This is Chapter 5 - "Specification of voltages and currents in new substations". This chapter is part of the complete training " “Design Concepts for Switchgear, Switchboards, BusDucts, and Substations"
Summary of the video
We start presenting the fundamentals and applications of load flow studies and short circuit studies. When planning a new substation to be inserted in the context of other neighbors’ substations of the power system, load flow studies are prepared to define the values of the rated currents and rated voltages which will be used in the specification of the several types of equipment. In the same approach, short circuit studies are prepared to define the values of short circuit currents and its duration as well as other paraments like the transient recovery voltages to be supported by circuit breakers
We show how the values obtained in these studies are added to the experience of the planners of the power utility to define future values.
The accuracy of these studies and the philosophy followed to use its values will define if the future substation may be a “low cost “project or not.
Simple examples of selection of the rated normal and rated short circuit values are shown. In the studies of short circuit, the examples use the free ATP / ATPDraw software. This is a powerful free tool used for decades all over the World. To know how to use it is a must for electrical engineers.