High voltage test for cables

Independent power laboratory for cable manufacturers

SuperGrid Institute provides advanced high voltage test for cables and accessories up to 640 kV. As an independent partner, we support cable manufacturers throughout the full product development cycle, from investigation to qualification.

With our exceptional test platforms and recognised expertise in high voltage testing, we help you accelerate innovation, reduce time-to-market and ensure full compliance with international standards.

Testing of high voltage cables:
from investigation to qualification

Our services cover the full range of testing of high voltage cables and accessories:

  • Qualification tests:
    Electrical type tests according to IEC 62895 & CIGRE TB 852.

  • Special tests:
    AC & DC withstand and breakdown, AC & DC ageing, thermal stability.

  • Investigation tests:
    Test protocol definition, combined hyperbaric & dielectric tests.

In january 2023, Nexans and SuperGrid Institute perform their first transient overvoltage test on a 525kV DC cable system
SuperGrid Institute cable testing services for cable suppliers and manufacturers.
Nexans and SuperGrid Institute perform their first TOV test on a 525kV DC cable system
Damped oscillations TOV testing 525kv dc at SuperGrid Institute

TOV tests for DC cables – up to 525 kV

SuperGrid Institute is one of the few institutes in Europe performing Transient Over Voltage (TOV) tests on DC cable systems up to 525 kV.

  • Unique test capabilities validated with Nexans on a 525 kV DC cable system.

  • Guarantee your HVDC cables withstand disruptive events such as converter station faults or grounding failures.

  • Strengthen the reliability and durability of your DC cables in real operating conditions.

Our references

Nexans and SuperGrid Institute successfully carried out a first Transient Overvoltage (TOV) test on a 525 kV DC cable system, consisting of two external terminations, two joints and an extruded DC cable. The DC cable system passed several sequences of zero-crossing damped over voltage tests at both 350 Hz and 6 kHz (see graph).

SuperGrid Institute is fully prepared to support European DC cable system manufacturers in the qualification of 525 kV DC cable systems by conducting extended type test programs, as required by Transmission System Operators (TSOs).

SuperGrid Institute offers a complete range of services
SuperGrid Institute offers a complete range of services
SuperGrid Institute offers a complete range of services

State of the art HV test platforms

Our high voltage test platforms are among the most advanced in Europe and can be adapted to specific applications for cable manufacturers.

  • Faraday cage:
    700 m², separable into two test areas (GIS, AIS, cable systems).

  • HVDC sources:
    up to 1200 kV, 20 mA, low partial discharge levels.

  • HVAC sources:
    up to 750 kV AC, with compensation for cable lengths up to 15 m.

  • Impulse generator:
    up to 2000 kV, with flexible adjustment.

  • Advanced measurement systems:
    ultra-low PD levels, leakage current monitoring, UHF/UV/ultrasound instruments.
SuperGrid Institute provide a wide range of cable testing services that cover the whole product development cycle, including investigation & qualification tests.

This may interest you

Press release: Nexans and SuperGrid Institute perform their first transient overvoltage test on a 525kV DC cable system

Energy World talks about our first TOV tests!

Download the technical leaflet

SuperGrid Institute Dielectric material characterisation & ageing platform

Complementary services for cable suppliers

Beyond testing, SuperGrid Institute also provides R&D and design support:

  • Insulation design services: support for solid and gas insulation materials (XLPE, thermoplastics, SF6 alternatives).

  • Thermo-electrical simulations (COMSOL) to optimise cable design.

  • Design assistance for the replacement of SF6 in DC cable accessories.

Frequently asked questions (FAQ)

To reach its ambitious targets, Europe needs to connect a substantial amount of renewable energy sources to the grid (450 GW of offshore wind by 2050). HVDC and MVDC cables will play a major role in the infrastructure necessary for renewable energy integration.

A wide range of topologies are envisaged for future land and subsea DC grids. Multi-terminal grids, mixed cable & overhead line systems, and hybrid AC / DC  power systems will progressively replace the single point-to-point DC links that are currently being built. Consequently, the testing requirements for DC cable systems will increase so as to maintain overall system reliability.

HVDC cable systems might be subject to system-specific transient overvoltage (TOV) during disrupting events such as a fault in a converter station or a failure to ground the cable itself.

Over the past several years, work has been undertaken to list and classify the most common TOV waveforms into a new CIGRE recommendation. The main European high-voltage laboratories have designed suitable test setups to adapt to clients’ requirements and perform a wide range of TOV tests.

You can fin the general main features of our high voltage test platforms in our dedicated page (equipement & specification) or in our brochure.

Voltage measurements are performed with factory calibrated dividers. All of our HVDC generators have embedded RC dividers.

Two additional PD-free dividers can be positioned to accommodate different test set-ups:

  • Universal RC divider, up to 2000 kV LI, 1800 kV SI, 1000 kV DC, 700 kV DC.
  • Capacitive divider up to 800 kV AC, with embedded PD measuring impedance.
  • GIS RC divider up to 850 kV DC.

Low electromagnetic noise levels suitable for PD measurements (<0.5 pC @ 600 kV DC) and leakage current measurements.

Other specific measurements can be carried out using the instruments available in the laboratory (UHF systems, UV systems, ultrasounds, electrometers, high speed camera, etc.).

Vincent Léger - Business Development Manager

Contact our expert

Vincent Léger, Business Development Manager