IEC TS 60034-25:2022 PDF

Overview

IEC TS 60034-25:2022 - "Rotating electrical machines - Part 25: AC electrical machines used in power drive systems - Application guide" - is a technical specification from the IEC that guides selection, design and installation of AC electrical machines operated from converter supplies (power drive systems). The fourth edition updates definitions, performance expectations and installation/derating guidance for machines used with modern converters while excluding the supply voltage interface (see IEC TS 61800-8).

Key topics and technical requirements

This application guide addresses practical machine and system interactions when feeding AC machines from converters. Major topics include:

• System characteristics: torque/speed capability, duty cycles, cooling and resonant speed bands.
• Losses and thermal effects: additional losses from converter supply, efficiency determination and temperature impacts on life expectancy.
• Acoustic and mechanical behavior: noise, vibration and torsional oscillation considerations for variable-speed operation.
• Insulation stress: winding voltage stresses, terminal overvoltages and mitigation methods.
• Bearing currents and shaft currents: sources of high-frequency bearing currents, common-mode effects and protection measures; Clause 8 updated for shaft currents.
• Installation guidance: earthing, bonding, cabling, output reactors, du/dt and sinusoidal filters, and motor termination units.
• Machine-specific guidance: permanent magnet (PM), cage induction and synchronous machines, including high-voltage and current-source converter cases.
• Derating: Annex D defines derating requirements for converter-fed machines.
• New definitions and requirements: converter capable motor and converter duty motor, plus performance expectations for converter-capable designs (Clause 18).

Practical applications and who uses this standard

IEC TS 60034-25:2022 is valuable for:

• Motor and drive manufacturers specifying design features for converter operation (e.g., insulation, bearing protection).
• Drive integrators and system engineers selecting motors for industrial power drive systems (pumps, fans, compressors, conveyors, process drives).
• Test and commissioning engineers applying installation, earthing and filter recommendations to reduce bearing currents and overvoltages.
• Specifiers, asset owners and maintenance teams assessing derating, lifetime effects and retrofit risks for motor–converter installations.
• Standards committees and safety assessors ensuring compatibility between converters and machines.

Related standards

• IEC TS 61800-8 - referenced for voltage at the power interface (excluded from this TS).
• Other IEC 60034 series documents - for general rotating machine characteristics and tests.

Keywords: IEC TS 60034-25:2022, rotating electrical machines, AC electrical machines, power drive systems, converter supply, converter capable motor, converter duty motor, bearing currents, insulation stress, derating, filters, installation guidance.