A simplified equivalent method of wind farm for reliability evaluation

The power system that only consists of traditional generators is easy to assess the reliability using Monte Carlo simulation because the generator can be seen as a two-state model. But the wind turbine generator cannot be treated as a two-state model in a power system with large scale wind power for the randomness and intermittent of wind. However, a simplified equivalent method of wind farm for reliability evaluation is proposed in this paper and used to turn a large scale wind farm that consists of different types and numbers of WTG to just one equivalent generator in the sense of reliability evaluation. The basic parameters in traditional algorithm such as the mean time to failure (MTTF) and the mean time to repair (MTTR) are replaced by the mean time to shake (MTTS) and the equivalent mean time to repair (EMTTR). The validity of the method is proved by the improved RTS79 system. The reliability index like EENS and LOLE are calculated using this equivalent method and its outcome are compared to that using traditional Monte Carlo simulation. This paper provide a new thought to simplify the model of wind turbines group and has some guiding effects on the power system reliability assessment considering large-scale wind power integration.