Transient Stability and Protection Evaluation of Distribution Systems with Distributed Energy Resources

• The connection of distributed energy resources (DERs) in power distribution systems (PDSs) may bring new technical issues that must be analyzed and discussed by distribution companies, and the distribution system operator (DSO) must be aware about them. The issues could be complications in regard to the system voltage profile, power quality, power flow control, energy management, and frequency control and protection. Understanding the impacts on the dynamic behavior of PDSs caused by the presence of DERs is fundamental to guarantee the operation within the criteria established by regulatory agencies. This work presents an analysis of unbalanced distribution systems. Therefore, a modified version of the IEEE 34-node system in the presence of a synchronous distributed generation (SG) and some photovoltaic generation systems (PVs) is chosen. After multiple simulations carried out using DIgSILENT PowerFactory software, a total of five scenarios were selected to show the voltage stability analysis and the influences of protection system in the stability and integrity of the machines and to demonstrate the behavior of synchronous machine in a true way. The events include faults, reclosing operation, islanding, and changing the number of PVs connected, in which the operational limits of the SG are evaluated. In addition, the protection schemes must satisfy the performance requirements of selectivity, reliability, and sensitivity in order to ensure the safety of the system. Thus, this work focuses beyond the conventional protection schemes based on overcurrent detection, being introduced with other complementary functions. The results show some changes with regard to the voltage profile along the feeder due to the variation of PVs connected to the system, in which a greater number increase the voltage system. Besides, the behavior of one of the PVs is analyzed, being observed the contribution of reactive power during the short-circuit event. Other important achievements are related to the protection scheme adopted, in which using more sensitive adjustments by the protection devices may prevent excessive torsional efforts and help to avoid the loss of system stability.

Ämnesord

TEKNIK OCH TEKNOLOGIER  -- Elektroteknik och elektronik -- Annan elektroteknik och elektronik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Electrical Engineering, Electronic Engineering, Information Engineering -- Other Electrical Engineering, Electronic Engineering, Information Engineering (hsv//eng)

Nyckelord

Electric Power Engineering

Elkraftteknik

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vet (ämneskategori)

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