Investigation of inertial support limits in wind turbines and the effects on the power system stability


Tezin Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, Elektrik ve Elektronik Mühendisliği Bölümü, Türkiye

Tezin Onay Tarihi: 2019

Öğrenci: ERENCAN DUYMAZ

Danışman: OZAN KEYSAN

Özet:

In this study, the inertial support implementation is studied for variable speed wind turbines with a full-scale power electronics. To increase the active power as desired, Machine Side Converter is modified with an additional control loop. In the first part of the thesis, active power of the wind turbine is increased to the limits and the maximum achievable active power is found out to be restricted by the wind speed. It is found that the wind turbine can increase its output power by 40% of rated power in the low and medium wind speeds. Moreover, even though the high speed scenarios give limited increased power, it does not require any speed recovery state. The probability of the inertial support is found according to the wind speed measurement taken from field. In the second part of the thesis, the synthetic inertia implementation is presented by the provision of inertial support which is proportional to the rate of change of frequency. The effect of the implementation in the P.M.Anderson test case is observed for different inertia constants. It is discovered that the effect of renewable penetration in the frequency stability is negligible when the synchronous generators are kept in the operation. Nonetheless, frequency stability in the test system gets more vulnerable to renewable energy penetration when the conventional generators are decommissioned by the economical concerns. In this case, the synthetic inertia implementation with different inertia constants possesses the ability to lower RoCoF following a frequency disturbance. The effects of the synthetic inertia on the Turkish electricity network is also investigated. Finally, the wind turbine inertial support is evaluated in terms of economics for the energy provider perspective.