Controller of elevator

• US 20010017242A1
• Filed: 02/20/2001
• Published: 08/30/2001
• Est. Priority Date: 02/28/2000
• Status: Active Grant

• Current Assignee: Korea Electric Power Corporation (Government of South Korea), Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Korea Electric Power Corporation (Government of South Korea), Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Kobayashi, Kazuyuki, Araki, Hiroshi, Suga, Ikuro, Tajima, Shinobu
• Granted Patent: US 6,435,312 B2
• Time in Patent Office: Days
• US Class Current: 187/296
• 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

This invention provides a controller of an elevator capable of performing smooth speed control by using a cheap power accumulating device of a low capacity even at a power failure time. Therefore, the controller has a converter 2, an inverter 4, a power accumulating device 11 arranged between DC buses 3, a charging-discharging control circuit 15 for controlling charging and discharging operations of the power accumulating device, a power failure detector 22, a current measuring instrument 23 and a voltage measuring instrument 24 for respectively detecting an output current and an output voltage of the inverter, a car load measuring instrument 25, an encoder 20, and a speed control circuit 21A for controlling an operation of the inverter, which has a table set with required power according to a speed and a car load, and calculates the required power from the table on the basis of a car load measuring value and a detecting speed at a power failure detecting time, and also calculates speed commands for controlling the speed of the elevator within a range of discharging ability power of the power accumulating device on the basis of comparison of the output power of the inverter, the required power and the discharging ability power.

Claims

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 from said converter to AC power of a variable voltage and a variable frequency and driving an electric motor and operating the elevator;

a power accumulating device 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 accumulated DC power at a power running operation time to the DC buses;

a charging-discharging control device for controlling charging and discharging operations of said power accumulating device with respect to said DC buses;

power failure detecting means for detecting a power failure;

current detecting means for detecting an output current of said inverter;

voltage detecting means for detecting an output voltage of said inverter;

car load measuring means arranged in a car of said elevator and measuring a car load;

speed detecting means for detecting an operating speed of said elevator; and

speed control means for controlling an operation of said inverter to perform speed control based on speed commands and a detecting value provided by said speed detecting means of the elevator;

the controller being characterized in that said speed control means has a table set with required power in accordance with the speed and the car load; and

output power of the inverter is calculated on the basis of a detected current value of said current detecting means and a detected voltage value of said voltage detecting means at a time of power failure detection using said power failure detecting means; and

the required power is calculated from said table on the basis of a car load measuring value measured by said car load measuring means and a detecting speed detected by said speed detecting means; and

the speed commands for performing the speed control are calculated within a range of discharging ability power on the basis of comparison of the calculated output power of the inverter, the calculated required power and the discharging ability power of said power accumulating device.

2. A controller of an elevator according to

claim 1

, wherein

a fixed value is set as the discharging ability power of said power accumulating device in said speed control means.

3. A controller of an elevator according to

claim 1

, wherein

the controller further comprises charging-discharging state measuring means for measuring at least one of a temperature, charging and discharging currents and charging and discharging voltages of said power accumulating device, and

said speed control means has a table set with a limited discharging current with respect to the discharging current and the discharging voltage, and the limited discharging current is calculated from said table on the basis of measuring values of the discharging current and the discharging voltage from said charging-discharging state measuring means, and the discharging ability power of said power accumulating device is calculated from the calculated limited discharging current and the measuring value of the discharging voltage.

4. A controller of an elevator according to

claim 3

, wherein

said speed control means has a table set with the limited discharging current with respect to the temperature, and the limited discharging current is calculated from said table on the basis of a measuring value of the temperature from said charging-discharging state measuring means, and the discharging ability power of said power accumulating device is calculated from the calculated limited discharging current and the measuring value of the discharging voltage.

5. A controller of an elevator according to

claim 3

, where in

said speed control means has a table set with the limited discharging current with respect to a charging degree as a value obtained by normalizing and accumulating a product of a charging-discharging current and a charging-discharging voltage by a capacity with a full charging state of said power accumulating device as a reference, and the limited discharging current is calculated from said table on the basis of the charging degree obtained on the basis of the measuring values of the discharging current and the discharging voltage from said charging-discharging state measuring means, and the discharging ability power of said power accumulating device is calculated from the calculated limited discharging current and the measuring value of the discharging voltage.

6. A controller of an elevator according to

claim 1

, wherein

said speed control means has a table set with a speed pattern in accordance with a load state, and the speed pattern is calculated from said table on the basis of a car load measuring value measured by said car load measuring means, and the speed commands according to the calculated speed pattern are generated.

7. A controller of an elevator according to

claim 1

, wherein

said power failure detecting means detects the power failure of said AC power source.

8. A controller of an elevator according to

claim 1

, wherein

said power failure detecting means detects the power failure on the basis of a detecting voltage of said DC buses.

9. A controller of an elevator according to

claim 1

, wherein

said speed control means continues acceleration if the elevator is accelerated when the discharging ability power is larger than the output power of the inverter.