Modelling of Frequency Controlled Induction Drive with Ventilator Type Load

Abstract

The great number of induction motors, controlled by frequency converters, is employed in pumps, fans and blowers. Their operation develops ventilator load of the motor. For matching dynamic characteristics of motor, load and converter, Simulink model of frequency controlled drive with smooth starting was developed and simulation results were analyzed .Simulation results were compared with experimental ones. Investigation of transients in the system with scalar control indicates good matching experimental and simulation results. Average torque value during starting at no load approximately is constant at assumed acceleration 600 rpm/s The maximum torque and current values at beginning of starting do not exceed rated those. Simulation of the drive with ventilator load at smooth starting and chosen ramp indicates the maximum torque value not exceeding rated that at the beginning of the starting transients. Afterwards the torque rises as the load increases with speed square. Steady-state speed error corresponds to 10℅ in the open loop system. For greater accuracy closed loop control system with speed feedback or vector control systems should be used. Ill. 7, bibl. 5 (in English; abstracts in English, Russian and Lithuanian).