ACS

Short Circuit Analysis

Overview

Short Circuit Analysis (SCA) calculates fault current sources to fault points, using programmable criteria for theoretical or reconstructed situations and scenarios. SCA uses the same solution algorithm as Distribution Power Flow (DPF), representing all loads, capacitor banks and short circuit faults as constant impedances. Source voltages behind the internal impedances are calculated based on the DPF solution.


When a fault occurs in an SCA context, the fault impedance will connect from the fault location to ground, or to another phase, depending upon the fault type. The positive–, negative– and zero–sequence networks are created, and the fault current is computed using the DPF.


SCA offers an array of controls and user–programmable conditions:


  • Study scope (study voltage level)
  • Fault locations (substation, feeder, node/device)
  • Faulted phases (any combination of single–, two– and three–phase to phase, and phase to ground)
  • Fault types
  • Fault impedance
  • Zero pre–fault currents

Voltage and current solutions, including fault current and its distribution in the faulted feeder sections, are represented in per–phase quantities, in graphic or tabular display. Excessive SCA ratings are compared to the related transformers, feeders, and switching operating limits, and are listed and highlighted. SCA supports multiple analysis scenarios, each of which can be stored in a separate saved case. Each of these scenarios can be set up independently, so that you can analyze more than a single aspect of a situation. Up to 20 different SCA study cases can be saved and retrieved.