Elevator – industrial lift truck – or stationary lift for vehicle – Having specific load support drive-means or its control – Includes control for power source of drive-means
Reexamination Certificate
2001-01-31
2002-09-24
Salata, Jonathan (Department: 2837)
Elevator, industrial lift truck, or stationary lift for vehicle
Having specific load support drive-means or its control
Includes control for power source of drive-means
C187S296000, C320S150000
Reexamination Certificate
active
06454053
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an elevator control apparatus that utilizes a power storage unit and, more particularly, to an elevator control apparatus adapted to control the temperature of the power storage unit.
2. Description of the Related Art
A conventional elevator control apparatus will be described with reference to an accompanying drawing.
FIG. 20
shows a construction of a conventional elevator control apparatus disclosed in, for example, Japanese Unexamined Patent Application Publication No. 61-267675.
The controlling apparatus shown in
FIG. 20
includes a commercial three-phase AC power source
1
, a converter
2
composed of diodes or the like, a capacitor
3
, an inverter
4
, a motor
5
, such as an induction motor, a hoisting machine
6
, an elevator car
7
, a counterweight
8
, and a rope
9
. The controlling apparatus further includes a power storage unit
10
composed of a battery, a charging and discharging (hereinafter referred to as “charge/discharge) circuit
11
composed of a DC/DC converter or the like for performing power conversion in both directions between two different DC voltages of a battery voltage and an inverter input voltage, a charge/discharge control circuit
12
for controlling the charge/discharge circuit
11
as to the direction of power conversion and battery currents, a voltage detector
13
, a voltage detector
14
for the power source, a battery current detector
15
, and a battery charge amount detector
16
.
An operation of the foregoing conventional elevator control apparatus will now be described with reference to the accompanying drawing.
If the AC power source
1
incurs a power failure, power is supplied to an input section of the inverter
4
from the power storage unit
10
through the charge/discharge circuit
11
. Thus, the motor
5
is driven by the inverter
4
to land an elevator.
In normal operation, if an inverter input voltage drops while the elevator is accelerating, power is supplied to the input section of the inverter
4
from the power storage unit
10
through the charge/discharge circuit
11
to restrain a voltage-drop at the input section of the inverter
4
.
Conversely, if the inverter input voltage rises due to regenerative electric power from the motor
5
while the elevator is being braked, power is supplied from the input section of the inverter
4
to the power storage unit
10
through the charge/discharge circuit
11
so as to charge the power storage unit
10
. When the charge amount of the power storage unit
10
becomes low, power is also supplied to the power storage unit
10
from the input section of the inverter
4
through the charge/discharge circuit
11
so as to charge the power storage unit
10
.
The conventional elevator control apparatus described above employs a battery for the power storage unit. Charge and discharge characteristics of the battery vary depending on temperature. There has been a problem in that charging all regenerative electric power of the elevator causes a sudden rise in the temperature of the battery especially at a low temperature, and a gas is generated in the battery, leading to significant deterioration of the battery.
SUMMARY OF THE INVENTION
Accordingly, the present invention has been made with a view toward solving the problem mentioned above, and it is an object of the present invention to provide an elevator control apparatus that is capable of measuring an atmospheric temperature and a temperature of a battery to control charging and discharging so as to restrain deterioration of the battery, and also capable of conducting control of economical charging and discharging of the, battery thereby to minimize waste of power.
To this end, according to one aspect of the present invention, there is provided an elevator control apparatus including: a converter for rectifying AC power to convert it into DC power; an inverter for converting the DC power into AC power of a variable voltage and a variable frequency; a controller for controlling a motor base on the AC power of a variable voltage and a variable frequency so as to operate an elevator; a power storage unit for storing the DC power; temperature detecting means for detecting a temperature of the power storage unit; a charge/discharge control circuit for controlling a charge/discharge electric energy based on the detected temperature and issuing a drive signal; and a charge/discharge circuit for charging and discharging the power storage unit based on the drive signal.
According to another aspect of the present invention, there is provided an elevator control apparatus including: a converter for rectifying AC power to convert it into DC power; an inverter for converting the DC power into AC power of a variable voltage and a variable frequency; a controller for controlling a motor based on the AC power of a variable voltage and a variable frequency so as to operate an elevator; a power storage unit for storing the DC power; temperature detecting means for detecting an environmental temperature; a charge/discharge control circuit for controlling a charge/discharge electric energy based on the detected temperature and issuing a drive signal; and a charge/discharge circuit for charging and discharging the power storage unit based on the drive signal.
In a preferred form of the present invention, the charge/discharge control circuit issues a drive signal so that charging is carried out within a permissible range of a charge state of the power storage unit if a detected temperature of the power storage unit is lower than a preset predetermined temperature.
In another preferred form of the present invention, the charge/discharge control circuit changes a setting range of the charge state of the power storage unit based on the detected temperature.
In yet another preferred form of the present invention, the charge/discharge control circuit changes an upper limit value of the charge state of the power storage unit based on a mean temperature of the temperatures detected during a preset predetermined period of time.
In still another preferred form of the present invention, the charge/discharge control circuit changes the upper limit value of the charge state of the power storage unit based on a lowest temperature of the temperatures detected during a preset predetermined period of time.
In a further preferred form of the present invention, the charge/discharge control circuit carries out control so that an input voltage of the inverter is set at a constant voltage of a preset predetermined voltage, carries out control so that, when charge current to the power storage unit reaches a preset predetermined upper limit value based on the detected temperature, the charge current does not exceed the upper limit value, and issues a drive signal for charging the power storage unit with regenerative electric power.
In another preferred form of the present invention, the charge/discharge control circuit carries out control to charge the power storage unit with regenerative electric power so that an input voltage of the inverter is set at a constant voltage of a preset predetermined voltage, and issues a drive signal for stopping charging the power storage unit with regenerative electric power when a voltage of the power storage unit reaches a preset predetermined upper limit value based on the detected temperature.
In yet another preferred form of the present invention, the charge/discharge control circuit carries out control so that charge current supplied to the power storage unit is set at a constant current of a preset predetermined current value, and issues a drive signal for charging the power storage unit with the regenerative electric power while conducting control to set the charge current supplied to the power storage unit at a constant current restricted to be lower than the predetermined current value if the detected temperature is not more than a first preset predetermined temperature or not less than a second preset predetermined temperature that is highe
Araki Hiroshi
Kobayashi Kazuyuki
Suga Ikuro
Tajima Shinobu
Tominaga Shinji
Leydig , Voit & Mayer, Ltd.
Mitsubishi Denki & Kabushiki Kaisha
Salata Jonathan
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