Risks of Cascading Contingencies in Islanded Operation of a Renewable Integrated Microgrid

The target of this paper is to explore the possibilities of cascading contingencies in a renewable integrated microgrid during its islanded operation. One key feature of a microgrid is its capability to operate in islanded mode when needed. However, an islanded microgrid may be susceptible to cascading tripping of distributed energy resource (DER) units due to unacceptable post-fault voltage/frequency recovery performance. To address this issue, this paper explores the impact of implementing the IEEE std. 1547-2018 on the operation of DER units. To this end, IEEE 43 bus industrial test system is considered as facility microgrid. This system is slightly modified to incorporate wind and PV generation and then simulated to examine voltage and frequency responses following a severe fault. The results show that a stringent grid code demands prompt tripping of DER units, which eventually leads to a blackout in the microgrid.