Assessment of voltage stability of an unbalanced distribution system with Type-3 wind generator

Type 3 wind generators like Doubly Fed Induction Generator(DFIG) are capable of providing reactive power support to the connected network. Thus interfacing them to the distribution network effects the voltage stability of the system. In this paper, the effect of the DFIG on an unbalanced distribution network has been evaluated using a voltage stability index calculated from power-flow analysis. The effect of different operating modes of DFIG at different wind speeds and different point of connection to the distribution network have been studied on IEEE standard 34 bus unbalanced distribution system. Effect of voltage regulators, tap limits and DFIG operating limits for unbalanced operation, on the system loadability has also been highlighted in this work.