Requirement
The industrial site studied was constructed in the 1950s and has been subject to many changes. The electricity distribution grid on the site contains several autonomous sources (turbine generators), distributed at various points on the HVA and HVB grids. The function of these generators is to supply the priority units in the event of a power grid problem (internal or external to the site).
The site was recently subject to two major incidents in less than six months on the main HVA distribution grid, incidents which resulted in the loss of supply to the priority units and the start-up of the autonomous sources supplying power to these units. Following these incidents, the operator undertook a campaign to modernize the excitation regulation for the turbine generators.
Model of a turbine generator (extract from the PSIM diagram)
This involved allowing the customer to understand the dynamic behaviour of its autonomous sources in the event of a transient event on the grid. The initial objective was to analyze and validate the causes of the incident. The second objective was to analyze the influence of modifications made to the excitation regulation and to detect the operating limits to impose on the autonomous sources after modification.
Realization
Capsim modelled the turbine generators (mechanical parts of the turbines, alternators and current and future regulation) based on documents and on-site tests. Thereafter, a representative part of the grid was modelled to analyze the behaviour of the autonomous sources during transient events. Various scenarios were represented to define the operating limits of the equipment and the network.
Results
The study was able to validate the effectiveness of modifications applied to the excitation regulation, to exclude certain operating configurations from the grid and to apply response elements to optimize and improve the protection plan for the site.
Reconstruction of the 1st incident
