Elevator control apparatus

• US 20010017235A1
• Filed: 01/30/2001
• Published: 08/30/2001
• Est. Priority Date: 02/28/2000
• Status: Active Grant

• Current Assignee: Mitsubushi Denki Kabushiki Kaisha
• Original Assignee: Mitsubushi Denki Kabushiki Kaisha
• Inventors: Kobayashi, Kazuyuki, Araki, Hiroshi, Suga, Ikuro, Tajima, Shinobu
• Granted Patent: US 6,439,347 B2
• Time in Patent Office: Days
• US Class Current: 187/290
• CPC Class Codes: B66B 1/285 with the use of a speed pattern generator
• CPC Class Codes: B66B 1/30 effective on driving gear , e.g. acting on power electronics, on inverter or rectifier controlled motor

Abstract

An elevator control apparatus solves a problem in that electric power produced in a regenerative mode of an elevator is thermally consumed by a regenerative resistor or the like rather than being effectively used. The elevator control apparatus in accordance with the present invention includes: 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 required power computing circuit for computing required power of the elevator based on a speed command of the controller; a charge/discharge control circuit for issuing a drive signal for conducting control by changing charge current, which is to be supplied to the power storage unit, based on regenerative electric power so as to charge the power storage unit with the regenerative electric power if required power of the elevator is negative, that is, if the regenerative electric power is available; and a charge/discharge circuit for charging the power storage unit with the regenerative electric power in accordance with the drive signal. Thus, regenerative electric power can be effectively used, contributing to energy saving.

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 required power computing circuit for computing required power of the elevator based on a speed command of the controller;

a charge/discharge control circuit which conducts control by changing charge current, which is to be supplied to the power storage unit, based on regenerative electric power, and issues a drive signal for charging the power storage unit with the regenerative electric power if required power of the elevator is negative, that is, if the regenerative electric power is available; and

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

2. 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 required power computing circuit for computing required power of the elevator based on a speed command of the controller;

a charge/discharge control circuit which carries out control such that a bus voltage between the converter and the inverter stays constant at a preset voltage that is not less than a voltage obtained by rectifying the AC power, and issues a drive signal for charging the power storage unit with the regenerative electric power if required power of the elevator is negative, that is, if the regenerative electric power is available; and

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

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 required power computing circuit for computing required power of the elevator based on a speed command of the controller and issuing a regenerative operation signal if the required power is negative;

a charge/discharge control circuit that starts charge control of regenerative electric power and issues a drive signal for charging the power storage unit with the regenerative electric power upon receipt of the regenerative operation signal; and

a charge/discharge circuit for starting 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 stops charge control of regenerative electric power and issues a drive signal for stopping charging the power storage unit with the regenerative electric power upon receipt of an elevator stop signal from the controller; and

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

5. 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 starts charge control of regenerative electric power and issues a drive signal for charging the power storage unit with the regenerative electric power when a bus voltage between the converter and the inverter reaches a preset predetermined voltage that is higher than a voltage obtained by rectifying the AC power; and

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

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 carries out control such that a bus voltage between the converter and the inverter stays constant at a preset voltage that is not less than a voltage obtained by rectifying the AC power, and stops the charge control of regenerative electric power and issues a drive signal for stopping charging the power storage unit with the regenerative electric power when charge current is controlled until it reaches zero; and

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

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 controls a charge current supplied to the power storage unit at a constant preset predetermined current value and issues a drive signal for charging the power storage unit with the regenerative electric power at the constant current; and

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

8. 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 stops charge control of regenerative electric power and issues a drive signal for stopping charging the power storage unit with the regenerative electric power when a bus voltage between the converter and the inverter reaches a preset predetermined voltage that is higher than a voltage obtained by rectifying the AC power; and

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

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 control circuit that controls charge current supplied to the power storage unit at a plurality of preset predetermined constant current values in steps based on the bus voltage between the converter and the inverter, and issues a drive signal for charging the power storage unit with regenerative electric power at constant current; and

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

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 control circuit which carries out control such that a bus voltage between the converter and the inverter stays constant at a preset predetermined voltage and that, when charge current supplied to the power storage unit reaches a preset predetermined upper limit value, the charge current stays at the upper limit value, and issues a drive signal for charging the power storage device with regenerative electric power; and

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

11. An elevator control apparatus according to claim 10, wherein

when the charge current supplied to the power storage unit reaches the predetermined upper limited value, and if the bus voltage exceeds a preset second predetermined voltage while charging the power storage unit at the upper limit value is being continued, then the charge/discharge control circuit causes a part of the regenerative electric power to be thermally consumed by a resistor.

12. 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 which carries out control such that a bus voltage between the converter and the inverter stays constant at a preset predetermined voltage, issues a first drive signal for charging the power storage unit with the regenerative electric power control, and stops charge control of the regenerative electric power and issues a second drive signal for stopping charging the power storage unit with the regenerative electric power when a voltage of the power storage unit reaches a preset predetermined upper limit value; and

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

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 control circuit which carries out control such that a bus voltage between the converter and the inverter stays constant at a preset predetermined voltage, issues a drive signal for charging the power storage unit with regenerative electric power, and carries out control such that the charge current supplied to the power storage unit reaches a predetermined upper limit value and issues a drive signal for charging the power storage unit with regenerative electric power when a voltage of the power storage unit reaches a preset predetermined voltage; and

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

14. An elevator control apparatus according to

claim 13

, wherein

when the voltage of the power storage unit reaches the preset predetermined voltage, and if the bus voltage exceeds a preset second predetermined voltage while charging the power storage unit at the upper limit value is being continued, then the charge/discharge control circuit causes a part of the regenerative electric power to be thermally consumed by a resistor.