ABSTRACT
Power system studies are required to evaluate the performance of the proposed or existing power system. The objective is to ensure that the system is safe, reliable, easy to operate, easy to maintain, and is reasonable in cost. Power system analysis software such as load flow, short circuit, harmonic analysis, protective device coordination, and stability is available for use on a personal computer at a reasonable cost. Studies such as switching transients and insulation coordination are carried out using a TNA (transient network analyzer) or an EMTP (electromagnetic transient program). Considerable experience has been gained with EMTP and with practical or tested models, and most transient studies are carried out using this software. The following points must be taken into consideration for the selection of a software package for common studies:
The software uses raw or nameplate data for input files and converts them into the selected base values. A package that uses a common database for more than one study such as load flow, short circuit, harmonic analysis, stability, etc., will save considerable time and minimize error.
In the case of a short-circuit study for equipment rating based on ANSI/IEEE standards, the program adjusts the impedance multiplier of the rotating machines. The output files provide X/R ratios, adjusted fault current for local and remote contribution that can be directly compared with the equipment rating.
