IEC 60071-11:2022 applies to high-voltage direct current (HVDC) systems. It specifies the principles on the procedures for the determination of the specified withstand voltages, creepage distance and air clearances for the equipment and the installations of these systems.
This document gives the insulation co-ordination principles related to line commutated converter (LCC) and voltage sourced converters (VSC) HVDC systems. The main principles of this document also apply to other special converter configurations of LCC, such as the capacitor commutated converter (CCC) as well as the controlled series compensated converter (CSCC), etc.
This document applies to insulation co-ordination of equipment connected between the converter AC bus (including the AC harmonic filters, the converter transformer, the circuit breakers) and the DC line side. The line and cable terminations in so far as they influence the insulation co-ordination of converter station equipment are also covered.
This document applies only for HVDC applications in power systems and not for industrial conversion equipment. Principles and guidance given are for insulation co-ordination purposes only. The requirements for human safety are not covered by this document.
This international standard replaces, in conjunction with IEC 60071-12, IEC 60071-5 published in 2014.
This edition includes the following significant technical changes with respect to IEC 60071‑5:2014:
- This standard applies to both LCC and VSC HVDC systems whereas IEC 60071-5 only dealt with LCC HVDC system;
- Annex C (normative) gives the recommended specified withstand voltage (LI and SI);
- Annex C (normative) gives the minimum air clearances;
- Annex E shows the correlation of clauses between this standard and IEC 60071-5:2014.