Inverter for use with winding system and method for controlling the same

Abstract

An inverter for controlling the speed of a motor driving a reel on which a coil of a work is built up so that the peripheral speed of the coil becomes equal to the feed speed of the work. The inverter includes a PWM control portion, an output frequency mean value calculation portion, a memory portion, a primary winding speed setting portion, and a summing and PI control portion. The output frequency mean value calculation portion sequentially computes mean values of the output frequency of the inverter during individual intervals of a series of predetermined intervals during the winding operation. The memory portion stores the mean value of a preceding interval. The primary winding speed setting portion sequentially set the command value of the output frequency of the inverter on the basis of the stored mean value. For example, the command value is set at the mean value of the preceding interval, or p times the mean value (p<1). The summing and PI control portion adds or subtracts a speed correction amount, which is obtained from the displacement of a dancer roll or the like, to or from the command value, and performs PI control on that result in order to determine the output frequency of the inverter during the present interval. This makes it possible to reduce both the speed correction amount and the oscillation amount of the dancer roll, and to realize a stable and accurate winding operation.

Dependencies are inferred from the claim text.