Fanuc Corporation

Mamoru Yaeshima

Yuuichi Yamada

Yasusuke Iwashita

Masatomo Shirouzu

Shinichi Horikoshi

Shinichi Kono

Naoto Ota

Koujirou Sakai

Shigeki Hanyu

Shunsuke Matsubara

Takashi Harada

Hiroyasu Sato

Masami Kimijima

A motor controller capable of effectively utilizing electrical energy accumulated in a capacitor and achieving a reduction in capacitance of the capacitor. The motor controller includes a converter that receives an input AC voltage and performs AC-to-DC power conversion thereon, an inverter that receives DC power and performs DC-to-AC conversion thereon, and a capacitor and a charging/discharging control circuit connected in parallel with a DC link between the converter and the inverter. Electrical energy is supplied from the capacitor to the DC link via the charging/discharging control circuit. The charging/discharging control circuit has a circuit for discharging electrical energy accumulated in the capacitor and for stepping up a voltage of the capacitor when discharging the electrical energy.

Motor controller

A motor driving apparatus comprises a charge/discharge control circuit for controlling charge to or discharge from a capacitor connected in parallel in a link section between a converter and an inverter, and a current control means for controlling discharge current from the charge/discharge control circuit. The current control means controls discharge current from the charge/discharge control circuit based on input current to the inverter or output current from the converter so that output current from the converter is equal to a prescribed value.

Motor driving apparatus

A motor driver capable of detecting the insulation deterioration of a motor easily and inexpensively is disclosed. The voltage supplied from an AC power supply () is rectified by a first rectifying circuit (Dto D) and smoothed by a capacitor (C) in a power supply unit (). The output voltage of the power supply unit () is converted into an AC voltage of a frequency and a motor (M) is driven by a motor drive amplifier (). Elements (RCRC) are connected between at least one of the positive electrode () and the negative electrode () of the output line () of the power supply unit () and the ground (GG). An insulation deterioration circuit () detects at least one of the voltage between the elements and the current flowing through the elements.

Motor driver

The drive of the motor is stopped, the electromagnetic switch contacts are switched OFF, and thereafter the first and second contact points are closed to form a closed circuit of the smoothing capacitor, second contact point, first and second resistors, motor coil, ground, ground, first contact point, and smoothing capacitor. Charging voltage of the smoothing capacitor is applied to the closed circuit. If an insulation resistance of the motor deteriorates, a current flowing through the closed circuit is increased. The increase of the current is detected by means of the potential difference across the first resistor Rin the closed circuit, to detect insulation resistance deterioration of the motor.

Insulation resistance deterioration detection method and insulation resistance deterioration detection device for motor, and motor driver

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.

A first and a second motor drive amplifiers connected to a motor drive power supply include a first and a second memories which store specifications of the amplifiers, respectively. A memory provided in a power supply unit stores an overcurrent detection value for detecting an overcurrent according to the specifications of the respective motor drive amplifiers. A microcontroller reads the specifications from the first and second memories, and integrates overcurrent detection values corresponding to the respective specifications. If a current sensor detects that a current exceeding a reference value calculated based on a set integrated value, the current sensor outputs an overcurrent detection signal.

Motor drive system

The present invention is directed to the provision of a servomotor driving apparatus that feeds energy stored in a power storage part connected with a DC link that connects a rectifier circuit with an inverter circuit so that the energy stored in the power storage part can be reduced. A motor driving apparatus () includes: a step-up type DC/DC converter circuit () for boosting voltage appearing at an output of the power storage part (C) connected with a DC link; and a DC/AC conversion circuit () for converting the boosted DC electric power into AC electric power and feeding it to an electric power source.

While the motor drive amplifier is not operating, electromagnetic switch contacts are held closed for a predetermined period of time, three-phase power is rectified by a rectifier circuit and a smoothing capacitor is charged. Then, the smoothing capacitor is discharged through a discharging resistor and, when a predetermined voltage is reached, a contact is closed, with the result that a closed circuit is formed by the smoothing capacitor, a detection resistor, a motor coil, motor insulation resistance, and ground. A voltage generating across the detection resistor due to leakage current is detected and compared with a reference value. If the detected voltage exceeds the reference value, an insulation degradation signal is delivered.

A motor driving apparatus including a regeneration control function and a power storage device for accumulating a regenerative current and for supplying an inverter section with electric power during acceleration. The inverter section is connected to a converter section by a DC link to which regeneration start detecting means and the power storage device are connected. When the regeneration start detecting means detects that a voltage at the DC link reaches a regeneration control start voltage, a controller controls switching elements and starts regeneration control. The regenerative current is accumulated in the capacitor through a diode. When a motor is in a power running state, the switching elements are turned on to apply the voltage at the power storage device to the DC link, and the charged power is utilized for motor acceleration. At that time, the regeneration control start voltage for the regeneration start detecting means is made higher, thereby preventing regeneration control from being activated due to application of the capacitor's voltage. Not only the regenerative current is effectively utilized by the power storage device, but also the regeneration control function can be utilized.

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Hadano, Japan

Mamoru Yaeshima