Motor driving apparatus

• US 20040245952A1
• Filed: 06/03/2004
• Published: 12/09/2004
• Est. Priority Date: 06/06/2003
• Status: Active Grant

• Current Assignee: Fanuc Ltd (Fanuc Corporation)
• Original Assignee: Fanuc Ltd (Fanuc Corporation)
• Inventors: Yamada, Yuuichi, Yaeshima, Mamoru, Hanyu, Shigeki
• Granted Patent: US 7,227,323 B2
• Time in Patent Office: Days
• US Class Current: 318/377
• 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 a regenerative electric power as well as an electric power from an AC power source, comprising:

a converter section for 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 for connecting said converter section and said inverter section;

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

a power storage section connected to said DC link, for 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.

2. A motor driving apparatus according to claim 1, further comprising a memory storing specifications of the motor driving apparatus, wherein the specifications read from said memory by the host controller are inputted 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 data of specifications.

3. A motor driving apparatus according to claim 1, further comprising the memory storing specifications of the motor driving apparatus, wherein said driving controller reads the specifications from said memory and transmits 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 for charging said capacitor by voltage of the DC link, a diode for charging said capacitor with the regenerative electric power in the decelerating drive of the AC motor and a discharging circuit for 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 for raising the voltage of the DC link and charging said capacitor to the upper limit of the charging voltage, a current limiting circuit for 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.