halstead; Nick V.; (Oak Grove,
MN) ; Drabek; Hans L.; (Saint Paul, MN) ;
Bollensen; Eric G.; (Columbia Heights, MN) ;
Alexander; James C.; (Saint Louis Park, MN) ; Leakey;
Tony; (Robbinsdale, MN) ; Williams; Gerald R.;
(Columbia Heights, MN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Cummins Power Generation IP, Inc. |
Minneapolis |
MN |
US |
|
|
Family ID: |
55438431 |
Appl. No.: |
15/836545 |
Filed: |
December 8, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
14477539 |
Sep 4, 2014 |
9841101 |
|
|
15836545 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F16H 61/46 20130101;
F02B 67/00 20130101 |
International
Class: |
F16H 61/46 20060101
F16H061/46; F02B 67/00 20060101 F02B067/00 |
Claims
1-19. (canceled)
20. A control system for controlling an alternating current (AC)
generator, the control system comprising: a sensor device
configured to measure a speed of movement of a gear or shaft of the
AC generator; and a control circuit configured to generate a
control signal based on the speed of movement of the AC generator
measured by the sensor device, wherein the control circuit is
further configured to transmit the control signal to a control
device configured to control a hydraulic motor coupled to drive the
AC generator.
21. The control system of claim 20, wherein the hydraulic motor is
controlled by a valve system.
22. The control system of claim 20, wherein the sensor device
comprises a Hall Effect sensor configured to measure a change in a
magnetic field caused by the movement of the AC generator.
23. The control system of claim 20, wherein the sensor device
comprises an optical encoder sensor, the optical encoder sensor
comprising a light source configured to generate light and a light
detection device configured to detect changes in the light
reflected off of the AC generator.
24. The control system of claim 20, wherein the sensor device
comprises a magnetic pickup sensor.
25. The control system of claim 20, wherein the control circuit is
configured to generate the control signal based on both the speed
of movement of the AC generator measured by the sensor device and
an AC output frequency of the AC generator measured using a second
sensor device.
26. The control system of claim 20, wherein the control circuit is
configured to generate the control signal to maintain an AC output
frequency of the AC generator within a threshold range of a target
AC output frequency.
27. A control system for controlling a hydraulically powered
alternating current (AC) generator, the control system comprising:
a sensor device configured to measure a speed of rotation of the
hydraulically powered AC generator; and a control circuit
configured to control the speed of rotation of the hydraulically
powered AC generator measured by the sensor device.
28. The control system of claim 27, wherein the sensor device is
configured to measure a speed of movement of a component of the
hydraulically powered AC generator.
29. The control system of claim 28, wherein the component is a gear
or shaft of the hydraulically powered AC generator.
30. The control system of claim 27, wherein the sensor device
comprises at least one of a Hall Effect sensor, an optical encoder
sensor, or a magnetic pickup sensor.
31. The control system of claim 27, wherein the control circuit is
configured to generate the control signal based on both the speed
of rotation of the hydraulically powered AC generator as measured
by the sensor device and an AC output frequency of the
hydraulically powered AC generator measured using a second sensor
device.
32. The control system of claim 27, wherein the control circuit is
configured to generate the control signal to maintain an AC output
frequency of the hydraulically powered AC generator within a
threshold range of a target AC output frequency.
33. The control system of claim 27, wherein the control circuit
further comprises: a hydraulic motor coupled to the hydraulically
powered AC generator; and a variable valve system coupled to the
hydraulic motor, wherein the control circuit alters a variable flow
rate of the variable valve system based on the speed of rotation of
the hydraulically powered AC generator measured by the sensor
device.
34. The control system of claim 33, wherein the variable valve
system comprises: a fixed valve configured to provide a
substantially constant flow rate of the fluid through the fixed
valve to the hydraulic motor coupled to the hydraulically powered
AC generator; and a variable valve configured to provide a variable
flow rate of the fluid through the variable valve to the hydraulic
motor coupled to the hydraulically powered AC generator.
35. A method of controlling a hydraulically powered alternating
current (AC) generator, comprising: measuring a speed of rotation
of the hydraulically powered AC generator with a first sensor; and
controlling the speed of rotation of the hydraulically powered AC
generator by controlling a variable flow of fluid to a hydraulic
motor coupled to the hydraulically powered AC generator.
36. The method of claim 35, wherein measuring the speed of rotation
of the hydraulically powered AC generator with the first sensor
further comprises measuring a speed of rotation of a component of
the hydraulically powered AC generator.
37. The method of claim 35, wherein the first sensor comprises at
least one of a Hall Effect sensor, an optical encoder sensor, or a
magnetic pickup sensor.
38. The method of claim 35, wherein controlling the speed of
rotation of the hydraulically powered AC generator further
comprises controlling the speed of rotation of the hydraulically
powered AC generator based on both the speed of rotation of the
hydraulically powered AC generator and an AC output frequency of
the hydraulically powered AC generator.
39. The method of claim 38, further comprising maintaining the AC
output frequency of the hydraulically powered AC generator within a
threshold range of a target AC output frequency.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of U.S. patent
application Ser. No. 14/477,539, filed on Sep. 4, 2014, which is
incorporated herein by reference in its entirety.
TECHNICAL FIELD
[0002] The present disclosure relates generally to the field of
generator control. More particularly, the present disclosure
relates to systems and methods for controlling provision of
hydraulic fluid used to drive a hydraulically powered alternative
current (AC) generator.
BACKGROUND
[0003] Hydraulically powered AC generators are useful for a variety
of applications. Such generators may be used, for example, to drive
various components of large vehicles, such as fire trucks.
Hydraulically powered AC generators are controlled by regulating an
amount of hydraulic fluid used to drive the generators. If the
amount of hydraulic fluid used to drive the generator is not
controlled accurately, the power output of the generator will vary
from a desired power output. This can result in reliability issues
for the components powered by the generator.
SUMMARY
[0004] One embodiment of the disclosure relates to a valve system
for controlling flow of a fluid to a hydraulically powered
alternating current (AC) generator. The valve system includes a
fixed valve configured to provide a substantially constant flow
rate of the fluid through the fixed valve to the hydraulically
powered AC generator. The valve system further includes a variable
valve configured to provide a variable flow rate of the fluid
through the variable valve to the hydraulically powered AC
generator. The valve system is configured to output fluid from both
the fixed valve and the variable valve to power the hydraulically
powered AC generator.
[0005] Another embodiment relates to a control system for
controlling flow of a fluid to a hydraulically powered alternating
current (AC) generator. The control system includes a sensor device
configured to measure a speed of movement of a component of the
hydraulically powered AC generator. The control system further
includes a control circuit configured to generate a control signal
based on the speed of movement of the component measured by the
sensor device. The control circuit is further configured to
transmit the control signal to a control device configured to
control a variable flow rate of the fluid output to the
hydraulically powered AC generator by a variable valve.
[0006] Another embodiment relates to a control system for
controlling flow of a fluid to a hydraulically powered alternating
current (AC) generator. The control system includes a valve system.
The valve system includes a fixed valve configured to provide a
substantially constant flow rate of the fluid through the fixed
valve to the hydraulically powered AC generator. The valve system
further includes a variable valve configured to provide a variable
flow rate of the fluid through the variable valve to the
hydraulically powered AC generator. The control system further
includes a sensor device configured to measure a speed of movement
of a component of the hydraulically powered AC generator. The
control system further includes a control circuit configured to
control the variable flow rate of the variable valve based on the
speed of movement of the component measured by the sensor device.
In some embodiments, the control circuit is configured to control
the variable flow rate of the variable valve to compensate for
changes in one or more operating conditions of the hydraulically
powered AC generator. In some embodiments, the one or more
operating conditions include at least one of a load, a temperature,
a pressure, or a pump input speed of the hydraulically powered AC
generator.
[0007] Another embodiment relates to a hydraulically powered
generator system. The system includes a hydraulically powered
alternating current (AC) generator configured to generate output
power based on flow of a fluid to the hydraulically powered AC
generator. The hydraulically powered generator system further
includes a valve system. The valve system includes a fixed valve
configured to provide a substantially constant flow rate of the
fluid through the fixed valve to the hydraulically powered AC
generator. The valve system further includes a variable valve
configured to provide a variable flow rate of the fluid through the
variable valve to the hydraulically powered AC generator. The
hydraulically powered generator system further includes a sensor
device configured to measure a speed of movement of a component of
the hydraulically powered AC generator. The hydraulically powered
generator system further includes a control circuit configured to
control the variable flow rate of the variable valve based on the
speed of movement of the component measured by the sensor device.
In some embodiments, the control circuit is configured to control
the variable flow rate of the variable valve to compensate for
changes in one or more operating conditions of the hydraulically
powered AC generator. In some embodiments, the one or more
operating conditions include at least one of a load, a temperature,
a pressure, or a pump input speed of the hydraulically powered AC
generator.
[0008] Yet another embodiment relates to a control system for
controlling flow of a fluid to a hydraulically powered alternating
current (AC) generator. The control system includes a speed
measurement module configured to measure a speed of movement of a
component of the hydraulically powered AC generator. The control
system further includes a control module configured to generate a
control signal based on the speed of movement of the component
measured by the speed measurement module. The control module is
further configured to transmit the control signal to a control
device configured to control a variable flow rate of the fluid
output to the hydraulically powered AC generator by a variable
valve.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The disclosure will become more fully understood from the
following detailed description, taken in conjunction with the
accompanying figures, wherein like reference numerals refer to like
elements, in which:
[0010] FIG. 1 is a block diagram illustrating a hydraulically
powered generator system according to an exemplary embodiment;
[0011] FIG. 2 is a block diagram of a control system for a
hydraulically powered generator according to an exemplary
embodiment;
[0012] FIG. 3 is a flow diagram of a process for controlling a
hydraulically powered generator according to an exemplary
embodiment;
[0013] FIG. 4 is an illustration of a valve system according to an
exemplary embodiment;
[0014] FIG. 5 is an another illustration of the valve system of
FIG. 4;
[0015] FIG. 6 is a side view of a motor including a speed
measurement device according to an exemplary embodiment;
[0016] FIG. 7 is another side view of the motor of FIG. 6;
[0017] FIG. 8 is a perspective view of the motor of FIG. 6; and
[0018] FIG. 9 is another perspective view of the motor of FIG.
6.
DETAILED DESCRIPTION
[0019] Before turning to the figures, which illustrate the
exemplary embodiments in detail, it should be understood that the
application is not limited to the details or methodology set forth
in the description or illustrated in the figures. It should also be
understood that the terminology is for the purpose of description
only and should not be regarded as limiting.
[0020] Referring generally to the figures, systems and methods that
may be used to control the provision of hydraulic fluid to a
hydraulically powered generator are provided according to exemplary
embodiments. FIG. 1 illustrates a block diagram of one exemplary
power system 100 including a hydraulically powered AC generator
system. The generator system includes a hydraulic motor 110 that is
driven by hydraulic fluid pumped through a fluid loop by a
hydraulic pump. The hydraulic pump may be driven by an engine 105,
such as an engine used to propel one or more movement components
(e.g., wheels, tracks, etc.) of a vehicle. Motor 110 may be used to
drive an alternator, which may generate electrical power for use in
powering one or more components connected to the generator, such as
electrically-driven components of a vehicle. In some embodiments,
the generator system shown in FIG. 1 may be, for example, a 6-15 kW
hydraulic generator used on rescue (e.g., fire fighting)
vehicles.
[0021] In some embodiments, the hydraulic fluid may be provided to
motor 110 through a single valve or orifice. Using a fixed diameter
orifice to provide the fluid to motor 110 may not allow the system
to adjust to changing conditions, and may result in an alternator
speed that diverges from a target frequency. In some
implementations, using a single variable valve to meter the fluid
flow rate may result in reduced alternator frequency and/or power
output stability, for example, due to insufficient control
resolution. For instance, a large valve may be used to bring the
system up to nominal flow rate, but the valve may be too large to
deliver precise adjustment to correct for small deviations in
target speed/frequency.
[0022] Some embodiments of the present disclosure may utilize two
or more valves to provide hydraulic fluid to a generator system. A
first, fixed valve (e.g., having a fixed diameter) may be used to
provide a substantially constant flow rate of the fluid through the
fixed valve to the generator. A second, variable valve may be used
to provide a variable flow rate of the fluid through the variable
valve to the generator. In some embodiments, the fluid may be
combined at an output of a valve system and transmitted to the
motor/generator. In some embodiments, the fixed valve may be
configured to provide the majority of the fluid to the generator
and allow the system to quickly arrive at nominal flow rate, and
the variable valve may allow the system to make more fine
adjustments to the flow rate and correct for small deviations in
target values (e.g., target speed/frequency).
[0023] In some implementations, variable flow rate may be
controlled by monitoring an AC output frequency of the generator to
determine an alternator speed. Such implementations may be
susceptible to load induced feedback and/or interference. For
example, variable frequency drive (VFD) devices can induce a
feedback through load lines and into the alternator. This feedback
may prevent the electronic control circuit from accurately
measuring the alternator speed/frequency of the generated power
output. Without accurately measuring the alternator
speed/frequency, the control circuit may cause adjustments in a
variable valve that can cause undesirable changes in the generator
output (e.g., changes that move the alternator speed/frequency away
from a desired target value). In some instances, this can result in
reduced control of alternator speed and/or occasional shutdown of
the generator system due to an overspeed and/or underspeed
condition. As the use of VFD devices becomes more prevalent in
electronic equipment (e.g., equipment in mobile rescue vehicles,
such as fire trucks), VFD compatibility will have increased
emphasis. It is noted that other loads and forms or profiles of
load induced feedback on the load lines and alternator output that
can interfere with accurate measurement and control of the
alternator are possible (such as sudden load changes or start up of
a large electrical load).
[0024] Some embodiments of the present disclosure may control the
flow of hydraulic fluid to the generator based at least in part on
a measured speed of a component (e.g., a physical component) of the
generator. In some such embodiments, a sensor device, such as a
Hall Effect sensor, optical sensor, or an induction sensor, may be
used to measure a speed of movement of a component of the motor
and/or alternator. In one implementation, the sensor device may
measure a speed of movement of a gear of the generator (e.g., a
motor gear) or of the rotor of the generator. It is also noted that
various other possible embodiments place the sensor on the
hydraulic motor, coupling shaft of the hydraulic generator, or
other rotating portion of the generator system. Measuring the speed
of movement of a physical component may provide a greater sensing
resolution than monitoring an AC output frequency of the generator.
Additionally, controlling the flow of hydraulic fluid by measuring
the speed of movement of a physical component may reduce or
eliminate adverse effects of feedback and/or interference imparted
onto the alternator by external electrical loads, such as VFD
devices. It is however noted that electronic monitoring of the AC
output of the generator for generator control purposes is possible
if done with elevated levels of filtering and processing.
[0025] Referring now to FIG. 2, a control system 200 that may be
used to control a flow of fluid to a hydraulically powered
generator, such as the generator shown in FIG. 1, is illustrated
according to an exemplary embodiment. System 200 includes a control
module 205 (e.g., a control circuit) configured to control flow of
fluid through a valve system 230 to motor 110. Control module 205
may include a processor 210, which may be any type of general
purpose or special purpose processor (e.g., FPGA, CPLD, ASIC,
etc.). Control module 205 may also include a memory 215, which may
include any type of computer or machine-readable storage medium
(e.g., RAM, ROM, PROM, magnetic storage, optical storage, flash
storage, etc.). Control module 205 may include an input/output
(I/O) module 225, which may include one or more interfaces that
allow control module 205 to communicate with other components.
[0026] Control module 205 may include one or more modules
configured to implement one or more functions of control module
205. In some embodiments, the modules may be implemented as
computer or machine-readable instructions stored in memory 215 that
are executable by processor 210 to perform the functions. In some
embodiments, the modules may additionally or alternatively be
implemented, in whole or in part, via hardware modules (e.g.,
integrated circuits).
[0027] In the illustrated embodiment, control module 205 includes a
variable valve control module 220 configured to generate control
signals for controlling a variable valve 240 of valve system 230.
Module 220 may receive a signal relating to an AC output frequency
for an alternator of the generator (e.g., connected to motor 110;
not shown in FIG. 2), and may generate the control signals for
controlling variable valve 240 based on the received signal. In
some embodiments, module 220 may generate the control signals based
on input signals received from a speed measurement module 250
configured to measure a movement speed of a physical component of
motor 110. In some embodiments, module 220 may additionally or
alternatively generate the control signals based on input
representative of the AC output frequency of the alternator (e.g.,
input from a circuit configured to monitor the AC output frequency.
For instance, in some such embodiments, signal filtering may be
utilized to allow for accurate output frequency determination in
the presence of substantial feedback/interference.
[0028] FIG. 3 illustrates a flow diagram of a process 300 for
controlling fluid flow to a hydraulically powered generator
according to an exemplary embodiment. Process 300 may be executed
by control module 205 of system 200 (e.g., by variable valve
control module 220).
[0029] Referring now to both FIGS. 2 and 3, control module 205 may
receive an input signal representative of a measured speed of a
physical component of the generator from speed measurement module
250 (305). In the illustrated implementation, speed measurement
module 250 measures a speed or rotation of a gear 270 of motor 110.
In some embodiments, speed measurement module 250 may be configured
to monitor teeth of the gear that protrude from a body of the gear.
For instance, speed measurement module 250 may detect the teeth as
they rotate about an axis. In some embodiments, speed measurement
module 250 may determine a speed of rotation of gear based on a
number of teeth detected over a determined period of time. Speed
measurement module 250 may output a signal representative of the
determined speed to control module 205 (e.g., may transmit the
signal to I/O module 225). In some embodiments, speed measurement
module 250 may output a signal representing detection of the teeth,
and control module 205 may determine the speed based on the signal.
Monitoring movement of a physical component may provide greater
speed/frequency sensing resolution than monitoring the AC output
voltage/frequency directly. Segregating the speed sense signal from
the AC voltage/frequency of the alternator may allow the system to
reduce or eliminate an effect of feedback/interference imparted
onto the alternator by external electrical loads, such as VFD
devices, particularly where the base technology of the sensor is
resistant to or not subject to electromagnetic interference from
the operation of the generator. The remaining discussion of FIG. 3
will focus on measurement of movement of gear 270; however, it
should be understood that, in various embodiments, any generator
component having movement related to a flow of hydraulic fluid
and/or the output power (e.g., AC output frequency) of the
generator may be monitored instead of, or in addition to, gear
270.
[0030] In some embodiments, speed measurement module 250 may be or
include a sensor 255 configured to monitor movement of gear 270. In
some embodiments, sensor 255 may be a Hall Effect sensor. The Hall
Effect sensor may detect movement of gear 270 based on a change in
a magnetic field caused by the movement of gear 270 (e.g., a
variation in the field caused by the presence and absence of teeth
in front of Hall Effect sensor at different times). The Hall Effect
sensor may output a signal representative of the variations in the
magnetic field over a detection time. For instance, the signal may
include peaks in magnetic field intensity when teeth pass in front
of the sensor, and troughs when the areas between the teeth are
present. Control module 205 may utilize the signal and detection
time to determine the speed of rotation of gear 270.
[0031] In some embodiments, system 200 may additionally or
alternatively utilize other types of sensors to measure speed of
rotation of gear 270. For instance, sensor 255 may be, or include,
an optical encoder sensor. The optical encoder sensor may include a
light source configured to generate light (e.g., light having a
predetermined intensity). The optical encoder sensor may also
include a light detection device (e.g., a photosensor) configured
to generate a signal representative of detected changes in the
light reflected off of the gear as the gear moves. Because the
variations in the light reflected off of corresponding portions of
the gear (e.g., teeth and portions between teeth) should be
relatively similar, the generated signal should have a
substantially periodic characteristic, and control module 205 may
determine portions representative of the teeth in the signal and
calculate the speed of rotation of gear 270 in a similar fashion as
described above.
[0032] In some embodiments, sensor 255 may be, or include, a
magnetic pickup sensor. The magnetic pickup sensor may function in
a manner similar to a Hall Effect sensor, but may sense a magnetic
object passing by the sensor (the Hall Effect sensor may sense a
Ferrous object that is or is not magnetized). In such an
embodiment, a magnetic element may be incorporated within or
coupled to the physical component of the generator (e.g., a
rotating assembly), and movement of the magnetic element (e.g.,
movement past a predetermined position) may be detected by the
magnetic pickup sensor.
[0033] In some embodiments, control module 205 may determine a
generator output frequency (e.g., AC output frequency) based on the
speed data (310). In some such embodiments, control module 205 may
utilize one or more processing equations to calculate an output
frequency corresponding to the speed data. For instance, in the
illustrated implementation, the output frequency is directly
proportional to the speed of movement of gear 270, and control
module 205 may calculate/estimate the output frequency based on the
measured speed. In some implementations, control module 205 may
utilize a lookup table or other data structure that
cross-correlates measured speed to estimated output frequency. Data
filtering or averaging may also be utilized to smooth the
measurements and transitions, and to remove outliers.
[0034] Module 205 may generate variable valve control signals based
on the speed data and/or generator frequency (315). The generated
control signals may be configured to cause a desired hydraulic flow
rate through valve system 230, which in turn may be configured to
cause a desired AC output frequency of the generator. In some
embodiments, module 205 may estimate a current output frequency
based on the speed determined from the input from speed measurement
module 250, may calculate a difference between the current output
frequency and a desired output frequency, and may generate a
control signal configured to cause variable valve 240 to increase
or decrease the hydraulic fluid flow rate to achieve the desired
output frequency. In some embodiments, module 205 may generate the
control signal utilizing the speed signal without calculating the
current output frequency as an intermediate step.
[0035] Module 205 may transmit the control signal to a variable
valve control device 235 (320). In some embodiments, variable valve
control device 235 may be configured to control movement of a plate
or other component of variable valve 240. Variable valve control
device 235 may be configured to control the amount (e.g.,
percentage) of opening of variable valve 240 (e.g., control the
diameter). For instance, variable valve control device 235 may be
configured to receive an electrical control signal from control
module 205 and effect physical movement of the plate based on the
control signal. In some embodiments, control module 205 may be
integrated with or coupled to valve system 230, and may itself
serve as variable valve control device 235.
[0036] Referring again to FIG. 2, in some embodiments, system 200
may utilize a multiple-valve valve system 230 including both
variable valve 240 and a fixed valve 245. Fixed valve 245 may
provide a substantially constant flow rate through a fixed-diameter
orifice, and variable valve 240 may provide a variable flow rate
through an orifice having a variable diameter that may be
controlled via control signals received from control module 205. In
some embodiments, fixed valve 245 may have a larger diameter and
may be configured to enable valve system 230 to increase flow
quickly to a nominal flow rate (e.g., upon a startup or restart
condition), and variable valve 240 may provide for fine control of
the hydraulic fluid flow rate through motor 110. In such
embodiments, the fluid flow may be divided through two parallel
paths to accomplish precise control of fluid flow rate. In some
embodiments, the primary flow path through fixed valve 245 may
provide a majority (e.g., approximately seventy percent or more) of
the nominal flow rate to motor 110, and the secondary flow path
through variable valve 240 may provide the remaining flow rate
(e.g., approximately thirty percent or less). By separating bulk
flow from variable flow, system 200 may be able to apply more
precise control of hydraulic flow rate, which may result in
increased generator stability (e.g., increased stability of power
output from the alternator).
[0037] In some embodiments, system 200 may utilize more than two
valves (e.g., multiple fixed valves and/or multiple variable
valves). In some such embodiments, control module 205 may be
configured to control which fixed valves are open/closed and/or an
opening level of variable valves based on generator operating
conditions, generator demand, current flow conditions (e.g., based
on input from speed measurement module 250), etc. In one such
embodiment, control module 205 may be configured to independently
control a first variable valve to provide a first flow rate and a
second variable valve to provide a second flow rate.
[0038] In some embodiments, variable valve 240 may be a
continuously variable proportional valve or a variable proportional
valve utilizing a series of discrete steps of fixed or
predetermined flow change. In some embodiments, control module 205
may be configured to adjust variable valve 240 to compensate for
changes in one or more generator operating conditions, such as
load, temperature, pressure, and/or pump input speed. In some
embodiments, changes in these conditions may be directly measured
using one or more sensors or other devices. In some embodiments,
changes in these conditions may be detected or inferred through
input from speed measurement module 250, input representative of an
AC output frequency of the alternator, and/or other types of
input.
[0039] Some embodiments of the present disclosure utilize a
multiple-valve system including a variable valve and a fixed valve,
and do not utilize a speed measurement module/sensor configured to
measure movement of a physical component. In some such embodiments,
control of the variable valve may be based on measurement of the AC
output frequency of the alternator. Other embodiments utilize a
speed measurement module/sensor configured to measure movement of a
physical component, and utilize a single-valve system (e.g., a
single variable valve). Other embodiments utilize both a
multiple-valve system including a variable valve and a fixed valve
and a speed measurement module/sensor configured to measure
movement of a physical component. All such embodiments are
contemplated within the scope of the present disclosure.
[0040] FIG. 4 illustrates valve system 230 according to one
exemplary embodiment. In the illustrated embodiment, valve system
230 includes a valve body 410 through which hydraulic fluid flows
and is metered by a fixed valve 245 and variable valve 240. Fixed
valve 245 includes a fixed orifice 405 that provide a substantially
constant flow rate through one of the parallel paths through valve
system 230. Hydraulic fluid is received through an input 415 of
valve system 230, is metered by variable valve 240 and fixed valve
245, and is sent forward through the motor through an output
420.
[0041] FIG. 5 is another illustration of valve system 230
illustrating some further detail of the components of fixed valve
245, according to one embodiment. The fixed valve 245 includes a
housing 515, a body 510, an orifice 505, and a fastener 520 (e.g.,
a nut) to fasten the components together. Different types of
orifice 505 may be utilized for different applications (e.g.,
different types of generators). For instance, in the illustrated
implementation, a first, smaller orifice may be utilized for a
generator having a smaller rated output (e.g., six, eight, ten,
etc. kW), and a second, larger orifice may be utilized for a
generator having a larger rated output (e.g., 15 kW). In the
illustrated embodiment, orifice 505 is a removable orifice.
Utilizing a removable orifice may allow valve system 230 to be
reused in different types of generators. In some implementations,
orifice 505 may be integrated with body 510, and may not be
removable. Utilizing a fixed orifice may prevent against errors
such as valve system 230 being assembled without an orifice, using
an incorrect orifice for an application, misplacing a removed
orifice, etc.
[0042] FIG. 6 is a side view of motor 110 including a speed
measurement device according to an exemplary embodiment. In the
illustrated embodiment, motor 110 includes an output shaft 610
configured to rotate in proportion to a flow of hydraulic fluid
through motor 110. In this embodiment, a speed of rotation of a
gear of motor 110 is monitored through the use of a Hall Effect
sensor 605. It is noted that placement of the sensor in the motor
110 aids in further isolating the sensor from any electromagnetic
interference from the generator.
[0043] FIG. 7 is another side view of the motor 110 illustrated in
FIG. 6. FIG. 7 shows an electrical cable 705 configured to transmit
signals to and/or from motor 110 and/or Hall Effect sensor 605. In
some implementations, cable 705 may be connected to a control
module such as control module 205. In some such implementations, a
speed sensing signal generated by Hall Effect sensor 605 may be
transmitted to the control module via cable 705.
[0044] FIGS. 8 and 9 illustrate additional perspective views of
motor 110.
[0045] The disclosure is described above with reference to
drawings. These drawings illustrate certain details of specific
embodiments that implement the systems and methods and programs of
the present disclosure. However, describing the disclosure with
drawings should not be construed as imposing on the disclosure any
limitations that may be present in the drawings. The present
disclosure contemplates methods, systems and program products on
any machine-readable media for accomplishing its operations. The
embodiments of the present disclosure may be implemented using an
existing computer processor, or by a special purpose computer
processor incorporated for this or another purpose or by a
hardwired system. No claim element herein is to be construed under
the provisions of 35 U.S.C. .sctn. 112, sixth paragraph, unless the
element is expressly recited using the phrase "means for."
Furthermore, no element, component or method step in the present
disclosure is intended to be dedicated to the public, regardless of
whether the element, component or method step is explicitly recited
in the claims.
[0046] As noted above, embodiments within the scope of the present
disclosure include program products comprising machine-readable
storage media for carrying or having machine-executable
instructions or data structures stored thereon. Such
machine-readable storage media can be any available media that can
be accessed by a general purpose or special purpose computer or
other machine with a processor. By way of example, such
machine-readable storage media can include RAM, ROM, EPROM, EEPROM,
CD ROM or other optical disk storage, magnetic disk storage or
other magnetic storage devices, or any other medium which can be
used to carry or store desired program code in the form of
machine-executable instructions or data structures and which can be
accessed by a general purpose or special purpose computer or other
machine with a processor. Combinations of the above are also
included within the scope of machine-readable storage media.
Machine-executable instructions include, for example, instructions
and data which cause a general purpose computer, special purpose
computer, or special purpose processing machine to perform a
certain function or group of functions. Machine or
computer-readable storage media, as referenced herein, do not
include transitory media (i.e., signals in space).
[0047] Embodiments of the disclosure are described in the general
context of method steps which may be implemented in one embodiment
by a program product including machine-executable instructions,
such as program code, for example, in the form of program modules
executed by machines in networked environments. Generally, program
modules include routines, programs, objects, components, data
structures, etc., that perform particular tasks or implement
particular abstract data types. Machine-executable instructions,
associated data structures, and program modules represent examples
of program code for executing steps of the methods disclosed
herein. The particular sequence of such executable instructions or
associated data structures represent examples of corresponding acts
for implementing the functions described in such steps.
[0048] Embodiments of the present disclosure may be practiced in a
networked environment using logical connections to one or more
remote computers having processors. Logical connections may include
a local area network (LAN) and a wide area network (WAN) that are
presented here by way of example and not limitation. Such
networking environments are commonplace in office-wide or
enterprise-wide computer networks, intranets and the Internet and
may use a wide variety of different communication protocols. Those
skilled in the art will appreciate that such network computing
environments will typically encompass many types of computer system
configurations, including personal computers, hand-held devices,
multi-processor systems, microprocessor-based or programmable
consumer electronics, network PCs, servers, minicomputers,
mainframe computers, and the like. Embodiments of the disclosure
may also be practiced in distributed computing environments where
tasks are performed by local and remote processing devices that are
linked (either by hardwired links, wireless links, or by a
combination of hardwired or wireless links) through a
communications network. In a distributed computing environment,
program modules may be located in both local and remote memory
storage devices.
[0049] An exemplary system for implementing the overall system or
portions of the disclosure might include a general purpose
computing device in the form of a computer, including a processing
unit, a system memory, and a system bus that couples various system
components including the system memory to the processing unit. The
system memory may include read only memory (ROM) and random access
memory (RAM) or other non-transitory storage medium. The computer
may also include a magnetic hard disk drive for reading from and
writing to a magnetic hard disk, a magnetic disk drive for reading
from or writing to a removable magnetic disk, and an optical disk
drive for reading from or writing to a removable optical disk such
as a CD ROM or other optical media. The drives and their associated
machine-readable media provide nonvolatile storage of
machine-executable instructions, data structures, program modules,
and other data for the computer.
[0050] It should be noted that although the flowcharts provided
herein show a specific order of method steps, it is understood that
the order of these steps may differ from what is depicted. Also two
or more steps may be performed concurrently or with partial
concurrence. Such variation will depend on the software and
hardware systems chosen and on designer choice. It is understood
that all such variations are within the scope of the disclosure.
Likewise, software and web implementations of the present
disclosure could be accomplished with standard programming
techniques with rule based logic and other logic to accomplish the
various database searching steps, correlation steps, comparison
steps and decision steps. It should also be noted that the word
"component" as used herein and in the claims is intended to
encompass implementations using one or more lines of software code,
and/or hardware implementations, and/or equipment for receiving
manual inputs.
[0051] The foregoing description of embodiments of the disclosure
have been presented for purposes of illustration and description.
It is not intended to be exhaustive or to limit the disclosure to
the precise form disclosed, and modifications and variations are
possible in light of the above teachings or may be acquired from
practice of the disclosure. The embodiments were chosen and
described in order to explain the principals of the disclosure and
its practical application to enable one skilled in the art to
utilize the disclosure in various embodiments and with various
modifications as are suited to the particular use contemplated.
* * * * *