Apparatus for controlling elevator

• US 20020053490A1
• Filed: 04/26/2001
• Published: 05/09/2002
• Est. Priority Date: 11/09/2000
• Status: Active Grant

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Banno, Hirokazu, Araki, Hiroshi, Tajima, Shinobu
• Granted Patent: US 6,471,013 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: Y02B 50/00 Energy efficient technologies in elevators, escalators and moving walkways, e.g. energy saving or recuperation technologies

Abstract

An apparatus for controlling an elevator which has a high energy-saving effect based on charging while using a low-capacity and low-priced secondary battery. The apparatus has a converter for converting an alternating current from an ac power supply into a dc power by rectifying the alternating current, an inverter for driving an electric motor by converting the dc power from the converter into variable-voltage variable-frequency ac power, the motor being driven for the operation of the elevator, and a power accumulator connected to a dc bus between the converter and the inverter. The power accumulator accumulates dc power from the dc bus during regenerative operation of the elevator, and supplies the accumulated dc power to the dc bus during power-drive operation of the elevator. The apparatus also has charge/discharge control circuit for controlling charging/discharging of the power accumulator from or to the direct current bus, and a measuring device for measuring at least one of the temperature, current and voltage of the power accumulator. The charge/discharge control circuit adjusts the maximum value of the current for charging/discharging of the power accumulator according to an output from the measuring device.

Claims

1. An apparatus for controlling an elevator, comprising:

a converter for converting an alternating current from an alternating current power supply into a direct current power by rectifying the alternating current;

an inverter for driving an electric motor by converting the direct current power from said converter into variable-voltage variable-frequency alternating current power, the electric motor being driven for the operation of an elevator;

a power accumulator connected to a direct current bus between said converter and said inverter, said power accumulator being capable of accumulating direct current power from the direct current bus during regenerative operation of the elevator, and also capable of supplying the accumulated direct current power to the direct current bus during power-drive operation of the elevator;

charge/discharge control means for controlling each of charging and discharging of said power accumulator from or to the direct current bus; and

measuring means for measuring at least one of temperature, current and voltage of said power accumulator,

wherein said charge/discharge control means adjusts the maximum value of the current for each of charging and discharging of said power accumulator according to an output from said measuring means.

2. An apparatus for controlling an elevator according to claim 1, wherein the output from said measuring means is a function of at least one of current, voltage and temperature of said power accumulator during charging and discharging.

3. An apparatus for controlling an elevator according to claim 1, wherein the state of charge stored in said power accumulator is grasped from the output from said measuring means before said power accumulator is overcharged or overdischarged to adjust charging and discharging.

4. An apparatus for controlling an elevator according to claim 1, wherein the charged amount of one of a fully-charged state and a completely-discharged state of said power accumulator is grasped from at least one of the outputs from said measuring means.

5. An apparatus for controlling an elevator according to claim 1, wherein said charge/discharge control means includes, as means for adjusting the maximum value of the current for each of charging and discharging, a current value limit circuit for limiting a charging/discharging current command value to a certain charging/discharging current limit value according to the output from said measuring means.

6. An apparatus for controlling an elevator according to claim 5, wherein said current value limit circuit multiplies the charging/discharging current command value by a constant such that the maximum value of the charging/discharging current to or from said power accumulator supposed from the elevator operation is limited to the charging/discharging current limit value.

7. An apparatus for controlling an elevator according to claim 5, wherein said current value limit circuit limits the charging/discharging current command value to the charging/discharging current limit value when the charging/discharging current command value exceeds the current limit value.

8. An apparatus for controlling an elevator according to claim 5, wherein said current value limit circuit sets the charging/discharging current limit value to a value obtained as the product of a constant and one of a battery specification value and a battery rated value of said power accumulator.