Vacuum level control system using variable frequency drive

摘要

A vacuum control for milking systems includes a vacuum pump driven by an electric motor which is activated by a variable frequency drive (VFD). The VFD is controlled during a milking phase by plc programmable controller and a proportional/integral (PI) controller which respond to a vacuum feedback sensor connected to the milking system. The plc controller differentiates between milk and wash phases and also provides a fixed preset speed control for a washing phase for the milking system. The integrator interfaces between a milk/wash controller and the plc.