POWER (LOAD) FLOW STUDY
Power flow (load flow) is the solution for the normal balanced three-phase steady-state
operating conditions of an electric power system. In general, power flow calculations are
performed for power system planning and operational planning, and in connection with
system operation and control. The data obtained from power flow studies are used for
the studies of normal operating mode. The load flow gives us the sinusoidal steady-state of the entire system − voltages, real and reactive power generated and absorbed, and line losses. Since the load is a static quantity and it is the power that flows through
transmission lines, the purists prefer to call this Power Flow studies rather than load
flow studies. We shall however stick to the original nomenclature of load flow.
Through the load flow studies, we can obtain the voltage magnitudes and angles at
each bus in the steady-state. This is rather important as the magnitudes of the bus
voltages are required to be held within a specified limit. Once the bus voltage
magnitudes and their angles are computed using the load flow, the real and reactive
power flow through each line can be computed.