Fixed-point DSP Algorithm for Flux Estimation in DTC IM Drive

A precise and simple for implementation DSP algorithm for flux estimation in direct torque controlled induction motor drive is presented. The main goal is to avoid using complex mathematical functions (square root and arc tan) and/or look-up tables for calculating flux amplitude and position. Complete algorithm, written in C, is at first analyzed in a simulation model and the final performance is examined on an Intel's 80C196KC20 microcontroller. Comparison to the standard functions in respect to the accuracy, execution time and implementation simplicity shows accurate performance needed for flux control in direct torque controlled drives.