Power System Operation and Control

1.5 ECONOMIC DISPATCH PROBLEM – NEGLECTING TRANSMISSION LINE LOSSES

The problem of ED can be easily solved when transmission line losses are neglected. As the losses are neglected, the system model can be understood as shown in Fig. 1.7, where n number of generating units are connected to a common bus bar, collectively meeting the total power demand P_D. It should be understood that share of power demand by the units does not involve losses.

Since transmission losses are neglected, total demand P_D is the sum of all generations of n-number of units. For each unit, a cost functions C_i is assumed and the sum of all costs computed from these cost functions gives the total cost of production C_T.

Fig 1.7 System with n-generators

where the cost ...