Motor driving apparatus

• US 7,227,323 B2
• Filed: 06/03/2004
• Issued: 06/05/2007
• Est. Priority Date: 06/06/2003
• Status: Active Grant

• Current Assignee: Fanuc Ltd (Fanuc Corporation)
• Original Assignee: Fanuc Ltd (Fanuc Corporation)
• Inventors: Yamada, Yuuichi, Hanyu, Shigeki, Yaeshima, Mamoru
• Primary Examiner(s): IP, SHIK LUEN PAUL
• Application Number:
  US10/859,237
• Publication Number:
  US 20040245952A1
• Time in Patent Office: 1,097 Days
• Field of Search: None
• US Class Current: 318/376
• CPC Class Codes: H02M 5/458 using semiconductor devices only
• CPC Class Codes: H02M 5/4585 having a rectifier with controlled elements
• CPC Class Codes: H02P 3/14 by regenerative braking
• CPC Class Codes: H02P 3/18 for stopping or slowing an ac motor

Abstract

A motor driving apparatus applicable to various types of motor driving apparatuses and having a power storage section for storing a regenerative current and supplying power to an inverter section at the time of acceleration. The motor driving apparatus further comprises a converter section, a DC link, and an inverter section, thereby driving a motor. Connected to the DC link is the power storage section including a capacitor, a charging circuit, a discharging circuit and a diode. The regenerative current produced at the motor deceleration is stored in the capacitor through the diode. The power stored in the capacitor is outputted to the DC link by turning a switching element of the discharging circuit ON at the motor acceleration. Furthermore, the charging circuit has a boost switching regulator circuit for charging the capacitor to the given upper limit voltage equal to or larger than voltage of the DC link and a current limitation circuit for limiting a charging current to the given upper limit. The upper limit of the charging current can be changed according to the type of the motor driving apparatus.

Claims

1. A motor driving apparatus for driving an AC motor using regenerative electric power as well as electric power from an AC power source, comprising:

a converter section rectifying and converting an alternating current from the AC power source into a direct current;

an inverter section connected to the AC motor and converting the converted direct current into an alternating current to drive the AC motor;

a DC link connecting said converter section and said inverter section;

a driving controller controlling an operation of said inverter section in accordance with control signals from a host controller;

a power storage section connected to said DC link, storing regenerative electric power in a decelerating drive of the AC motor and discharging the stored electric power in an accelerating drive of the AC motor, said power storage section having an interface with the host controller or said driving controller so that upper limits of charging current/voltage are changeable in accordance with data inputted through said interface from the host controller or the driving controller; and

a memory storing specifications of the motor driving apparatus,

wherein upper limits of charging current/voltage of said power storage section are set in accordance with the specifications read from said memory and inputted through the interface.

2. A motor driving apparatus according to claim 1, wherein the host controller reads the specifications from said memory and inputs the specifications to said power storage section through the interface so that the upper limit of the charging current of said power storage section is set in accordance with the inputted specifications.

3. A motor driving apparatus according to claim 1, wherein said driving controller reads the specifications from said memory unit and inputs the specifications to said power storage section through the interface so that the upper limit of the charging current of said power storage section is set in accordance with the inputted specifications.

4. A motor driving apparatus according to claim 1, wherein said power storage section comprises a capacitor, a charging circuit charging said capacitor by voltage of the DC link, a diode charging said capacitor with the regenerative electric power in the decelerating drive of the AC motor and a discharging circuit discharging the electric power stored in said capacitor in the accelerating drive of the AC motor.

5. A motor driving apparatus according to claim 4, wherein said charging circuit includes a boost switching regulator raising the voltage of the DC link and charging said capacitor to the upper limit of the charging voltage, a current limiting circuit limiting the charging current to the upper limit thereof, and charging current/voltage adjusting means for adjusting the upper limit of the charging voltage and the upper limit of the charging current to said boost switching regulator and said current limiting circuit, respectively, in accordance with the inputted data of specifications.

6. A method for driving an AC motor using regenerative electric power as well as electric power from an AC power source, comprising:

rectifying and converting an alternating current from the AC power source into a direct current;

converting the converted direct current into an alternating current to drive the AC motor;

driving the AC motor using the alternating current converted from direct current; and

charging a capacitor of a power storage section with regenerative electric power in the decelerating drive of the AC motor and discharging the electric power stored in the capacitor in the accelerating drive of the AC motor;

wherein regenerative electric power is stored in the power storage section in which upper limits of charging current/voltage are changeable in accordance with data inputted by either a host controller or a driving controller.

7. A method for driving a motor with a motor driving apparatus, comprising:

rectifying and converting an alternating current from the AC power source into a direct current;

converting the converted direct current into an alternating current to drive the AC motor;

driving the motor using the alternating current converted from direct current; and

charging a capacitor of a power storage section with regenerative electric power in the decelerating drive of the AC motor and discharging the electric power stored in the capacitor in the accelerating drive of the AC motor;

wherein regenerative electric power is stored in the power storage section and a charging current is controlled at a value equal to or less than a current value acceptable in a converter section of the motor driving apparatus, based on transmitted specifications of the motor driving apparatus.