Determination of Protection and Relay CoordinationStrategy in Electrical Power Systems Based on Renewable Energy Generation Resource Using Petri Net Method

The principle of protection in electrical power system targets to determinate at timely of accruing faults and to isolate at the most appropriate time of the faulted sections of the power grid. this situation is realized through coordination among the protective devices. the involvement of renewable energy generation resources to the energy transmission system complicates the network protection, thus undermining the security coordination or decreasing the protection coordination zone. in particular, such issues become even more vigorous in power networks with effect of renewable energy resource generations. therefore, the conventional power protection methods are insufficient in such networks, requiring software strategies involving the renewable energy generation resources. for that purpose in this study, petri net method is used for estimating the faulted section in power transmission network in the presence of renewable energy generation resources and designing of protection coordination schemes. the information about the status of protection elements acquired from the automation system was adopted as input to the petri net method. renewable energy resource generations effect can increase the risk of disharmony among protection systems. the accuracy of petri net models are improved by phase angle shifts in the voltage waveforms of renewable energy generation resources and the main power supply using fast fourier transform (fft) through which the petri net model inputs was corrected.