Impacts of Tie-Lines and Wind Generator Location on Small Signal Stability of a Power System

This paper analyses the impact of tie-lines connecting different areas of power system and the location of wind farms on the small signal stability of a power system. The analysis is conducted using Monte Carlo simulation via modal analysis. The random samples are generated from two-parameter Weibull distribution to obtain possible representation of wind speed needed for the generation of wind power using Latin hypercube sampling techniques. The sampling technique allows the usage of a small sample size, which helps in reducing the simulation cost without jeopardising the accuracy of the result. Different scenarios are created and the oscillatory modes are calculated for different operating condition. The changes in modal characteristic of the system due to different operating conditions are evaluated by observing the movement on the complex plane. The results of the modal analysis for each scenario are validated using time domain simulation. Some of the key results show that wind power can have either positive or negative impact on the oscillation of a power system depending on the location in which it is integrated into the power system. It is also found out that strengthening the weak tie-lines can greatly improve the inter-area mode. This paper is useful in the planning stage of wind power projects.