A comparative evaluation of high performance current regulation strategies for vector controlled induction motor drives

Vector control is a most effective strategy to achieve rapid and accurate torque/speed control of AC motors. Its principle is to identify the machine rotor flux axis, and to then use this knowledge to control in-phase and quadrature current components to achieve precise torque control under varying load conditions. Accurate current regulation is essential for good vector control. However, while AC current regulation has been intensely researched over many years, designing a good current regulator still remains an uncertain mix of theory and practice. This paper presents a detailed comparison of four alternative PI and hysteresis based current regulation strategies, and compares the performance of a standard vector controller using these strategies. The results show that when properly tuned, all four strategies are essentially equivalent, and the choice between them need only be made on the basis of convenience and/or cost.