Evolutionary algorithm EPSO helping doubly-fed induction generators in ride-through-fault

A tuning process of the PI (proportional-integral) controller gains of a doubly-fed induction generator´s (DFIG) rotor side converter is described in this work. The purpose is to tune PI controllers to help the DFIG to survive to network faults, avoiding being tripped-off by under-voltage relays. The ride-through-fault capability of DFIGs improves system reliability and allows them to participate in the control and stabilization of a power system following system disturbances. The robust tuning of the DFIG rotor side converter´s PI controllers may avoid undesired disconnections from the grid by, for instance, preventing over-currents in its variable frequency AC/DC/AC converter. This work presents an evolutionary particle swarm optimization-based (EPSO) approach to this tuning, with the aim of helping to limit the line-to-line voltage dip at the DFIG´s terminals after a short-circuit, in order to avoid its tripping-off. The EPSO-based algorithm developed is validated at a typical Portuguese 15 kV distribution network with the integration of a DFIG, using the transient electromagnetic software package PSCAD/EMTDCtrade.