U.S. patent application number 09/741159 was filed with the patent office on 2001-08-09 for elevator control apparatus using charge/discharge control circuit for power storage apparatus.
Invention is credited to Araki, Hiroshi, Kobayashi, Kazuyuki, Suga, Ikuro, Tajima, Shinobu.
Application Number | 20010011618 09/741159 |
Document ID | / |
Family ID | 18504589 |
Filed Date | 2001-08-09 |
United States Patent
Application |
20010011618 |
Kind Code |
A1 |
Tajima, Shinobu ; et
al. |
August 9, 2001 |
Elevator control apparatus using charge/discharge control circuit
for power storage apparatus
Abstract
To reduce a total power amount required to drive an elevator by
a commercial power supply during a peak power-consumption time
period, for instance, afternoon in summer time, a control apparatus
for this elevator is arranged by employing: a converter for
rectifying AC electric power to be converted into DC electric
power; and inverter for inverting the DC electric power into AC
electric power having a variable voltage and a variable frequency;
a motor driven by said AC electric power having the variable
voltage and the variable frequency so as to operate an elevator; a
power storage apparatus for charging thereinto electric power; and
charge/discharge control means for controlling charging/discharging
operation with respect to the power storage apparatus based upon a
charging target value every time with respect to the power storage
apparatus.
Inventors: |
Tajima, Shinobu; (Tokyo,
JP) ; Araki, Hiroshi; (Tokyo, JP) ; Suga,
Ikuro; (Tokyo, JP) ; Kobayashi, Kazuyuki;
(Tokyo, JP) |
Correspondence
Address: |
LEYDIG VOIT & MAYER, LTD
700 THIRTEENTH ST. NW
SUITE 300
WASHINGTON
DC
20005-3960
US
|
Family ID: |
18504589 |
Appl. No.: |
09/741159 |
Filed: |
December 21, 2000 |
Current U.S.
Class: |
187/290 ;
318/801 |
Current CPC
Class: |
B66B 1/302 20130101;
B66B 1/308 20130101; H02J 3/32 20130101 |
Class at
Publication: |
187/290 ;
318/801 |
International
Class: |
B66B 001/06; H02J
009/00 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 28, 1999 |
JP |
11-374880 |
Claims
What is claimed is:
1. A control apparatus of an elevator, comprising: a converter for
rectifying AC electric power to be converted into DC electric
power; an inverter for inverting said DC electric power into AC
electric power having a variable voltage and a variable frequency;
a motor driven by the AC electric power having the variable voltage
and the variable frequency so as to operate the elevator; a power
storage apparatus for charging thereinto electric power; and
charge/discharge control means for controlling charging/discharging
operation with respect to said power storage apparatus based upon a
charging target value every time with respect to said power storage
apparatus.
2. An elevator control apparatus as claimed in claim 1 wherein: the
charging target value is set to be a lower charging target value
during a peak power-consumption time period, and also is set to be
a higher charging target value during a time period other than the
peak power-consumption time period; and said charge/discharge
control means controls the charging/discharging operation of the
power storage apparatus in accordance with the charging target
value.
3. An elevator control apparatus as claimed in claim 1 wherein: the
charging target value is set to a maximum charging target value
within a predetermined time period just before the peak
power-consumption time period, and is gradually decreased in the
peak power-consumption time period.
4. An elevator control apparatus as claimed in claim 1 wherein: the
charging target value is set in such a manner that the charging
target value is gradually increased during periods minimal
operation of the elevator, and becomes a maximum target value at a
time before full scale operation of the elevator.
5. An elevator control apparatus as claimed in claim 1 wherein: the
charging target value corresponds to such a charging amount by
which at least said elevator is operable in an emergency case.
6. An elevator control apparatus as claimed in claim 1 wherein: in
such a case that a charging amount of said power storage apparatus
is smaller than the charging target value, the discharging
operation from said power storage apparatus is stopped.
7. An elevator control apparatus as claimed in claim 6 wherein:
when the elevator is stopped, said power storage apparatus is
charged by using electric power supplied from a commercial power
supply.
8. An elevator control apparatus as claimed in claim 1 wherein:
when said power storage apparatus is charged by using the electric
power supplied from a commercial power supply, a current value of
the commercial power supply is limited.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention generally relates to an elevator
control apparatus using a power storage apparatus.
[0003] 2. Description of the Related Art
[0004] One conventional control apparatus of an elevator is
indicated in FIG. 5. Referring now to a structural arrangement of
FIG. 5, this conventional elevator control apparatus is arranged by
a motor 2 such as an induction motor coupled to a commercial AC
power supply 1 (will be referred to as a "commercial power supply"
hereinafter), a drive machine 3, a rope 4, a car 5 of the elevator,
and a balance weight 6. Both the elevator car 5 and the balance
weight 6 connected to both ends of the rope 4 can be elevated by
rotary-driving this drive machine 3. As a result, passengers in the
elevator car 5 can be conveyed to a predetermined floor.
[0005] In FIG. 5, reference numeral 8 shows a controller. The
controller 8 determines starting/stopping of the elevator, and
produces a position/speed instruction of this elevator. Reference
numeral 11 indicates a converter which is constructed of a diode
and the like. This converter 11 rectifies AC electric power
supplied from the commercial power supply 1 to produce DC electric
power. Reference numeral 15 represents an inverter which is
constructed of a transistor, an IGBT (Insulated-Gate Bipolar
Transistor), and the like. This inverter 15 inverts the DC electric
power converted by the converter 11 into AC electric power having a
variable AC voltage and a variable AC frequency. Reference numeral
16 shows a regenerative resistor. This regenerative register 16 is
connected to a bus line existing between the converter 11 and the
inverter 15. Also, reference numeral 17 indicates a regenerative
resistor control circuit which is connected to both the
regenerative resistor 16 and the bus line.
[0006] The above-explained balance weight 6 of the elevator is
designed to be balanced when the properly-selected number of
passengers gets into the elevator car 5. As this properly-selected
number of passengers, for example, the half number of a capacity of
this car 5 may be selected. Now, in such a case that the entire
weight of the car 5 into which this properly-selected number of
passengers gets is balanced with the balance weight 6, operation of
this elevator (car 5) will now be considered. When this elevator is
accelerated, the speed of this elevator is increased while this
elevator consumes the electric power supplied from the commercial
power supply 1. Conversely, when the elevator is decelerated, the
speed of this elevator is decreased while returning the stored
kinetic energy to the corresponding electric power. In this case,
such an elevator operation in which a speed of this elevator is
increased while consuming electric power supplied from this
commercial power supply 1 is referred to as a "powering operation."
Also, such an elevator operation in which a speed of this elevator
is decreased while returning kinetic energy to electric power is
referred to as "regenerative operation."
[0007] The electric power produced by this regenerative operation
is converted into thermal energy by both the regenerative resistor
16 and the regenerative resistor control circuit 17 so as to be
consumed.
[0008] Also, reference numeral 7 shows an encoder which is provided
on the drive machine 3. Reference numeral 12 indicates a current
detecting apparatus. This current detecting apparatus 12 is
provided between the motor 2 and the inverter 15. Reference numeral
13 indicates an inverter control circuit which is connected to the
encoder 7, the controller 8, and the current detecting apparatus
12. Reference numeral 14 indicates a gate drive circuit which is
connected to both the inverter control circuit 13 and the inverter
15.
[0009] In response to the instruction issued from the controller 8,
the inverter control circuit 13 rotary-drives the motor 2 based on
both the current feedback from the current detecting apparatus 12
and the speed feedback from the encoder 7 mounted on the drive
machine 3, so that this inverter control circuit 13 can realize
both the positional/speed control of the elevator. Also, the
inverter control circuit 13 controls the output voltage/frequency
of the inverter 15 via the gate drive circuit 14.
[0010] The conventional elevator control apparatus continuously
receives the supply of electric power from the commercial power
supply 1 to operate this elevator irrespective of degrees of power
demands. For example, peak electric power is required in the
afternoon of summer time. During this time range, a total power
consumption is wanted to be reduced. However, the conventional
elevator control apparatus can hardly reduce a total power
consumption during such a peak power-consumption time period.
[0011] As previously explained, since the electric power is
consumed in synchronization with the elevator operation in the
conventional elevator control apparatus, a total power consumption
during the peak power-consumption time period cannot be
reduced.
SUMMARY OF THE INVENTION
[0012] The present invention has been made to solve the
above-explained problems, and therefore, has an object to provide
an elevator control apparatus capable of reducing a total power
consumption of a commercial power supply during, for instance, a
peak power-consumption-time period.
[0013] An elevator control apparatus, according to an aspect of the
present invention, is comprised of: a converter for rectifying AC
electric power to be converted into DC electric power; an inverter
for inverting the DC electric power into AC electric power having a
variable voltage and a variable frequency; a motor driven by the AC
electric power having the variable voltage and the variable
frequency so as to operate an elevator; a power storage apparatus
for charging thereinto DC electric power; and charge/discharge
control means for controlling charging/discharging operation with
respect to the power storage apparatus based upon a charging target
value every time with respect to the power storage apparatus.
[0014] Also, the charging target value owned by the elevator
control apparatus of the present invention is set as follows: a
target value during a peak power-consumption time period is set to
be a small value in order that a total power consumption during
such a peak power-consumption time period can be reduced.
[0015] Also, the charging target value owned by the elevator
control apparatus, according to the present invention, corresponds
to such a charging amount by which at least the elevator is
operable in an emergency case.
[0016] Also, according to the elevator control apparatus of the
present invention, in such a case that a charging amount of the
power storage apparatus is smaller than the charging target value,
the discharging operation from the power storage apparatus is
stopped.
[0017] Furthermore, according to the elevator control apparatus of
the present invention, when the elevator is stopped, the power
storage apparatus is charged by using electric power supplied from
a commercial power supply.
[0018] Also, according to the elevator control apparatus of the
present invention, when the power storage apparatus is charged by
using the electric power supplied from a commercial power supply, a
current value of the commercial power supply is limited.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] For a better understanding of the present invention,
reference is made of a detailed description to be read in
conjunction with the accompanying drawings, in which:
[0020] FIG. 1 schematically indicates an arrangement of a control
apparatus of an elevator, according to an embodiment mode 1 of the
present invention;
[0021] FIG. 2 is a line graph representing a charging target value
of a power storage apparatus 21 every hour, which is set to a
charging target instruction apparatus 20 of the elevator control
apparatus shown in FIG. 1;
[0022] FIG. 3 schematically represents an arrangement of a control
apparatus of an elevator, according to an embodiment mode 5 of the
present invention;
[0023] FIG. 4 is a flow chart describing an elevator control method
executed in the elevator control apparatus according to the
embodiment mode 5; and
[0024] FIG. 5 schematically shows an arrangement of a conventional
control apparatus for an elevator.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0025] Referring now to drawings, various preferred embodiments of
the present invention will be described more in detail.
ARRANGEMENT OF FIRST ELEVATOR CONTROL APPARATUS
[0026] First, a control apparatus of an elevator, according to an
embodiment mode 1 of the present invention, will now be described
with reference to FIG. 1. That is, FIG. 1 is a structural diagram
schematically indicating an arrangement of the elevator control
apparatus according to this embodiment mode 1. In FIG. 1, reference
numeral 20 indicates a charging target instruction apparatus which
is constituted by a general-purpose microprocessor and a program
operable in this microprocessor. The charging target instruction
apparatus 20 is connected to a controller 8. This charging target
instruction apparatus 20 sets a charging target value. Reference
numeral 21 indicates a power storage apparatus which is constituted
by a battery and the like.
[0027] Reference numeral 22 indicates a charge/discharge control
circuit which is arranged by a DC/DC converter and the like. This
charge/discharge control circuit 22 is connected to bus lines
coupled among the charging target instruction apparatus 20, the
power storage apparatus 21, the converter 11, and the inverter
15.
[0028] Also, the charging target value outputted from the charging
target instruction apparatus 20 is entered into this
charge/discharge control circuit 22.
[0029] It should be noted that the inverter 15 owns a function of
another inverting operation. That is, AC regerative power generated
from the motor 2 is inverted into DC regenerative power.
[0030] It should also be noted the same reference numerals shown in
FIG. 5 will be employed as those for denoting the same, or similar
circuit elements of FIG. 1, and therefore, descriptions thereof are
omitted. Only different circuit portions from those of FIG. 5 will
be explained.
[0031] Next, the charging target value set in the charging target
instruction apparatus 20 will now be explained with reference to
FIG. 2. FIG. 2 is a line graph indicative of a charging target
value of the power storage apparatus 21 every hour.
[0032] In an example of this charging target value shown in FIG. 2,
the power storage apparatus 21 is charged by using night-time
(e.g., 0:00 AM to 6:00 AM) electric power; the electric power
stored in this power storage apparatus 21 is gradually discharged
therefrom so as to be used to operate the elevator during day time
(e.g., 12:00 PM to 6:00 PM); a charging amount of this power
storage apparatus 21 is relatively reduced during evening time
(e.g., 6:00 PM to 0:00 PM); and a charging amount of this power
storage apparatus 21 is increased during night time. In the night
time, substantially no elevator is operated. As explained above,
the power storage apparatus 21 is charged in a time range (night
time) during which substantially no elevator is operated, and
furthermore, the charging target value is gradually increased in
order that the instantaneous power amount required for charging the
power storage apparatus 21 is suppressed. As a result, the electric
power rates required for charging the power storage apparatus 21
may be suppressed to low rates. Then, since the charging target
value may be made as a maximum charging target value at a time (for
example, 6:00 AM) before full scale operation of the elevator is
commenced, this elevator control apparatus can satisfactorily
accept such full scale operation of the elevator.
[0033] It should also be understood that if the power storage
apparatus 21 is brought into the fully charged state in a time
range while the elevator is operated, then the regenerative
electric power generated by the regenerative operation of the
elevator may not be stored into this power storage apparatus 21,
but may be consumed as generation energy, namely a waste of
regenerative power. This fact cannot satisfy effective charging
operation in view of energy-saving and electric power-saving. As a
consequence, while the power storage apparatus 21 is allowable to
be continuously charged by the regenerative power, and may be
preferably charged by the commercial power supply. For instance,
while two sorts of charging target value are set, namely a
charge-end target value (a first value) and a charge-start
instruction value (a second value), the power storage apparatus 21
is charged by way of the regenerative power when the charging
amount is in between the two charging target values, whereas the
power storage apparatus 21 is charged by way of both the commercial
power supply and the regenerative power when the charging amount is
equal to or smaller than this charge-start instruction value. At
this charge-end target value, the charging operation is ended. The
charge-start instruction value is set to be lower than this
charge-end target value, and commences the charging operation by
the commercial power supply when the charging amount is
reduced.
[0034] Also, even in such a case that the charging target value is
set to the minimum value in the night time range during which most
of the elevators are stopped, the power storage apparatus 21 is
required to have a certain charging amount in order to cope with an
emergency such as power interruption. As explained above, since the
power storage apparatus 21 owns such a certain charging amount,
even when emergencies such as power interruption and earthquake
happen to occur, occurrences of secondary disasters can be
prevented. For example, passengers are locked up in elevators.
FIRST ELEVATOR CONTROL METHOD
[0035] Next, a description will now be made of an elevator control
method executed in the elevator control apparatus according to the
first embodiment mode. For the sake of a simple explanation, it is
now assumed that the charging operation from the commercial power
supply 1 to the power storage apparatus 21 is carried out when the
elevator is stopped, and the elevator is basically operated while
electric power is supplied thereto from the power storage apparatus
21.
[0036] When the elevator is operated, the charge/discharge control
circuit 22 controls the voltage outputted to the inverter 15 so as
to supply the electric power to the inverter 15.
[0037] It should also be noted that the charge/discharge control
circuit 22 measures/controls both the current value and the voltage
value with respect to the electric power outputted from the power
storage apparatus 21, so that this charge/discharge control circuit
22 may continuously grasp both the charging amount and the use
amount of the electric power in the power storage apparatus 21.
[0038] Also, even when the regenerative power is produced by way of
the regenerative operation of the elevator, namely even when the
regenerative power is returned to the power storage apparatus 21 so
as to be stored thereinto, the charge/discharge control circuit 22
measures/controls both the current value and the voltage value of
this regenerative power, and thus may continuously grasp the
charging amount of the power storage apparatus 21.
[0039] It should also be understood that when the charging amount
of the power storage apparatus 21 becomes equal to or smaller than
a predetermined charging target value set by the charging target
instruction apparatus 20, the supply of electric power from the
power storage apparatus 20 to the inverter 15 is partially limited
while the elevator is driven in the powering operation mode, and
this supply of electric power is replaced by the supply of electric
power from the commercial power supply 1. Alternatively, the supply
of electric power from the power storage apparatus 21 may not be
partially limited, but may be entirely limited. In this alternative
case, the supply of electric power to the inverter 15 is completely
carried out from the commercial power supply 1.
[0040] Also, in such a case that the charging amount of the power
storage apparatus 21 becomes equal to or smaller than a
predetermined charging target value set by the charging target
instruction apparatus 20, when the elevator operation is stopped,
the power storage apparatus 21 may be charged by way of the
commercial power supply 1 so as to achieve such a predetermined
charging target value.
[0041] Further, since the charging target value just before a peak
power-consumption time period is set to a large target value, a
sufficiently large amount of electric power can be stored in the
power storage apparatus 21 just before the peak power-consumption
time period. Also, since this charging target value is set to a
small target value during the peak power-consumption time period,
the elevator can be operated and controlled by using the electric
power sufficiently stored in the power storage apparatus 21 during
the peak power-consumption time period. As a consequence, the power
consumption of the commercial power supply 1 during the peak
power-consumption time period can be suppressed. Also, in such a
case that the charging target value in the peak power-consumption
time period is gradually decreased while time has elapsed, the
electric power is similarly and gradually discharged from the power
storage apparatus 21. As a result, it is possible to avoid such a
phenomenon that the entire electric power is completely discharged
at an initial stage of the peak power-consumption time period, and
therefore the electric power can be supplied under a stable
condition.
[0042] In the usual case, such a peak power-consumption time period
is commenced after 12:00 PM, especially 1:00 PM to 4:00 PM. For
instance, a power-consumption peak is higher especially in the
afternoon of summer time.
[0043] As previously described in detail, in accordance with the
elevator control apparatus of this first embodiment mode, while the
electric power is charged to the power storage apparatus 21, the
operation of this elevator is controlled by using this stored
electric power. As a result, a total power consumption required for
operating and also controlling the elevator can be reduced. In
particular, a total power consumption of the commercial power
supply during the peak power-consumption time period can be
reduced.
[0044] Also, in accordance with the elevator control apparatus of
this first embodiment mode, since the power storage apparatus 21 is
charged by using the regenerative power, a total amount of electric
power energy can be reduced, resulting in an energy-saving
effect.
[0045] Also, in accordance with the elevator control apparatus of
this first embodiment mode, the charging/discharging control
operation is carried out in such a manner that the regenerative
power is charged into the power storage apparatus. As a result, the
regenerative power can be effectively utilized.
[0046] Also, in accordance with the elevator control apparatus of
this first embodiment mode, since the power storage apparatus 21 is
charged based upon the charging target value previously set by the
charging target instruction apparatus 20, a total amount of
electric power of the commercial power supply 1 at such a peak
power-consumption time period during day time in summer can be
restricted.
[0047] Furthermore, in accordance with the elevator control
apparatus of this first embodiment mode, the power storage
apparatus 21 is charged by using the night-time electric power, and
the stored electric energy is discharged at the peak
power-consumption time period during day time, so that a total
amount of electric power of the commercial power supply 1 can be
limited based on the charging target value previously set by the
charging target instruction apparatus 20. As a consequence, while
the total amount of electric power of the commercial power supply
at the peak power-consumption time period is suppressed to a low
consumption value, the elevator can be operated and controlled.
[0048] Recently, reductions in a total power consumption during a
peak power-consumption time period can suppress excessively large
amounts of power generating facilities and furthermore, can
decrease loads given to earth environments. Such power reductions
are also socially required in connection with the earth
environmental problems. Accordingly, the power reductions during
the peak power-consumption time period may be one of the very
important aspects, and therefore, the elevator control apparatus
according to the present invention may have a significant key
point.
[0049] Another elevator control method may be conceived, since
electric power rates at night time are cheaper than electric power
rates at day time. Under this electric power rates condition, while
the capacity of the power storage apparatus 21 is set to a
sufficiently large capacity, a total power consumption required for
operating the elevator per 1 day may be completely supplied from
the electric power stored in this power storage apparatus 21 during
night time. However, this elevator control method may have a
practical problem. That is, if the capacity of the power storage
apparatus 21 is set to such a large capacity, then the facility
cost is considerably increased.
[0050] As a consequence, the desirable capacity of the power
storage apparatus 21 should be selected for the elevator control
apparatus by considering the electric power rates required to
operate the elevator, namely the operation expense, and further,
the manufacturing cost of this power storage apparatus 21, namely
the product cost, i,e., totally low cost.
SECOND ELEVATOR CONTROL APPARATUS
[0051] Next, a control apparatus of an elevator, according to a
second embodiment mode of the present invention, will now be
explained. It should be understood that since an arrangement of the
elevator control apparatus according to this second embodiment mode
is similar to that of the elevator control apparatus shown in FIG.
1 according to the above-explained first embodiment mode,
explanations thereof are omitted.
[0052] Subsequently, a description will now be made of an elevator
control method executed in the elevator control apparatus according
to this second embodiment mode. As to the elevator control method
performed in the elevator control apparatus of this second
embodiment mode, a charging amount of a power storage apparatus 21
is controlled based upon a charging target value set by a charging
target instruction apparatus 20, and furthermore,
charging/discharging operations are controlled in response to a
charging condition of this power storage apparatus 21.
[0053] First, when a charging amount stored in the power storage
apparatus 21 is equal to or larger than a predetermined charging
target value, a charge/discharge control apparatus 22 controls the
power storage apparatus 21 to discharge therefrom electric power
which is required to perform powering operation of the elevator, so
that this charge/charge control apparatus 22 operates and controls
the elevator. Also, regenerative electric power generated while the
elevator is driven in the regenerative operation mode is charged
into the power storage apparatus 21 so as to replenish such
electric power which is discharged while the elevator is driven in
the powering operation mode.
[0054] Also, when a charging amount stored in the power storage
apparatus 21 is smaller than the predetermined charging target
value, the charge/discharge control apparatus 22 controls the
commercial power supply 1 to supply therefrom electric power which
is required while the elevator is driven in the powering operation
mode, and stops the supply of electric power from the power storage
apparatus 21. Then, this charge/discharge control apparatus 22
performs such a control operation that regenerative power generated
while the elevator is driven in the regenerative operation mode is
charged to the power storage apparatus 21.
[0055] In general, when the power storage apparatus 21 is directly
charged by using the commercial power supply 1 and the charged
electric power is outputted to the inverter 15, there is a more or
less power loss due to a relation to a charging/discharging
efficiency. However, in the elevator control apparatus of this
second embodiment mode, such regenerative power which has been
conventionally converted into thermal energy to be consumed can be
used to charge the power storage apparatus 21, resulting in an
improvement of the energy-saving effect.
[0056] Also, while the charging target value is set to a lower
charging target value during a peak power-consumption time period
and the charging target value is set to a higher charging target
value during the normal power consumption time period, the
regenerative power may be charged into the power storage apparatus
21 during the normal power consumption time period whereas this
charged regenerative power may be discharged therefrom during the
peak power-consumption time period. As a result, a total amount of
electric power of the commercial power supply 1 during the peak
power-consumption time period may be reduced.
[0057] As previously explained, while the regenerative power
generated when the elevator is driven in the regenerative operation
mode is charged into the power storage apparatus 21, this charged
regenerative power is utilized so as to drive the elevator in the
powering operation mode, so that the reduction effect in electric
power of the commercial power supply 1 can be achieved. More
specifically, a total power consumption during the peak
power-consumption time period of the commercial power supply 1 can
be reduced. It should also be noted that the regenerative power
charged in the power storage apparatus 21 may be used to partially
replenish, or entirely replenish the electric power required to
drive the elevator in the powering operation mode. When the
elevator control apparatus is equipped with such a power storage
apparatus 21 capable of partially replenishing the electric power
required to drive the elevator in the powering operation mode, this
power storage apparatus 21 can be manufactured in low cost, as
compared with another power storage apparatus capable of completely
supplying all electric power required to drive the elevator in the
powering operation mode.
THIRD ELEVATOR CONTROL APPARATUS
[0058] Next, a control apparatus of an elevator, according to a
third embodiment mode of the present invention, will now be
explained. It should be understood that since an arrangement of the
elevator control apparatus according to this third embodiment mode
is similar to that of the elevator control apparatus shown in FIG.
1 according to the above-explained first embodiment mode,
explanations thereof are omitted.
[0059] Subsequently, a description will now be made of an elevator
control method executed in the elevator control apparatus according
to this third embodiment mode.
[0060] First, when a charging amount stored in the power storage
apparatus 21 is equal to or larger than a charging target value, a
charge/discharge control apparatus 22 executes such a control
operation as follows: That is, electric power is discharged from
the power storage apparatus 21 which is required to perform
powering operation of the elevator, so that this electric power is
supplied to the elevator. Also, regenerative power generated while
the elevator is driven in the regenerative operation mode is
charged into to the power storage apparatus 21.
[0061] Also, when a charging amount stored in the power storage
apparatus 21 is smaller than the charging target value, the
charge/discharge control apparatus 22 controls the
charging/charging operation in the commercial power supply 1. As
indicated in the second embodiment mode, the charging/discharging
operation is controlled while the elevator is driven in both the
regenerative operation mode and the powering operation mode. In
addition, in such a case that the charging amount of the power
storage apparatus 21 is smaller than the charging target value,
when the elevator is stopped, the power storage apparatus 21 of
this embodiment mode is charged by the commercial power supply 1
under control of the charge/discharge control apparatus 22.
[0062] It should be understood that the recharging operation by the
commercial power supply 1 is carried out in order to satisfy the
charging target value.
[0063] Also, the charging operation to this power storage apparatus
21 is controlled in accordance with the below-mentioned manner.
First, just before the peak power-consumption time period of the
commercial power supply 1, the charging target value of the power
storage apparatus 21 is set to be larger than the electric power
amount used in this peak time period. Also, during this peak time
period, the charging target value of the power storage apparatus 21
is set to be smaller than the above-explained charging target value
set just before the peak power-consumption time period.
[0064] Then, during the peak power-consumption time period, the
elevator is operated by mainly receiving the electric power
supplied from the power storage apparatus 21.
[0065] As previously explained, since the charging target value
during the peak time period is set to be such a small target value,
when the elevator is stopped, this elevator can be controlled by
receiving a small amount of charging power from the commercial
power supply 1. As a result, the charging operation to the power
storage apparatus 21 can be continuously controlled in a proper
manner, and furthermore, the total amount of electric power of the
commercial power supply 1 during the peak time period can be
reduced.
[0066] On the other hand, while various improvements have been made
in the power storage apparatus 21, the manufacturing cost thereof
is gradually decreased. However, if the power storage apparatus has
large capacity enough to supply all electric power required to
operate the elevator during day time from the apparatus, then the
manufacturing cost thereof is still expensive. Therefore, the
combination between the commercial power supply and the power
storage apparatus as explained in this third embodiment mode is
realized.
[0067] As explained above, since the elevator control apparatus of
this third embodiment mode operates the elevator while controlling
the charging/discharging operation of the power storage apparatus
based upon a predetermined charging target value, this elevator
control apparatus is no longer equipped with such a high-cost power
storage apparatus 21 having a large capacity, and therefore, can be
constituted in low cost.
[0068] Also, in accordance with the elevator control apparatus of
this third embodiment mode, the regenerative power generated when
the elevator is driven in the regenerative operation mode is
charged to the power storage apparatus 21 so as to be utilized. As
a result, the energy-saving effect can be achieved. In particular,
since a total amount of electric power used during the peak
power-consumption time period of the commercial power supply 1 can
be reduced, this elevator control apparatus can contribute to
prevention of increasing in the commercial power generating
facility.
FOURTH ELEVATOR CONTROL APPARATUS
[0069] Next, a control apparatus of an elevator, according to a
fourth embodiment mode of the present invention, will now be
explained. It should be understood that since an arrangement of the
elevator control apparatus according to this fourth embodiment mode
is similar to that of the elevator control apparatus shown in FIG.
1 according to the above-explained first embodiment mode,
explanations thereof are omitted.
[0070] Subsequently, a description will now be made of an elevator
control method executed in the elevator control apparatus according
to this fourth embodiment mode.
[0071] First, when a charging amount stored in the power storage
apparatus 21 is equal to or larger than a charging target value, a
charging/discharging control apparatus 22 controls the power
storage apparatus 21 to discharge therefrom electric power and then
operates the elevator in the powering operation mode by using the
electric power which has been changed in this power storage
apparatus 21. Also, in this case, the charge/discharge control
apparatus 22 uses the regenerative power generated when the
elevator is driven in the regenerative operation mode so as to
charge this regenerative power into the power storage apparatus
21.
[0072] Also, when a charging amount stored in the power storage
apparatus 21 is equal to or smaller than the charging target value,
the charge/discharge control apparatus 22 executes the following
charging/discharging control operations with respect to the power
storage apparatus 21. That is, these charging/discharging control
operations correspond to such conditions that the elevator is
driven in the regenerative operation mode, and the powering
operation mode, and also the elevator is stopped as represented in
the third embodiment mode.
[0073] Then, in the case that the charging amount stored in the
power storage apparatus 21 is equal to or smaller than a
predetermined charging target value and furthermore the elevator is
stopped, the power storage apparatus 21 is charged by using the
electric power supplied from the commercial power supply 1. At this
time, the recharging/charging control apparatus 22 may restrict the
electric power to be charged into the power storage apparatus 21.
In other words, while the power storage apparatus 21 is charged by
way of the commercial power supply 1, the charge/discharge control
apparatus 22 controls the electric power supplied from the
commercial power supply 1 by using a power limiting value for
limiting a current value and a voltage value, for example, limited
within 1 KW.
[0074] The reason why the charging operation to the power storage
apparatus 21 is controlled based upon the power limiting value with
respect to the supplied power is given to consider the electric
power rate system. In general, an electric power rate system is not
directly proportional only to a used electric power amount (KWh),
but also is directly proportional to used maximum electric power
(KW). Therefore, in order to reduce electric power rates of the
elevator control apparatus, not only an energy-saving in which
total amount (KWh) of electric power supplied from the commercial
power supply 1 by storing and reusing the regenerative power must
be reduced, but also the maximum electric power (KW) required when
the commercial power supply 1 is used must be limited.
[0075] Therefore, in accordance with the elevator control apparatus
of this fourth embodiment mode, storing/reusing of the regenerative
power are limited. Moreover, the maximum electric power supplied
from the commercial power supply 1 is limited. As a consequence, it
is possible to accomplish such an elevator control apparatus
capable of operating the elevator in lower cost.
ARRANGEMENT OF FIFTH ELEVATOR CONTROL APPARATUS
[0076] Referring now to FIG. 3, an elevator control apparatus
according to a fifth embodiment mode of the present invention will
be described. FIG. 3 is a structural diagram schematically
indicating an arrangement of the elevator control apparatus
according to this fifth embodiment mode. In FIG. 30, reference
numeral 30 indicates a charging target input apparatus which is
constituted by a personal computer and the like. This charging
target input apparatus 30 corresponds to a terminal used to input a
charging target value to either a power storage apparatus 21 or a
charging target instruction apparatus 20 employed in the elevator
control apparatus according to this fifth embodiment mode. It
should be noted that a charging target value is entered to the
charging target input apparatus 30 according to this fifth
embodiment mode in relation to time, day, week, month, season,
year, and elevator operation condition. Alternatively, as this
charging target value, while a plurality of items may be combined
with each other, such a combined item may be set to this charging
target input apparatus 30.
[0077] Also, reference numeral 31 represents a charging target
storing means which is connected to the charging target input
apparatus 30. In this charging target storing means 31, the
charging target value entered by the charging target input
apparatus 30 is stored.
[0078] Reference numeral 32 shows a clock. This clock 32 outputs
information related to either a present time instant or a calendar
at this time.
[0079] Reference numeral 33 indicates a charging amount setting
value extracting means which is connected to both the charging
target storing means 31 and the clock 32. This charging amount
setting value extracting means 33 extracts a charging target value
"Qc" from the charging target storing means 31 based upon the
information related to the time and the calendar entered from the
clock 32. This charging target value Qc is defined based on this
time and calendar.
[0080] Reference numeral 34 shows a charging/discharging current
detector, namely a so-called "current detector". This
charging/discharging current detector 34 detects a current
passing/flowing from a bus line connected between a converter 11
and an inverter 15 into a charge/discharge control circuit 41.
[0081] Reference numeral 35 denotes a charging amount calculating
means which is connected to the charging/discharging current
detector 34. This charging amount calculating means 35 calculates
electric energy "Q" stored in a power storage apparatus 21 based
upon a current value detected by the charging/discharging current
detector 34. In other words, the charging amount calculating means
35 accumulates a current value passing/flowing into/from the power
storage apparatus 21, so that the electric energy Q stored in the
power storage apparatus 21 is calculated. It should also be
understood that the method for calculating the electric energy Q is
not limited to the above-explained method of accumulating the
current value passing/flowing into/from the power storage apparatus
21.
[0082] Reference numeral 36 shows a charging amount comparing means
which is connected to both the charging amount setting value
extracting means 33 and the charging amount calculating means 35.
This charging amount comparing means 36 compares the charging
target value Qc with the electric energy Q.
[0083] Reference numeral 37 shows a scale used to detect a load
loaded on a car 5 of an elevator, namely the total number of
passengers within the elevator car 5. A detection result obtained
from this scale 37 is employed as one of information used to judge
as to whether an operation of this elevator just after the scale 37
detects the load corresponds to a powering operation, or a
regenerative operation.
[0084] Reference numeral 38 represents an elevator control
information extracting means which is connected to the scale 37.
This elevator control information extracting means 38 extracts
control information of the elevator. This elevator control
information is the total number of passengers present within the
car 5 corresponding to the detection result of the scale 37, and an
operation mode of the elevator. This operation mode of the elevator
indicates a powering operation mode in which electric power is
discharged from the power storage apparatus 21, a regenerative
operation mode in which electric power is charged into the power
storage apparatus 21, a stop mode in which the elevator is
stopped.
[0085] Reference numeral 39 represents a charging/discharging
instructing means which is connected to both the charging amount
comparing means 36 and the elevator control information extracting
means 38. This charging/discharging instructing means 39
judges/instructs as to whether the electric power is charged into
the power storage apparatus 21, or the electric power is discharged
from the power storage apparatus 21 based upon the comparison
result between the charging target value Qc and the electric energy
Q, and the control information of this elevator.
[0086] It should also be understood that the charging/discharging
operation executed based on the elevator control information is to
control the charging/discharging operation based on both the load
given to the elevator car 5 and the drive direction of this
elevator car 5. Either an ascending operation under light load or a
descending operation under heavy load corresponds to a regenerative
operation, which constitutes a charge mode in which the power
storage apparatus 21 is charged. To the contrary, either an
ascending operation under heavy load or a descending operation
under light load corresponds to a powering operation which
constitutes a discharge mode in which the power storage apparatus
21 is discharged.
[0087] Reference numeral 40 denotes an input/output unit voltage
detector which is connected to the charging/discharging instructing
means 39. This input/output unit voltage detector 40 detects a
voltage value "V" appearing between the converter 11 and the
inverter 15 of the charge/discharge control circuit 22. In response
to this detection result, the charging operation to the power
storage apparatus 21 and the discharging operation from the power
storage apparatus 21 may be switched.
[0088] Also, reference numeral 41 indicates a charge/discharge
control circuit which corresponds to a charge/discharge control
means. This charge/discharge control circuit 41 is connected to
both the charging/discharging instructing means 39 and the
input/output unit voltage detector 40. In response to an
instruction issued from either the charging/discharging instructing
means 39 or the input/output unit voltage detector 40, this
charge/discharge control circuit 41 charges the electric power of
the DC main circuit between the converter 11 and the inverter 15
with the power storage apparatus 21, and/or discharges the electric
power stored in the power storage apparatus 21 to this DC main
circuit. Alternatively, the charge/discharge control circuit 41 may
judge as to whether or not either the charge mode or the discharge
mode is proper by employing the voltage value V detected by the
input/output unit voltage detector 40. This charge/discharge
control circuit 41 executes such a judgement based on the voltage
value V by checking as to whether or not the voltage value V
detected by the input/output unit voltage detector 40 is higher
than a predetermined voltage value Vp. However, in the case that
the instruction issued from the charging/discharging instructing
means 39 is not made coincident with the judgment based on the
voltage value V detected by the input/output unit voltage detector
40, the instruction issued from the charging/discharging
instructing means 39 may be processed with a top priority.
[0089] It should be understood that the basic contents of the
charge/discharge modes are given as follows: In the charge mode,
the elevator is driven in the regenerative operation irrespective
of the electric energy Q; the voltage value V exceeds the voltage
value Vp; and the elevator is stopped when the electric energy Q is
equal to or smaller than the charging target value Qc. In the
discharge mode, the elevator is driven in the powering operation
irrespective of the electric energy Q; and the voltage value V
becomes lower than the voltage value Vp. In such a case that the
elevator is driven in the powering operation when the electric
energy Q becomes smaller than the charging target value Qc, the
charging/discharging operation may not be performed. Also, when the
electric energy Q is made coincident with the charging target value
Qc, if the elevator is stopped, then the charging/discharging
operation may not be performed.
[0090] As previously explained, while the charge mode is executed
with employment of the power storage apparatus 21, since the
elevator is operated by using the electric power charged into this
power storage apparatus 21, it is possible to suppress an increase
in peak electric power, as viewed from the commercial power supply.
Thus, power consumption can be suppressed.
FIFTH ELEVATOR CONTROL METHOD
[0091] Referring now to FIG. 4, a description will be made of an
elevator control method executed in the elevator control apparatus
according to this fifth embodiment mode. That is, FIG. 4 is a flow
chart describing the elevator control method performed in the
elevator control apparatus of the fifth embodiment mode.
[0092] At a first step (hereinafter abbreviated to s) 01 of the
flow chart shown in FIG. 4, the charging amount comparing means 36
judges as to whether or not the electric energy Q of the power
storage apparatus 21 calculated by the charging amount calculating
means 35 exceeds the charging target value Qc extracted by the
charging amount setting value extracting means 33. When this
electric energy Q does not exceed the charging target value Qc,
this control process is advanced to a S02, whereas when this
electric energy Q exceeds the charging target value Qc, the control
process is advanced to a S03.
[0093] At the S02, the charging/discharging instructing means 39
does not allow the execution of this discharge mode by the
charge/discharge control circuit 41. This may avoid the decrease in
the electric energy Q which occurs when the discharge operation is
carried out, although the electric energy Q stored in the power
storage apparatus 21 is equal to or smaller than a predetermined
charging target value Qc. As previously explained, since the
charging/discharging instructing means 39 does not allow the
execution of this discharge mode, namely instructs stopping of the
discharge operation, the electric energy Q can easily exceed the
charging target value Qc. Even when the electric energy Q does not
exceed the charging target value Qc, the power storage apparatus 21
may discharge the electric power in an exceptional case. When the
process operation defined at this S02 is ended, the control process
is advanced to a further S05.
[0094] At the S03, the charge/discharge control circuit 41 confirms
as to whether or not the elevator is stopped. While the elevator is
stopped, the control process is advanced to a S04. To the contrary,
when the elevator is not stopped, the control process is advanced
to a S05.
[0095] At the S04, a charging current which is charged into the
power storage apparatus 21 while the elevator is stopped is limited
to a current equal to or lower than a predetermined value I.sub.L.
While the elevator is stopped, the power storage apparatus 21 is
charged by using not the regenerative power generated when the
elevator is driven in the regenerative operation mode, but by using
the electric power of the commercial power supply 1. However, such
a condition that the commercial power supply 1 capable of
continuously supplying sufficiently large electric power is
employed although the elevator is stopped may consume a large
amount of the commercial power supply 1, and furthermore, may
disturb the reduction in the peak electric power from the
commercial power supply 1. The charging operation from the
commercial power supply 1 while the elevator is stopped may be
carried out only by replenishing the electric power lower than the
charging target value Qc for the power storage apparatus 21. Also,
since this charging operation need not be carried out in an urgent
condition, the charging current value is limited in order not to
unnecessarily increase the power consumption of this commercial
power supply 1. Therefore, while the elevator is stopped, the
current value of this charging current charged into the power
storage apparatus 21 is limited so as to suppress the power
consumption of the commercial power supply 1. Moreover, while the
peak electric power of the commercial power supply 1 is reduced,
the power storage apparatus 2 can be charged. When this process
operation of the S04 is ended, the control process is advanced to a
S10.
[0096] At the S05, the charge/discharge control circuit 41 judges
as to whether or not the voltage value V appearing on the bus line
between the converter 11 and the inverter 15 exceeds a
predetermined voltage value Vc. That is, when the voltage value V
is higher than the predetermined voltage value Vc, since the bus
line voltage is brought into such a high voltage condition due to
the regenerative power, the charge mode is set by which the power
storage apparatus 21 can be charged. Conversely, when the voltage
value V is lower than the predetermined voltage value Vc, since
this condition is such that the electric power required to drive
the elevator is shortage, the electric power is supplied from the
power storage apparatus 21 to the DC main circuit. It should be
understood that when the voltage value V is made coincident with
the predetermined voltage value Vc, it is assumed that neither the
charge mode nor the discharge mode is instructed, but the stop mode
is instructed. When the voltage value V exceeds the predetermined
voltage value Vc, the control process is advanced to a S06.
Conversely, when the voltage value V does not exceed the
predetermined voltage value Vc, the control process is advanced to
a S07.
[0097] At the S06, the charge mode is set. That is, an instruction
is issued in such a manner that the charge/discharge control
circuit 41 can be operated in the charge mode. When this process
operation is ended, the control process is advanced to a S10.
[0098] At the S07, the charge/discharge control circuit 41 judges
as to whether or not the discharge mode is allowed. This judgment
is made so as to prevent the following problem. That is, when the
power storage apparatus 21 is not yet charged up to the charging
target value Qc, the discharge mode is executed, so that the
electric energy Q stored in this power storage apparatus 21 is
further reduced. As a result, in this discharge mode, only when
this discharge mode is allowed, the power storage apparatus 21
discharges the stored electric power. When the discharge mode is
allowed, the control process is advanced to a S08, whereas when the
discharge mode is not allowed, the control process is advanced to a
S09.
[0099] At the S08, the discharge mode is set. In other words, such
an instruction is issued in such a way that the charge/discharge
control circuit 41 can be operated in the discharge mode. When this
process operation of the S08 is ended, the control process is
advanced to the S10.
[0100] At the S09, the stop mode is set. In other words, such an
instruction is issued in such a way that the charge/discharge
control circuit 41 is not operated in either the discharge mode or
the charge mode. When this process operation of the S09 is ended,
the control process is advanced to the S10.
[0101] At the S10, the charge/discharge control circuit 41 is
operated in the set operation mode. In other words, such an allow
is made that the charge/discharge control circuit 41 can be
operated in the set mode. When either the charging operation or the
discharging operation can be performed in the charge/discharge
control circuit 41, this charge/discharge control circuit 41 is
operated in the set operation mode.
[0102] It should also be noted that the charge/discharge control
circuit 41 monitors the voltage appearing in either the DC main
circuit or the power storage apparatus 21, and may check as to
whether or not either the charging operation or the discharging
operation can be carried out based upon the respective structural
elements.
[0103] No specific explanation is made of the control operation
with respect to the converter 11 in this fifth embodiment mode.
This is because this converter 11 may be formed in a controllable
form. That is, since this converter 11 is supposed to be formed by
a diode bridge, this converter 11 may be formed by using a
switching element such as a transistor.
[0104] As explained above, when the converter 11 is controllable,
the charging/discharging operations for the power storage apparatus
21 can be carried out by increasing/decreasing the voltage
appearing on the output side of the converter 11, namely the
voltage value V of the DC main circuit.
VARIOUS ADVANTAGES
[0105] While the various preferred embodiments of the present
invention have been described in detail, the below-mentioned
various advantages thereof can be achieved.
[0106] According to the elevator control apparatus of the present
invention, is comprised of: the converter for rectifying AC
electric power to be converted into DC electric power; the inverter
for inverting the DC electric power into AC electric power having
the variable voltage and the variable frequency; the motor driven
by the AC electric power having the variable voltage and the
variable frequency so as to operate the elevator; the power storage
apparatus for charging thereinto AC electric power; and
charge/discharge control means for controlling charging/discharging
operation with respect to the power storage apparatus based upon
the charging target value every time with respect to the power
storage apparatus. Since the electric power stored in the power
storage apparatus is utilized based upon the charging target value
every time, the power consumption of the commercial power supply
can be reduced.
[0107] Also, the charging target value owned by the elevator
control apparatus according to the present invention may indicate
such a charging amount by which the elevator can be operated in the
emergency case. Since the power storage apparatus is charged based
upon this charging target value, even when emergencies such as
power interruption and earthquake happen to occur, occurrences of
secondary disasters can be prevented. For example, passengers are
locked upon in elevators.
[0108] Furthermore, the power storage apparatus employed in the
elevator control apparatus, according to the present invention, is
charged by the commercial power supply when the elevator is
stopped. That is, this power storage apparatus can be charged while
using spare time during the elevator operation and also suppressing
such a phenomenon that the power consumption is instantaneously
increased. As a result, a total amount of electric power supplied
from the commercial power supply during the peak power-consumption
time period can be suppressed.
[0109] Also, in accordance with the elevator control apparatus of
the present invention, when the power storage apparatus is charged
by using the electric power supplied from the commercial power
supply, the current value of this commercial power supply is
limited. As a consequence, low-cost operation of this elevator can
be realized based upon the electric power rate system which is
directly proportional to the used maximum electric power.
* * * * *