A new calculation method of short-circuit currents contributed by doubly-fed wind turbines cluster

A new calculation method of short-circuit currents (SCCs) with doubly fed induction generators (DFIGs) is proposed in this paper, aiming to cope with the calculation difficulty caused by DFIGs and complex cluster topology. Firstly, the paper analyzes the fault characteristic of DFIG with crowbar protection and simplifies the calculation process. Secondly, the equivalent impedance model of DFIG cluster under different connection types is introduced and the new SCC calculation method is given. At last, the accuracy of the method is verified with PSCAD/EMTDC and the comparison with the national standard calculation method is analyzed. The results are of positive significance for the electric safety design of the doubly-fed wind turbines cluster.