I think you are interested in difference equations like : https://au.mathworks.com/matlabcentral/answers/81270-is-matlab-solving-difference-equations

Also https://au.mathworks.com/matlabcentral/answers/325773-solving-difference-equation-with-its-initial-conditions

and https://au.mathworks.com/matlabcentral/answers/108668-how-can-i-implement-a-simple-difference-equation-and-plot-the-resulting-output-all-using-matlab

Dear @ Muhammad Ali sir i don't want MatLab code I require a Simulink diagram for the above equation, sir, as shown below

K V Thulasi Ram ,

The equation shown there is a difference equation. Hence, it can be transformed into z domain. Converting the above difference equation into z-domain we get Vdcref(z) = (2-z-1)Vdc(z). In short, a z domain transfer function which takes input as Vdc and gives output as Vdcref while the transfer function is (2-z-1). This z-domain transfer function can be implemented using the "Discrete Transfer Fcn" block of Simulink.

Thanks, sir @ kharan shiluveru for ur valuable suggestion for the development of Simulink block