A Fuzzy Adaptive Pi Controller Based DTC Induction Motor Drive
Direct torque control is used over Field oriented control (FOC) because of its simple control structure and in steady state, transient state operating conditions shows better torque control. Direct torque control has the advantages like robust and fast torque responsive. But in low speed operation stator flux estimation raises difficulty due to improper working of an open loop voltage model observer and existence of an open loop integrator. Hence an adaptive flux observer is implemented which eliminates open loop integration, therefore improves the machine performance by minimizing stator current distortions, fast response of rotor speed, stator flux electro-magnetic torque without ripple, constant switching frequency. Voltage distortions are modelled using a non-linear inverter. In this paper a novel approach is seen where fuzzy logic controller is adapted which overcomes high torque ripples and improves the system performance. Simulation results are carried out for the proposed system.
S.Sridhar, Dr.N.Yadaiah, C.Anil Kumar.