Hybrid Optimization Technique to Solve Unit Commitment of Electric Power System

Abstract

Electricity plays a significant role in community life and the development of various sectors of the economy. The standard of living and growth of any country depends on the per capita electric energy consumption. In the past decades, electricity demand has been increased gradually, due to industrialization, modern transportations demand, domestic appliances, etc. Therefore, the dependency of electricity generation from coal and petroleum-based power plant has been increased in the electric systems. The electric power systems consist of generation, transmission, and distribution systems. In the electric power systems, the large number of thermal power plants is connected to different load centers through the transmission network. Hence, the study of the generation system having multiple types of generating units is a challenging task for utility planners. The thermal units take some time to start-up/shut-down the generation. Moreover, the power generation from thermal units depends on the ramp-up/ramp-down rate of generators. Because of this, utility companies need an optimum unit commitment (UC) decision in advance when to turn ON or OFF the generating units. The main objective of the UC problem is to minimize the total system production cost of thermal units with the satisfaction of power system constraints. The UC problem is subjected to various constraints such as the generation capacities, ramp rate limit, minimum up/down time, and reserve requirement. The day-ahead UC is a mixed-integer nondeterministic, polynomial, and highly dimensional hard problem of electric power systems. In electric power systems, the optimum UC schedule of generating units has played an important role in the saving of fuel cost. In the current scenario, the structure of the power system is transforming from the conventional centralized system to the deregulated environment. In the deregulation environment, the generation companies (GENCOs) act as a service provider, and the main motive of GENCOs is to achieve the maximum profit.