  In recent years, the implementation of the demand response (DR) programs in
the power systems scheduling and operation is increased. DR is used to improve
the consumers' and power providers economic condition. That said, optimal power
flow is a fundamental concept in the power system operation and control. The
impact of exploiting DR programs in the power management of the systems is of
significant importance. In this paper, the effect of time-based DR programs on
the cost of 24-hour operation of a power system is presented. The effect of the
time of use and real-time pricing programs with different participation factors
are investigated. In addition, the systems operation cost is studied to analyze
the DR programs' role in the current power grids. For this aim, the 14-bus IEEE
test system is used to properly implement and simulate the proposed approach.
