Separated Phase–Current Controls Using Inverter-Based DGs to Mitigate Effects of Fault Current Contribution from Synchronous DGs on Recloser–Fuse

Abstract

Synchronous distributed generators (SDGs) significantly affect recloser–fuse coordination due to the high fault current contribution. This paper proposes a separated phase–current control using inverter-based distributed generators (IBDGs) to remove the effects of fault current contributions from SDGs during unsymmetrical faults. The three-phase current produced by IBDGs is independently controlled. While the total fault current is reduced by adjusting the current phase angle in the faulty phase, the energy in the DC-link capacitor (Cdc) is delivered to the grid in order to avoid the rise of DC-link voltage (Vdc) by means of injection of the active current into the nonfaulty phase. To maintain the proper grid voltage, the voltage regulation feature is installed in the IBDGs. Moreover, current estimations programmed within the IBDGs are introduced to avoid the performance degradation of separated phase–current controls caused by phasor measurement units (PMUs). The dynamic performance of the separated phase–current controls using IBDGs was evaluated using an IEEE 34-node radial test feeder. According to the simulation results, the IBDGs could eliminate the effects of fault current contributions from the SDG without interruption since the disconnections caused by excessive Vdc were prevented. They could also regulate the grid voltage in the nonfaulty phase.

Improving the Power Supply Performance in Rural Smart Grids with Photovoltaic DG by Optimizing Fuse Selection

“…The case studies have been designed for three different locations of the DG in the network (bus/nodes 633, 646, and 652) and different levels of DG power penetration, specifically 25%, 50%, 75%, and 100%. The different case studies have been simulated with DIgSILENT © software from Power Factory [15], as this power system simulation software has a specific library for electrical protection. The locations of the DG in the distribution network are included in Table 1, the distance to the substation being also included in each case.…”

“…Chaitusaney and Yokoyama have studied in detail the impact of the DG on the system stability, considering the lack of coordination between protection devices [14]. Finally, Boonyapakdee et al analyzed the dynamic coordination of recloser fuses affected by synchronous distributed generators [15].…”

Online Estimation of Short-Circuit Fault Level in Active Distribution Network

“…Therefore, a safety margin is imposed to enhance the accuracy of the disturbance direction identification. The practical criterion is formulated as Equation (10).…”

“…In this paper, it is experimentally set as 0.01. Equation (10) ensures that those unclear disturbance conditions with Dir laying in a small vicinity of zero, will be ignored. Such conditions could be simultaneous disturbances on both grid and load side, or those with slight voltage and current fluctuations.…”

“…In Reference [1], the equivalent current sources are established for the positive and the negative sequence components, considering the inherent characteristics of IBDGs during low-voltage ride-through (LVRT). A simple equivalent circuit is proposed in Reference [10], to evaluate the short-circuit current with IBDGs. The models mentioned above are nonlinear and require the node impedance matrices as well.…”