2.1 INTRODUCTION

It was seen in the previous chapter that the total system load is optimally divided among the various generating units by equating their incremental generating costs. However, it was assumed that power transfer from the generating station to the load center does not involve transmission line losses. It is unrealistic to neglect transmission losses, particularly when long distance power transmission is involved. Transmission losses vary from 5 to 15 percent of the total load. Therefore, it is essential to account for transmission losses while developing an economic load dispatch policy. This chapter deals with the economic scheduling problem by considering transmission line losses.