Overview

ETAP DC Short Circuit Analysis complies with IEC 61660 standard, targeting dc auxiliary systems in power plants and substations. Short circuit calculations present challenges for DC Systems equipped with rectifiers, DC Smoothing Capacitors, DC Motors, and Batteries. The computations outlined by IEC 61660 attempt to accurately model the dynamic contributions of these elements for the proper determination of protective device ratings.

Key Features / IEC 61660 Key Features

• Device duty evaluation for DC Systems 
• Quasi Steady-State and Peak fault current values
• Partial short-circuit contributions
• Common branch calculations
• Peak time
• Rise & Decay time constants
• Element modeling according to IEC 61660
• AC Commutation Impedance
• DC Smoothing Reactor
• Interconnected AC/DC systems
• Result Annotations
• Reports
• Plots

Benefits of using IEC 61660 / Benefits / IEC 61660 in ETAP - Benefits

Accelerate Efficiency

Adhering to the IEC 61660 standard involves using element models with non-linear characteristics and an iterative solution process. Calculating multiple faults in large scale systems with common branch scenarios is a time intensive solution. Using ETAP to perform short-circuit analysis complying with the IEC 61660 standard allows users to advance past the calculation process and analyze the results instantaneously, this includes viewing result annotations, comprehensive reports, and plots.

AC/DC Interconnectivity

ETAP allows users to interweave AC and DC systems together for a robust analysis with elements such as Charger (Rectifier), UPS, and Inverter. The Charger (Rectifier) element, modeled in accordance with IEC 61660 takes into account AC fault contributions and AC system impedance in order to solve for DC system faults

Fault Analysis

There are many aspects to a successful short-circuit analysis such as device duty evaluation and protective device coordination. Using ETAP with the IEC 61660 standard facilitates users to perform device duty evaluations based on the peak short-circuit contributions as well as the quasi steady-state results. Users also have the option to perform a device duty evaluation using the total bus fault current or based on maximum through fault current.

Challenges

Integrating the IEC 61660 standard into the ETAP ecosystem guarantees the integrity of the results as well as its capabilities. The ability to assess the outcome of a study is greatly enhanced by being able to view immediate results on the single line diagram, generate comprehensive reports, interact with plots, and have automatic device duty evaluations. ETAP provides a complete element model in accordance with IEC 61660 in addition to elements not specified in the standard. This includes lithium-ion batteries, UPS, photo-voltaic cells, and protective devices.