The Evaluation of Short Circuit Current to Achieve Optimal Design and Protection for Elements in Power Network with Renewable Energy

From the past decade, the renewable energy resource is continually increasing in the distribution power networks to provide the green power energy, which is the realized objective in power energy using of the consumer in the present time. In addition of renewable energy resource in the distribution network, which is as though addition of power source in network, will be caused to increase short circuit level in network. To be certain that elements in the distribution power network can be absorbed the energy (short circuit current) due to short circuit and system protection can be properly operated, there must be recalculation and reanalysis of power system by regrading of the power supply ability of that power sources connected in network. Therefore, the evaluation and analysis of short circuit current in the distribution power network that contains with renewable energy resource (Solar Energy) is proposed in this paper. The recommended practice for short circuit current calculation according to IEC60909 standard is applied in evaluation and analysis, and then the recommended practice for protection and coordination according to IEEE242 standard is applied in design protection relay setting and coordination. All of procedures in evaluation, analysis and design are done on ETAP by simulation of short circuit situation in the model of distribution power network, which it can illustrate the guideline to achieve the optimal design of elements and maintain the proper operation of system protection by using protection relays in the distribution power network with renewable energy escalation.