Power Electronics and Studies

Our HVDC & FACTS expertise

Our services

The large-scale development of renewable energy sources in transmission grids, along with public demand to avoid the construction of new overhead lines, has led to an increase in the installation of long high-voltage underground cables, as well as the addition of dynamic reactive power support and new HVDC links using underground DC cables. The increasing introduction of power electronics-based devices into the network has a significant impact on grid performance and reliability, which requires improvements to control and protection systems and an understanding of dynamic behavior.

RTE international provides power system services with a focus on HVDC and FACTS. We offer comprehensive services to meet the needs of the ever-changing power industry. Its team of experts coming from diverse backgrounds and specialized in Power Electronics and Power Systems tackles a wide variety of technical challenges in power transmission.

Testing HVDC/FACTS control and protection systems

Testing the implementation of new control & protection (C&P) functions several years after their commissioning requires specialized tools and skills.

  • Testing C&P software update
  • Acceleration of the equipment’s service recovery
  • Analysis of the events recorded on site

Dynamic performance analysis of HVDC/FACTS

Detailed power system studies with HVDC/FACTS.

  • Development of converter station models for EMT simulations
  • EMT simulations with complex AC grids
  • Real-time simulations with physical C&P cubicles
  • Identification of potential interactions

Integration of renewables

Specific analysis for the connection of wind farms to transmission grids.

  • Harmonic amplification analysis
  • Sizing harmonic filters
  • Time domain EMT simulations for transformer and cable energization

Real-time simulations with HVDC/FACTS control replicas

The largest multi-builder HVDC/FACTS real-time simulation laboratory in Europe

  • Studying interaction phenomena related to HVDC and FACTS devices
  • Studying and testing multi-vendor and multi-power systems
  • Training engineers and supporting maintenance activities
  • Testing control and protection software updates
  • Networking studies and improving offline models

Principle of real-time simulation with physical control replicas

  • More than 10 real-time simulators
  • 2000 m² of technical premises hosting HVDC and FACTS control replicas
  • Rooms dedicated hosting third party project replicas


Power system studies

Analysis of complex systems

  • HVDC/FACTS systems in transmission networks
  • Integration of long AC cables or reactive compensation device
  • Integration of wind farms

Different types of analysis

  • Simulation of electromagnetic transients (EMT)
  • Harmonic analysis
  • Transient stability simulation
  • Harmonic analysis and impedance locus calculation

Example of harmonic analysis for the connection of an offshore wind farm

TSOs usually provide harmonic impedances at the point of common coupling for wind farms. RTE determines the harmonic impedances based on the minimum and maximum short circuit of the system. The final harmonic study reflects the results of several thousand simulations corresponding to different grid topologies and load conditions.

The overall results are summarized as surfaces in the RX plane (R: real part of the impedance and X: imaginary part of the impedance).

HVDC/FACTS project management

Supporting projects from planning to maintenance

  • Technical specification for HVDC/FACTS equipment
  • Improving specifications and optimizing system performance
  • Tender evaluation for HVDC applications
  • Analysis of design reports
  • Witnessing control and protection factory tests
  • Preparation of testing and commissioning procedures for HVDC/FACTS control and protection systems
  • Supervising site tests
  • Training engineers and supporting maintenance activities


Wide range of topics for HVDC projects and EMT simulation

  • HVDC-LCC and HVDC-VSC basics
  • HVDC control and protection
  • HVDC modelling and studies
  • Maintenance of HVDC systems and integration into AC grids
  • HVDC VSC project management
  • EMT modelling and simulations – basic concepts
  • EMT modelling and simulations – advanced concepts for transmission grids

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