IEEE Std C57.142-2010 PDF

Full title and description

IEEE Guide to Describe the Occurrence and Mitigation of Switching Transients Induced by Transformers, Switching Device, and System Interaction — a guide that addresses transformer performance in the presence of oscillatory switching transients produced by interactions among the switching device, transformer, load and system; it describes operating conditions that can produce oscillatory transient voltages harmful to transformer insulation, characterizes system and transformer behavior, and outlines mitigation methods (focused on mechanical switching devices).

Abstract

This guide explains how oscillatory switching transients arise when switching devices, transformer terminals, system source and loads interact, how those transients can produce internal winding voltages that may overstress insulation, methods to characterize transformer impedance versus frequency and internal voltage development, and practical mitigation options (for example RC snubbers and other damping methods). The document includes two generic examples and annexes on frequency-response methods and statistical switch studies.

General information

• Status: Inactive — Inactive‑Reserved (inactivated 25 March 2021); the project has a subsequent revision/draft (C57.142-2025).
• Publication date: Designation year 2010 (IEEE Std C57.142‑2010); board approval 8 December 2010; published 27 April 2011 (ANSI approval 23 August 2011).
• Publisher: IEEE (IEEE Power & Energy Society / Transformers Committee).
• ICS / categories: 29.180 — Transformers, reactors (power transformer application and testing).
• Edition / version: IEEE Std C57.142‑2010 (guide edition associated with the 2010 designation; published April 2011).
• Number of pages: Approximately 56 pages in the published guide (commercial listings and catalogue entries report 56 pages).

Scope

The guide addresses applications where transformer terminals experience oscillatory switching transients that may excite transformer natural frequencies and produce internal voltages damaging to insulation. It focuses on mechanical switching device actions (closing, interruption, reignition and current‑chopping phenomena) and their interaction with transformer and system impedance; it does not treat semiconductor switching devices and excludes some heavily inductive switching applications addressed elsewhere. Annexes provide methods for determining impedance versus frequency, natural frequencies, and statistical approaches for switch‑study analysis.

Key topics and requirements

• Identification of switching events and system/transformer configurations that produce oscillatory transients.
• Transformer impedance versus frequency and transfer functions to determine internal winding voltage development.
• Characterization of switching device behavior (closing transients, current chopping, reignition) and their effect on transient spectra.
• Assessment of insulation stress from high‑frequency transient components and guidance on when a concern exists.
• Mitigation methods (e.g., resistor‑capacitor snubbers, system damping, surge arresters and layout/cabling considerations) and two illustrative examples.
• Informative annexes covering analytic/numerical methods to compute impedance versus frequency, natural frequency calculation, and recommended study/statistical methods.

Typical use and users

Used by power‑utility engineers, transformer and switchgear manufacturers, consulting electrical engineers, testing laboratories, and standards committees to: assess vulnerability of transformer installations to switching transients, select or design mitigation (snubbers, damping), interpret frequency‑response characteristics, and inform acceptance/installation practices. It supports engineers performing switch‑study analyses, transformer designers concerned with high‑frequency behavior, and asset‑management staff evaluating failure causes.

Related standards

Related IEEE C57 series guidance and standards on transformers and diagnostic/acceptance practices (examples include guides on frequency response analysis, loading, evaluation and reconditioning, and monitoring); other C57 guides (C57.104, C57.140, C57.148, C57.149, C57.143, etc.) are commonly referenced in conjunction with C57.142 for transformer condition assessment and application guidance.

Keywords

switching transients, oscillatory transients, transformer impedance, natural frequency, internal winding voltage, snubber, RC snubber, current chopping, reignition, mitigation, frequency response, switch studies, transformer insulation stress.

FAQ

Q: What is this standard?

A: It is an IEEE Guide (designated C57.142‑2010) that explains the occurrence and mitigation of oscillatory switching transients affecting power transformers and their insulation systems.

Q: What does it cover?

A: It covers the causes and characterization of oscillatory switching transients produced by interactions among switching devices, transformer terminal/network impedances and loads; transformer frequency‑dependent behavior; how internal winding voltages can be amplified at natural frequencies; and practical mitigation methods and examples (focused on mechanical switching).

Q: Who typically uses it?

A: Utility system engineers, transformer manufacturers, switchgear suppliers, consulting engineers, test labs, and asset‑management or protection engineers performing switch studies, vulnerability assessments, or mitigation design.

Q: Is it current or superseded?

A: The C57.142‑2010 guide was published (April 27, 2011) and later placed Inactive‑Reserved (inactivated 25 March 2021). IEEE records show a subsequent revision activity (C57.142‑2025 draft) as the follow‑on; therefore C57.142‑2010 is not the current active revision for new practice. Users should consult the IEEE Standards site or the newer revision/draft for the latest, active guidance.

Q: Is it part of a series?

A: Yes — it is part of the IEEE C57 family of transformer standards and guides covering application, testing, monitoring and diagnostic methods for power transformers. Practitioners commonly use it alongside other C57 guides (frequency response, loading, evaluation, monitoring).

Q: What are the key keywords?

A: Switching transients, oscillatory transients, transformer natural frequency, internal winding voltage, snubber/RC mitigation, frequency response, current chopping, reignition, insulation stress.