U.S. patent application number 13/807048 was filed with the patent office on 2013-04-25 for horsepower control system of a hybrid excavator and control method therefor.
This patent application is currently assigned to VOLVO CONSTRUCTION EQUIPMENT AB. The applicant listed for this patent is Jin-Seop Kim, Chun-Han Lee. Invention is credited to Jin-Seop Kim, Chun-Han Lee.
Application Number | 20130103272 13/807048 |
Document ID | / |
Family ID | 45441354 |
Filed Date | 2013-04-25 |
United States Patent
Application |
20130103272 |
Kind Code |
A1 |
Lee; Chun-Han ; et
al. |
April 25, 2013 |
HORSEPOWER CONTROL SYSTEM OF A HYBRID EXCAVATOR AND CONTROL METHOD
THEREFOR
Abstract
Disclosed are a horsepower control system for a hybrid excavator
and a control method thereof which controls the driving of a
generator driver or a swing motor driver with a swing power ratio
of 1 and a hydraulic power ratio of 1 in a first operation mode,
and with a swing power ratio of r (a user set value) and a
hydraulic power ratio of 1-r in a second operation mode. When the
power required by the user is fully used, energy from an energy
storage is used to maximize work capacity. When the total
horsepower used is limited to the range of horsepower available,
the limited use of the driving device is at a level of horsepower
similar to that of a typical system, thereby minimizing fuel
consumption.
Inventors: |
Lee; Chun-Han; (Gimhae-si,
KR) ; Kim; Jin-Seop; (Changwon-si, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Lee; Chun-Han
Kim; Jin-Seop |
Gimhae-si
Changwon-si |
|
KR
KR |
|
|
Assignee: |
VOLVO CONSTRUCTION EQUIPMENT
AB
Eskilstuna
SE
|
Family ID: |
45441354 |
Appl. No.: |
13/807048 |
Filed: |
July 6, 2010 |
PCT Filed: |
July 6, 2010 |
PCT NO: |
PCT/KR10/04387 |
371 Date: |
December 27, 2012 |
Current U.S.
Class: |
701/50 |
Current CPC
Class: |
E02F 9/2091 20130101;
B60Y 2200/412 20130101; E02F 9/123 20130101; E02F 9/2075 20130101;
E02F 9/2095 20130101; B60K 2025/005 20130101; E02F 9/2217 20130101;
E02F 9/20 20130101; F02D 29/04 20130101 |
Class at
Publication: |
701/50 |
International
Class: |
E02F 9/20 20060101
E02F009/20 |
Claims
1. A horsepower control system for a hybrid excavator, comprising:
an engine; a hydraulic pump configured to be driven by the engine
to drive a hydraulic actuator by hydraulic fluid; a generator
configured to be driven by the engine to generate electric energy;
an energy storage device configured to charge the electric energy
generated from the generator and supply the electric energy to an
swing electric motor; and a power controller configured to control
the driving operation of a generator driver or a swing motor driver
with a swing power ratio of 1 (or 100%) and a hydraulic horsepower
ratio of 1 using both the power of the energy storage device and
the horsepower of the engine when a first operation mode according
to a user setting is selected, thereby maximizing the operation
amount of the excavator, and configured to control the driving
operation of the generator driver or the swing motor driver with a
swing power ratio of r (i.e., a user set value) and a hydraulic
horsepower ratio of 1-r using either the power of the energy
storage device or the horsepower of the engine when a second
operation mode according to a user setting is selected, thereby
minimizing fuel consumption through the limitation of the
horsepower.
2. The horsepower control system according to claim 1, wherein the
energy storage device is either a battery or a super capacitor
capable of storing the electric energy, or an accumulator capable
of storing hydraulic energy.
3. A horsepower control method of a horsepower control system for a
hybrid excavator including an engine, a hydraulic pump configured
to be driven by the engine to drive a hydraulic actuator by
hydraulic fluid, a generator configured to be driven by the engine
to generate electric energy, and an energy storage device
configured to charge the electric energy generated from the
generator and supply the electric energy to an swing electric
motor, the horsepower control method comprising the steps of:
controlling the driving operation of a generator driver or a swing
motor driver with a swing power ratio of (or 100%) and a hydraulic
horsepower ratio of 1 (or 100%) using both the power of the energy
storage device and the horsepower of the engine when a first
operation mode according to a user setting is selected, thereby
maximizing the operation amount of the excavator; and controlling
the driving operation of the generator driver or the swing motor
driver with a swing power ratio of r (i.e., a user set value) and a
hydraulic horsepower ratio of 1-r using either the power of the
energy storage device or the horsepower of the engine when a second
operation mode according to a user setting is selected, thereby
minimizing fuel consumption through the limitation of the
horsepower.
Description
TECHNICAL FIELD
[0001] The present invention relates to a horsepower control system
for a hybrid excavator and a control method thereof, and more
particularly, to such a swing power control system for a hybrid
excavator and a control method thereof, in situations where it is
necessary to use the full power required by a user without
limitation, using the energy of an energy storage device is
positively used to maximize the operation amount, however in the
cases where it is necessary to use the full power within the range
of an available horsepower, the driving device is limitedly used at
a horsepower level that is similar to the horsepower level of the
existing system to minimize fuel consumption.
BACKGROUND ART
[0002] A conventional hybrid excavator related technology is
disclosed in Korean Patent Application No. 10-2007-137478 in which
equipment is controlled by a prescribed rule to enhance efficiency
of the operation, or in Korean Patent Application No.
10-2001-7016523 in which the operation pattern of a user is read
automatically so as to be applied to the control of equipment.
However, Korean Patent Application No. 10-2001-7016523 has a
difficulty accurately reflecting an actual operational condition,
and is merely aimed at reducing fuel consumption but not at
increasing the operation amount of the equipment.
DISCLOSURE OF INVENTION
Technical Problem
[0003] Accordingly, the present invention has been made to solve
the above-mentioned problem occurring in the prior art, and it is
an object of the present invention to provide a power control
system for a hybrid excavator and a control method thereof, in
situations where it is necessary to use the full power required by
a user without limitation, a horsepower level is used which is
approximately two times higher than the horsepower level of the
existing excavator without providing any additional constituent
element and incurring any additional costs to maximize the
operation amount, while in the case where it is desired to use the
full power within the range of an available horsepower, each
driving device is limitedly used at a horsepower level that is
similar to the horsepower level of the existing system to minimize
fuel consumption.
Technical Solution
[0004] To achieve the above objectives, in one aspect, the present
invention provides a horsepower control system for a hybrid
excavator, including: an engine; a hydraulic pump configured to be
driven by the engine to drive a hydraulic actuator by hydraulic
fluid; a generator configured to be driven by the engine to
generate electric energy; an energy storage device configured to
charge the electric energy generated from the generator and supply
the electric energy to an swing electric motor; and a power
controller configured to control the driving operation of a
generator driver or a swing motor driver with a swing power ratio
of 1 (or 100%) and a hydraulic horsepower ratio of 1 using both the
power of the energy storage device and the horsepower of the engine
when a first operation mode, according to a user setting is
selected, thereby maximizing the operation amount of the excavator,
and configured to control the driving operation of the generator
driver or the swing motor driver with a swing power ratio of r
(i.e., a user set value) and a hydraulic horsepower ratio of 1-r
using either the power of the energy storage device or the
horsepower of the engine when a second operation mode according to
a user setting is selected, thereby minimizing fuel consumption
through the limitation of the horsepower.
[0005] Preferably, the energy storage device may be either a
battery or a super capacitor capable of storing the electric
energy, or an accumulator capable of storing hydraulic energy.
[0006] To achieve the above objectives, in another aspect, the
present invention provides a horsepower control method of a
horsepower control system for a hybrid excavator including an
engine, a hydraulic pump configured to be driven by the engine to
drive a hydraulic actuator by hydraulic fluid, a generator
configured to be driven by the engine to generate electric energy,
and an energy storage device configured to charge the electric
energy generated from the generator and supply the electric energy
to a swing electric motor. The horsepower control method including
the steps of: controlling the driving operation of a generator
driver or a swing motor driver with a swing power ratio of 1 (or
100%) and a hydraulic horsepower ratio of 1 (or 100%) using both
the power of the energy storage device and the horsepower of the
engine when a first operation mode according to a user setting is
selected, thereby maximizing the operation amount of the excavator;
and controlling the driving operation of the generator driver or
the swing motor driver with a swing power ratio of r (i.e., a user
set value) and a hydraulic horsepower ratio of 1-r using either the
power of the energy storage device or the horsepower of the engine
when a second operation mode according to a user setting is
selected, thereby minimizing fuel consumption through the
limitation of the horsepower.
Advantageous Effects
[0007] The horsepower control system for a hybrid excavator and a
control method thereof according to the present invention as
constructed above has the following advantages.
[0008] In the case where it is desired to use the full power
required by a user without limitation, energy of an energy storage
device is used at a horsepower level which is greatly higher than
the instantaneous horsepower level of the conventional hydraulic
system without providing any additional constituent element and
incurring any additional costs to maximize the operation amount and
improve a user's convenience, while in the case where it is desired
to use the full power within the range of an available horsepower,
each driving device is limitedly used at a horsepower level that is
similar to the horsepower level of the conventional hydraulic
system to minimize fuel consumption.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The above and other objects, features and advantages of the
present invention will be more apparent from the following detailed
description taken in conjunction with the accompanying drawings, in
which:
[0010] FIG. 1 is a block diagram illustrating the construction of a
horsepower control system for a hybrid excavator according to the
present invention;
[0011] FIG. 2 is a flowchart sequentially illustrating the control
operation of a horsepower control system for a hybrid excavator
according to the present invention; and
[0012] FIG. 3 is a table illustrating the relationship between an
operation mode and a swing power ratio/a hydraulic horsepower
ratio.
EXPLANATION ON REFERENCE NUMERALS OF MAIN ELEMENTS IN THE
DRAWINGS
[0013] 101: engine 102: hydraulic pump
[0014] 103: generator 104: swing electric motor
[0015] 105: energy storage device 106: generator driver
[0016] 107: swing motor driver 108: power controller
[0017] 109: user setting input means
BEST MODE FOR CARRYING OUT THE INVENTION
[0018] Now, a horsepower control system for a hybrid excavator and
a control method thereof according to the preferred embodiments of
the present invention will be described hereinafter in detail with
reference to the accompanying drawings.
[0019] FIG. 1 is a block diagram illustrating the construction of a
horsepower control system for a hybrid excavator according to the
present invention.
[0020] As shown in FIG. 1, the horsepower control system of the
present invention includes an engine 101, a hydraulic pump 102 that
is configured to be driven by the engine 101 to drive a hydraulic
actuator by hydraulic fluid, a generator 103 that is configured to
be driven by the engine 101 to generate electric energy, and an
energy storage device 105 configured to charge the electric energy
generated from the generator 103 and supply the electric energy to
an swing electric motor 104. For example, the energy storage device
105 may be either a battery or a super capacitor capable of storing
electric energy, or an accumulator capable of storing hydraulic
energy. The horsepower control system for a hybrid excavator
further includes a power controller 108. The power controller 108
is configured to control the driving operation of a generator
driver 106 or a swing motor driver 107 with a swing power ratio of
1 (or 100%) and a hydraulic horsepower ratio of 1 (or 100%) using
both the power of the energy storage device 105 and the horsepower
of the engine 101 when a first operation mode according to a user
setting is selected (or when a maximum power set switch is turned
on), thereby maximizing the operation amount of the excavator, and
is configured to control the driving operation of the generator
driver 106 or the swing motor driver 107 with a swing power ratio
of r (i.e., a user set value) and a hydraulic horsepower ratio of
1-r using either the power of the energy storage device 105 or the
horsepower of the engine when a second operation mode according to
a user setting is selected (or when a maximum power set switch is
turned off), thereby minimizing fuel consumption through the
limitation of the horsepower.
[0021] Herein, the power controller 108 sets the swing power ratio
according the user setting and then identifies the operation mode
selected by the user. As a result of the identification, if it is
determined that the first operation mode is selected by the user
(i.e., in the case where it is desired to use the full power
required by the user without limitation), the power controller 108
controls the generator driving operation of the generator driver
106 or the swing electric motor driving operation of the swing
motor driver 107 with a swing power ratio of 1 (or 100%) and a
hydraulic horsepower ratio of 1 (or 100%) using both the power of
the energy storage device 105 and the horsepower of the engine 101
to thereby maximize the operation amount of the excavator. On the
other hand, if it is determined that the operation mode selected by
the user is the second operation mode but not the first operation
mode (i.e., in the case where it is desired to use the full power
within the range of an available horsepower), the power controller
108 controls the swing electric motor driving operation of the
generator driver 106 or the swing electric motor driving operation
of the swing motor driver 107 with a swing power ratio of r (i.e.,
a user set value) and a hydraulic horsepower ratio of 1-r at a
horsepower level that is similar to the horsepower level of the
existing system, i.e., using either the power of the energy storage
device 105 or the horsepower of the engine 101 to thereby minimize
fuel consumption through the limitation of the horsepower.
[0022] The generator driver 106 serves to control the driving
operation of the generator 103 differently according to different
operation modes (e.g., first and second operation modes) under the
control of the power controller 108. For example, if the operation
mode selected by the user is the first operation mode (i.e., in the
case where it is desired to use the full power required by the user
without limitation), the generator driver 106 controls the driving
operation of the generator 103 under the control of the power
controller 108 with a swing power ratio of 1 (or 100%) and a
hydraulic horsepower ratio of 1 (or 100%) using both the power of
the energy storage device 105 and the horsepower of the engine 101
to thereby maximize the operation amount of the excavator. On the
contrary, if the operation mode selected by the user is the second
operation mode (i.e., in the case where it is desired to use the
full power within the range of an available horsepower), the
generator driver 106 controls the driving operation of the
generator 103 under the control of the power controller 108 with a
swing power ratio of r (i.e., a user set value) and a hydraulic
horsepower ratio of 1-r at a horsepower level that is similar to
the horsepower level of the existing system, i.e., using either the
power of the energy storage device 105 or the horsepower of the
engine 101 to thereby minimize fuel consumption through the
limitation of the horsepower.
[0023] The swing motor driver 107 serves to control the driving
operation of the swing electric motor 104 differently according to
different operation modes (e.g., first and second operation modes)
under the control of the power controller 108. For example, if the
operation mode selected by the user is the first operation mode
(i.e., in the case where it is desired to use the full power
required by the user without limitation), the swing motor driver
107 controls the driving operation of the swing electric motor 104
under the control of the power controller 108 with a swing power
ratio of 1 (or 100%) and a hydraulic horsepower ratio of 1 (or
100%) using both the power of the energy storage device 105 and the
horsepower of the engine 101 to thereby maximize the operation
amount of the excavator. On the contrary, if the operation mode
selected by the user is the second operation mode (i.e., in the
case where it is desired to use the full power within the range of
an available horsepower), the swing motor driver 107 controls the
driving operation of the swing electric motor 104 under the control
of the power controller 108 with a swing power ratio of r (i.e., a
user set value) and a hydraulic horsepower ratio of 1-r at a
horsepower level that is similar to the horsepower level of the
existing system, i.e., using either the power of the energy storage
device 105 or the horsepower of the engine 101 to thereby minimize
fuel consumption through the limitation of the horsepower.
[0024] The user setting input means 109 may include a key switch
for selecting different operation modes (e.g., first and second
operation modes) independently, or may include only a key switch
for selecting the first operation mode in which it is desired to
use the full power required by the user without limitation). In
this case, the other operation mode, i.e., the second operation
mode may be set as a default mode. Additionally, the user setting
input means 109 may further include a means for inputting a swing
power ratio value according to a user setting.
MODE FOR INVENTION
[0025] Hereinafter, the control operation of the horsepower control
system for a hybrid excavator according to the present invention
will be described with reference to FIG. 2.
[0026] FIG. 2 is a flowchart sequentially illustrating the control
operation of a horsepower control system for a hybrid excavator
according to the present invention.
[0027] As shown in FIG. 2, in the control operation of the
horsepower control system, first, at step S201, the power
controller sets a swing power ratio inputted according to a user
setting.
[0028] Subsequently, the program proceeds to step S202 where the
power controller identifies the operation mode selected by the
user.
[0029] As a result of the identification, if it is determined at
step S202 that the first operation mode is selected by the user
(i.e., in the case where it is desired to use the full power
required by the user without limitation), the program proceeds to
step S203 where the power controller 108 controls the generator
driving operation of the generator driver 106 or the swing electric
motor driving operation of the swing motor driver 107 with the
ratio according to the following Equation 1 using both the power of
the energy storage device 105 and the horsepower of the engine 101
to thereby maximize the operation amount of the excavator:
Swing power ratio=1 (or 100%), and
Hydraulic horsepower ratio=1 (or 100%). Equation 1
[0030] On the contrary, if it is determined at step S202 that the
operation mode selected by the user is the second operation mode
(i.e., in the case where it is desired to use the full power within
the range of an available horsepower), the program proceeds to step
S204 where the power controller 108 controls the swing electric
motor driving operation of the generator driver 106 or the swing
electric motor driving operation of the swing motor driver 107 with
the ratio according to the following Equation 2 at a horsepower
level that is similar to the horsepower level of the existing
system, i.e., using either the power of the energy storage device
105 or the horsepower of the engine 101 to thereby minimize fuel
consumption through the limitation of the horsepower:
Swing power ratio=r, and
Hydraulic horsepower ratio=1-r , Equation 2
[0031] wherein r is a user set value.
[0032] As such, the present invention is constructed such that in
the case where it is desired to use the full power required by a
user without limitation, energy of the energy storage device is
used at a horsepower level which is greatly higher than the
instantaneous horsepower level of the existing system to maximize
the operation amount, while in the case where it is desired to use
the full power within the range of an available horsepower, each
driving device is limitedly used at a horsepower level that is
similar to the horsepower level of the existing system to minimize
fuel consumption.
[0033] FIG. 3 is a table illustrating the relationship between an
operation mode and a swing power ratio/a hydraulic horsepower
ratio.
[0034] As shown in FIG. 3, when the first operation mode is
selected by the user (i.e., in the case where it is desired to use
the full power required by a user without limitation), the driving
operation of the driving device is controlled with a swing power
ratio of 1 (or 100%) and a hydraulic horsepower ratio of 1 (or
100%), thereby maximizing the operation amount of the excavator. On
the other hand, when the second operation mode is selected by the
user (i.e., in the case where it is desired to use the full power
within the range of an available horsepower), power ratio of r
(i.e., a user set value) and a hydraulic horsepower ratio of 1-r ,
thereby minimizing fuel consumption through the limitation of the
horsepower. the driving operation of the driving device is
controlled with a swing
INDUSTRIAL APPLICABILITY
[0035] The inventive horsepower control method can be used in the
horsepower control system for a hybrid excavator.
[0036] In the case where it is desired to use the full power
required by a user without limitation, energy of an energy storage
device is used at a horsepower level which is greatly higher than
the instantaneous horsepower level of the existing system to
maximize the operation amount of the excavator, while in the case
where it is desired to use the full power within the range of an
available horsepower, each driving device is limitedly used at a
horsepower level that is similar to the horsepower level of the
existing system to minimize fuel consumption.
* * * * *