Modelling and simulation of the effects of grid connected wind farms on the Cyprus electricity grid

Abstract

Electricity generation in Cyprus is concentrated on the east part of the island. Often power surges to the west where the grid is weak, upset the system. The author simulated a system of grid connected wind farms situated at the west of the island, which could alleviate the east-west power surge problem. The wind farms considered consist of 300 kW, high speed, horizontal axis, induction machine turbines supplying energy to the grid at various penetration levels. Linearised dynamic models were used for the wind farms taking into account wind speed changes from a cut-in speed of 3 m/s to a cut-out speed of 24 m/s. Load flows and transient stability analysis simulations were performed so that to ascertain the effect of the wind farms on the system voltage profiles as well as the system eigenvalues. Participation matrix analysis was also carried out in order to determine whether the wind farm related state variables have a significant effect on the system eigenvalues and thus on system stability. Finally, the transmission line impedances were varied (simulating grids of different strengths) to show the changes in the system robustness before and after the introduction of the grid connected wind farms.