Active Fault Management for Microgrids

Fault Current Negative Contribution Method for Inverter-Based Distributed Generators Under Grid Unbalanced Fault

“…The larger the fault current, the higher the capacity of the grid equipment is needed to improve electrical stability [7]; 2) The increasing fault current will speed up the replacement of grid equipment, thus increase the grid investment, since the electrical equipment is planned and designed based on its ability to withstand fault currents [8]; 3) The IBDGs fault current will interfere the coordination operation between the primary protection and secondary protection of the original relay protection of ADN, increasing the difficulty of coordination between protection and reclosing [9]- [10]; 4) The IBDGs fault current will lead to a certain sensitivity reduction of the related overcurrent protective relay, and even cause protection blinding or false tripping of related relay [11]- [13]; 5) With the increase in the capacity and scale of IBDGs, the ADN is facing the danger of excessive fault current [14]. Once the fault current cannot be removed by circuit breakers, the fault current can even cause cascading fault [15].…”

Active Fault Current Limitation for Low-Voltage Ride-Through of Networked Microgrids

“…Otherwise, the increased part of fault current will cause serious consequences when system fault current exceeds the maximum endurance of electric equipment [12]- [13]. First, the injection of MGs fault current will lead to the costly upgrades of grid components, such as transmission lines, transformers, circuit breakers, and fuses [14]. Second, the additional MGs fault current will increase the difficulty of relay protection, even causing protection failure and catastrophic damage, which would threaten grid security and stability [15].…”