Adaptive Complementary Sliding Mode Control for Synchronous Reluctance Motor with Direct-Axis Current Control

In order to design a high-performance synchronous reluctance motor (SynRM) drive system, a novel adaptive complementary sliding mode (ACSM) speed control and an effective d-axis current control (EDCC) are proposed in this study. Firstly, a classical proportional-integral based field-oriented control of the SynRM drive with a constant d-axis current command is introduced. However, the constant d-axis current command is obtained by trial and error method or satisfying the minimum excitation current of the SynRM. More importantly, the constant value of the d-axis current command is not suitable for the highly nonlinear and time-varying SynRM drive at the varied load torque conditions. Therefore, an ACSM speed control with the d-axis current control (ACSMSC-DCC) system is designed for the speed regulation of the SynRM. The ACSM speed control is proposed to generate the q-axis current commands, and an EDCC by using the stator flux estimator is proposed to produce the d-axis current commands. Finally, the proposed ACSMSC-DCC system is implemented in a 32-bit floating-point digital signal processor TMS320F28075 and its effectiveness are verified by some experimental results.