Quality Assurance & Quality Control of HVDC Cable Systems

Insulators

The cable industry in general is in a phase of expansion and the HVDC cable market in particular is experiencing unprecedented growth along with an increase in technology performance needs. These trends are the result of electricity deregulation that started in the 1990s but today, because of the global awareness of climate change, is shifting the curve even more dramatically upwards.

Fig. 1: Development in system voltage of extruded cable systems (type tested and PQ tested).

Higher voltages and power transfer, larger projects and greater associated cable lengths as well as the rapid introduction of advanced new technologies are necessary and welcome but also lead to the need for higher reliability. At such a time, when pressure is high on all stakeholders to deliver more and with greater speed, it makes sense to pause and reflect not only on potential benefits but also on risks linked to these endeavours.

Are there differences in huge HVDC projects compared to earlier smaller HVAC projects and can it be assumed that this is just business as usual? Or should there be a period of reflection and gathering experience from ongoing projects to consider such aspects as quality assurance, engineering and proper testing methods?

For example, the role of Quality Assurance and Quality Control is to guarantee that cable systems and technical solutions perform their function as originally defined and designed. Often, when discussing QA and QC focus is immediately placed on the manufacturing phase. However, errors during the early design phase can lead to a malfunctioning system once a project has been in operation for several years. Similarly, sub-suppliers who correctly deliver their products to specifications that are not themselves suitably updated for the specific product or technology can result in decreased reliability of the resulting system. Moreover, miscommunication can lead to a incorrectly designed, manufactured or installed products. Furthermore, tests and quality control procedures that have well served earlier industrial projects do not necessarily cover the methodologies and tests necessary to guarantee quality of a new technology. It is therefore fundamental to realize that QA and QC must cover a wide range of functions in an interconnected chain.

Attend the 2022 INMR WORLD CONGRESS to meet and listen to cable design and testing expert, Dr. Marc Jeroense from Sweden. He will explain why the cable industry is witnessing a significant increase in yearly HVDC cable project volume and review the performance characteristics of these systems, including voltage, power, temperature, project cable length and grid criticality. With decreasing design margins due to higher stresses and temperatures, he will discuss the need for increased and additional Quality Assurance and Quality Control. Specific ideas and methodologies will also be presented.