Integrating distributed generation using decentralised voltage regulation

Voltage rise is a significant limitation when connecting large volumes of distributed generation (DG), particularly in rural distribution networks. One means of allowing further capacity penetration is to control voltage regulation devices such as on-load tap changers in a coordinated manner considering the variability of demand and generation. This approach, however, requires the deployment of communication systems, making it a potentially expensive option. To date, most DG technologies feature capabilities such as provision of reactive power or power factor control. Nonetheless, the “fit and forget” approach for the connection of DG units to distribution networks neglects a more active, decentralised management where those and other capabilities could be used without the need of further infrastructure. This work proposes a decentralised control scheme where wind power-based DG units have a dual operation mode (power factor control and voltage control) in order to maintain the voltage at the connection bus within limits. Generators are also able to curtail their power output as a last resort to regulate the local voltage. Time-series analyses demonstrate the effectiveness of the decentralised methodology in adequately integrating DG capacity.