Pressure control system of the pumping units with frequency-controlled induction motor

The ever-increasing demands to the quality of production processes are associated with the pumping of non-viscous liquids, which indicate the need in improving operating conditions of liquid transfer systems with centrifugal pumps, including by means of mathematical modeling. The purpose of the paper is to develop a system for stabilizing the pressure in the calculated point by a scalar frequency-controlling of an induction motor speed, and to study its dynamic operation modes. The following methods are used in the research: theory of the variable frequency drive and electrical machines, methods of operational calculus, theory of centrifugal bladed machines. As a result, a scheme for controlling the pressure of the centrifugal pumping unit in the calculated point by controlling the rotational speed of the induction motor and determining calculated pressure indirectly using the respective models of the centrifugal pump was developed.