Elevator apparatus with rechargeable power supply and discharge control

• US 20020179376A1
• Filed: 08/01/2002
• Published: 12/05/2002
• Est. Priority Date: 02/28/2000
• Status: Active Grant

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Kobayashi, Kazuyuki, Araki, Hiroshi, Tominaga, Shinji, Suga, Ikuro, Tajima, Shinobu
• Granted Patent: US 6,522,099 B2
• Time in Patent Office: Days
• US Class Current: 187/290
• CPC Class Codes: B66B 1/30 effective on driving gear , e.g. acting on power electronics, on inverter or rectifier controlled motor
• CPC Class Codes: H02J 7/34 Parallel operation in networks using both storage and other dc sources, e.g. providing buffering H02J7/14 takes precedence
• CPC Class Codes: H02P 23/06 Controlling the motor in four quadrants
• CPC Class Codes: Y02B 50/00 Energy efficient technologies in elevators, escalators and moving walkways, e.g. energy saving or recuperation technologies

Abstract

An elevator control apparatus solves a major problem with a conventional elevator control apparatus in that a state of charge of a battery is not always maintained at 100% because of the need for securing an allowance for charging regenerative electric power, causing generation of an inert material in the battery with a resultant decrease in an apparent charging capacity of the battery and a shortened life of the battery. The elevator control apparatus in accordance with the invention includes a converter, an inverter, a controller for controlling a motor based on AC power of a variable voltage and a variable frequency supplied from the inverter so as to operate an elevator; a power storage unit for storing DC power; a charge/discharge control circuit that issues a drive signal such that an amount of discharge from the power storage unit increases within a range of power that can be discharged when an elevator is driven immediately following completion of uniform charging, and a charge/discharge circuit for carrying out discharge from the power storage unit in accordance with the drive signal. This arrangement permits quick discharging while effectively using discharge electric power until a state of charge is reached wherein regenerative electric power can be charged.

Claims

1. An elevator control apparatus comprising:

a converter for rectifying AC power 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 the variable voltage and the variable frequency so as to operate an elevator;

a power storage unit for storing the DC power;

a charge/discharge control circuit that issues a drive signal such that an amount of discharge from the power storage unit increases within a range of power that can be discharged when an elevator is driven immediately following completion of uniform charging; and

a charge/discharge circuit for carrying out discharge from the power storage unit in accordance with the drive signal.

2. An elevator control apparatus according to claim 1,

wherein the charge/discharge control circuit sets a discharge amount of the power storage unit to a preset maximum value until a preset reference value of a charge state is reached, immediately following the completion of the uniform charging.

3. An elevator control apparatus comprising:

a converter for rectifying AC power 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 the variable voltage and the variable frequency so as to operate an elevator;

a power storage unit for storing the DC power;

a charge/discharge control circuit that issues a drive signal for controlling charge current to a predetermined constant current value when charging the power storage unit with regenerative electric power if a charge state of the power storage unit indicates a predetermined value or more immediately following completion of uniform charging; and

a charge/discharge circuit for charging the power storage unit with the regenerative electric power in accordance with the drive signal.

4. An elevator control apparatus comprising:

a converter for rectifying AC power 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 the variable voltage and the variable frequency so as to operate an elevator;

a power storage unit for storing the DC power;

a charge/discharge control circuit that issues a drive signal for starting uniform charging of the power storage unit at a preset time when the elevator is least frequently used; and

a charge/discharge circuit for starting the uniform charging of the power storage unit in accordance with the drive signal.

5. An elevator control apparatus according to claim 4,

wherein the charge/discharge control circuit issues a drive signal for starting uniform charging of the power storage unit at a preset time in the nighttime.

6. An elevator control apparatus comprising:

a converter for rectifying AC power 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 the variable voltage and the variable frequency so as to operate an elevator;

a power storage unit for storing the DC power;

a charge/discharge control circuit that issues a drive signal for performing uniform charging of the power storage unit during a halt of the elevator based on information regarding an elevator operation supplied by the controller, measures a time of the uniform charging by a timer, issues a drive signal for interrupting the uniform charging and stopping the timer when the elevator is being started, totalizes an amount of discharge from the power storage unit up to that moment, and, when the elevator is stopped again, issues a drive signal for correcting a charging time corresponding to the totalized amount of discharge based on the uniform charging time measured by the timer before restarting the uniform charging, and also restarts measurement of uniform charging time by the timer; and

a charge/discharge circuit for starting or interrupting uniform charging of the power storage unit in accordance with the drive signals.

7. An elevator control apparatus comprising:

a converter for rectifying AC power 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 the variable voltage and the variable frequency so as to operate an elevator;

a power storage unit for storing the DC power;

a charge/discharge control circuit that issues a drive signal for starting uniform charging of the power storage unit when a preset two or more days have passed from a day when previous uniform charging was started; and

a charge/discharge circuit that starts uniform charging of the power storage unit in accordance with the drive signal.

8. An elevator control apparatus according to claim 7,

wherein the charge/discharge control circuit issues a drive signal for starting uniform charging of the power storage unit on a preset day of the week when the elevator is used less frequently.

9. An elevator control apparatus comprising:

a converter for rectifying AC power 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 the variable voltage and the variable frequency so as to operate an elevator;

a power storage unit for storing the DC power;

a charge/discharge circuit for charging the power storage unit and causing the power storage unit to discharge according to a drive signal; and

a charge/discharge control circuit that controls a charge state of the power storage unit and outputs a drive signal for charging the power storage unit or causing the power storage unit to discharge, and changes a set application range of the charge state of the power storage unit based on an open circuit voltage of the power storage unit immediately following completion of uniform charge.

10. An elevator control apparatus comprising:

a converter for rectifying AC power 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 the variable voltage and the variable frequency so as to operate an elevator;

a power storage unit for storing the DC power;

a charge/discharge circuit for charging the power storage unit and causing the power storage unit to discharge according to a drive signal; and

a charge/discharge control circuit that controls a charge state of the power storage unit and outputs a drive signal for charging the power storage unit or causing the power storage unit to discharge, and corrects the charge state immediately following completion of uniform charge of the power storage unit.

11. An elevator control apparatus according to claim 10,

wherein the charge/discharge control circuit sets the charge state of the power storage unit immediately following completion of uniform charging of the power storage unit to 100%.

12. An elevator control apparatus according to claim 10,

wherein the charge/discharge control circuit decides a value of a fully charged state of the power storage unit based on an open circuit voltage of the power storage unit immediately following completion of uniform charging of the power storage unit.

13. An elevator control apparatus comprising:

a converter for rectifying AC power 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 the variable voltage and the variable frequency so as to operate an elevator;

a power storage unit for storing the DC power;

a charge/discharge circuit for charging the power storage unit and causing the power storage unit to discharge according to a drive signal; and

a charge/discharge control circuit that controls a charge state of the power storage unit and outputs a drive signal for charging the power storage unit or causing the power storage unit to discharge, performs uniform charging of the power storage unit at constant current in a plurality of steps, and maintains the charge state of the power storage unit at 100%, if a charge state of the power storage unit exceeds 100%, until discharge from the power storage unit is carried out even when more than 100% charging is performed.

14. An elevator control apparatus comprising:

a converter for rectifying AC power 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 the variable voltage and the variable frequency so as to operate an elevator;

a power storage unit for storing the DC power;

a charge/discharge circuit for charging the power storage unit and causing the power storage unit to discharge according to a drive signal; and

a charge/discharge control circuit that controls a charge state of the power storage unit and outputs a drive signal for charging the power storage unit or causing the power storage unit to discharge, calculates a current value that is uniquely determined relative to a value obtained by detecting a charge current supplied to the power storage unit, a DC bus voltage output by the converter, and a voltage of the power storage unit, and a charge current command value so as to provide a command value, and PWM-controls the charge/discharge circuit thereby to control the charge current supplied to the power storage unit by using the command value.