IEC 62068:2013

Overview

IEC 62068:2013 defines a general method for evaluating the electrical endurance of electrical insulating materials (EIM) and electrical insulation systems (EIS) exposed to repetitive voltage impulses. Published by the International Electrotechnical Commission (IEC), this international standard applies to all types of electrical equipment operating at any voltage level, provided they are connected to electronic power supplies and require insulation endurance evaluation under repetitive voltage impulses. The standard establishes procedures for screening and relatively assessing the endurance of insulating materials and systems using standardized testing approaches.

IEC 62068:2013 replaces IEC 62068-1:2003, aligning its definitions with other key IEC technical specifications, and provides crucial guidelines for manufacturers, testing bodies, and quality assurance professionals to ensure robust and safe insulation performance in environments affected by repetitive electrical impulses.

Key Topics

• Scope of Application: Covers electrical equipment containing insulation systems that are subject to voltage impulses, especially those powered by electronic supplies.
• Test Procedures: Outlines general test procedures to:
  • Screen electrical insulating materials and systems under impulse stress.
  • Evaluate endurance through comparative analysis of time-to-failure or number of impulses to failure.
• Endurance Assessment: Introduces methods to determine the relationship between applied voltage and expected insulation lifespan.
• Statistical Evaluation: Describes the use of statistical models, such as the Weibull distribution, to analyze test results.
• Influencing Factors: Details how temperature, mechanical stress, humidity, voltage magnitude, impulse repetition rate, and polarity affect insulation endurance.
• Measurement Definitions: Standardizes key parameters, such as Repetitive Partial Discharge Inception Voltage (RPDIV) and Repetitive Partial Discharge Extinction Voltage (RPDEV).
• Impulses: Specifies characteristics of test voltage impulses (rise time, repetition rate, duration, polarity) to accurately simulate real-world operation.

Applications

The guidelines in IEC 62068:2013 are highly valuable for numerous industries and applications where the electrical insulation system is exposed to repetitive voltage impulses. These include:

• Electric Motors: Evaluation of stator windings in applications with variable frequency drives.
• Transformers and Power Cables: Ensuring insulation durability under switching conditions and electronic power supply impulses.
• Power Supply and Filter Capacitors: Validating insulation reliability in electronic power conversion contexts.
• Printed Circuit Boards (PCBs): Screening PCB insulation for endurance against repetitive electrical impulses in power electronics.
• Power Module Drives: Assessing insulation performance in modules subjected to high-frequency switching.

Meeting IEC 62068:2013 ensures that selected EIM and EIS can withstand service conditions, reduce premature failures, and improve safety and operational reliability.

Related Standards

To effectively implement IEC 62068:2013, users should consider familiarity with several closely related standards:

• IEC 60505: Evaluation and qualification of electrical insulation systems.
• IEC 62539: Guide for the statistical analysis of electrical insulation breakdown data.
• IEC/TS 61934: Electrical measurements of partial discharges under short rise time and repetitive voltage impulses.
• IEC/TS 60034-18-42: Qualification and acceptance tests for partial discharge resistant insulation systems in rotating machines.
• IEC 60270: High-voltage test techniques for partial discharge measurements.

Integration of these standards supports comprehensive insulation system evaluation, in line with current best practices for electrical endurance testing and safety.

By following IEC 62068:2013, organizations can achieve consistent, reliable assessment of insulation performance, critical for the durability and safety of modern electrical and electronic equipment exposed to repetitive voltage impulses.