Implementation of VVVF drive for a three phase induction machine

This paper presents the design and implementation of induction machine drives by estimating a slip in fluid load and the Variable Voltage Variable Frequency (VVVF) drive scheme based on Sinusoidal Pulse Width Modulation (SPWM) technique for a three phase induction motor has been applied for use. The work involves implementation of a closed-loop control scheme for an induction motor. The VVVF technique is used extensively in the industry as it provides the accuracy required at minimal cost. For the slip estimation, a value of the stator flux is accordingly required. However estimating stator flux is complicated and even adopting flux sensors increase the cost. In this paper, complex and economic problems are solved by simplified slip estimation and VVVF control. The analysis is made with 3.2kW induction motor which used for fluid load. The implementation of VVVF drive applied simplified slip estimation is proposed and its validity is demonstrated by experimental results