Digital computers in power system analysis

Programmes have been developed for carrying out power-system load studies and transient stability studies on an automatic electronic digital computer. The methods employed are similar to those used at present on network analysers, but improvements have been made where possible. In the method of solving load studies, loads and generation are represented by equivalent admittances to neutral, and nodal voltage equations are used. A control programme which automatically adjusts the reactive-power generation and transformer taps to keep the voltages within satisfactory limits has been developed. A programme to carry out transient stability calculations for a multi-machine system, using the standard step-by-step method, has been written, together with a programme to calculate the power-equation coefficients needed to compute the power transfer at the end of each interval. Significant generator characteristics like saliency, flux decrement, voltage-regulator action, damping and governor action, which are normally neglected in network-analyser studies, have been included in the programme. It is shown that the use of computers is a highly efficient and economic method for the solution of power-system problems.