Critical Review of Cigrè Technical Brochure 852

Abstract

In November 2021 the Cigrè WG B1.61 issued Technical Brochure 852, entitled “Recommendations for testing DC extruded cable systems for power transmission at a rated voltage up to and including 800 kV”. In some respects, this TB is mostly in line with previous TB 219:2003 and TB 496:2012, but it has also introduced novelties, like revisions of test criteria, regimes and methods, and special Temporary Overvoltage tests. Nevertheless, TB 852:2021 has several gaps and weak points. First and foremost, despite the statement “Wherever possible, the tests are based on existing recommendations, standards and practices”, TB 852:2021 neglects IEEE stds. 1732:2017 and 2862:2020, relevant respectively to space charge measurements on HVDC cables and AC voltage test with Partial Discharge (PD) measurement; such topics are very important for the performance and reliability of HVDC cable systems. The gaps and weak points of TB 852:2021 are treated here, aiming at improving it, also in view of future IEC standards and forthcoming HVDC cable projects at increasing levels of voltage, power and length.