IEEE Revises, Reaffirms Power, Energy Standards

June 27, 2009 // Published as a news service by IHS

The first standard to be revised, IEEE P421.2 - Guide for Identification, Testing and Evaluation of the Dynamic Performance of Excitation Control Systems, will update the existing standard, first published in 1990, with respect to new test equipment and methods and changes in two other standards in the IEEE 421 family.

This guide includes criteria, definitions and test procedures for evaluating the performance of excitation control systems for synchronous machines as applied by electric utilities.

The second standard to be revised is IEEE P43 - Recommended Practice for Testing Insulation Resistance of Rotating Machinery, which describes the recommended procedure for measuring insulation resistance of armature and field windings in rotating machines rated 1 HP, 750 watts or greater.

It applies to synchronous machines, induction machines, direct current machines and synchronous condensers. Contained within this document is the general theory of insulation resistance (IR) and polarization index (PI), as well as factors affecting the results, test procedures, methods of interpretation, test limitations and recommended minimum values

The approved, revised standards are IEEE C62.22 - Guide for the Application of Metal-Oxide Surge Arresters for Alternating-Current Systems and IEEE C62.92.5 - Guide for the Application of Neutral Grounding in Electrical Utility Systems, Part V - Transmission Systems and Subtransmission Systems.

Four existing standards were also reaffirmed:

• IEEE C37.106 - IEEE Guide for Abnormal Frequency Protection for Power Generating Plants.
• IEEE C57.111 - IEEE Guide for Acceptance of Silicone Insulating Fluid and Its Maintenance in Transformers.
• IEEE C62.21 - IEEE Guide for the Application of Surge Voltage Protective Equipment on AC Rotating Machinery 1000 V and Greater.
• The related corrigendum to IEEE C62.21, IEEE C62.21/Cor1.