This guide discusses the basic concepts involved in studies of harmonic analysis of industrial and commercial power systems. The need for such an analysis, recognition of potential problems, corrective measures, required data for analysis, and benefits of using a computer as a tool in a harmonic-analysis study are also addressed in this recommended practice. This recommended practice was originally from Chapter 10 of the IEEE Brown Book, IEEE Std 399-1997, Recommended Practice for Industrial and Commercial Power Systems Analysis but includes major modifications based on the latest technological advancements.
This standard was developed by the IEEE Technical Books Coordinating Committee of the Industrial and Commercial Power Systems Department of the Industry Applications Society, as part of a project to repackage the popular IEEE Color Books. The goal of this project is to speed up the revision process, eliminate duplicate material, and facilitate use of modern publishing and distribution technologies. This recommended practice describes how to conduct harmonic studies and analysis of industrial and commercial power systems. The basic concepts are described first. This is followed by a discussion of how to determine the need for a harmonic-analysis study, how to assemble the required data, how to recognize potential problems, and how to implement corrective measures.
This publication provides a recommended practice for conducting harmonic studies and analysis of power systems in commercial and industrial facilities. It is likely to be of greatest value to the power-oriented engineer with limited commercial or industrial plant experience. It can also be an aid to all engineers responsible for the electrical design of commercial and industrial facilities. However, it is not intended as a replacement for the many excellent engineering texts and handbooks commonly in use, nor is it detailed enough to be a design manual. It should be considered a guide and general reference on analysis of commercial and industrial facilities.
Topics of this standard are organized in the following sequence:
- Harmonic-analysis objectives
- Harmonic-analysis methodologies and applicable standards
- System and component models for use in computer simulations for harmonic analysis
- Data required for computer simulations
- Common data collection and preparation procedures
- Importance of model and data validation
- Typical harmonic-analysis study scenarios, solution parameters, and results and reports interpretation
- Preferred features for harmonic-analysis tools
- Illustration examples
Sources of Harmonics
The main sources of harmonics in industrial and commercial power systems are static power converters used as rectifiers for various industrial processes and for other applications such as adjustable/variable speed drives, uninterruptible power system (UPS), chargers, switched-mode supplies, static frequency converter, cycloconverters, etc. Arc furnaces and saturated magnetic devices are also harmonic sources.
The guidelines for the acceptance of harmonic distortion at Point of Common Coupling (PCC) level are defined in IEEE Std 519, and the interharmonic effects to voltage flickers at other system levels are also discussed. By modeling power system impedances as a function of frequency and harmonic sources as injecting currents or forced voltages, a harmonic study can be made to determine the effect of the harmonic contributions from nonlinear loads on the voltages and currents in the power system.