Effect of fault current limiter on shaft torsional torque

We investigated the influence of a resistive type (R-type) and inductive type (L-type) fault current limiter (FCL) on the behaviour of the shaft torsional torque of a synchronous generator installed in a consumer system connected to a utility distribution system. In the case that the generator has relatively low natural oscillation frequency f 0 under about 40 Hz, the L-type FCL suppresses the maximum value of the shaft torsional torque τ sm to lower level than the R-type FCL. The R-type FCL with low limiting resistance may instead increase τ sm under the condition of low f 0 . On the other hand, for higher f 0 , R-type FCL limits τ sm at any limiting resistance as well as L-type FCL. The limiting effect of R-type FCL on τ sm is larger than that of L-type FCL.