Requirement
On an existing oil installation consisting of several platforms, the production of electricity and the power supply for water injection pumps on the platforms was being directly realized by ageing turbine generators. The obsolescence of this equipment led the operator to develop an electricity power grid using a shore-based electricity plant and an underwater connecting cable (between 20 and 30 km long at a depth of 30 m) linking the plant to the various platforms.
As part of this renovation project, it was necessary to evaluate the impact of normal transient events (load connection, load shedding, connection of the generator to the grid) and incidental events (short-circuit, loss of the generator, etc.) on the electrical power supply to the platforms.
Realization
CAPSIM have constructed a numerical model of the power plant, platforms and undersea cables using ETAP software. CAPSIM also identified the at-risk cases for which the stability should be checked and constructed the associated simulation scenarios.
Results
The study was able to verify the following points :
- The transient stability of the islanded network
- The correct sizing of the electrical distribution equipment (cables, transformers, etc...)
- The need for load shedding after a fault or loss of a generator
- The capacity to start up the largest motors on the grid
- The re-acceleration of the induction motors after an electrical fault
Changes in voltage and frequency with time during the loss of a generator
