The deregulated power system was introduced due to new developments in power systems (PS) brought about by the robust development of society and the industry’s growing demand for electricity. The multi-source power system considers the non-linearity of thermal plants when utilizing various power generation sources, including wind, hydro, and thermal generating units. Power system control in a traditional and deregulated environment (DE) will be presented in this project, which addresses the issue of stabilizing the load frequency in the power source like previous systems. In both traditional and deregulated power systems, the load frequency is controlled by the slide controller using the proposed Automatic Load Frequency Control (ALFC) model. There are three GEN-COs (thermal, hydropower, and wind power) and two DISCOs in each area. For each of the three deregulated scenarios, a simulation was run. The project demonstrates how the deregulated power system’s frequency can be stabilized using the high-order integral sliding control method.