Index-based voltage dip consideration in optimal planning of SDGs by applying a modified Monte Carlo simulation method

摘要

In this paper, system performance from voltage dip point of view is evaluated and a methodology is proposed tornconsider dip events in SDG planning. A modified MCS method is introduced for stochastic evaluation of voltagerndip. Based on the stochastic evaluation, appropriate indices are proposed, which take into consideration voltage diprnmagnitude and the vulnerability of sensitive loads to this phenomenon. Voltage dip indices are optimized, and optimalrnlocation and size of SDGs are determined to improve system voltage dip performance. The following conclusion couldrnbe taken from this study:rn1. The proposed methodology could be helpful in a system with sensitive and important loads in which load supportrnmay carry more economic burden than other economic issues such as power loss and network investment deferral.rnMoreover, it can be used as an intermediate stage or in a multiobjective DG planning program combining voltage diprnperformance with other economic objectives.rn2. From power quality standpoint, SVDN is a more appropriate index than SADM, and it is more compatible withrnstandards on voltage dip and can convey a straight economic meaning.rn3. Although the distribution network operator might not always be the decision maker about SDG units' locationsrnin the network, these indices are still helpful in voltage dip assessment and the methodology can managernencouraging policies of SDG installation and be useful in network planning and comparing different expansionrnscenarios.rn4. Synchronous DGs may improve system voltage dip performance, if they are optimally planned and operated. In thernpresence of SDGs, both indices SADM and SVDN are enhanced and system encounters fewer sever voltage dips andrnfewer trips of sensitive equipment. Synchronous distributed generations are capable of lowering the total dip cost.rnHowever, it must be admitted that in industrial plants with sensitive loads like petrochemical sites, the more reliablernand accepted solution is uninterrupted power supply.rn5. The buses at the electrical centers of a meshed system are more appropriate locations for SDG installation to improvernvoltage dip performance.