A voltage sag analysis software tool for determine areas of vulnerability

Voltage sags are recognized as the most important power quality problem. They may cause sensitive equipments to trip, thus have major economic impact. In this study, a voltage sag analysis is required to determine the voltage sag characteristics, the likelihood of a voltage sag occurrence and areas of vulnerability in power distribution systems. This paper presents a software development of a voltage sag analysis tool using the PSS engine application program interface library, Microsoft C+ + and Visual Basic. The objective is to develop stand-alone software for voltage sag analysis with extended features to the existing commercial power system analysis packages. The important features included in the program are the multiple sliding faults analysis together with the three phases load flow and short circuit analysis including multiple and sliding faults analysis. Voltage sag "areas of vulnerability" can be determined from the voltage sag analysis output. Results are presented in tabular form and stored in exchangeable file format. The program has been tested on a real power distribution network and the results are found to be satisfactory when compared with the results from using the commercial power system software PSS/ADEPT.