The effects of reactive power provision from the distribution grid on redispatch cost

With a shift from central to decentralized generation, the question arises whether renewable energy sources can contribute to the provision of ancillary services and to which extent. This work assesses the effects of reactive power provision from wind turbines connected to the 110 kV distribution grid on redispatch cost. For this purpose a redispatch model is developed that does not only consider thermal line limits, but also voltage stability. Calculations show that especially in situations with very high wind feed-in, reactive power provision from the distribution grid is able to decrease redispatch and curtailment cost.