This document provides an off-line measurement method of the partial discharge inception and extinction voltage on winding insulation under repetitive impulse voltage. This document is relevant to rotating machines supplied by a voltage source converter.dition 1.0 2021-04 TECHNICAL SPECIFICATION colour inside Rotating electrical machines – Part 27-5: Off-line measurement of partial discharge inception voltage on winding insulation under repetitive impulse voltage IEC TS 60034-27-5:2021-04(en) THIS PUBLICATION IS COPYRIGHT PROTECTED Copyright ？ 2021 IEC, Geneva, Switzerland All rights reserved. Unless otherwise specified, no part of this publicatio