| 摘要 |
PROBLEM TO BE SOLVED: To (1) easily stop a traveling crane in a target position by reaccelerating the traveling crane from the current operating speed or inverting the crane when it is about to stop before the target position; (2) enable adjustment of acceleration/deceleration torque of an inverter during traveling motor operation and accelerating, decelerating and inverting operation and perform smooth acceleration or deceleration without largely increasing load swing; and (3) provide responsiveness of the traveling crane ten times larger than that of a V/F inverter and absorb load swing by an operator through accelerating/decelerating operation. SOLUTION: (1) To enable rapid acceleration and inversion and enhance the responsiveness, a speed detection means is provided. (2) The inverter performs control such as vector control with a speed sensor, vector control without a sensor and control by the speed detection means by speed estimation calculation. (3) During coasting operation, with power on, maximum torque of the motor is restricted and the brake is applied. (4) After completion of the coasting operation, a target speed instruction is set during reacceleration or inversion and then, operation is performed by changeable torque restriction. COPYRIGHT: (C)2009,JPO&INPIT
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