The investigations leading to the specification of a digital computer for power system operational studies

Abstract

This thesis is an account of investigations carried out within the Electrical Engineering Department of the University of Sydney while the author was under the employment of the Snowy Mountains Hydro Electric Authority. When the project was commenced in November, 1956, the digital differential analyser "ADA" was under construction in the Electrical Engineering Department, and it was understood that another digital differential analyser was to be built for the Snowy Mountains Hydro Electric Authority. This second computer was to be specifically designed for the solution of a System Operational Problem, which had previously taken many "man—years" of manual calculations for its solution. The starting point of the project was then to gain familiarity with the system Operational Problem. This was carried out by studying the methods used in a series of manual calculations carried out by Engineers of the Authority. The object of the calculations was to derive figures corresponding to the optimum performance of the system. The method proposed for carrying this out was very simple and straight—forward. A set of system parameters was assumed; a set of operating instructions were derived from fundamental principles, (such as the minimisation of spill) and operating experience and the performance of the system was calculated from a set of records (of inflows and other data) covering a period of 50 years. By inspection of the results, modifications to the parameters or to the operating instructions would be made, and the calculations would be repeated. The operating instructions were based on the known state of the storages, the known parameters of the system and the current values of the monthly inflows. No knowledge of future inflows was assumed. The second aim of the project was to investigate the capabilities of the digital differential analyser, which had been accredited with many of the outstanding advantages of both analogue and digital computers. It had been stated that the programming was extremely simple, as it resembled that of the analogue computer or the mechanical differential analyser. It was also claimed that the computer possessed a great deal of flexibility (in the form of special integrator functions), as its logical organisation was entirely digital.