Print this page Harmonic Analysis Basics
Velimir Lackovic, MScEE
Course Outline
A harmonic-producing load can affect other loads if significant voltage distortion is caused. The voltage distortion caused by the harmonic-producing load is a function of both the system impedance and the amount of harmonic current injected. The mere fact that a given load current is distorted does not always mean there will be undue adverse effects on other power consumers. If the system impedance is low, the voltage distortion is usually negligible in the absence of harmonic resonance. However, if harmonic resonance prevails, intolerable harmonic voltage and currents are likely to result.
The general procedure is to first develop a model that can accurately simulate the harmonic response of the present system and then to add a model of the new addition. Analysis is also commonly done to evaluate alternatives for correcting problems found by measurements.
Only very small circuits can be effectively analyzed without a computer program. Typically, a computer program for harmonic analysis will provide the engineer with the capability to compute the frequency response of the power system and to display it in a number of useful graphical forms. The programs provide the capability to predict the actual distortion based on models of converters, arc furnaces, and other nonlinear loads.
This course includes
a multiple choice quiz at the end,
Learning Objective
At the conclusion of this course, the student will:
- Basic theory behind harmonic phenomena in the power system;
- How harmonic phenomena is modelled for the purpose of system analysis;
- How harmonics can affect the quality of electrical energy;
- Consequences of high harmonic levels and what mitigations measures can be applied; and
- Commercial software modelling techniques, simulation performance and interpretation of the results.
Intended Audience
This course is intended for electrical engineers.
Benefit to Attendees
Attendee of this course will understand basic harmonic principles, their cause and impact to the electrical system. Also attendee will learn how to perform harmonic study, propose mitigation measures and size harmonic filters.
Course Introduction
Nonlinear loads represent a growing portion of the total load of a commercial or industrial power system. This means harmonic studies are an important part of any system design and operation. Fortunately, the software available to assist us with harmonic analysis has grown also.
If we model power system impedances as a function of frequency, we can determine the effect of harmonic contributions produced by nonlinear loads on voltage and current in a power system.
Course Content
In this lesson, you are required to download and study the following course content in PDF format:
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Course Summary
In this course we will discuss the underlying concepts of harmonic analysis in relation to industrial and commercial power systems. Reasons that require this analysis, the recognition of problems that may arise in the process, methods of correcting and preventing these issues, the data required to perform this analysis, and the benefits of technology in performing a harmonic analysis study will also be addressed.
Quiz
Once you finish studying the above course content, you need to take a quiz to obtain the PDH credits.
DISCLAIMER: The materials contained in the online course are not intended as a representation or warranty on the part of PDH Center or any other person/organization named herein. The materials are for general information only. They are not a substitute for competent professional advice. Application of this information to a specific project should be reviewed by a registered architect and/or professional engineer/surveyor. Anyone making use of the information set forth herein does so at their own risk and assumes any and all resulting liability arising therefrom.
