U.S. patent application number 09/788447 was filed with the patent office on 2001-08-30 for controller of elevator.
Invention is credited to Araki, Hiroshi, Kobayashi, Kazuyuki, Suga, Ikuro, Tajima, Shinobu.
Application Number | 20010017240 09/788447 |
Document ID | / |
Family ID | 18573532 |
Filed Date | 2001-08-30 |
United States Patent
Application |
20010017240 |
Kind Code |
A1 |
Araki, Hiroshi ; et
al. |
August 30, 2001 |
Controller of elevator
Abstract
This invention provides a controller of an elevator in which a
space for mounting a power accumulating device can be saved and the
controller can be applied to the elevator having no machine room.
Therefore, the controller has power accumulating means arranged
between DC buses between a converter and an inverter, and
accumulating DC power from the DC buses at a regenerative operation
time of the elevator and supplying the DC power accumulated on the
DC buses at a power running operation time; and
charging-discharging control means for controlling charging and
discharging operations of the power accumulating means with respect
to the DC buses. The power accumulating means is constructed by a
secondary battery and a DC-DC converter for controlling charging
and discharging operations of the secondary battery, and the
secondary battery is constructed by connecting plural cells in
series to each other. The secondary battery is arranged at any one
of four corners within an ascending/descending path, a portion near
a rail, or a portion near a cable within the ascending/descending
path.
Inventors: |
Araki, Hiroshi; (Tokyo,
JP) ; Tajima, Shinobu; (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: |
18573532 |
Appl. No.: |
09/788447 |
Filed: |
February 21, 2001 |
Current U.S.
Class: |
187/290 |
Current CPC
Class: |
B66B 1/302 20130101;
Y02B 50/00 20130101 |
Class at
Publication: |
187/290 |
International
Class: |
B66B 001/06 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 28, 2000 |
JP |
2000-051945 |
Claims
What is claimed is:
1. A controller of an elevator comprising: a converter for
rectifying AC power from an AC power source and converting the AC
power to DC power; an inverter for converting the DC power to AC
power of a variable voltage and a variable frequency and driving an
electric motor and operating the elevator; power accumulating means
arranged between DC buses between said converter and said inverter,
and accumulating DC power from the DC buses at a regenerative
operation time of the elevator and supplying the DC power
accumulated on the DC buses at a power running operation time; and
charging-discharging control means for controlling charging and
discharging operations of said power accumulating means with
respect to said DC buses; the controller being characterized in
that said power accumulating means is constructed by a secondary
battery and a DC-DC converter for controlling charging and
discharging operations of the secondary battery, and said secondary
battery is constructed by connecting plural cells in series to each
other.
2. A controller of an elevator according to claim 1, wherein the
secondary battery of said power accumulating device is constructed
by connecting plural cells in series to each other in a bar shape
and arranging the cells in a vertical direction within an
ascending/descending path.
3. A controller of an elevator according to claim 1, wherein the
secondary battery of said power accumulating device is constructed
by plural set batteries such that terminal portions of the plural
cells are fixedly connected to each other and female screw
terminals are attached to both ends of each set battery as one set,
and the plural set batteries are connected to each other in one bar
shape by using a double-end stud and are stored into a cylindrical
case.
4. A controller of an elevator according to claim 1, wherein each
of the cells of said power accumulating device is arranged with the
side of a pressure safety valve facing upward.
5. A controller of an elevator according to claim 1, wherein said
power accumulating device is arranged in a clearance of an
ascending/descending path and a car.
6. A controller of an elevator according to claim 1, wherein said
power accumulating device is arranged at any one of four corners
within an ascending/descending path, a portion near a rail, or a
portion near a cable within the ascending/descending paths
7. A controller of an elevator according to claim 1, wherein a
cooler for forced air cooling is arranged at any one of above,
below, or both above and below of said power accumulating
device.
8. A controller of an elevator according to claim 1, wherein an air
cooling fan for flowing a wind in a vertical direction is attached
to said power accumulating device.
9. A controller of an elevator according to claim 7, wherein the
controller further comprises: a temperature measuring device for
measuring a temperature of said power accumulating device; and a
control device for operating said cooler when a detecting
temperature of said temperature measuring device is equal to or
greater than a predetermined value.
10. A controller of an elevator according to claim 9, wherein said
temperature measuring device measures the temperature of a side
face of a cell near a terminal end on an unarranging side of said
cooler, or the temperature of a side face of a cell near a center
when said cooler is arranged on each of both sides.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to a controller of an elevator of an
energy saving type to which a secondary battery such as a nickel
hydrogen battery, a nickel cadmium battery, a lithium ion battery,
etc. is applied.
[0003] 2. Description of the Related Art
[0004] FIG. 4 is a view showing the basic construction of a
controller for controlling the operation of an elevator by applying
a conventional secondary battery thereto.
[0005] In FIG. 4, reference numerals 1 and 2 respectively designate
a three-phase AC power source and a converter constructed by a
diode, etc. and converting AC power outputted from the three-phase
AC power source 1 to DC power. The DC power converted by the
converter 2 is supplied to a DC bus 3. The operation of an inverter
4 is controlled by a speed controller for controlling a speed
position of the elevator and described later. A direct current
supplied through the DC bus 3 is converted to an alternating
current of predetermined desirable variable voltage and variable
frequency and an AC motor 5 is driven so that a hoisting machine 6
of the elevator directly connected to the AC motor 5 is rotated.
Thus, a rope 7 wound around the hoisting machine 6 controls
elevating and lowering operations of a car 8 and a counterweight 9
connected to both ends of this rope 7 and passengers within the car
8 are moved to a predetermined stage floor.
[0006] Here, weights of the car 8 and the counterweight 9 are
designed such that these weights are approximately equal to each
other when passengers half a number limit ride in the car 8.
Namely, when the car 8 is elevated and lowered with no load, a
power running operation is performed at a lowering time of the car
8 and a regenerative operation is performed at a elevating time of
the car 8. Conversely, when the car 8 is lowered in the number
limit riding, the regenerative operation is performed at the
lowering time of the car 8 and the power running operation is
performed at the elevating time of the car 8.
[0007] An elevator control circuit 10 is constructed by a
microcomputer, etc., and manages and controls an entire operation
of the elevator. A power accumulating device 11 is arranged between
DC buses 3 and accumulates power at the regenerative operation time
of the elevator, and supplies the accumulated power to the inverter
4 together with the converter 2 at the power running operation
time. The power accumulating device 11 is constructed by a
secondary battery 12 and a DC-DC converter 13 for controlling
charging and discharging operations of this secondary battery
12.
[0008] Here, the DC-DC converter 13 has a voltage lowering type
chopper circuit and a voltage raising type chopper circuit. The
voltage lowering type chopper circuit is constructed by a reactor
13a, a gate 13b for charging current control connected in series to
this reactor 13a, and a diode 13c connected in reverse parallel to
a gate 13d for discharging current control described later. The
voltage raising type chopper circuit is constructed by the reactor
13a, the gate 13d for discharging current control connected in
series to this reactor 13a, and a diode 13e connected in reverse
parallel to the above gate 13b for charging current control
operations of the gate 13b for charging current control and the
gate 13d for discharging current control are controlled by a
charging-discharging control circuit 15 on the basis of a measuring
value from a charging-discharging state measuring device 14 for
measuring charging and discharging states of the power accumulating
device 11 and a measuring value from a voltage measuring instrument
18. A current measuring instrument arranged between the secondary
battery 12 and the DC-DC converter 13 is used as the
charging-discharging state measuring device 14 in this conventional
example.
[0009] A gate 16 for regenerative current control and a
regenerative resistor 17 are arranged between DC buses 3. The
voltage measuring instrument 18 measures the voltage of a DC bus 3.
A regenerative control circuit 19 is operated on the basis of
regenerative control commands from a speed control circuit
described later. The gate 16 for regenerative current control is
constructed such that an ON pulse width is controlled on the basis
of control of the regenerative control circuit 19 when a measuring
voltage provided by the voltage measuring instrument 17 is equal to
or greater than a predetermined value at the regenerative operation
time. Regenerated power is discharged in the regenerative resistor
17 and is converted to thermal energy and is consumed.
[0010] An encoder 20 is directly connected to the hoisting machine
6. The speed control circuit 21 controls a position and a speed of
the elevator by controlling an output voltage and an output
frequency of the inverter 4 on the basis of speed commands and a
speed feedback output from the encoder 22 based on commands from
the elevator control circuit 10.
[0011] An operation of the controller having the above construction
will next be explained.
[0012] At a power running operation time of the elevator, power is
supplied to the inverter 4 from both the three-phase AC power
source 1 and the power accumulating device 11. The power
accumulating device 11 is constructed by the secondary battery 12
and the DC-DC converter 13, and an operation of this power
accumulating device 11 is controlled by the charging-discharging
control circuit 15. In general, the number of secondary batteries
12 is reduced as much as possible and an output voltage of each
secondary battery 12 is lower than the voltage of the DC bus 3 so
as to make the controller compact and cheaply construct the
controller. The voltage of the DC bus 3 is basically controlled
near a voltage provided by rectifying a three-phase AC of the
three-phase AC power source 1. Accordingly, it is necessary to
lower the bus voltage of the DC bus 3 at a charging time of the
secondary battery 12 and raise the bus voltage of the DC bus 3 at a
discharging time of the secondary battery 12. Therefore, the DC-DC
converter 13 is adopted. Operations of the gate 13b for charging
current control and the gate 13d for discharging current control in
this DC-DC converter 13 are controlled by the charging-discharging
control circuit 15.
[0013] FIGS. 5 and 6 are flow charts showing controls of the
charging-discharging control circuit 15 at its discharging and
charging times.
[0014] The control of the charging-discharging control circuit 15
at the discharging time shown in FIG. 5 will first be
explained.
[0015] A current control minor loop, etc. are constructed in
voltage control of a control system and the control operation may
be more stably performed. However, for simplicity, the control of
the charging-discharging control circuit 15 is here explained by a
control system using the bus voltage.
[0016] First, the bus voltage of the DC bus 3 is measured by the
voltage measuring instrument 17 (step S11). The
charging-discharging control circuit 15 compares this measuring
voltage with a predetermined desirable voltage set value and judges
whether the measuring voltage exceeds the voltage set value or not
(step S12). If no measuring voltage exceeds the set value, the
charging-discharging control circuit 15 next judges whether the
measuring value of a discharging current of the secondary battery
12 provided by the charging-discharging state measuring device 14
exceeds a predetermined value or not (step S13).
[0017] When the measuring voltage exceeds the set value by these
judgments, or when the measuring value of the discharging current
of the secondary battery 12 exceeds the predetermined value even if
no measuring voltage exceeds the set value, an adjusting time DT is
subtracted from the present ON time to shorten an ON pulse width of
the gate 13d for discharging current control and a new gate ON time
is calculated (step S14).
[0018] In contrast to this, when it is judged in the above step S13
that no measuring value of the discharging current of the secondary
battery 12 provided by the measuring device 14 exceeds the
predetermined value, a new gate ON time is calculated by adding the
adjusting time DT to the present ON time so as to lengthen the ON
pulse width of the gate 13d for discharging current control (step
S15). Thus, ON control of the gate 13d for discharging current
control is performed on the basis of the calculated gate ON time,
and the calculated gate ON time is stored to a built-in memory as
the present ON time (step S16).
[0019] Thus, a more electric current flows from the secondary
battery 12 by lengthening the ON pulse width of the gate 13d for
discharging current control. As a result, supply power is increased
and the bus voltage of the DC bus 3 is increased by the power
supply. When the power running operation is considered, the
elevator requires the power supply and this power is supplied by
discharging from the above secondary battery 12 and power supply
from the three-phase AC power source 1. When the bus voltage is
controlled such that this bus voltage is higher than an output
voltage of the converter 2 supplied from the three-phase AC power
source 1, all power is supplied from the secondary battery 12.
However, the controller is designed such that all power is not
supplied from the secondary battery 12, but is supplied from the
secondary battery 12 and the three-phase AC power source 1 in a
suitable ratio so as to cheaply construct the power accumulating
device 11.
[0020] Namely, in FIG. 5, the measuring value of the discharging
current is compared with a supply allotment corresponding current
(predetermined value). If this measuring value exceeds the
predetermined value, the ON pulse width of the gate 13d for
discharging current control is lengthened and a supply amount is
further increased. In contrast to this, when no measuring value of
the discharging current exceeds the predetermined value, the ON
pulse width of the gate 13d for discharging current control is
shortened and the power supply is clipped. Thus, since power
supplied from the secondary battery 12 is clipped among power
required in the inverter 4, the bus voltage of the DC bus 3 is
reduced so that the power supply from the converter 2 is started.
These operations are performed for a very short time so that a
suitable bus voltage is actually obtained to supply required power
of the elevator. Thus, power can be supplied from the secondary
battery 12 and the three-phase AC power source 1 in a predetermined
desirable ratio.
[0021] The control of the charging-discharging control circuit 15
at the charging time shown in FIG. 6 will next be explained.
[0022] When there is power regeneration from the AC motor 5, the
bus voltage of the DC bus 3 is increased by this regenerated power.
When this voltage is higher than an output voltage of the converter
2, the power supply from the three-phase AC power source 1 is
stopped. When there is no power accumulating device 11 and this
stopping state is continued, the voltage of the DC bus 3 is
increased. Therefore, when a measuring voltage value of the voltage
measuring instrument 17 for detecting the bus voltage of the DC bus
3 reaches a certain predetermined voltage, the regenerative control
circuit 19 is operated and closes the gate 16 for regenerative
current control. Thus, power flows through the regenerative
resistor 17 and the regenerated power is consumed and the elevator
is decelerated by electromagnetic braking effects. However, when
there is the power accumulating device 11, this power is charged to
the power accumulating device 11 by the control of the
charging-discharging control circuit 15 with a voltage equal to or
smaller than a predetermined voltage.
[0023] Namely, as shown in FIG. 6, if the measuring value of the
bus voltage of the DC bus 3 provided by the voltage measuring
instrument 17 exceeds the predetermined voltage, the
charging-discharging control circuit 15 detects that it is a
regenerative state, and increases a charging current to the
secondary battery 12 by lengthening the ON pulse width of the gate
13b for charging current control (step S21.fwdarw.S22.fwdarw.S23).
When the regenerated power from the elevator is reduced in a short
time, the voltage of the DC bus 3 is also correspondingly reduced
and no measuring value of the voltage measuring instrument 17
exceeds the predetermined voltage. Accordingly, the ON pulse width
of the gate 13b for charging current control is shortly controlled
and charging power is also reduced and controlled (step
S21.fwdarw.S22.fwdarw.S24).
[0024] Thus, the bus voltage is controlled in a suitable range and
a charging operation is performed by monitoring the bus voltage of
the DC bus 3 and controlling the charging power. Further, energy is
saved by accumulating and re-utilizing power conventionally
consumed in the regenerated power.
[0025] In recent years, an elevator requiring no machine room,
e.g., an elevator having no machine room by arranging a winding
machine 6 and a control board within an ascending/descending path
is spread. In the elevator of an energy saving type shown in the
above conventional example, many power accumulating devices 11 are
required so that a space for mounting these power accumulating
devices is a problem.
SUMMARY OF THE INVENTION
[0026] To solve the above problems, an object of this invention is
to provide a controller of an elevator in which a space for
mounting power accumulating devices can be saved and the controller
can be applied to the elevator having no machine room.
[0027] To achieve this object, a controller of an elevator in this
invention comprises a converter for rectifying AC power from an AC
power source and converting the AC power to DC power; an inverter
for converting the DC power to AC power of a variable voltage and a
variable frequency and driving an electric motor and operating the
elevator; power accumulating means arranged between DC buses
between the converter and the inverter, and accumulating DC power
from the DC buses at a regenerative operation time of the elevator
and supplying the DC power accumulated on the DC buses at a power
running operation time; and charging-discharging control means for
controlling charging and discharging operations of the power
accumulating means with respect to the DC buses; the controller
being characterized in that the power accumulating means is
constructed by a secondary battery and a DC-DC converter for
controlling charging and discharging operations of the secondary
battery, and the secondary battery is constructed by connecting
plural cells in series to each other.
[0028] Further, the secondary battery of the power accumulating
device is constructed by connecting plural cells in series to each
other in a bar shape and arranging the cells in a vertical
direction within an ascending/descending path.
[0029] Further, the secondary battery of the power accumulating
device is constructed by plural set batteries such that terminal
portions of the plural cells are fixedly connected to each other
and female screw terminals are attached to both ends of each set
battery as one set, and the plural set batteries are connected to
each other in one bar shape by using a double-end stud and are
stored into a cylindrical case.
[0030] Further, each of the cells of the power accumulating device
is arranged with the side of a pressure safety valve facing
upward.
[0031] Further, the power accumulating device is arranged in a
clearance of an ascending/descending path and a car.
[0032] Further, the power accumulating device is arranged at any
one of four corners within an ascending/descending path, a portion
near a rail, or a portion near a cable within the
ascending/descending path.
[0033] Further, a cooler for forced air cooling is arranged at any
one of above, below, or both above and below of the power
accumulating device.
[0034] Further, an air cooling fan for flowing a wind in a vertical
direction is attached to the power accumulating device.
[0035] Further, the controller further comprises a temperature
measuring device for measuring a temperature of the power
accumulating device; and a control device for operating the cooler
when a detecting temperature of the temperature measuring device is
equal to or greater than a predetermined value.
[0036] Further, the temperature measuring device measures the
temperature of a side face of a cell near a terminal end on an
unarranging side of the cooler, or the temperature of a side face
of a cell near a center when the cooler is arranged on each of both
sides.
BRIEF DESCRIPTION OF THE DRAWINGS
[0037] FIG. 1 is an explanatory view showing the construction of a
secondary battery portion of a power accumulating device in this
invention.
[0038] FIG. 2 is an explanatory view showing the connecting
construction of a set battery 22 of a long bar shape in FIG. 1.
[0039] FIG. 3 is an explanatory view showing a mounting example of
a secondary battery 12 of the power accumulating device 11 within
an ascending/descending path of an elevator.
[0040] FIG. 4 is a block diagram showing the construction of a
controller of an elevator in a conventional example.
[0041] FIG. 5 is a flow chart showing the control of a
charging-discharging control circuit 15 shown in FIG. 4 at its
discharging time.
[0042] FIG. 6 is a flow chart showing the control of the
charging-discharging control circuit 15 shown in FIG. 4 at its
charging time.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0043] Similar to the conventional example, an elevator in this
invention has a construction shown in FIG. 4, and charging and
discharging operations of a secondary battery of a power
accumulating device are performed. However, in this invention, as
described later, a hoisting machine is arranged in a pit portion
within an ascending/descending path, and a control board having the
other control constructions is arranged in an inner wall of the
ascending/descending path, and no machine room is provided in a top
portion of the ascending/descending path.
[0044] In this invention, the secondary battery of the power
accumulating device is constructed by connecting plural cells in
series. Thus, a mounting space of the power accumulating device is
saved and this invention is applied to the elevator having no
machine room.
[0045] Concrete embodiments will next be described in detail.
[0046] Embodiment mode 1
[0047] FIG. 1 is a view showing a constructional example of a
secondary battery portion of a power accumulating device in an
embodiment mode 1 of this invention.
[0048] In FIG. 1, reference numeral 22 designates a set battery
used in the secondary battery 12 of the power accumulating device
11 shown in FIG. 4. As shown in FIG. 2 (refer (a)), this set
battery 22 has a structure in which plural cells 23 such as nickel
hydrogen batteries, etc. are combined and connected in series to
each other. Each of the cells 23 has a pressure safety valve 23a
for reducing an internal pressure of the battery at its abnormal
time.
[0049] The plural cells 23 are connected to each other by welding,
etc. so as to reduce contact resistance between terminals of the
cells. As shown in FIG. 2 (refer (b)), female screw terminals 25
are attached by welding, etc. to both ends of the set battery 22.
As shown in FIG. 2 (refer (b) and (c)), these plural set batteries
22 are connected in series to each other by a double-end stud
terminal 25 constructed by a male screw. Namely, as shown in FIG. 2
(refer (b)), predetermined plural set batteries 22 are connected in
series to each other by the double-end stud terminal 25 in
accordance with a required capacity or voltage so that one set
battery of a longer bar shape is constructed.
[0050] In FIG. 1, a cylindrical metallic case 26 is made of
aluminum, etc. The set battery 22 of a long bar shape is sealed
into this metallic case 26 in close contact with this metallic case
so as not to reduce heat conduction. A required number of cooling
fins 27 are attached to the metallic case 26 in accordance with
predetermined required cooling ability such that a wind flows in a
vertical direction. A cooling fan 28 is attached above or below the
set battery 22, or both above and below the set battery 22 in
accordance with necessity. Reference numeral 29 designates a wind
channel duct. In FIG. 1, the wind channel duct 29 is formed in a
rectangular parallelepiped shape, but may be also set to a
cylindrical duct in accordance with an arranging place. When no
forced air cooling is performed, the cooling fan 28 and the wind
channel duct 29 are not required.
[0051] A temperature detecting sensor 30 measures the temperature
of a side face of a cell near a terminal end on at least an
unarranging side of the cooling fan 28, or the temperature of a
side face of a cell near a center when the cooling fan 28 is
arranged on each of both sides. A cooling fan drive controller 31
operates a cooler if the temperature measured by the temperature
detecting sensor 30 is equal to or greater than a predetermined
value.
[0052] FIG. 3 is a view showing a mounting example of the secondary
battery 12 of the power accumulating device 11 having the above
construction within an ascending/descending path of the
elevator.
[0053] In FIG. 3, reference numerals 32, 33 and 34 respectively
designate a guide rail of a car 8, a balance weight 9, etc. of the
elevator shown in FIG. 4, an ascending/descending path, and an
electric wire within the ascending/descending path 33. A hoisting
machine 6 shown in FIG. 4 is arranged in a pit portion of the
ascending/descending path 33. A control board 36 having a control
construction shown in FIG. 4 is arranged in an inner wall of the
ascending/descending path 33, and no machine room is arranged in a
top portion of the ascending/descending path.
[0054] The set battery 22 used as the secondary battery 12 is
arranged in a vertical direction within the ascending/descending
path 33 in a state in which the part with pressure safety valve 23a
is arranged upward. The set battery 22 is arranged at each of four
corners of the ascending/descending path 33, or a portion near the
rail, or a portion near a cable arranged in the
ascending/descending path 33, in a clearance of the
ascending/descending path 33 and the car. This is because
attachment can be commonized and space is effectively utilized when
the set battery 22 is arranged at each of the four corners of the
ascending/descending path 33 which are dead spaces, or the guide
rail 32 arranged in the vertical direction within the
ascending/descending path 33, or a side of the electric wire
34.
[0055] Accordingly, the controller of the elevator has the
following effects as mentioned above.
[0056] Since the plural cells 23 are connected in series and are
constructed in a bar shape as the secondary battery 12 of the power
accumulating device 11, an arranging space is effectively arranged
in the vertical direction within the ascending/descending path 33
and is greatly saved in the case of an elevator of a type having no
machine room.
[0057] In the case of the cell 23 having the pressure safety valve
23a, the pressure safety valve 23a is arranged in an upward
direction so that no function of the safety valve is
obstructed.
[0058] Space is also effectively utilized when the set battery 22
is arranged at each of the four corners of the ascending/descending
path 33 which are dead spaces. Also, attachment can be commonized
and space is effectively utilized when the set battery 22 is
arranged in the guide rail 32 arranged in the vertical direction
within the ascending/descending path 33 and is arranged on a side
of the electric wire 34 within the ascending/descending path.
[0059] Further, cooling effects can be efficiently obtained in a
saved space by using the cooling fin 27 and the cooling fan 28 with
respect to the secondary battery having the possibility that
charging and discharging characteristics become worse and further
the battery is broken with respect to an excessive increase in
temperature.
[0060] In the case of air cooling using only the cooling fin 27,
the cooling fin 27 is arranged such that a wind flows in the
vertical direction of the ascending/descending path 33.
Accordingly, the cooling can be efficiently performed by the wind
in the vertical direction generated by running the elevator so that
cooling fan 28 is not required and further space can be saved.
[0061] The temperature sensor 30 is arranged in a supposing
position of a maximum temperature of the set battery 22 so that the
number of temperature sensors 30 can be minimized.
[0062] Further, energy can be saved by the temperature sensor 30
and the cooling fan drive controller 33 since cooling is performed
only when the temperature is equal to or higher than a
predetermined temperature, i.e., only at a necessary time.
[0063] As mentioned above, in accordance with this invention,
plural cells are connected in series and are constructed as the
secondary battery of the power accumulating device. Accordingly, a
mounting space of the power accumulating device can be saved and
this invention can be applied to an elevator having no machine
room.
* * * * *