A second-order auto disturbance rejection controller for matrix converter fed induction motor drive

Matrix converter (MC) is superior to drive induction motor since it has more attractive advantages than conventional pulse width modulation (PWM) inverter like the absence of large dc-link capacitor, unity input power factor and bi-directional power flow. However, due to the direct conversion characteristic of MC, the drive performance of induction motor is easy to be influenced by input voltage disturbances of the MC, and the stability of induction motor drive system fed by MC would be affected by load sudden change as well. A 2^nd order nonlinear robust auto disturbance rejection controller (ADRC) is applied to the MC fed induction motor drive system, taking the place of proportional-integral (PI) regulator. In the drive system, the effects of external disturbance (input voltage disturbance and sudden change of load torque) and model internal disturbance are estimated and compensated by ADRC. Using this controller, the anti-disturbance capability of the drive system under abnormal input voltage conditions can be enhanced. In addition, the dynamic drive performances of induction motor are also improved, such as fast responses of speed change and load torque change. Simulation results verify the effectiveness of the proposed controller.