Motor driving apparatus
AssigneeFanuc Corporation
InventorsYasusuke Iwashita, Shinichi Horikoshi, Takashi Harada, Masakazu Niwa, Koujirou Sakai
Life of this patent
Estimating the term…
Abstract
During motor acceleration control period that starts at time T1, if power supply output or supply current exceeds a predetermined level at time T2, PWM control in a PWM converter is turned off until a deceleration control period of T3 to T4 ends. As a result, DC link voltage (voltage of a power storage device) at the start of the deceleration control at time T3 drops to provide space for storing regenerative power; since the PWM control in the PWM converter is off during the deceleration control period, the regenerative power can be stored into the power storage device and reused in the next control cycle.
Claims11
A motor driving apparatus comprising:
- a PWM converter which, under PWM control, converts AC power supplied from a power source into DC power and vice versa;
- a PWM inverter which converts the DC power output from said PWM converter into variable-frequency AC power and vice versa, and which drives a motor with said variable-frequency AC power;
- a power storage device, provided between said PWM converter and said PWM inverter, that can store electric power in an amount capable of driving said motor;
- and
- a control circuit which turns on and off said PWM control in said PWM converter, and wherein
- the voltage of said power storage device is controlled by said PWM converter so as to be a voltage higher than a supply voltage during the period that said PWM control is turned on by said control circuit, and
- power is supplied to said motor from said power storage device that has been charged to the voltage higher than said supply voltage, and regenerative power occurring during a deceleration control period of said motor is recovered by said power storage device when said PWM control is turned off by said control circuit.
Dependencies are inferred from the claim text.