Intrasystem transmission losses

THIS paper describes a new method of calculating transmission losses within power systems. Reasonable accuracy is obtained with longhand calculation, although the same general scheme with the load-flow determinations carried out on a d-c calculating board would provide greater accuracy with less work. The use of an a-c calculating board with separate tabulations of kilowatt and kilovar flows would be even more advantageous. The method is based on the principle of superimposing the load distribution from each source, determining the current in each line as a sum of the individual load flows (with each in its proper direction), squaring this expression for current, and setting up an equation for losses in terms of megawatt generation at the various plants and of megawatt flows (in or out) at each interchange point. An outward flow of power at an interchange point is considered negative generation.