Real time in simulink model

Hi! I'm working on a project that consist of a model of two solar cells under the control of tracking and back-tracking algorythms. I have used Simulink to build the model, and Stateflow for the tracking and B-T controller, and it works well, but I need it to work under real time simulation, since the sun is in constant motion and my model only takes into account the solar angle taken when I start the simulation, so the power does not change never, although the simulation time was larger. Would you kindly help me? Thanks