In sliding mode control, determining the appropriate coefficient constant involves a meticulous process balancing system dynamics and control objectives. It necessitates a thorough analysis of system characteristics, desired performance metrics, and stability considerations. The coefficient constant is adjusted iteratively through simulations or experiments, aiming to achieve robustness against uncertainties while ensuring fast convergence to the sliding surface. Factors such as system nonlinearity, disturbance rejection, and control effort constraints play crucial roles in selecting an optimal coefficient constant for effective control law implementation

Sikander Hans Thank you for the response. How is the process of balancing system dynamics and control objectives carried out? Please can you recommend or site a material that explains this

In summary, to determine an appropriate coefficient constant for DFIG active and reactive power control in sliding mode, start with a reasonable initial value, use simulation to evaluate performance, and adjust the coefficient constant until satisfaction in terms of system stability and transient response.