Synthesis of direct torque and rotor flux control algorithms by means of sliding-mode theory

This paper is an attempt to synthesize the direct torque and rotor flux control (DTRFC) algorithms of induction motor using sliding-mode theory. The choice of the sliding-mode theory has been motivated by the presence of switches in the voltage-source inverter (VSI). Changes in the state of the switches cause the variation in the topology of the controlled system. In addition, this theory offers a mathematical process that allows rigorous procedures of analysis and synthesis. The developed voltage vector is generated by two methods: direct control of the VSI (hysteresis VSI control), and indirect control of the VSI using space-vector modulation. In addition, taking into account the complementarity of the advantages of each VSI control algorithm, the high dynamic performance of the direct control and the smoothness of the indirect control, the idea of the dynamic reconfiguration of DTRFC algorithms is proposed.