INVERTER CONTROL DEVICE FOR ELEVATOR

摘要

PURPOSE:To eliminate starting shock and instability of speed at the time of stopping retardation by providing a means for adding a torque boosting current equivalent to a torque-portion due to friction in the mechanical system of an elevator to a torque current command. CONSTITUTION:In a vector control calculation unit 7, a calculation unit 71 calculates the magnitude of a composite vector when a vector current command IT and an excitation current command I0 intersect at right angles to each other, to obtain a current command II. The current command II is added to a torque- boosting current IB by an adder 21, and II + IB serves as a conversion factor of a D/A converter 8. When starting the machine and stopping retardation, an electric motor is driven by the current obtained by adding the torque-boosting current IB to the current command II obtained from the torque current command IT and the excitation current command I0 to compensate for shortage of torque caused by friction in the mechanical system at the time of starting the machine and to restrict vibration produced at the time of putting the machine into a slow-speed operation for stopping the retardation by the torque-boosting current IB.