AC Power Systems
From 1929 to the late 1960s, large alternating current power systems were modelled and studied on AC network analyzers ( or transient network analyzers). These were an outgrowth of the DC calculating boards used in the very earliest power system analysis. These systems were essentially models of the power system, with generators, transmission lines, and loads represented by miniature electrical components with scale values in proportion to the modeled system. Model components were interconnected with flexible cords to represent the schematic of the modeled system. To reduce the size of the model components, the network analyzer was energized at a higher frequency than the 50 Hz or 60 Hz utility frequency, and model circuits were energized at relatively low voltages to allow for safe measurement with adequate precision. Typically, results accurate to around 2% of measurement could be obtained.
AC network analyzers were much used for power flow studies, short circuit calculations, and system stability studies, but were ultimately replaced by numerical solutions running on digital computers. While the analyzers could provide real-time simulation of events, with no concerns about numeric stability of algorithms, the analyzers were costly, inflexible, and limited in the number of buses and lines that could be simulated. Since the multiple elements of the AC network analyzer formed a powerful analog computer, occasionally problems in physics and chemistry were modeled (by such researchers as Gabriel Kron of General Electric), during the period up to the late 1940s prior to the ready availability of general-purpose digital computers.
Read more about this topic: Network Analyzer (electrical)
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