High voltage cable system optimization
We have been responsible for optimization of several high voltage and medium voltage cable systems in various industries. In order to provide the best solution for our Clients we have made specialized calculations, simulations and analysis.
Electrisim was appointed by Client to optimize underground high voltage cable (110 kV). The main task was to analyze all technical aspects of the cable and to provide technical specification (type, cross-sections, section length etc.) of the final cable system solution.
Description of the system
The work was part of construction of new wind farm where the high voltage underground cable (24 km trench length) connects the wind farm’s substation to the grid operator’s substation.
Electrisim carried several types of analyses to determine the optimal high voltage cable system. The scope of work included:
- Load flow analysis,
- Short circuit analysis,
- Calculation of continuous current rating based on IEC 60287 (for different scenarios, including cable installation in steel pipe). Determination of thermal current-carrying capacity of the conductor, sheathing, shielding and short-circuit forces,
- Calculation of the cyclic and emergency current rating of cables based on IEC 60853,
- Comparing the ampacity results with Finite Element Method,
- Power/energy losses calculation,
- CAPEX/OPEX analysis,
- Earthing/bonding specification,
- Determination of capacitance, charging current, earth-fault current, inductance, induced voltages and currents in ground wires, metal sheaths, and shielding,
- Selection of cable joint positions,
- Geotechnical tests on cable route for the verification of thermal resistivity,
- Trench backfilling specification, including selection of Fluidized Thermal Backfills, size of backfill envelope, trench size, configuration of cables,
- Calculation of pulling forces,
- Calculation of electric and magnetic fields around cable systems,
- Overvoltage, surge analysis (connecting surges, lightning etc.),
- Specification of cable temperature monitoring system and the effective use of results.