Nonlinear Disturbance Observer-Based Sliding Mode Control for the PMSM with Matched and Mismatched Disturbances

<div>The robustness validation under different amplitudes of parameter perturbation. (a) Speed curve under the SMC scheme. (b) <i>q</i>-axis current curve under the SMC scheme. (c) Speed curve under the NDO-SMC scheme. (d) <i>q</i>-axis current curve under the NDO-SMC scheme.</div>

Mathematical Problems in Engineering

fig7

Figure 7

Figure 7: Nonlinear Disturbance Observer-Based Sliding Mode Control for the PMSM with Matched and Mismatched Disturbances 