IEC 60034-18-42-2020 Rotating electrical machines – Part 18-42: Partial discharge resistant electrical insulation systems (Type II) used in rotating electrical machines fed from voltage converters – Qualification tests.
This part of IEC 60034 defines criteria for assessing the insulation system of stator/rotor windings of single or polyphase AC machines which are subjected to repetitive impulse voltages, such as those generated by pulse width modulation (PWM) converters, and are expected to experience and withstand partial discharge activity during service. It specifies electrical qualification tests on representative specimens to verify fitness for operation with voltage-source converters. It also describes an additional classification system which defines the limits of reliable performance under converter-fed conditions. Although this document deals with voltage converters, it is recognised that there are other types of converters that can create repetitive impulse voltages.
For these converters, a similar approach to testing can be used. Qualification of insulation systems may not be required for rotating machines which are only fed from voltage converters for starting and so they are excluded from this document.
2 Normative references The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
IEC 60034-1 :201 0, Rotating electrical machines – Part 1: Rating and performance IEC 60034-1 8-1 :201 0, Rotating electrical machines – Part 18-1: Functional evaluation of insulation systems. General guidelines
IEC 60034-1 8-31 , Rotating electrical machines – Part 18-31: Functional evaluation of insulation systems – Test procedures for form-wound windings – Thermal evaluation and classification of insulation systems used in rotating machines
IEC 60034-1 8-32, Rotating electrical machines – Part 18-32: Functional evaluation of insulation systems – Test procedures for form-wound windings – Evaluation by electrical endurance
IEC 60034-1 8-41 :201 4, Rotating electrical machines – Part 18-41: Partial discharge free (Type I) electrical insulation systems used in rotating electrical machines fed from voltage converters – Qualification and quality control tests
IEC TS 60034-27, Rotating electrical machines – Part 27: Off-line partial discharge measurements on the stator winding insulation of rotating electrical machines
IEC TS 61 934, Electrical insulating materials and systems – Electrical measurement of partial discharges (PD) under short rise time and repetitive voltage impulses
3 Terms and definitions For the purposes of this document, the following terms and definitions apply. ISO and IEC maintain terminological databases for use in standardization at the following addresses:
• IEC Electropedia: available at
• ISO Online browsing platform: available at
3.1 partial discharge PD electric discharge that only partially bridges the insulation between electrical conductors Note 1 to entry: It may occur inside or outside the insulation or adjacent to an electrical conductor.
3.2 partial discharge inception voltage PDIV lowest voltage at which partial discharges are initiated in the test arrangement when the voltage applied to the test object is gradually increased from a lower value at which no such discharges are observed Note 1 to entry: With sinusoidal applied voltage, the PDIV is defined as the r.m.s. value of the voltage. With impulse voltages, the PDIV is defined as the peak to peak voltage. 3.3 repetitive partial discharge inception voltage RPDIV minimum peak to peak impulse voltage at which more than five PD pulses occur on ten voltage impulses of the same polarity.IEC 60034-18-42 pdf download.