Objectives
Review of direct current system analysis topics, including
battery sizing, load flow, and short-circuit analysis

Analysis of sample DC electrical distribution systems using
the PTW software

Discussion of the unique characteristics of DC
equipment and systems

Discussion of component sizing, including battery and
battery charger sizing

Review of lead-acid and Nickel-cadmium battery characteristics

Discussion of the importance of load flow analysis in the
design of DC systems

Discussion of short-circuit and coordination analysis results

Discussion of compliance with various standards

Prerequisites Basic computer skills

A working knowledge of SKM PTW Software is highly desirable,
but not required

Students are urged to review:
• IEEE Brown Book Std 399 - 1997, Chapter 16
• IEEE 485-1997, “IEEE Recommended Practice for Sizing
Lead-Acid Batteries for Stationary Applications”
• IEEE 946-2004, “IEEE Recommended Practice for the Design
of Safety-Related DC Auxiliary Power Systems for Nuclear
Power Generating Stations”
• IEEE 1115-2000, “IEEE Recommended Practice for Sizing
Nickel-Cadmium Batteries for Stationary Applications”
• IEEE 1184-1994, “IEEE Guide for the Selection/Sizing of
Batteries for Uninterruptible Power Systems”
• IEEE 1375-1998, “IEEE Guide for the Protection of
Stationary Batteries”
• IEC Std 61660 Part 1, “Short Circuit Currents in D.C.
Auxiliary Installations In Power Plants and Substations,
Part 1: Calculation of Short-Circuit Currents”

Course DescriptionThis course involves the application of the Power*Tools program to analyze example DC electrical distribution systems. Battery sizing, load-flow, and short-circuit studies will be reviewed and then performed using the software. Students will earn 1 CEU for this 1-day course.

Target AudienceThis course is intended for electric power engineers
responsible for the design and analysis of direct current
electrical power distribution systems. A basic understanding
of electrical distribution system analysis is required.

Typical Industrial and Commercial Power System Example Review of distribution system analysis topics including battery sizing, battery charger sizing, time dependent load flow, and short-circuit analysis Discussion of component characteristics and sources of data Discussion of compliance with various standards Discussion of considerations when selecting battery type Examination and interpretation of PTW study results and potential problem areas in a DC power system Discussion of methods and procedures on completing a typical study

Typical Generator and Rectifier Supplied Power System Example Discussion of equipment characteristics and sources of data Review of distribution system analysis topics including load flow, and short-circuit analysis Examination and interpretation of PTW study results

Typical Lead-Acid and Nickel-Cadmium Battery Characteristic Examples Review and interpretation of manufacturer's battery characteristic data Entry of characteristic data into PTW Library

Hands-On Lab - Analysis of Example Battery Supplied Distribution System in PTW Examples of equipment data Alternatives in battery sizing and load flow analysis ANSI and IEC methods for short circuit analysis Interpretation of PTW equipment evaluation results

Hands-On Lab - Generator and Rectifier Supplied DC Distribution System in PTW Examples of equipment data Options for load flow and short circuit studies Considerations applicable to large DC motors and generators Interpretation of PTW equipment evaluation results