U.S. patent application number 13/561281 was filed with the patent office on 2013-09-19 for control device, control method, and electric motor car.
This patent application is currently assigned to KABUSHIKI KAISHA TOSHIBA. The applicant listed for this patent is Hirotoshi Kawai, Takeru KOGA, Satoshi Koizumi, Masayuki Nogi. Invention is credited to Hirotoshi Kawai, Takeru KOGA, Satoshi Koizumi, Masayuki Nogi.
Application Number | 20130245868 13/561281 |
Document ID | / |
Family ID | 47076040 |
Filed Date | 2013-09-19 |
United States Patent
Application |
20130245868 |
Kind Code |
A1 |
KOGA; Takeru ; et
al. |
September 19, 2013 |
CONTROL DEVICE, CONTROL METHOD, AND ELECTRIC MOTOR CAR
Abstract
A control device for an electric motor car comprising: a switch
which is installed between a power supply source and a power line
drawn through the electric motor car; a battery which supplies
power to a main motor of the electric motor car; a step-up unit,
which is installed between the power line and the battery,
configured to increase a voltage; and a control unit which breaks a
connection between the power supply source and the power line using
the switch when braking the electric motor car, increases the power
supplied from the battery using the step-up unit, and performs
regenerative braking in the main motor to which the increased power
is supplied.
Inventors: |
KOGA; Takeru; (Tokyo,
JP) ; Nogi; Masayuki; (Tokyo, JP) ; Kawai;
Hirotoshi; (Tokyo, JP) ; Koizumi; Satoshi;
(Tokyo, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
KOGA; Takeru
Nogi; Masayuki
Kawai; Hirotoshi
Koizumi; Satoshi |
Tokyo
Tokyo
Tokyo
Tokyo |
|
JP
JP
JP
JP |
|
|
Assignee: |
KABUSHIKI KAISHA TOSHIBA
Tokyo
JP
|
Family ID: |
47076040 |
Appl. No.: |
13/561281 |
Filed: |
July 30, 2012 |
Current U.S.
Class: |
701/22 |
Current CPC
Class: |
B60L 2220/12 20130101;
B60L 2200/26 20130101; B60L 15/2009 20130101; B60L 2210/12
20130101; B60L 2210/14 20130101; B60L 50/53 20190201; B60L 2240/423
20130101; B60L 2240/427 20130101; Y02T 10/64 20130101; B60L 2240/12
20130101; Y02T 10/70 20130101; Y02T 10/72 20130101; B60L 2260/167
20130101; B60L 9/18 20130101; B60L 7/10 20130101; B60L 7/14
20130101; B60L 58/12 20190201 |
Class at
Publication: |
701/22 |
International
Class: |
B60L 15/00 20060101
B60L015/00 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 16, 2012 |
JP |
P2012-060063 |
Claims
1. A control device for an electric motor car comprising: a switch
which is installed between a power supply source and a power line
drawn through the electric motor car; a battery which supplies
power to a main motor of the electric motor car; a step-up unit,
which is installed between the power line and the battery, and
which is configured to increase a voltage supplied from the
battery; and a control unit which, when a regenerative breaking to
brake the electric motor car is used and when a speed of the
electric motor car is faster than a reference speed, breaks a
connection between the power supply source and the power line using
the switch and increases the voltage supplied from the battery by
instructing the step-up unit to perform a step-up operation so as
to expand an effective range of the regenerative braking.
2. (canceled)
3. The control device according to claim 1, wherein the control
unit does not instruct the step-up unit to perform the step-up
operation when the speed of the electric motor car is slower than
the reference speed.
4. The control device according to claim 3, wherein the reference
speed is a speed at which a value of a regenerated current, when
performing electric braking using a battery voltage of the battery,
is equal to or larger than a value of a current flowing to the main
motor.
5. The control device according to claim 1, further comprising a
storage unit which stores correlation information between the
reference speed and a regenerated current, wherein the control unit
determines whether to instruct the step-up unit to perform the
step-up operation in accordance with the correlation information
stored in the storage unit.
6. The control device according to claim 1, wherein the control
unit controls a voltage of the power line at a battery voltage of
the battery in a power running mode, and after a regeneration
operation is started by braking the electric motor car, the control
unit breaks the connection between the power supply source and the
power line using the switch and instructs the step-up unit to
perform the step-up operation.
7. The control device according to claim 1, wherein the control
unit increases a voltage of the power line by using the step-up
unit in a power running mode of the electric motor car using the
battery.
8. A control method of controlling an electric motor car, the
electric motor car including (i) a power line, which is connected
to an external power supply source and which is drawn through the
electric motor car, and (ii) a battery which supplies power to a
main motor of the electric motor car, the control method
comprising: when using regenerative braking to brake the electric
motor car and when a speed of the electric motor car is faster than
a predetermined speed, (i) interrupting a connection between the
power supply source and the power line, and (ii) increasing a
voltage supplied from the battery so as to expand an effective
range of the regenerative braking.
9-11. (canceled)
12. The control method according to claim 8, wherein when the speed
of the electric motor car is slower than the predetermined speed,
the voltage supplied from the battery is not increased, and the
battery is charged by the regenerative braking of an electric brake
using the main motor.
13. The control method according to claim 8, further comprising:
controlling a voltage of the power line at a battery voltage of the
battery in a power running mode, and after a regeneration operation
is started by braking the electric motor car, interrupting the
connection between the power supply source and the power line and
increasing the voltage supplied from the battery.
14. The control method according to claim 13, further comprising:
determining whether the battery is charged to a predetermined
value, and starting the regenerative braking of an electric brake
when the battery is not charged to the predetermined value.
15. An electric motor car comprising: a switch which is installed
between an external power supply source and a power line drawn
through the electric motor car; a battery which supplies power to a
main motor; a step-up unit which is installed between the power
line and the battery, and which is configured to perform a step-up
operation; a control unit which, when using regenerative braking to
brake the electric motor car and when a speed of the electric motor
car is faster than a reference speed, interrupts a connection
between the power supply source and the power line using the
switch, and increases the power supplied from the battery using the
step-up unit so as to expand an effective range of the regenerative
braking; and a carriage on which at least one of the battery and
the control unit is provided.
16. The electric motor car according to claim 15, wherein when the
speed of the electric motor car is slower than the reference speed,
the control unit does not increase the power supplied from the
battery using the step-up unit.
17. The electric motor car according to claim 15, wherein the
control unit controls a voltage of the power line at a battery
voltage of the battery in a power running mode, and after a
regeneration operation is started by braking the electric motor
car, the control unit interrupts the connection between the power
supply source and the power line using the switch and increases the
power supplied from the battery using the step-up unit.
18. A control device for an electric motor car comprising: a switch
which is installed between a power supply source and a power line
drawn through the electric motor car; a battery which supplies
power to a main motor of the electric motor car; a step-up unit
which is installed between the power line and the battery, and
which is configured to increase a voltage supplied from the
battery; and a control unit which breaks a connection between the
power supply source and the power line using the switch when
braking the electric motor car, increases the power supplied from
the battery using the step-up unit, and performs regenerative
braking in the main motor to which the increased power is supplied,
wherein the control unit controls a voltage of the power line at a
battery voltage of the battery in a power running mode, and after a
regeneration operation is started by braking the electric motor
car, the control unit breaks the connection between the power
supply source and the power line using the switch and performs a
step-up operation using the step-up unit.
19. A control device for an electric motor car comprising: a switch
which is installed between a power supply source and a power line
drawn through the electric motor car; a battery which supplies
power to a main motor of the electric motor car; a step-up unit
which is installed between the power line and the battery, and
which is configured to increase a voltage supplied from the
battery; and a control unit which breaks a connection between the
power supply source and the power line using the switch when
braking the electric motor car, increases the power supplied from
the battery using the step-up unit, and performs regenerative
braking in the main motor to which the increased power is supplied,
wherein the control unit increases a voltage of the power line by
using the step-up unit in a power running mode of the electric
motor car using the battery.
20. An electric motor car comprising: a switch which is installed
between an external power supply source and a power line drawn
through the electric motor car; a battery which supplies power to a
main motor; a step-up unit which is installed between the power
line and the battery, and which is configured to perform a step-up
operation; a control unit which interrupts a connection between the
power supply source and the power line using the switch when
braking the electric motor car, increases the power supplied from
the battery using the step-up unit, and performs regenerative
braking in the main motor to which the increased power is supplied;
and a carriage on which at least one of the battery and the control
unit is provided, wherein the control unit controls a voltage of
the power line at a battery voltage of the battery in a power
running mode, and after a regeneration operation is started by
braking the electric motor car, the control unit interrupts the
connection between the power supply source and the power line using
the switch and performs the step-up operation using the step-up
unit.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is based upon and claims the benefit of
priority from the prior Japanese Patent Application No.
2012-060063, filed on Mar. 16, 2012, the entire contents of which
are incorporated herein by reference.
FIELD
[0002] Embodiments described herein generally relate to a control
device, a control method, and an electric motor car.
BACKGROUND
[0003] In an electric motor car which runs on an electric power
supply from a power source such as an overhead contact line, a main
motor is activated as a generator and a regenerated current from
the generator is returned to the overhead contact line etc.
Thereby, a regenerative brake control, which has same function with
a status where a car is braked, is used.
[0004] Further, in recent years, a battery may be mounted on the
conventional electric motor car. In this kind of electric motor
car, batteries are respectively installed in plural trailer cars
constituting the electric motor car. The respective batteries
mounted on the respective trailer cars in a distributed state are
connected in parallel to each other through a power line, and the
power line is drawn through the train. At this time, since the
battery voltage is too low with respect to the driving performance
of the vehicle, the battery voltage is increased to a high voltage
by a step-up chopper installed inside the vehicle when the vehicle
starts to run. That is, the step-up chopper applies a battery
voltage increased up to a rated voltage necessary for an inverter
that generates power for driving the motor. Such a technology of
driving the electric motor car through the power line and the
step-up chopper has been proposed. The above mentioned technology
is disclosed in Japanese Patent Application Laid-Open No.
2001-352607, and contents of which are hereby incorporated by
reference. Further, when the regenerated current is generated from
the main motor, drive control of decreasing the main circuit
voltage and returning the regenerated current to the battery are
performed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1 is a diagram illustrating a configuration of a main
circuit of an electric motor car control device of an electric
motor car according to a first embodiment.
[0006] FIG. 2 is a diagram illustrating a relation between a main
motor induced voltage and a speed when braking a vehicle.
[0007] FIG. 3 is a flowchart illustrating a procedure of a process
in a power running mode of the electric motor car in the electric
motor car control device according to the first embodiment.
[0008] FIG. 4 is a flowchart illustrating a procedure of a process
in a stop mode of the vehicle in the electric motor car control
device according to the first embodiment.
DETAILED DESCRIPTION
[0009] In the above-described electric motor car, the battery
voltage is designed to be lower than the voltage of the overhead
contact line in many cases in order to receive power from the
overhead contact line.
[0010] In the electric motor car having such a conventional
battery, the regeneration efficiency of the main motor is defined
by the main circuit voltage in the regenerative brake control when
the main motor rotates at a high speed. Accordingly, when the
necessary brake force exceeds the electric brake force which may be
regenerated based on the main circuit voltage, the brake force
necessary for stopping or decelerating the vehicle is not
sufficiently obtained. As a result, there is a need to use an air
brake. When the air brake is used, energy is wasted due to the heat
generation, which causes a problem that the regeneration efficiency
decreases.
[0011] In view of the above circumstances, an aspect of embodiments
provides a control device for an electric motor car comprising: a
switch which is installed between a power supply source and a power
line drawn through the electric motor car; a battery which supplies
power to a main motor of the electric motor car; a step-up unit,
which is installed between the power line and the battery,
configured to increase a voltage; and a control unit which breaks a
connection between the power supply source and the power line using
the switch when braking the electric motor car, increases the power
supplied from the battery using the step-up unit, and performs
regenerative braking in the main motor to which the increased power
is supplied.
[0012] According to an aspect of embodiments, the electric motor
car control device which improves the regeneration efficiency is
provided.
First Embodiment
[0013] FIG. 1 is a diagram illustrating a configuration of a main
circuit of an electric motor car control device 100 of an electric
motor car according to a first embodiment. As illustrated in FIG.
1, the electric motor car control device 100 receives power by
connecting a contactor 101 to a power supply source (not
illustrated) (for example, an overhead contact line, a third rail,
or the like). Then, the electric motor car control device 100 is
connected to a power line 102 through the contactor 101 from the
overhead contact line.
[0014] The contactor 101 is installed between the overhead contact
line and the power line 102 which is drawn through the electric
motor car, and is controlled by a train control management system
(hereinafter, referred to as a TCMS) 150 so that the contactor 101
is connected to or disconnected from the overhead contact line.
[0015] Then, the power line 102 is connected to the respective
constituents such as an inverter and a charger through high-speed
breakers 103_1, 103_2, and 103_3. Then, the electric motor car
control device 100 includes the train control management system
(TCMS) 150.
[0016] The TCMS 150 controls the respective constituents of the
electric motor car control device 100. For example, the TCMS 150
may control the contactor 101 or a step-up/step-down chopper 120.
Further, the TCMS 150 may realize the regenerative braking using
main motors 108_1 and 108_2. Furthermore, as illustrated in FIG. 1,
the electric motor car control device 100 is placed on a carriage,
and main motors 108_1 and 108_2 are mechanically connected to
vehicle wheels so as to apply a drive force or a brake force
thereto.
[0017] In the embodiment, the voltage of the power which is
supplied from the overhead contact line to the power line 102 is
exemplified as 600 V, but the voltage value is not limited thereto,
and the appropriate voltage may be supplied in accordance with the
embodiment.
[0018] Further, in the electric motor car control device 100
according to the embodiment, a resistor 104_1, a switching element
105_1, a reactor 109_1, a capacitor 106_1, an inverter 107_1, and
the main motor 108_1 are connected to the power line 102 through
the high-speed breaker 103_1.
[0019] When the inverter 107 1 performs a power running operation
by the power supplied from the battery 110, the TCMS 150 does not
operate the step-up/step-down chopper 120, and the power supplied
from the battery 110 reaches the power line 102 through a diode
125. Accordingly, when the battery voltage is DC 600 V, the voltage
of the power line 102 also becomes DC 600 V.
[0020] Then, the TCMS 150 performs control in which the switching
element 105_1 is turned off and the resistor 104_1 and the
capacitor 106_1 are connected in series to each other so as to
charge the capacitor 106_1. After the capacitor 106_1 is charged,
the switching element 105_1 is turned on, and power is supplied to
the capacitor 106_1 and the inverter 107_1 connected in parallel to
each other. The power supply target is not limited to the battery
110, and may be the overhead contact line.
[0021] Then, when using the electric brake, the electric motor car
control device 100 allows the main motor 108_1 to serve as a
generator, so that kinetic energy is converted into electric
energy. Accordingly, a regenerated current lreg flows to the power
line 102.
[0022] Further, in the electric motor car control device 100
according to the embodiment, a resistor 104_2, a switching element
105_2, a reactor 109_2, a capacitor 106_2, an inverter 107_2, and
the main motor 108_2 are connected to the power line 102 through
the high-speed breaker 103_2 so as to perform the above-described
operation.
[0023] Further, in the electric motor car control device 100
according to the embodiment, the battery 110 and the
step-up/step-down chopper 120 are connected to the power line 102
through the high-speed breaker 103_3.
[0024] The battery 110 supplies power to the main motors 108_1 and
108_2 through the step-up/step-down chopper 120 and the inverters
107_1 and 107_2. Further, the battery 110 may supply power to the
TCMS 150 or the respective units inside the electric motor car.
Further, the battery 110 is charged by the regenerative braking
through the electric brake using the main motors 108_1 and
108_2.
[0025] The step-up/step-down chopper 120 is installed between the
power line 102 and the battery 110, and includes a reactor 127, a
capacitor 126, the diode 125 of the upper arm, an IGBT 122 of the
upper arm, a diode 124 of the lower arm, an IGBT 123 of the lower
arm, and a reactor 121. Then, the TCMS 150 increases or decreases
the power by controlling any one of the IGBT 122 of the upper arm
and the IGBT 123 of the lower arm. Accordingly, the power supplied
from the battery 110 may be increased or decreased.
[0026] As illustrated in FIG. 1, in the electric motor car control
device 100 according to the embodiment, the respective inverters
107_1 and 107_2 which drive the main motors 108_1 and 108_2 are
connected to the power line 102. Then, the step-up/step-down
chopper 120 is connected between the power line 102 and the battery
110.
[0027] Then, the electric motor car control device 100 according to
the embodiment drives the electric motor car by the power supplied
from the battery or the power supplied from the overhead contact
line in a power running mode. Further, the electric motor car
control device 100 enables the entire regenerative electric brake
by increasing the power using the step-up/step-down chopper 120
during the regenerative braking from the high speed. Next, the
reason why the voltage is increased will be described.
[0028] FIG. 2 is a diagram illustrating a relation between the main
motor induced voltage and the speed when braking the vehicle. In
FIG. 2, the horizontal axis indicates the speed of the vehicle, and
the vertical axis indicates the main motor current value and the
regenerated current value. When the voltage of the power line 102
is DC 600 V, the relation may be expressed by a line 201
representing the characteristics of the main motor current and a
line 202 representing the regenerated current.
[0029] When the step-up/step-down chopper 120 is stopped in the
power running mode of the electric motor car, the voltage of the
power line 102 becomes the battery voltage according to the battery
110. In the power running mode, the constant torque control is
performed up to a speed at which the induced voltages of the main
motors 108_1 and 108_2 reach the battery voltage, and the constant
torque may not be output at the higher speed. For this reason, the
TCMS 150 performs acceleration by the control in which the torque
values of the main motors 108_1 and 108_2 are decreased.
[0030] Incidentally, in the brake operation, a constant brake force
is demanded until the electric motor car stops from the high speed.
For this reason, when the brake is operated from the high speed, as
illustrated in FIG. 2, the induced voltages of the main motors
108_1 and 108_2 become equal to or larger than the battery voltage
of the battery, so that the control may not be performed.
[0031] For example, when the brake is operated at the speed V2 of
the vehicle, the supplement corresponding to a difference in
current 210 is needed using the air brake when the voltage of the
power line 102 is DC 600 V.
[0032] For this reason, there is a need to increase the voltage of
the power line 102 in order to enable the control using the entire
electric brake. Therefore, the electric motor car control device
100 according to the embodiment changes the power line voltage,
through the power running operation and the regeneration operation,
by performing the charge control to the battery 110 of the
step-up/step-down chopper 120.
[0033] For example, when the voltage of the power line 102 is
increased to DC 800 V, a relation is obtained between a line 203
representing the characteristics of the main motor current and a
line 204 representing the regenerated current. Due to such a
relation, there is no need to use the air brake even at the speed
V2 of the vehicle.
[0034] In other words, in the electric motor car control device 100
according to the embodiment, since the region where the constant
current flows in the main motor current is widened by increasing
the voltage of the power line 102 to DC 800 V, entire kinetic
energy may be recycled by the electric brake through the
regeneration operation using the entire electric brake when braking
the electric motor car. However, since the overhead contact line
connected to the power line 102 is DC 600 V, the power line 102 may
not be increased to DC 800 V while being connected to the overhead
contact line.
[0035] Therefore, in the embodiment, the TCMS 150 activates the
main motors 108_1 and 108_2 as the generator, the contactor 101 is
controlled so that the connection to the overhead contact line is
interrupted when performing regenerative braking using the electric
brake. After the interruption, the TCMS 150 controls the
step-up/step-down chopper 120 so that the power supplied from the
battery is increased and hence the voltage of the power line 102 is
increased to DC 800 V.
[0036] Then, the current lreg which is regenerated by the electric
brake (the regenerative braking) flows as a charging input current
to the step-up/step-down chopper 120. At this time, the TCMS 150
controls the step-up/step-down chopper 120 in a step-down mode, and
charges the battery 110 of DC 600 V by decreasing the voltage from
DC 800 V to DC 600 V.
[0037] As illustrated in FIG. 2, in a case of the speed V1 of the
vehicle, entire kinetic energy of the vehicle may be recycled by
the electric braking even at DC 600 V through the regenerative
braking using the electric brake. Therefore, the TCMS 150 may
perform control so that the voltage of the power line 102 is
changed in response to the speed of the vehicle.
[0038] In the embodiment, the TCMS 150 determines whether the
voltage is increased by the step-up/step-down chopper 120 based on
whether the speed is equal to or faster than the reference speed Vt
when enabling the electric brake. For example, when it is
determined that the speed of the vehicle is equal to or faster than
the reference speed Vt, the TCMS 150 controls the step-up/step-down
chopper 120 so that the power supplied from the battery 110 is
increased to DC 800 V. The reference speed indicates a speed in
which the value of the regenerated current when enabling the
electric brake by the battery voltage of the battery 110 becomes
equal to or larger than the value of the current flowing to the
main motors 108_1 and 108_2.
[0039] In fact, since the torque values of the main motors 108_1
and 108_2 are small when activating the electric brake, the
regenerated current also decreases. For this reason, even at the
speed equal to or faster than the reference speed Vt, the
regenerative braking may be performed by the electric brake using
DC 600 V. In other words, in the region below the boundary line 201
illustrated in FIG. 2, the regenerative braking may be performed by
the electric brake using DC 600 V.
[0040] Therefore, in the embodiment, when it is determined that the
speed is equal to or faster than the reference speed Vt, the TCMS
150 first starts the regenerative braking using the electric brake
at DC 600 V. Then, the TCMS 150 may control the contactor 101 so
that the connection to the overhead contact line is interrupted and
the voltage is increased by the step-up/step-down chopper 120
before the regenerated current exceeds the boundary line 201 of
FIG. 2.
[0041] Then, when the contactor 101 is connected to the overhead
contact line again so as to enable the power running mode of the
vehicle, the TCMS 150 detects an overhead contact line voltage
using an overhead contact line voltage detection unit (not
illustrated), matches the voltage of the power line 102 to the
overhead contact line voltage, and connects the contactor 101
thereto.
[0042] Further, since there is no need to perform the switching
using the step-up/step-down chopper 120 in the power running mode,
it is possible to suppress a loss caused by the switching using the
step-up/step-down chopper 120.
[0043] Next, the power running operation of the electric motor car
in the electric motor car control device 100 according to the
embodiment will be described. FIG. 3 is a flowchart illustrating
the above-described procedure in the electric motor car control
device 100 according to the embodiment.
[0044] First, the TCMS 150 of the electric motor car control device
100 determines whether the range of a state of charge (hereinafter,
referred to as an SOC) of the battery 110 is sufficient (for
example, a full charged value, a predetermined value or more, and
the like) (step S301).
[0045] When it is determined that the range of the SOC of the
battery 110 is sufficient (Yes in step S301), the TCMS 150 supplies
the power supplied from the battery 110 to the inverters 107_1 and
107_2 so as to drive the main motors 108_1 and 108_2, whereby the
power running operation of the vehicle is performed (step
S302).
[0046] On the other hand, when it is determined that the range of
the SOC of the battery 110 is not sufficient (No in step S301), the
TCMS 150 drives the main motors 108_1 and 108_2 by the power
supplied from the overhead contact line connected through the
contactor 101, whereby the power running operation of the vehicle
is performed (step S303).
[0047] Next, the process when stopping the vehicle in the electric
motor car control device 100 according to the embodiment will be
described. FIG. 4 is a flowchart illustrating the above-described
procedure in the electric motor car control device 100 according to
the embodiment.
[0048] When the brake is enabled, the TCMS 150 of the electric
motor car control device 100 determines whether the range of the
SOC of the battery 110 is sufficient (for example, a full charged
value or a predetermined value or more) (step S401).
[0049] When it is determined that the range of the SOC of the
battery 110 is sufficient (Yes in step S401), the TCMS 150
maintains the connection to the overhead contact line using the
contactor 101, and the TCMS 150 performs the brake control by using
any one or more of the air (mechanic) brake and the electric brake
(step S402). The regenerated current which is generated by the
electric brake is returned to the overhead contact line.
Alternatively, a heat radiation process may be performed as heat
through a resistor or the like.
[0050] On the other hand, when the TCMS 150 determines that the
range of the SOC of the battery 110 is not sufficient (No in step
S401), the TCMS 150 first activates the main motors 108_1 and 108_2
as the generator so as to start the regenerative braking using the
electric brake (step S403). Subsequently, the TCMS 150 controls the
contactor 101 so that the connection between the overhead contact
line and the power line 102 is interrupted (step S404).
[0051] Subsequently, the TCMS 150 determines whether the speed of
the vehicle is equal to or faster than the reference speed which
may be controlled by the electric brake using DC 600 V illustrated
in FIG. 2 (step S405). Furthermore, the reference speed is set to a
predetermined speed, and in the embodiment, the reference speed is
set to the reference speed Vt illustrated in FIG. 2.
[0052] When it is determined that the speed is slower than the
reference speed Vt which maybe controlled by the electric brake (No
in step S405), the TCMS 150 maintains the power line 102 at DC 600
V, normally turns on the IGBT 122, and normally turns off the IGBT
123 (step S406). Accordingly, the TCMS 150 does not increase or
decrease the voltage using the step-up/step-down chopper 120, but
performs the regenerative braking through the electric brake using
the main motors 108_1 and 108_2, so that the battery 110 is charged
by the regenerated current without causing a switching loss (step
S407).
[0053] On the other hand, when it is determined that the speed is
equal to or faster than the reference speed Vt which may be
controlled by the electric brake (Yes in step S405), the TCMS 150
increases the voltage of the power line 102 to DC 800 V by using
the step-up/step-down chopper 120 (step S407). The regenerative
braking through the electric brake using the main motors 108_1 and
108_2 at DC 800 V is started. Then, after the regenerative braking
using DC 800 V is started, the TCMS 150 decreases the inflowing
regenerated current to DC 600 V in the step-down mode of the
step-up/step-down chopper 120 and charges the battery 110 (step
S409).
[0054] Further, the TCMS 150 according to the embodiment performs
control in which the voltage of the power line 102 is increased to
a high voltage by using the step-up/step-down chopper 120 as
described above during the regeneration. Incidentally, when the
inverters 107_1 and 107_2 transfer the regenerated energy to the
power line 102, the voltage of the power line 102 increases in a
state where there is no portion receiving the regenerated energy.
Therefore, in order to maintain the increasing voltage at the
reference voltage of the high voltage (in the embodiment, DC 800
V), the TCMS 150 performs control in which the charging current to
the battery 110 is increased when the voltage of the power line 102
becomes larger than the reference voltage and the charging current
to the battery 110 is decreased when the voltage becomes smaller
than the reference voltage.
[0055] Furthermore, in the embodiment, an example has been
described in which the voltage is increased to 800 V, but the
increased voltage value is not limited thereto. For example, the
increased voltage may have a voltage value which may be used for
the regenerative braking using the electric brake without using the
air (mechanic) brake.
[0056] In the embodiment, since entire kinetic energy may be
recycled by performing the regenerative braking using the entire
electric brake without using the air brake when charging the
battery 110, the efficiency of the energy may be improved.
[0057] In the electric motor car control device 100 according to
the embodiment, since the on-off control of the IGBTs 122 and 123
of the step-up/step-down chopper 120 is not performed in the power
running mode, the loss of the charging unit may be reduced.
MODIFIED EXAMPLE 1
[0058] Further, when the power line 102 does not need to be
normally maintained at DC 800 V during the regenerative braking and
for example, the speed of the vehicle is slower than the reference
speed Vt, the TCMS 150 may return the voltage of the power line 102
to DC 600 V by using the step-up/step-down chopper 120.
[0059] When the voltage of the power line 102 is returned to DC 600
V, the TCMS 150 may control the contactor 101 so that the overhead
contact line and the power line 102 are connected to each other. In
this case, the regenerated current may be returned to the overhead
contact line.
MODIFIED EXAMPLE 2
[0060] Further, in the embodiment, an example has been described in
which the determination is performed based on whether the speed is
the reference speed Vt. However, a table illustrating the
correlation between the speed of the vehicle and the regenerated
current (or the main motors 108_1 and 108_2) for each voltage of
the power line 102 indicated by FIG. 2 is stored in a storage unit
(not illustrated), and the TCMS 150 may determine whether to
perform a step-up operation by referring to the table.
[0061] In the modified example 2, the TCMS 150 performs the
step-up/step-down control using the step-up/step-down chopper 120
in response to the correlation between the speed of the vehicle and
the regenerated current, that is, whether the speed is included in
the speed region which is defined by the boundary line 201 of FIG.
2. Accordingly, the more specific regenerative braking may be
realized.
MODIFIED EXAMPLE 3
[0062] In the above-described embodiment, an example has been
described in which the voltage in the power running mode of the
vehicle is the battery voltage. However, the voltage in the power
running mode is not limited to the battery voltage of the battery
110. Therefore, in the modified example 3, the TCMS 150 performs a
step-up operation using the step-up/step-down chopper 120 in the
power running mode.
[0063] That is, the TCMS 150 increases the voltage of the power
line 102 in the power running mode by increasing the voltage using
the step-up/step-down chopper 120 in the power running mode.
Accordingly, the power running performance may be improved.
[0064] The electric motor car control device 100 according to the
above-described embodiment and the above-described modified
examples drives the vehicle by the battery voltage in the power
running mode. However, since the voltage is increased to the high
voltage by the step-up/step-down chopper 120 during the electric
braking (the regenerative braking) from the high speed, the entire
regenerative electric braking may be performed. Accordingly, entire
kinetic energy is converted into electric energy, so that it may be
returned to the battery 110. Accordingly, the regeneration
efficiency improves.
[0065] Incidentally, in the related art, when the battery mounted
on the battery driven electric motor car is mounted with a
sufficient capacity, the mounting space needs to be ensured and the
weight is very heavy, which causes a big burden. Therefore, it is
very important to efficiently use the energy of the battery.
[0066] Therefore, in the electric motor car control device 100
according to the above-described embodiment and the above-described
modified examples, the high regeneration efficiency is realized
with the above-described configuration, whereby the mounted battery
amount may be decreased.
[0067] Some embodiments of the invention have been described, but
the embodiments are merely examples and do not limit the scope of
the invention. The novel embodiments may be realized as various
embodiments, and various omissions, substitutions, and changes
maybe performed within the scope not departing from the spirit of
the invention. The embodiments or the modifications are included in
the scope or the spirit of the invention, and are included in the
invention disclosed in claims and the equivalents thereto.
[0068] For example, in an example of the embodiment, the contactor
enables or disables the connection of the overhead contact line to
the power line drawn through the electric motor car. However, the
invention is not limited to the contactor, and a semiconductor
switch may be used. Further, the equivalents may be used.
Furthermore, any unit capable of performing the electric connection
and disconnection may be used.
[0069] As the unit of increasing or decreasing the power supplied
from the battery, the step-up/step-down chopper is used in the
embodiment of the specification. However, the invention is not
limited to the step-up/step-down chopper, and the function of the
inverter may be used as described in the paragraph `0051`. Further,
the equivalents may be used, and any unit capable of increasing or
decreasing the voltage may be used.
* * * * *