Controller of elevator

• US 20010017239A1
• 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 6,422,351 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
• 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

Abstract

This invention provides a controller of an elevator capable of performing stable speed control by using a cheap power accumulating device of a low capacity even at a discharging control 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. The speed control circuit 21A calculates output power of the inverter, and calculates discharging ability power of the power accumulating device on the basis of a measuring value of charging and discharging states. The speed control circuit 21A also calculates a limit power maximum value given by a sum of the discharging ability power and limit power of an AC power source, and changes speed commands on the basis of comparison of the output power of the inverter and the limit power maximum value.

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 outputted 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 to the DC buses at a power running operation time;

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

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;

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

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

speed detecting means for detecting a speed of said elevator; and

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

the controller being characterized in that said speed control means calculates output power of the inverter on the basis of a detected current value of said current detecting means and a detected voltage value of said voltage detecting means, and calculates discharging ability power of said power accumulating device on the basis of a measuring value of said charging-discharging state measuring means, and calculates a limited power maximum value given by a sum of the discharging ability power and limited power of said AC power source, and changes speed commands on the basis of comparison of the output power of said inverter and said limited power maximum value.

2. A controller of an elevator according to

claim 1

, wherein

said speed control means has a table set with a limited discharging current with respect to a discharging current and a discharging voltage, and calculates the limited discharging current 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 calculates the discharging ability power of said power accumulating device from the calculated limited discharging current and the measuring value of the discharging voltage.

3. A controller of an elevator according to

claim 1

, wherein

said speed control means has a table set with a 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 100%, and the limited discharging current is calculated from said table on the basis of the charging degree obtained 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 plural tables according to the temperature of said power accumulating device, and selects a table according to a temperature measuring value provided by said charging-discharging state measuring means.

5. A controller of an elevator according to

claim 1

, wherein

said speed control means has a table setting a speed pattern according to a load state, and calculates the speed pattern from said table on the basis of a car load measuring value measured by car load measuring means and generates speed commands according to the calculated speed pattern when it is judged on the basis of a measuring value provided by said charging-discharging state measuring means that said power accumulating device is broken.

6. A controller of an elevator according to

claim 1

, wherein

said speed control means has a table set with a maximum speed command value with respect to a car load and the discharging ability power of said power accumulating device, and calculates the discharging ability power of said power accumulating device on the basis of a measuring value of said charging-discharging state measuring means, and calculates maximum speed commands from said table on the basis of a car load measuring value measured by car load measuring means and the calculated discharging ability power, and changes speed commands on the basis of comparison of the speed commands and the maximum speed commands.

7. A controller of an elevator according to

claim 5

, wherein

said speed control means has plural speed pattern tables corresponding to the car load and the discharging ability power of said power accumulating device, and calculates the discharging ability power of said power accumulating device on the basis of the measuring value of said charging-discharging state measuring means, and selects said tables on the basis of the car load measuring value measured by said car load measuring means, and performs speed control according to a selected speed pattern.