Transmission Systems

Due to the expansion of renewables and the dismantling of conventional power plants, the transmission systems are currently subject to major changes. In periods of high feed-in of power from renewable sources in particular, power is fed back from the distribution networks, while the load flows over long distances and the exchange of power with the network partners increases as well.

New transmission technologies and the complex characteristics of power systems without synchronous generation play a role as well. Current planning scenarios provide for the use of HVDC VSC systems for the transmission of power over long distances.

Consulting Services - Overview

  • Grid Development Plans (GDP)
  • Feasibility studies
  • Comparative AC/DC concept studies
  • SVC, FACTS and HVDC systems (LCC/VSC)
  • Phase angle regulating transformers (demand, design, protection)
  • Concept analyses for transmission technologies (overhead lines, cables)
  • Technical problems of underground cables
  • Steady-state voltage stability
  • Analyses of the reactive power demand
  • Requirements regarding reactive power exchange with lower-level distribution networks
  • Concepts for meeting the reactive power demand (steady-state/dynamic; parallel/serial)
  • Sub-synchronous resonances (SSR)
  • Analysis and assessment of the steady-state and dynamic system stability, taking the voltage, rotor angle, and frequency stability into account
  • Feasible stability concepts (e.g. realisation of required fault clearing times)
  • Analysis of grid oscillations
  • Power system stabiliser (PSS) tuning
  • System control and operating reserve
  • Analysis and assessment of the stability of parallel control structures in the transmission system
  • Requirements regarding the load change rates of generating units
  • Strategies and technical requirements for system restoration after an outage
  • Criteria for black-start capability
  • Electromagnetic transient processes
  • Insulation coordination
  • Optimisation of system operation (e.g. switching sequences, maintenance processes)
  • Effects of a quantitative change of rotating masses on the system
  • Minimum rotating masses required for secure system operation
  • Design, control and operation of systems without synchronous generation
  • Technical analyses of offshore transmission systems (AC/DC)
  • Reliability of supply as part of system security; consequences for the plant configuration
  • Harmonics in transmission systems (sources, propagation, planning level)
  • Technical specifications of operating equipment
  • Cost-benefit analyses
  • Combined system and market studies
  • Requirements for switchgear in case of switching near the generator (absence of zero-crossings of the fault current)