Short Circuit Current Calculation

The Short Circuit Current Calculation 4 hour PDH online course is a part of the Electrical category courses and presents the subject of short-circuit studies in a very structured fashion. First, a simple equivalent circuit is developed for a generic power system, system impedances are recalculated to common base and fault are calculated at various locations throughout the system. A detailed explanation is offered for calculation of three phase faults. Explained techniques can be also verified by any commercial power system software package.

Short-circuit studies are done to determine the magnitude of the prospective currents flowing throughout the power system at various time intervals after a fault occurs. The magnitude of the currents flowing through the power system after a fault varies with time until they reach a steady-state condition. The information is used to select fuses, breakers, and switchgear ratings in addition to setting protective relays.

This behavior is due to system characteristics and dynamics. During this time, the protective system is called on to detect, interrupt, and isolate these faults. The duty imposed on this equipment is dependent upon the magnitude of the current, which is dependent on the time from fault inception. This is done for various types of faults (three phase, phase-to-phase, double-phase-to-ground, and phase-to-ground) at different locations throughout the system.

This course is intended for use by electrical engineers, design and construction professionals, students and others interested in learning about short circuit current calculation.

Learning Objectives

Upon completion of this course, you will be able to explain and calculate the following:

• Fault analysis according to industry standards
• Models of branch elements
• Impedance diagram
• System modelling and computational techniques
• Extent of the model
• Extent and requirements of short circuit current studies
• Factors affecting accuracy of short-circuit studies
• Computer solutions