ABSTRACT
Load flow is a solution of the steady-state operating conditions of a power system. Load flow studies are performed using digital computer simulations. This chapter examines the power flow over power transmission lines, which is somewhat distinct and a problem by itself. It considers two-port networks, i.e., a single transmission line, to appreciate the principles and complexities involved. The chapter discusses the concepts of instantaneous power, average power, apparent power, and reactive power in detail. The conservation of energy concept (Tellegen's theorem) is based on Kirchoff laws and states that the power generated by the network is equal to the power consumed by the network. As the transmission line length increases, the receiving end voltage rises above the sending end voltage, due to line capacitance. This is called the Ferranti effect. Mode propagation gives rise to further distortion of multiconductor lines. The corona discharges form when the electrical field intensity exceeds the breakdown strength of air and local ionization occurs.
