Fault approximation tool for grid-connected inverter-interfaced distributed generators

Abstract

A novel fault approximation tool (FAT) is presented for use in distribution networks with a high penetration of inverter-interfaced distributed generation. The FAT does not rely on balanced operation nor an absolute reference point for voltage calculations, both of which are required for Newton-Raphson load flow calculations. Simulations show that the FAT provides an accurate representation of the transient and steadystate fault response for unbalanced faults when juxtaposed with a detailed small-signal model. The `subtransient' response of the inverter-interfaced distributed generation is omitted to remove data considered extraneous from the perspective of distribution line protection analysis. The FAT is not appropriate for analysing the efficacy of distributed generation local protection and is inappropriate for islanded applications. The FAT is designed explicitly for the purpose of utility line protection design and analysis. Abstract-A novel fault approximation tool (FAT) is presented for use in distribution networks with a high penetration of inverter-interfaced distributed generation. The FAT does not rely on balanced operation nor an absolute reference point for voltage calculations, both of which are required for NewtonRaphson load flow calculations. Simulations show that the FAT provides an accurate representation of the transient and steadystate fault response for unbalanced faults when juxtaposed with a detailed small-signal model. The 'sub-transient' response of the inverter-interfaced distributed generation is omitted to remove data considered extraneous from the perspective of distribution line protection analysis. The FAT is not appropriate for analysing the efficacy of distributed generation local protection and is inappropriate for islanded applications. The FAT is designed explicitly for the purpose of utility line protection design and analysis.

Grid Connection Studies for Large-Scale Offshore Wind Farms Considering High Penetration of Regional Renewables

“…The subtransient impedance, X d ″ , is typically applied to determine the short circuit current as a generator internal impedance when responses are determined by most transmission system relays [22][23][24]. In the PSS/E, the subtransient impedance is used, along with the generator internal voltage, as input data for fault calculations.…”

Impact of Momentary Cessation Voltage Level in Inverter-Based Resources on Increasing the Short Circuit Current

“…Numerous papers have discussed IBR models and fault responses in electromagnetic transients including DC (EMTDC) for short time durations [15][16][17][18][19][20]. These options are applicable for analysis of small power systems.…”