Economic Operation of Power Systems -1
Economic Distribution of Loads between the Units of a Plant
Economic Sharing of Loads between Different Plants
Automatic Generation Control
Load Frequency Control
Coordination between LFC and Economic Dispatch
A good business practice is the one in which the production cost is minimized without sacrificing
the quality. This is not any different in the power sector as well. The main aim here is to reduce the
production cost while maintaining the voltage magnitudes at each bus. In this chapter we shall discuss the
economic operation strategy along with the turbine-governor control that are required to maintain the
power dispatch economically.
A power plant has to cater to load conditions all throughout the day, come summer or winter. It is
therefore illogical to assume that the same level of power must be generated at all time. The power
generation must vary according to the load pattern, which may in turn vary with season. Therefore the
economic operation must take into account the load condition at all times. Moreover once the economic
generation condition has been calculated, the turbine-governor must be controlled in such a way that this
generation condition is maintained. In this chapter we shall discuss these two aspects.
Economic operation of power systems
One of the earliest applications of on-line centralized control was to provide a central facility, to
operate economically, several generating plants supplying the loads of the system. Modern integrated
systems have different types of generating plants, such as coal fired thermal plants, hydel plants, nuclear
plants, oil and natural gas units etc. The capital investment, operation and maintenance costs are different
for different types of plants.
The operation economics can again be subdivided into two parts.
i) Problem of economic dispatch, which deals with determining the power output of each plant to meet the
specified load, such that the overall fuel cost is minimized.
ii) Problem of optimal power flow, which deals with minimum – loss delivery, where in the power flow,
is optimized to minimize losses in the system.